Aktis Oncology - 10-K annual report

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

OR

For the transition period from _________________ to _________________

Commission File Number: 001-43047

Aktis Oncology, Inc.

(Exact name of Registrant as specified in its Charter)

Registrant’s telephone number, including area code: (617) 461-4023

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

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Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). YES ☒ NO ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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The Registrant did not have a public float on the last business day of its most recently completed second fiscal quarter because there was no public market for the Registrant’s common equity as of such date.

The number of shares of Registrant’s Common Stock and Class A common stock outstanding as of March 10, 2026 was 53,403,173 and 1,872,829, respectively.

DOCUMENTS INCORPORATED BY REFERENCE

None.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. Forward-looking statements are neither historical facts nor assurances of future performance. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “estimate,” “believe,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions intended to identify statements about the future, although not all forward-looking statements contain these identifying words. These forward-looking statements include, without limitation, statements about the following:

We have based these forward-looking statements largely on our current expectations and projections about our business, the industry in which we operate and financial trends that we believe may affect our business, financial condition, results of operations and prospects, and these forward-looking statements are not guarantees of future performance or development. These forward-looking statements speak only as of the date of this Annual Report on Form 10-K and are subject to a number of risks, uncertainties and assumptions described in the section titled “Risk Factors” and elsewhere in this Annual Report on Form 10-K. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein for any reason after the date of this report to conform these statements to new information, future events or otherwise.

You should read this Annual Report on Form 10-K and the documents that we reference herein and have filed with the SEC as exhibits to this Annual Report on Form 10-K with the understanding that our actual future results, levels of activity, performance and events and circumstances may be materially different from what we expect.

SUMMARY RISK FACTORS

The risk factors summarized and detailed below could materially harm our business, operating results and/or financial condition, impair our future prospects and/or cause the price of our common stock to decline. These are not all of the risks we face, and other factors not presently known to us or that we currently believe are immaterial may also affect our business if they occur. A summary of the material risks that may affect our business, operating results and financial condition include, but are not necessarily limited to, those relating to:

Table of Contents

PART I

Item 1. Business.

Overview

We are a clinical-stage oncology company focused on expanding the breakthrough potential of targeted radiopharmaceuticals to large patient populations, including those not addressed by existing platform technologies. The field of targeted radiopharmaceuticals is currently led by two marketed products that illustrated transformative survival outcomes and quality of life benefits can be conferred by delivering radioisotopes to solid tumors. These leading products, which target prostate specific membrane antigen or somatostatin-2 receptor, are each currently approved in only one tumor type, yet have seen considerable commercial uptake and have become fundamental pillars of cancer treatment. Despite these advances, we believe that the field of radiopharmaceuticals is still in its infancy, with many emerging companies still primarily focused on these same two targets. In contrast, we see a significant opportunity to broaden the cancer patient populations benefiting from targeted radiopharmaceuticals by developing next-generation technologies that expand the scope of tumor targets for which it is possible to safely deliver a powerful payload of an alpha-emitting radioisotope. To ensure patient demand is reliably met, we are also establishing efficient end-to-end supply, with a combination of critical internal capabilities paired with established external vendors. Through these efforts, we seek to maximize clinical utility across multiple indications in multiple tumor types, and to expand the commercial uptake of radiopharmaceuticals beyond the traditional nuclear medicine setting and into the more expansive clinical oncology setting.

We have built a proprietary miniprotein radioconjugate platform that aims to safely confer breakthrough efficacy to a broad range of patient populations. Our miniprotein radioconjugates are designed to selectively deliver the tumor-killing properties of radioisotopes to targeted tumors with high tumor penetration and prolonged tumor retention, while being rapidly cleared from normal organs and tissues to minimize systemic radiation exposure. Our miniproteins have demonstrated the ability to potently bind to tumor targets outside the scope of current delivery technologies such as peptide-based radioconjugates. We are leveraging the capabilities of our platform technology, together with our expertise and know-how in radiopharmaceutical development, supply chain and manufacturing, to address these challenges with the aim of advancing a deep pipeline of programs against a broad range of tumor targets that have not been successfully targeted with radiopharmaceuticals.

Our platform capabilities have generated a pipeline of several novel product candidates. Our most advanced program is a radiopharmaceutical targeting Nectin-4. It is a miniprotein radioconjugate with multi-indication potential across multiple tumor types, in clinical development for the treatment of locally advanced or metastatic urothelial cancer, or UC, and multiple other Nectin-4 expressing solid tumor types. The learnings from the optimization of our Nectin-4 program, the first miniprotein radioconjugate ever advanced into human investigational studies, are being applied to benefit the development of our robust pipeline of several other unpartnered miniprotein radioconjugate programs, which are designed to address other clinically-validated targets.

Our lead product candidate, [225Ac]Ac-AKY-1189, contains a miniprotein, AKY-1189, that specifically binds to Nectin-4, and is conjugated via chelation to actinium-225, 225Ac. 225Ac, is an alpha-emitting radioisotope that when conjugated to a prostate specific membrane antigen, or PSMA, binding peptide has been shown to confer increased anticancer activity in the post-chemotherapy setting of metastatic castration-resistant prostate cancer compared to an identical PSMA binding peptide with beta-emitting Lutetium-177, or 177Lu. Nectin-4 is a surface protein found on a wide variety of tumors and has very limited expression in normal adult tissues. Nectin-4 is also the target of Padcev, an antibody-drug conjugate, or ADC, approved worldwide for the treatment of locally advanced or metastatic UC. Padcev has an annualized treatment cost of approximately $500,000 and had worldwide sales of $1.9 billion in 2024, with estimated peak sales of up to $7.0 billion.

Despite the commercial success of Padcev, its impact beyond UC has been limited likely due to the need to develop a companion diagnostic for tissue testing when utilizing an ADC. In contrast, we intend to use imaging radioisotopes conjugated to AKY-1189 to select patients most likely to benefit from therapeutic treatment with [225Ac]Ac-AKY-1189. We believe the commercial impact of Padcev validates Nectin-4 as an anticancer target in UC and that significant unmet medical need exists for our lead product candidate in post-Padcev UC. Additionally, we see potential to treat several non-UC Nectin-4-expressing tumor types such as breast cancers and lung cancers. We believe that the therapeutic potential of [225Ac]Ac-AKY-1189 across multiple tumor types is supported by our preclinical studies and data collected by a third-party physician in South Africa pursuant to Section 21 of the Medicines and Related Substances Act, or MRSA, which demonstrated the ability of radiolabeled AKY-1189 to specifically localize to Nectin-4 expressing tumors and rapidly clear from normal organs and tissues. In April 2025, the U.S. Food and Drug Administration, or the FDA, cleared our investigational new drug, or IND, application for [225Ac]Ac-AKY-1189 for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors. We have commenced a multi-site Phase 1b clinical trial in the United States and anticipate preliminary results from the Part-1 dose escalation portion of this trial in the first quarter of 2027.

To overcome the manufacturing challenges and supply chain reliability issues that have historically hindered the development and commercialization of radiopharmaceuticals, we are focused on investing in manufacturing and ensuring supply chain continuity and reliability. We have built significant internal capabilities, including subject matter expertise for our product manufacturing processes and a state-of-the-art radiopharmaceutical development suite. Additionally, we have partnered with multiple domestic and international isotope suppliers that provides us priority access to 225Ac, and with multiple contract manufacturers for the production of our drug product, which collectively are designed to create redundancies across all components of our supply chain. We are also establishing our own current good manufacturing practice, or cGMP, facility to enhance flexibility, increase control, and establish a hybrid internal and external clinical supply chain. We believe our team’s expertise and experience in the development of radiopharmaceuticals will allow us to address the challenges presented by the half-life of radioactive isotopes and establish an efficient supply chain from production to patient administration.

We believe that radiopharmaceuticals represent one of the most promising modalities for the treatment of solid tumors. Approved radiopharmaceuticals have demonstrated the ability to overcome the challenges of conventional cancer treatments and provide patients with targeted therapies that have superior efficacy and better tolerability. We believe our approach is validated by, and builds upon, the clinical and commercial success of current radiopharmaceuticals and that our approach has the potential to further transform the cancer treatment paradigm for large patient populations.

Our proprietary miniprotein radioconjugate platform

We created our proprietary miniprotein radioconjugate platform to build on the successes of currently available radiopharmaceuticals and enable the discovery of next-generation precision radiopharmaceuticals. We are leveraging our platform to discover and develop radiopharmaceutical therapies that selectively deliver the tumor-killing properties of radioisotopes to targeted tumors with high tumor penetration and prolonged retention, with the goal of enhancing the safety and tolerability profile by rapidly clearing from normal organs and tissues to minimize systemic radiation exposure. Our miniprotein radioconjugates are designed for use with either imaging isotopes to select patients expressing the target, or therapeutic isotopes to treat tumors. The radioconjugates are formed by a chelation reaction to bind the isotopes to DOTA, which is covalently linked to the tumor-targeting miniprotein. This approach will enable clinicians to first visualize and verify target tumor engagement using an imaging radioisotope, thereby identifying the patients who are most likely to benefit from our therapy.

Our platform has enabled us to engineer potent, precision miniprotein-based radioconjugates that bind to the surface targets on tumor cells to localize radioisotope payloads. Miniproteins are polypeptides of less than one hundred amino acids that are amenable to biologic and medicinal chemistry optimization methods. We are prioritizing miniprotein binders of 40 to 70 amino acids in length, which are classified as biologics from a regulatory perspective providing a twelve-year exclusivity period for approved products. Miniproteins have differentiated and highly attractive properties as radioconjugates based on their antibody-like ability to potently and selectively bind to a highly diverse set of tumor targets, while having the pharmacologic profile of small peptides to enable high tumor penetration and rapid clearance from the body. We believe that miniproteins have many of the advantages of larger biologics like antibodies, as well as advantages of the smallest binders like peptides, without the limitations specific to either

class. In particular, based on our preclinical studies, we believe miniproteins have the following beneficial characteristics for use in radiopharmaceuticals:

We strengthen our miniprotein discovery workflow by incorporating artificial intelligence, or AI, technologies. We use various AI tools to help us select the best radiopharmaceutical biological targets, generate miniprotein libraries based on naturally evolved protein domains, design new miniprotein structures de novo using generative AI, and support our optimization efforts using machine learning models that are trained on our proprietary data. We can uniquely couple these state-of-the-art AI approaches with our wet-lab capabilities and our acquired expertise in discovery and optimization of miniprotein binders.

Manufacturing and supply

Manufacturing challenges and ensuring supply chain continuity and reliability have historically hindered the development and commercialization of radiopharmaceuticals. To overcome these challenges, we have established manufacturing and supply chain capabilities that are designed to be reliable and capital efficient with the ability to scale to meet global commercial demand for large cancer patient populations. Our end-to-end supply chain capabilities are orchestrated by our seasoned radiopharmaceutical development and manufacturing team that has experience advancing radiopharmaceutical programs from preclinical to commercialization. We have a state-of-the-art radiopharmaceutical development suite to apply our proprietary insights into process, formulation, and product development for preclinical, first-in-human, clinical trial, and commercial manufacturing and supply.

In addition, we have multiple domestic and international isotope supply agreements spanning therapeutic and diagnostic uses, including agreements with NorthStar Medical Technologies, LLC, TerraPower Isotopes, LLC and Niowave, Inc., among others, with priority access to 225Ac.

We have partnered with leading contract manufacturing organizations to facilitate reliable and efficient supply, including co-located drug product manufacturing with 225Ac and 64Cu production to reduce costs, improve product turnaround time, and ease supply logistics, for our proprietary targeted miniprotein radiopharmaceutical precursors and products. Leveraging this network of partners, we are currently manufacturing drug product for our clinical trial. Additionally, we are building an internal cGMP radiopharmaceutical facility to enhance flexibility, increase control, and establish a hybrid internal and external clinical supply chain of our product candidates. We expect our manufacturing facility to be fully operational in the second half of 2026. As we grow our organization, we are continuing to evaluate options for internal commercial manufacturing to complement our network of commercial contract manufacturers.

Our pipeline

We are leveraging our proprietary miniprotein radioconjugate platform to discover and develop a deep pipeline of targeted radiopharmaceutical programs to address unmet needs in prevalent solid tumors. Our most advanced program, [225Ac]Ac-AKY-1189, is targeting Nectin-4 expressing solid tumors, including locally advanced or metastatic UC, breast cancer, NSCLC, colorectal cancer and cervical cancer. Our second most advanced program, [225Ac]Ac-AKY-2519, is targeting B7-H3 expressing solid tumors, such as prostate, lung and breast cancers.

Beyond [225Ac]Ac-AKY-1189 and [225Ac]Ac-AKY-2519, we have a robust discovery pipeline of several unpartnered miniprotein radioconjugate programs in the discovery phase that focus on clinically-validated targets. Our learnings from the optimization of [225Ac]Ac-AKY-1189 are being applied to benefit the development of [225Ac]Ac-AKY-2519 and these subsequent programs. We retain exclusive, worldwide development and commercialization rights to all our current product candidates and discovery programs. We also have a discovery collaboration with Eli Lilly and Company, or Eli Lilly, to generate novel anticancer radiopharmaceuticals against targets beyond the scope of our unpartnered pipeline programs.

[225Ac]Ac-AKY-1189 targeting Nectin-4 expressing tumors

Our lead product candidate, [225Ac]Ac-AKY-1189, was generated using our miniprotein radioconjugate platform and is designed to deliver 225Ac, a highly potent alpha-emitting radioisotope, to Nectin-4 expressing tumors. Nectin-4 is a cell-surface protein found on a wide variety of tumors and has very limited expression in normal adult tissues. Nectin-4 is also the target of enfortumab vedotin, or Padcev, an approved ADC for the treatment of locally advanced and metastatic UC. Although Padcev has validated Nectin-4 as an oncology target, there has been limited clinical development activity to design other therapeutics targeting other Nectin-4 expressing tumors, which may be due to the need to develop a companion diagnostic for tissue testing when utilizing an ADC. In contrast, we intend to use imaging radioisotopes conjugated to AKY-1189 to readily select patients most likely to benefit from therapeutic treatment with [225Ac]Ac-AKY-1189.

We believe AKY-1189, when conjugated to a radioisotope, has the potential to treat UC as well as other Nectin-4 expressing tumors by selectively delivering cytotoxic radioisotopes such as 225Ac to Nectin-4 expressing tumors to kill the tumor. AKY-1189’s short plasma half-life is designed to limit its radiation exposure to sensitive organs like bone marrow. We have also specifically designed AKY-1189 to minimize reabsorption by the kidneys to avoid potential toxicity concerns associated with renally-cleared radiopharmaceuticals.

In our preclinical studies, [225Ac]Ac-AKY-1189 has demonstrated antitumor activity and increased overall survival in animals inoculated with Nectin-4 expressing cancer cell xenografts. It also demonstrated a compelling biodistribution profile, with low absorbed doses observed outside of the tumor, which supports [225Ac]Ac-AKY-1189’s potential to widen the therapeutic window. Furthermore, the Section 21 data included clinical imaging and dosimetry data from radioactive imaging radioisotope conjugates of AKY-1189, [68Ga]Ga-AKY-1189 and [177Lu]Lu-AKY-1189, which enabled assessment of tumor uptake and retention in 15 patients with solid tumors known to have high Nectin-4 expression, including UC, breast cancer, NSCLC, colorectal cancer and cervical cancer. In this assessment, AKY-1189 was observed to specifically localize and be retained in all tumor types examined, while being rapidly cleared from normal organs and tissues, including the kidney, with no adverse events observed. In this assessment, we also observed tumor uptake and retention at levels we expect to be sufficient to drive efficacious responses, based on similar measurements to those of leading marketed radiopharmaceuticals.

We have commenced a multi-site Phase 1b trial in the United States for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors and anticipate preliminary results from the Part-1 dose escalation portion of this trial in the first quarter of 2027. An imaging radioisotope is being used to directly assess tumor binding by AKY-1189 and identify patients most likely to respond to [225Ac]Ac-AKY-1189 with the aim of delivering early clinical therapeutic signals across multiple Nectin-4 expressing tumor types. Patients determined to be Nectin-4 positive will move to the [225Ac]Ac-AKY-1189 dose-escalation portion of the trial. That phase of the study will investigate increasing doses of [225Ac]Ac-AKY-1189. Following completion of each dose level, safety of the drug will be assessed by a safety review committee and, if deemed safe, enrollment of the next higher dose level will commence. In December 2025, we disclosed that we had completed the first dose level of the Part 1 dose escalation of the Phase 1b clinical trial and had commenced enrollment of the next dose level. Enrollment in the trial remains on track, and we expect to present data from the Part 1 dose escalation in the first quarter of 2027. Upon completion of the dose escalation portion, a dose expansion portion will be conducted in patients with locally advanced or metastatic UC and other Nectin-4 expressing tumors. [225Ac]Ac-AKY-1189 was granted Fast Track Designation by the FDA in February 2026 for the treatment of locally advanced or metastatic UC in patients who had progressed on or after prior systemic therapies.

[225Ac]Ac-AKY-2519 targeting B7-H3 expressing tumors

Our second product candidate, [225Ac]Ac-AKY-2519, is designed to deliver 225Ac to B7-H3 (CD276) expressing tumors, including prostate, lung and other solid tumors. B7-H3 is a cell-surface protein that is highly expressed in many types of solid tumors, while having limited expression in normal tissues. We estimate that approximately 90% of all metastatic castration-resistant prostate cancers, 80% of NSCLCs and 70% of small cell lung cancers, express B7-H3, while also being expressed on other solid tumors like breast cancers. High expression of B7-H3 has been associated with poor overall survival outcomes and a lack of responsiveness to anti-PD-1 therapeutics in several tumor types. B7-H3 has attracted substantial clinical development efforts across different modalities, including ADCs, with several late-stage ADCs demonstrating preliminary efficacy signals and acceptable safety profiles. Regarding the potential for B7-H3 as a target in prostate cancer, we believe B7-H3 to be differentiated from PSMA for imaging and treatment due to its high tumor expression and limited expression in normal organs and tissues, such as kidneys and salivary glands.

In our preclinical studies, [225Ac]Ac-AKY-2519 has demonstrated robust antitumor activity and increased overall survival in mice inoculated with B7-H3 expressing cancer cell xenografts. It also demonstrated a compelling biodistribution profile, with low absorbed doses observed outside of the tumor.

[68Ga]Ga-AKY-2519 and [177Lu]Lu-AKY-2519 uptake in tumors and normal tissue biodistribution is currently being assessed in patients with various B7-H3 expressing solid tumors. To date, each of [68Ga]Ga-AKY-2519 and [177Lu]Lu-AKY-2519 has demonstrated robust tumor uptake with low uptake in normal tissues and a differentiated biodistribution profile, showcasing rapid clearance from normal organ and tissues, including kidneys. We expect the results of the imaging and dosimetry assessment in patients with various tumor types to be reported in mid-2026. In March 2026, our INDs for [225Ac]Ac-AKY-2519 and for [64

Cu]Cu-AKY-2519 were cleared by the FDA to proceed to a Phase 1b clinical trial. We expect to initiate the multi-site Phase 1b clinical trial mid-2026.

Eli Lilly collaboration

In May 2024, we entered into a discovery collaboration with Eli Lilly to leverage our proprietary miniprotein radioconjugate platform to generate novel anticancer radiopharmaceuticals against targets beyond the scope of our unpartnered pipeline programs. We received a $60.0 million upfront cash payment in addition to an equity investment and are eligible to receive up to an additional $1.2 billion upon achievement of preclinical, clinical, regulatory, and commercial milestones, as well as tiered royalties. We are responsible for program discovery of a defined set of targets selected by Eli Lilly through initial human imaging studies and Eli Lilly is responsible for worldwide clinical development and commercialization from Phase 1 clinical trials onward. We retain worldwide rights to our proprietary pipeline programs, including our lead Nectin-4 targeting program.

Our team

We have assembled an experienced management team with deep expertise in drug development, approval, and commercialization, with members of our management being involved in the approval and commercialization of 14 currently marketed FDA-approved products. Our team is led by executives who have significant experience in company-building in the biopharmaceutical industry and a shared vision to build a leading radiopharmaceutical company. The experience of our President and Chief Executive Officer, Matthew Roden, PhD, in the biopharmaceutical industry includes leadership positions in corporate strategy and business development at Bristol Myers Squibb, and senior equity research coverage of the biotechnology sector at J.P. Morgan and UBS. He also serves as an Entrepreneur Partner at MPM BioImpact and on the Boards of Directors of other biotechnology companies. Our Chief Financial Officer, Kyle D. Kuvalanka, brings over 20 years of experience as a senior leader in the biopharmaceutical industry, having served in executive leadership roles at ROME Therapeutics, Syros Pharmaceuticals, Blueprint Medicines and Goldfinch Bio. Paul L. Feldman, PhD, our Chief Scientific Officer, was Co-founder and Chief Executive Officer of Phoundry Pharmaceuticals and, upon its acquisition by Intarcia Therapeutics, served as Head of Discovery and Translational Medicine at Intarcia. In his previous roles at GlaxoSmithKline, he was directly involved in the discovery of five approved drugs. Shulamit Ron-Bigger, PhD, our Chief Operating Officer, previously served as Head of Strategy and Operations for the Research and Early Development organization at Bristol Myers Squibb. Akos Czibere, MD, PhD, our Chief Medical Officer, has extensive experience in clinical development, most recently serving as Therapeutic Area Development Head of Hematology-Oncology at Pfizer. Dr. Czibere has been directly involved in the approval of six oncology drugs, including Elrexfio and Talzenna. Tyler Benedum, PhD, our Chief Technical Officer, previously served as Vice President of Chemistry, Manufacturing, and Controls Development at Avid Radiopharmaceuticals, a wholly-owned subsidiary of Eli Lilly, where he oversaw global commercial and clinical trial radiopharmaceutical manufacturing and played a key role in developing and advancing Amyvid and Tauvid through marketing authorization approval and commercialization.

Our company was co-founded by Todd Foley, a Managing Director at MPM BioImpact, who is currently Chair of our Board of Directors; Patrick Baeuerle, PhD, an MPM BioImpact Advisor, and currently a member of our Scientific Advisory Board; and Brian Goodman, PhD, a Partner at Vida Ventures.

Expanding the potential of radiopharmaceuticals

We believe that the field of radiopharmaceuticals is still in its infancy and is poised to become a fundamental pillar of cancer care and deliver transformative survival and quality of life outcomes for patients. External beam radiation therapy, or EBRT, has proven to be an effective option for cancer treatment but has limitations including lack of sufficient precision to avoid collateral damage to normal organs and tissues. Radiopharmaceuticals have the ability to deliver high levels of radiation directly and precisely to diseased tissue by combining the proven tumor-killing ability of radiation therapy with the high degree of molecular precision provided by their targeting components, offering cancer patients better outcomes than other anticancer modalities.

Several radiopharmaceutical drugs have been developed and commercialized in an expanding field, demonstrating the significant market potential of radiopharmaceuticals. Commercial adoption of Pluvicto and Lutathera, along with expanding operational and commercial infrastructure, positions radiopharmaceuticals as the next emerging modality. To date, the development of radiopharmaceutical candidates has been primarily focused on two biological targets: PSMA, the target of Pluvicto; and SSTR2, the target of Lutathera. Our company was founded with the aim of maximizing the impact of radiopharmaceuticals by bringing excellence to all aspects of radiopharmaceutical drug development, by discovering therapeutic candidates that broaden the set of targets and tumors that are addressed by radiopharmaceuticals. As a result, none of our programs target PSMA or SSTR2. We instead focus on leveraging our miniprotein radioconjugate platform to a broader set of addressable targets such as Nectin-4 and B7-H3, which are expressed in tumor types such as lung, breast, bladder, prostate and gastrointestinal tumors, and collectively account for an estimated 193,000 and 215,000 incident cases per year, respectively.

Radioisotopes used in radiopharmaceuticals fall into two classes: alpha-emitting and beta-emitting radioisotopes. Alpha particles are much larger and heavier than beta particles, with higher energy and shorter travel distances. Although both alpha-emitting and beta-emitting radioisotopes cause damage to the DNA of tumor cells resulting in tumor cell death, there are distinct differences. Beta-emitting radioisotopes create single-strand DNA breaks and can travel to more distant cells not in direct contact with the delivery point of the radiopharmaceutical. In contrast, alpha-emitting radioisotopes create catastrophic double-stranded

DNA breaks and are 1,000 times more potent in cell killing than beta-emitters but can only travel two to three cell lengths. Radiopharmaceuticals using alpha-emitting radioisotopes also offer advantages with administration as they result in less radiation exposure to the clinic staff during administration, as well as convenience to patients with no post-treatment restrictions on having contact with other people.

In third-party studies, alpha-emitting radioconjugates have also demonstrated increased anticancer activity in patients with tumors that did not respond to beta-emitting radioconjugates. As seen in the graphic below, a patient with widespread metastatic disease was observed to have progressive disease following treatment with two cycles of 177Lu-PSMA-617. Subsequent treatment with 225Ac-PSMA-617 resulted in profound regression of disease. Objective response rates of over 30% have been observed in academic trials of 225Ac-PSMA-617, and a recent company-sponsored trial of 225Ac-containing PSMA-617 radioligand showed a 43% response rate in patients previously treated with 177Lu-containing PSMA-617 radioligand therapies. These results illustrate the powerful efficacy potential for 225Ac-containing targeted radioconjugates.

Anticancer activity of alpha-emitting radioconjugates in patients with tumors that did not respond to beta-emitting radioconjugates

We believe alpha radioconjugates represent a significant opportunity for improved clinical outcomes for patients with cancer. Due to the inherent advantages and breakthrough efficacy potential, we are initially focused on alpha-emitting radioisotopes. However, our miniprotein radioconjugates have the ability to deliver both alpha-emitting and beta-emitting radioisotopes, which we believe expands the potential impact and tumor treatment options available for our radiopharmaceuticals.

Our proprietary miniprotein radioconjugate platform

We were founded to improve outcomes for cancer patients by pioneering a new class of targeted radiopharmaceuticals to unlock the benefit of the modality for prevalent tumor types that have historically been beyond the reach of radiopharmaceuticals. Our ability to leverage the killing power of a radioconjugate provides significant opportunity for discovering targeted radiopharmaceuticals with the potential to transform the cancer treatment paradigm for patients with a broad set of tumor types. Our aim is to discover targeting molecules that can bind with high affinity and prolonged duration on cancer cells to maximize efficacy, while having high selectivity and short residence time in the rest of the body to avoid toxicity to normal organs and tissues.

Our founders created our company with a focus on a category of polypeptides, referred to as miniproteins. Miniproteins consist of manifold scaffolds of less than one hundred amino acids in length that fold into a stable tertiary structure, making them larger than small peptides but smaller than large biologics. Similar to larger biologics, such as antibodies, miniproteins possess the ability to recognize and bind with high selectivity to a highly diverse set of tumor targets, but lack some of the known radiopharmaceutical property limitations of antibodies, including long circulating half-life and poor tumor uptake. Miniproteins also share some of the pharmacological profile advantages of small peptides such as high tumor penetration and short plasma half-life. However, miniproteins are able to bind to, and exhibit high selectivity for, tumor targets that are less tractable with smaller peptides. We believe miniproteins possess pharmacological properties that make them ideal targeting molecules for radiopharmaceutical product development, since they retain the advantages of large biologics and smaller peptides without the limitations specific to either class. We are focused on the discovery of novel miniproteins that are 40 to 70 amino acids in length, which categorizes them as biologics from a regulatory perspective, providing a twelve-year exclusivity period for approved products.

Our miniprotein radioconjugates offer both the potential for both potent antitumor activity and an enhanced safety and tolerability profile. The small size of miniproteins allows them to rapidly penetrate tumors. Furthermore, our miniprotein radioconjugates are able to internalize into cancer cells, which we believe drives prolonged retention. We have reproducibly

generated high affinity miniprotein binders to specific tumor targets. Tumor killing is achieved through delivery of absorbed radiation dose, which is enhanced by high tumor penetration, high binding affinity for tumor targets, and prolonged retention of drug in the tumor.

Two of the major concerns for toxicity with radiopharmaceuticals are renal damage due to radiation exposure in the kidney and hematological toxicity due to bone marrow exposure. The short plasma half-lives of miniproteins results in rapid clearance through the kidneys, limiting the overall radiation exposure of normal organs and tissues, such as the blood, bone marrow and skin, while the high target selectivity of our miniproteins further reduces off-target binding and exposure risk. We have built on this beneficial profile and engineered our product candidates to minimize their renal reabsorption using primary sequence modifications. Our lead optimization efforts have resulted in decreases in renal retention and increases in tumor uptake, which attributes are predicted to widen the therapeutic index of our product candidates relative to other radiopharmaceutical constructs.

Our miniprotein platform is designed to broaden the number of tumor targets addressable by radiopharmaceuticals. Our miniproteins bind to targets with high affinity, which enables highly selective and potent binding to targets through protein-protein intermolecular contacts and allows them to potentially bind to many protein targets, whether or not it has a cleft or other structural feature commonly required for peptide binders.

Our platform enables rapid advancement to product candidate and first-in-human evaluation. Miniproteins can be synthesized using solid phase peptide synthesis. This allows the evaluation of a large number of variants and enables the establishment of rich structure-activity relationships and site-specific modifications, including the incorporation of unnatural amino acids, to optimize for the desired drug-like properties.

Our proprietary miniprotein radioconjugate platform uniquely combines the following non-exhaustive list of technologies we use during our discovery process:

We routinely apply our platform to rapidly generate and optimize miniprotein binders to tumor cell targets, not only selecting for product candidates that bind to their targets with high selectivity and affinity, but also optimizing for other properties that we believe will increase their potential as high-value therapeutics. As illustrated below, this iterative process to optimize miniproteins utilizes computational design with biological evolution and medicinal chemistry.

Iterative process optimizing miniprotein discovery combines computational design, biological evolution and medicinal chemistry.

Learnings from our Nectin-4 program and discovery programs have enabled additional technological advancements to be incorporated into subsequent programs, including our B7H3 program, to enhance our miniprotein radioconjugate platform and efficiently advance novel radiopharmaceutical programs.

Enhancing our discovery efforts by utilizing AI

AI, and its sub-categories of machine learning, deep learning, generative AI, and expert systems, are making a significant impact in the pharmaceutical industry and spawning many new companies and technologies. We have been utilizing AI to advance our miniprotein discovery and development over the past several years. Our reliance on AI has increased with advancement of AI tools, especially with accumulation of experimental data that informs AI models. Within discovery, we use AI tools to help us select radiopharmaceutical biological targets, generate miniprotein libraries based on naturally evolved protein domains, and design new

miniprotein structures de novo using generative AI. In addition, we apply machine learning to critical experimental datasets and use structure-based modeling to support optimization of our miniprotein binders.

Recent advances in de novo design software have been used to design small-molecule, peptide, macrocycle, and antibody binders to proteins. More recently, this software has been adapted and modified by us and others to design miniprotein binders to biological targets. We can uniquely couple these state-of-the-art AI approaches with our wet-lab capabilities and our acquired expertise in discovery and optimization of miniprotein binders.

We utilize AI tools throughout the entire process of advancing our radiopharmaceutical pipeline. In particular, we apply AI technology and yeast surface display to discover miniprotein binders to targets of interest in two ways: (1) to re-engineer naturally evolved protein-domain folds into libraries with hundreds of millions of variants each, from which target-binding miniproteins are captured by yeast surface display, and (2) to design novel miniproteins specifically for binding to biological targets of interest, and to use yeast surface display to identify the most successful designs.

In addition to our internal work using and advancing AI tools, we continue to assess potential third-party partners who are using AI tools, in order to further advance our specific discovery capabilities.

[225Ac]Ac-AKY-1189: Our lead product candidate targeting Nectin-4 expressing tumors

Our lead product candidate, [225Ac]Ac-AKY-1189, was discovered using our miniprotein platform and is designed to deliver 225Ac, a highly potent alpha-emitting radioisotope, to Nectin-4 expressing tumors. The therapeutic potential of [225Ac]Ac-AKY-1189 is supported by our preclinical studies and an investigator-initiated clinical imaging and dosimetry assessment demonstrating the ability of AKY-1189 radioconjugates to specifically localize to Nectin-4-expressing tumors and rapidly clear from normal organs and tissues. In April 2025, the FDA cleared our IND for [225Ac]Ac-AKY-1189 for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors. We have commenced a multi-site Phase 1b clinical trial in the United States and anticipate preliminary results from the Part-1 dose escalation portion of this trial in the first quarter of 2027. [225Ac]Ac-AKY-1189 was granted Fast Track Designation by the FDA in February 2026 for the treatment of locally advanced or metastatic UC in patients who had progressed on or after prior systemic therapies.

Nectin-4: a clinically validated oncology target

Nectin-4 is the target of Padcev which is approved worldwide for the treatment of locally advanced or metastatic UC. Nectin-4 is a surface protein that is expressed in a wide variety of solid tumor types and has very limited expression in normal adult tissues. Robust expression of Nectin-4 has been reported in various solid tumor indications, including UC, breast, NSCLC, colorectal, pancreatic, ovarian, cervical, head and neck, gastric, and esophageal cancers, with Nectin-4 expression levels of approximately 50%-95% observed in multiple tumor types. Up to an estimated 193,000 cancer patients are diagnosed annually in the United States with solid tumors that may express Nectin-4. The expression of Nectin-4 is associated with poor patient prognosis and unfavorable tumor progression. We believe that elevated Nectin-4 expression in these solid tumors supports our ongoing evaluation of [225Ac]Ac-AKY-1189 in UC and beyond.

Elevated Nectin-4 mRNA expression expressed in multiple tumor types

Background on UC and other Nectin-4 expressing solid tumors

UC is a cancer that begins in the cells that line the urethra, bladder, ureters, renal pelvis and other organs. Over 90% of bladder cancers in the United States are UCs. The National Cancer Institute estimated that there would be greater than 83,000 new cases of bladder cancer and approximately 16,800 bladder cancer related deaths in the United States in 2024. Bladder cancer represents 4% of all cancers in the United States and is the fourth most common cancer in men, though less common in women. In 2024, the total number of patients with locally advanced or metastatic UC in the United States was estimated to be approximately 18,000. Annually, an estimated 4,200 patients are diagnosed with metastatic UC.

Until recently, the most common treatment for patients diagnosed with locally advanced or metastatic UC was chemotherapy with platinum-based drugs, such as carboplatin or cisplatin in combination with gemcitabine. Patients with metastatic disease that progressed during or after platinum-based chemotherapy were increasingly being treated with checkpoint immunotherapy. A number of PD-1 and PD-L1 checkpoint inhibitors have been approved by the FDA for use in refractory bladder cancer with objective response rates observed in clinical trials between 15% to 21%.

Due to the ubiquitous and robust expression of Nectin-4 in UC, no companion diagnostic or tissue testing for Nectin-4 is required. To date, there is only one approved Nectin-4 targeted therapy for UC, the ADC enfortumab vedotin, marketed as Padcev by Pfizer and Astellas. Padcev in combination with pembrolizumab is the standard of care for first-line treatment of patients with locally advanced or metastatic UC with no clear standard of care for subsequent lines of therapy. In locally advanced or metastatic UC patients previously treated with a PD-1 or PD-L1 inhibitor and/or platinum-based chemotherapy, treatment with Padcev monotherapy led to a 40.6% overall response rate and improved overall survival to 12.9 months compared to 9.0 months for patients treated with chemotherapy. In treatment-naïve patients with locally advanced or metastatic disease, Padcev in combination with pembrolizumab led to a 67.7% overall response rate and an overall survival of 31.5 months compared to 16.1 months for patients treated with chemotherapy. These data from Padcev in combination with pembrolizumab led to its recommendation as a first-line treatment for patients with locally advanced or metastatic bladder cancer. Sales of Padcev in 2024 were approximately $1.9 billion with estimated peak sales of up to $7.0 billion.

Although Padcev received initial regulatory approval from the FDA in 2019 for the treatment of locally advanced or metastatic UC, it has not been approved for the treatment of other Nectin-4-expressing tumors and there has been limited clinical development activity to design therapeutics targeting other Nectin-4 expressing tumors, which may be due to the need to develop a companion diagnostic for tissue testing when utilizing an ADC. In clinical trials leading to the initial approval of Padcev, Nectin-4 expression was observed in all 120 UC patients with available tumor biopsies, and the FDA agreed that the use of an in vitro diagnostic for Nectin-4 expression was not essential to the safe and effective use of Padcev.

Other cancers, including breast, NSCLC, colorectal and cervical have been shown to express Nectin-4, though overexpression may not be as ubiquitous as in UC. Breast cancer is the second most common type of cancer in women in the United States with more than an estimated 360,000 patients diagnosed in 2024. Lung cancer is the third most common cancer in the United States with 235,000 patients diagnosed annually and more people in the United States dying from lung cancer than any other type of cancer. NSCLC is the most common type of lung cancer, accounting for about 80% to 85% of all lung cancer cases. Colorectal cancer develops in the colon or rectum with 150,000 new cases in the United States estimated in 2024. Cervical cancer starts in the cells lining the cervix, the lower part of the uterus, and it is estimated that approximately 13,800 new cases of invasive cervical cancer were diagnosed in the United States in 2024.

We believe there is a significant opportunity to develop novel therapies with improved therapeutic profiles in these large patient populations with significant unmet medical needs.

Our solution: [225Ac]Ac-AKY-1189

Our lead product candidate, [225Ac]Ac-AKY-1189, contains a miniprotein, AKY-1189, that specifically binds to Nectin-4, which is conjugated via chelation to 225Ac. AKY-1189 is a 45-amino-acid miniprotein covalently attached to an established radioisotope chelator, DOTA, through a short, chemically stable linker. In our preclinical mouse models, AKY-1189 was observed to specifically localize to Nectin-4 expressing tumors while minimizing exposure to the kidneys and other normal organs and tissues. Clinical imaging and dosimetry assessments using [68Ga]Ga-AKY-1189 and [177Lu]Lu-AKY-1189 in patients demonstrated high tumor uptake of AKY-1189 in UC and four other tumor types known to express Nectin-4, while being rapidly cleared from the body and avoiding normal organs and tissues.

Discovery and development of AKY-1189 utilizing our miniprotein radioconjugate platform

We have leveraged our proprietary miniprotein radioconjugate platform to discover and develop AKY-1189 following an evaluation of millions of potential candidates through a combination of computational modeling, directed evolution, functional screening, in vivo profiling and medicinal chemistry. Our approach enabled us to optimize the physicochemical, potency, and pharmacological properties of miniprotein binders that led to the discovery of AKY-1189.

AKY-1189 is engineered to be thermally stable to at least 75°C to enable the manufacture of [225Ac]Ac-AKY-1189. The conjugated radiopharmaceutical is designed to maintain radiochemical stability for at least four days to support central manufacturing and enable flexible distribution and clinical administration.

The binding affinity, referred to as KD, of AKY-1189 to Nectin-4 was determined to be 0.22 nanomolar, or nM, by surface plasmon resonance. The Ki, or inhibitory constant, which also measures binding affinity, of this miniprotein to Nectin-4 expressing tumor cells was determined to be 0.82 nM, and within the range of 0.1 nM to 1 nM targeted by therapeutic antibodies designed to deliver cytotoxins to tumors, such as ADCs. No off-target binding of AKY-1189 was detected when tested at a concentration of 450 times higher than its KD for Nectin-4. This selectivity testing was conducted for more than 6,200 surface expressed or secreted proteins, including Nectin-1, -2, and -3. Furthermore, no binding was observed in a tumor cell line in which the gene for Nectin-4 had been removed by CRISPR knockout. We believe the binding affinity and selectivity of AKY-1189 supports a favorable risk-benefit profile.

In addition to high Nectin-4 binding affinity, we designed AKY-1189 to be minimally retained in the kidney. Our optimization process is exemplified by examining the progression of the properties from our earlier Nectin-4 targeted miniproteins, AKY-807 and AKY-1162, to AKY-1189. In vitro binding assays demonstrated that AKY-807 was a potent and selective binder to Nectin-4 expressing tumor cells but in vivo imaging studies with an imaging radioisotope, [111In]In-AKY-807, demonstrated that the AKY-807 also localized to the kidneys. However, while some localization in the kidneys was expected given renally-cleared molecules are subject to reabsorption in the kidney, we observed that high levels remained in the kidneys for 22 hours after dosing. Through a series of sequence modifications to the miniprotein, we generated a series of molecules, including AKY-1162 and AKY-1189, that improved the Nectin-4 binding affinity and tumor binding, while simultaneously reducing kidney retention. As seen in the images below, there was considerable improvement in the lack of kidney retention, coupled with improvement in tumor uptake from AKY-807 to AKY-1162 to AKY-1189.

AKY-1189’s rapid tumor uptake and kidney washout 22 hours after administration compared with previous miniproteins

Brightly colored areas depict presence of imaging radioisotope in mice implanted with xenograft tumors on right forelimb

Figure left shows low kidney uptake and more rapid washout of AKY-1189 over 22 hours compared to other miniproteins. Figure right depicts more rapid and retained tumor uptake of AKY-1189 over 22 hours compared to other miniproteins.

In vivo preclinical studies

Tumor and normal tissue uptake

To assess the potential of AKY-1189 in tumor xenograft models we used two versions of the HT-1376 human UC cell line, which is epithelial-like cell isolated from the urinary bladder of a patient with cancer. The expression levels were determined by

histochemical staining and scored using the Histochemical Scoring Assessment, or H-score, which has a range of 0-300, with higher scores representing higher expression. In one cell line, noted as low expression in the image below, Nectin-4 expression was limited to the endogenous levels of the cell line, with an H score of 175. In the other cell line, noted as representative expression in the image below, we used genetic engineering to increase the level of Nectin-4 expression to more closely match that observed in representative metastatic UC patient biopsies, with an H-score of 291. Between 55% to 90% of metastatic UC patients are initially diagnosed with a H-score similar to the representative expression cell line.

Nectin-4 expression in the modified HT-1376 cell line matched that observed in a representative biopsy from a metastatic UC patient that has high levels of Nectin-4 expression

We assessed the ability of AKY-1189 to localize to tumors in a mouse xenograft model using the representative Nectin-4 expressing HT-1376 cell line. Dosing with the imaging radioisotope [111In]In-AKY-1189 allowed quantitative measurement of [111In]In-AKY-1189 biodistribution using single-photon emission computed tomography, or SPECT, imaging. Within minutes of dosing, the highest levels of [111In]In-AKY-1189 were found in the tumor. These levels in the tumor were maintained for approximately two hours, after which the levels slowly declined over the 24-hour observation period, with retention observed for up to three days after dosing. In contrast, the levels of [111In]In-AKY-1189 observed in the kidneys rose within minutes after dosing and then rapidly declined as [111In]In-AKY-1189 was eliminated from the body. This desired preclinical biodistribution profile, high tumor uptake and reduced exposure to organs and normal tissues, supported the advancement of [225Ac]Ac-AKY-1189. We believe this biodistribution profile enables a wide therapeutic window for [225Ac]Ac-AKY-1189 in treating patients with Nectin-4 expressing tumors.

AKY-1189 was localized and retained in tumors, while being rapidly washed out from the kidneys

Brightly colored areas depict presence of imaging radioisotope four hours after dosing (left) and 24 hours after dosing (right), in mice implanted with xenograft tumors on right forelimb

Figure left shows low kidney uptake and rapid washout of AKY-1189 over 24 hours. Figure right depicts high, rapid and retained tumor uptake of AKY-1189 over 24 hours.

Based on our modeling of the pharmacokinetics of AKY-1189 and scaling to projected human doses, we estimate that a dose of 7.4 MBq of [225Ac]Ac-AKY-1189, a standard dose of 225Ac-based radiopharmaceuticals that has demonstrated anticancer effects, will result in a low systemic and kidney exposure to radiation. The ability to deliver a radiopharmaceutical at a dose that is both safe and efficacious is critical and these preclinical predictions lie well within what we believe is a viable range for eventual clinical development and, if approved, commercialization. We believe that the therapeutic window of [225Ac]Ac-AKY-1189 can improve tolerability and patient quality of life and provide the opportunity to potentially explore higher doses that could improve efficacy.

The profile of [225Ac]Ac-AKY-1189 provides the potential for flexibility in both the schedule and administered dose before approaching the EBRT benchmark limit of 23 RBE5Gy for kidneys. This is a level at which EBRT has been associated with a risk of chronic kidney disease in five percent of patients five years after dosing.

Dosimetry scaling suggests that the radiation exposure to the kidney in humans will be well within the range generally considered to be acceptable in the field and below thresholds associated with kidney toxicity

Antitumor activity of [225Ac]Ac-AKY-1189

As shown below, [225Ac]Ac-AKY-1189 also had increased antitumor activity in both high and low Nectin-4 expressing tumors in xenograft models. In our preclinical study, we observed that mice bearing HT-1376 tumors expressing low or representative levels of Nectin-4 were administered with either a single intravenous dose of 1 µCi, or microcuries, of [225Ac]Ac-AKY-1189 or vehicle (n=8 mice per group). Treatment with [225Ac]Ac-AKY-1189 resulted in a mean tumor regression of 53% in the representative Nectin-4 expressing tumors by day 25 (n=8 remaining animals) and an overall survival rate of 75% at the end of an eight-week observation period where median survival was not reached during the observation period. Treatment with vehicle in the representative Nectin-4 expressing tumors had no surviving animals at the end of the observation period and had a median overall survival of 28.5 days (n=5 remaining animals at day 25). In low Nectin-4 expressing tumors, [225Ac]Ac-AKY-1189 treatment led to an average tumor growth inhibition of 62% at day 25 (n=8 remaining animals at day 25) and led to a median survival of 49 days. In low Nectin-4 expressing tumors, treatment with vehicle led to a median survival of 26.5 days (n=6 remaining animals at day 25). Body weight was monitored as a surrogate of overall animal health. Animal weights remained constant throughout the treatment period, indicating that [225Ac]Ac-AKY-1189 treatment was well tolerated.

[225Ac]Ac-AKY-1189 had increased antitumor activity in both high and low Nectin-4 expressing tumors in xenograft models

Furthermore, treatment of mice harboring HT-1376 tumors with a single dose of [225Ac]Ac-AKY-1189 resulted in improved tumor growth inhibition compared to multiple doses of Padcev, assessed in the same study. The mice expressing low levels of Nectin-4 were treated with a single intravenous dose of 2 µCi of [225Ac]Ac-AKY-1189 on day zero. As depicted below, this resulted in a mean tumor growth inhibition of 75% at day 38 compared to 53% inhibition after three administrations of Padcev on day zero, 7 and 14 (depicted in figure A below). Animal weights remained constant during the treatment period, indicating that both regimens were well-tolerated (depicted in figure B below). To compare the antitumor activity and tolerability of Padcev, we calculated the dose to be used in mice based off the approved clinical dose and regimen. The dosing regimen used for Padcev of 3mg/kg once a week for three weeks in mice, demonstrated plasma exposures with an area under the curve, or AUC, of 88 µg*day/mL (depicted in figure C below), similar to those observed in patients treated with the clinical regimen of 1.25mg/m2 (AUC = 111+38 µg*day/mL). AUC is a measure of drug exposure over time. When comparing this clinically relevant dose of Padcev to [225Ac]Ac-AKY-1189, we observed a favorable response for [225Ac]Ac-AKY-1189 in Padcev responsive tumors.

A single administration of [225Ac]Ac-AKY-1189 resulted in greater inhibition of tumor growth than Padcev in low Nectin-4 expressing tumors in xenograft models

Cmax denotes maximum drug concentration; T1/2 denotes time required to decrease drug concentration by half

Named patient use pursuant to Section 21 of South Africa’s Medicines and Related Substances Act

Mike Sathekge, MD, Head of Nuclear Medicine Department, University of Pretoria and Steve Biko, Academic Hospital, and President and Chief Executive Officer, Nuclear Medicine Research Infrastructure, or NuMeRI, administered radioconjugated AKY-1189 provided by us to a limited number of their patients in South Africa pursuant to Section 21 of the MRSA, which allows healthcare providers to administer unregistered medicines to patients, as authorized by SAPHRA.

AKY-1189 conjugated to an imaging radioisotope, [68Ga]Ga-AKY-1189, was dosed in 20 patients with UC, breast cancer, NSCLC, colorectal cancer and cervical cancer. Of these 20 patients, all 20 were available for safety and normal tissue distribution assessment, and 15 were evaluable for tumor uptake. A subset of nine patients underwent kidney dosimetry with [177Lu]Lu-AKY-1189 and eight patients were evaluable for quantitative assessment of the absorbed dose of radiation to the kidney and bone marrow. One patient also received

AKY-807 conjugated to the same imaging isotopes allowing for intra-patient comparison of tumor uptake and absorbed dose to the kidney. In line with the preclinical predictions, AKY-1189 showed superior tumor uptake with less radiation exposure to the kidneys compared to AKY-807, with no adverse events observed.

The figure below depicts normal tissue distribution of [68Ga]Ga-AKY-1189, and robust tumor uptake, including in brain metastasis. Dark areas in the image below depict uptake of [68Ga]Ga-AKY-1189.

Representative PET/CT image of a patient dosed with [68Ga]Ga-AKY-1189 after 1 hour

Tumor uptake was evaluated with [68Ga]Ga-AKY-1189 in 15 patients via PET/CT one hour post-injection. Standard uptake values, or SUVs, were calculated using standard methodology also utilized in standard diagnostic PET/CT images. As depicted in the chart below, SUVs were consistently at or above the levels expected to be required for efficacy and in line with SUVs reported for approved radiopharmaceuticals. This was observed across all tumor types assessed including UC, breast cancer, NSCLC, colorectal cancer and cervical cancer, as depicted in the image below on the left. For context, in an editorial published in 2023, Michael Hofman depicted the observed SUVmax for various approved radiopharmaceuticals, including Pluvicto, Lutathera and

purported next alpha generation therapies. His study set forth the observed SUVmax for PSMA and SSTR in the range from 10-100, as depicted in the image below on the right.

Increasing tumor uptake with [177Lu]Lu-AKY-1189 with no accumulation observed in normal tissues observed at 48 hours

1 ~5.55 GBq (150mCi) administered activity

The figures above depict normal tissue deposition and tumor uptake of [177Lu]Lu-AKY-1189 during a 48-hour period. Dark areas in image depict tissue and tumor uptake of [177Lu]Lu-AKY-1189. At 24 hours post administration, [177Lu]Lu-AKY-1189 exposure increased in the tumors without accumulation of exposure to normal tissues.

The [177Lu]Lu-AKY-1189 data suggests the predicted absorbed dose to the kidney (median absorbed dose of 0.30 gray/gigabecquerel, or Gy/GBq) and bone marrow (median absorbed dose: 0.01 Gy/GBq) allows for six or more therapeutic doses to be safely administered. These data are consistent with other approved radiopharmaceuticals, including Pluvicto, where the kidneys and bone marrow are not considered dose-limiting organs, when conjugated to either 177Lu or 225Ac. We plan to evaluate these findings in future clinical trials.

Our clinical development strategy

In April 2025, the FDA cleared our IND for [225Ac]Ac-AKY-1189 for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors. We have commenced a multi-site Phase 1b clinical trial in the United States and anticipate preliminary results from the Part-1 dose escalation portion of this trial in the first quarter of 2027. The Phase 1b trial in the United States will enroll approximately 150 patients and follow a dose escalation strategy utilizing the Bayesian Optimal Interval, or BOIN,

design, which is a method used for early phase dose-finding based on model-assisted design elements and is used to determine a suitable dose for consideration in later-stage oncology trials. The Phase 1b trial will only enroll patients with locally advanced or metastatic UC in the dose escalation portion. Imaging and dosimetry in the United States trial will be done with [64Cu]Cu-AKY-1189 allowing for multiple timepoint assessments through PET/CT. No imaging selection criteria are employed through dose escalation. Patients will receive up to six cycles of [225Ac]Ac-AKY-1189 at increasing dose levels. Following completion of dose escalation, dose expansions will be conducted in locally advanced or metastatic UC (n=30), triple-negative breast cancer (n=30) and a basket cohort of other tumors known to have high Nectin-4 expression, including NSCLC, colorectal cancer and cervical cancer (n=40). The primary endpoint of the trial will be to assess safety and tolerability of [225Ac]Ac-AKY-1189. Secondary endpoints include objective response rate (as measured by RECIST v1.1, a standard way to measure the response of a tumor to treatment), duration of response, progression-free survival, overall survival, changes in quality of life, and to characterize pharmacokinetic and pharmacodynamic profiles.

In December 2025, we disclosed that we had completed the first dose level of the Part 1 dose escalation of the Phase 1b clinical trial and had commenced enrollment of the next dose level. Enrollment in the trial remains on track, and we expect to present data from the Part 1 dose escalation in the first quarter of 2027. Upon completion of the dose escalation portion, a dose expansion portion will be conducted in patients with locally advanced or metastatic UC and other Nectin-4 expressing tumors. Based on the results of our trial, we plan to seek alignment with the FDA to conduct a pivotal Phase 2 trial for accelerated approval of [225Ac]Ac-AKY-1189 for locally advanced or metastatic UC and other Nectin-4 expressing tumors. [225Ac]Ac-AKY-1189 was granted Fast Track Designation by the FDA in February 2026 for the treatment of locally advanced or metastatic UC in patients who had progressed on or after prior systemic therapies.

[225Ac]Ac-AKY-2519 targeting B7-H3 expressing tumors

Our second product candidate, [225Ac]Ac-AKY-2519, is designed to deliver 225Ac to B7-H3 (CD276) expressing tumors, including prostate, lung and other solid tumors. B7-H3 is a cell-surface protein that is highly expressed in many types of solid tumors, while having limited expression in normal tissues. In the United States, an estimated 146,000 patients are diagnosed with metastatic NSCLC, small cell lung cancer or prostate cancer annually. We estimate that approximately 90% of all metastatic castration-resistant prostate cancers, 80% of NSCLCs and 70% of small cell lung cancers, express B7-H3, while also being expressed on other solid tumors like breast cancers. High expression of B7-H3 has been correlated with poor overall survival and a lack of responsiveness to anti-PD-1 therapeutics in several tumor types. B7-H3 has attracted substantial clinical development efforts across different modalities, including antibody-drug conjugates, with several late-stage antibody-drug conjugates demonstrating preliminary efficacy signals and acceptable safety profiles. Regarding the potential for B7-H3 as a target in prostate cancer, we believe B7-H3 may be superior to PSMA for imaging and treatment of patients with prostate cancer due to higher sensitivity and tumor specificity with a clean normal tissue expression profile.

We discovered AKY-2519, a highly potent and specific binder of B7-H3, characterized it, and advanced it to a development candidate in the fourth quarter of 2024. AKY-2519, a proprietary 49-amino acid rationally designed miniprotein, met all of our pre-specified development candidate criteria including those for potency, selectivity, thermal stability, radiochemical stability, and solubility. AKY-2519 also met or exceeded our desired pharmacokinetic and biodistribution benchmarks while demonstrating robust preclinical efficacy.

Preclinical studies of [225Ac]Ac-AKY-2519

As shown below, [225Ac]Ac-AKY-2519 demonstrated dose-dependent antitumor activity after a single administration in mice harboring a non-small cell lung cancer cell, or NSCLC, line-derived xenograft tumor. Mice treated with a [225Ac]Ac-AKY-2519 showed marked tumor growth inhibition of 92% for the 1.0 µCi dose and 80% for the 0.5 µCi dose, compared to vehicle (n=8 mice per group), and a best response of 48% regression at the 1.0 µCi group. The observed tumor growth inhibition led to prolonged survival for mice treated at each dose level compared to vehicle-treated mice. Body weight remained constant throughout the treatment period, suggesting that both dose levels of [225Ac]Ac-AKY-2519 were well tolerated.

[225Ac]Ac-AKY-2519 demonstrated antitumor activity and increased survival in xenograft models

An analysis of B7-H3 expression across human tumor microarrays demonstrated that B7-H3 is highly expressed in multiple solid tumor indications, specifically squamous NSCLC, squamous esophageal, prostate and triple-negative breast cancers, or TNBC. Levels of B7-H3 expression across these indications are comparable to the level of expression of the mouse model utilized in our preclinical studies, supporting the translational relevance of this model and suggesting that a majority of patients in these indications express equivalent or higher levels of B7-H3 compared to the mouse model that responded robustly to [225Ac]Ac-AKY-2519 treatment.

B7-H3 expression across multiple tumor types

Our development strategy for [225Ac]Ac-AKY-2519

[68Ga]Ga-AKY-2519 and [177Lu]Lu-AKY-2519 uptake in tumors and normal tissue biodistribution is currently being assessed in patients with various B7-H3 expressing solid tumors. To date, each of [68Ga]Ga-AKY-2519 and [177Lu]Lu-AKY-2519 has demonstrated compelling tumor uptake across different tumor types with low uptake in normal tissues and a differentiated biodistribution profile, showcasing rapid clearance from normal organ and tissues, including the kidney. We expect the results of the imaging and dosimetry assessment in patients with various tumor types to be reported in mid-2026. In March 2026, our INDs for [225Ac]Ac-AKY-2519 and for [64Cu]Cu-AKY-2519 were cleared by the FDA to proceed to a Phase 1b clinical trial. We expect

to initiate the multi-site Phase 1b clinical trial mid-2026. We currently anticipate that the Phase 1b program will follow a dose escalation strategy utilizing the BOIN design. The Phase 1b program is planned to enroll patients with mCRPC, NSCLC or small cell lung cancer, using [64Cu]Cu-AKY-2519 for dosimetry and imaging and [225Ac]Ac-AKY-2519 for therapy. Following completion of dose escalation, dose expansions are planned for mCRPC and lung cancers. The primary endpoint will be to assess safety and tolerability of [225Ac]Ac-AKY-2519. Secondary endpoints will include objective response rate (as measured by RECIST v1.1), duration of response, progression-free survival, overall survival, changes in quality of life, and to characterize pharmacokinetic and pharmacodynamic profiles.

Competition

The development and commercialization of new radiopharmaceutical products is highly competitive. We face and will continue to face competition from third parties that use radiopharmaceuticals and from companies focused on more traditional therapeutic modalities. Potential competitors also include academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection, and establish collaborative arrangements for research, development, manufacturing, and commercialization of new products.

We consider our most direct competitors to be companies developing targeted alpha-based radiopharmaceuticals for the treatment of cancer. There are several companies developing targeted alpha-based radiopharmaceuticals for the treatment of cancer, including Abdera Therapeutics, Actinium Pharmaceuticals, Inc., Alpha9 Oncology, Inc., Artbio AS, Bayer AG, Convergent Therapeutics, Fusion Pharmaceuticals Inc. (acquired by AstraZeneca), Johnson & Johnson, Mariana Oncology, Inc. (acquired by Novartis AG), Perspective Therapeutics, POINT Biopharma Global Inc. (acquired by Eli Lilly), RadioMedix, Inc., Radionetics Oncology, RayzeBio, Inc. (acquired by Bristol Myers Squibb) and Telix Pharmaceuticals Limited. These companies are targeting a wide range of solid and hematologic malignancies using various alpha emitting isotopes, including radium-223, lead-212, and 225Ac. The first and only approved alpha particle-based therapy is Bayer’s Xofigo (radium-223) which is a salt of radium that cannot easily and robustly be attached to a targeting molecule, but naturally localizes to regions where cancer cells infiltrate bone. Xofigo was approved in 2013 for the treatment of prostate cancer with symptomatic bone metastases.

There are several companies with approved beta-emitting radiopharmaceuticals, including Lantheus Holdings, Novartis, Bayer, Sirtex, Boston Scientific and Q BioMed Inc. and other companies developing beta-emitting radiopharmaceuticals, including POINT Biopharma Global (acquired by Eli Lilly), ITM Isotope Technologies Munich SE, Y-Mabs and Telix Pharmaceuticals Limited. The beta emitting isotopes used by these companies include iodine-131, 177Lu, strontium-89 and yttrium-90. A recently approved beta particle-based radiopharmaceutical is Novartis’ Pluvicto, which was approved by the FDA in 2022 for the treatment of patients with metastatic prostate cancer.

Our competitors will also include companies that are or will be developing other treatment methods, including those utilizing other radioisotopes, as well as therapies for the same indications in oncology that we are targeting. In addition to the competitors we face in developing radiopharmaceuticals, we will also face competition in the indications we expect to pursue. To compete effectively with these existing therapies, we will need to demonstrate that our therapies are favorable to existing therapeutics and obtain comparable coverage and reimbursement for our product candidates.

Many of our current or future competitors have significantly greater financial resources and expertise in research and development, isotope supply chain logistics, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, obtaining reimbursement for and marketing of approved products than we do. Mergers and acquisitions in the biotechnology, pharmaceutical and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we or our collaborators may develop. Our competitors also may obtain FDA or other foreign regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we or our collaborators are able to enter the market. Even if the product candidates we may develop in the future achieve regulatory approval, they may be priced at a significant premium over competitive products if any have been approved by then, resulting in reduced competitiveness. Moreover, technological advances or products developed by our competitors may render our technologies or product candidates we may develop in the future obsolete, less competitive, or not economical. The key competitive factors affecting the success of [225Ac]Ac-AKY-1189 and our other current and future product candidates, if approved, are likely to be their efficacy, safety, convenience, price, the level of generic competition and the availability of reimbursement from government and other third-party payors.

Intellectual property

Our success depends in part on our ability to obtain, maintain, protect, defend and enforce proprietary protection for our product candidates and other discoveries, inventions, trade secrets and know-how that are critical to our business operations. Our success

also depends in part on our ability to operate without infringing, misappropriating or otherwise violating the intellectual property or proprietary rights of others, and in part on our ability to prevent others from infringing, misappropriating or violating our intellectual property or proprietary rights. A discussion of risks relating to intellectual property is provided under the section titled “Risk factors—Risks related to intellectual property.”

With respect to our [225Ac]Ac-AKY-1189 program, as of March 1, 2026, we own one pending international patent application filed under the Patent Cooperation Treaty, or a PCT Application, one issued U.S. patent, one pending U.S. non-provisional utility application and two pending foreign non-provisional patent applications in each of Taiwan and Argentina, which are directed to, among other things, composition of matter and uses of [225Ac]Ac-AKY-1189. We do not own or license, and do not expect to own or license, any patents or patent applications that cover the radioactive payload in [225Ac]Ac-AKY-1189, which is 225Ac. The issued U.S. patent and any patents issuing from the patent applications we own or future patent applications that we may file based on these applications are expected to expire in 2044, excluding any patent term adjustments or extensions that may be available and assuming timely payment of all appropriate maintenance, renewal, annuity or other governmental fees.

With respect to our [225Ac]Ac-AKY-2519 program, as of March 1, 2026, we own one pending PCT Application, one pending U.S. non-provisional utility application, and two pending foreign non-provisional patent applications in each of Taiwan and Argentina, which are directed to, among other things, composition of matter and uses of [225Ac]Ac-AKY-2519. We do not own or license any issued patents related to our [225Ac]Ac-AKY-2519 program. In addition, we do not expect to own or license any patents or patent applications that cover the radioactive payload in [225Ac]Ac-AKY-2519, which is 225Ac. Any patents issuing from the patent applications we own or future patent applications that we may file based on these applications are expected to expire in 2044, excluding any patent term adjustments or extensions that may be available and assuming timely payment of all appropriate maintenance, renewal, annuity or other governmental fees.

With respect to our platform program, as of March 1, 2026, we own one pending PCT Application, 22 pending non-provisional patent applications in each of Australia, Brazil, Canada, Chile, China, Colombia, Eurasia, Europe, Israel, India, Japan, Morocco, Mexico, Peru, Philippines, Saudi Arabia, South Africa, South Korea, Taiwan, Tunisia, United Arab Emirates, and the United States, and one pending U.S. provisional patent application. We do not own or license any issued patents related to our platform program. Any patents that issue from the patent applications we own or future patent applications that we may file based on these applications are expected to expire in 2043, 2045 and 2046, excluding any patent term adjustments or extensions that may be available and assuming timely payment of all appropriate maintenance, renewal, annuity or other governmental fees.

With respect to our discovery programs, as of March 1, 2026, we own one pending PCT Application, one pending U.S. provisional patent application, and four non-provisional patent applications (one each in China, Europe, the United States and South Africa), each of which is directed to compositions of matter and uses for miniproteins against our targets of interest. We do not own or license any issued patents related to our discovery programs. Any patents issuing from the patent applications we own or future patent applications that we may file based on these applications are expected to expire in 2043, 2044 and 2046, excluding any patent term adjustments or extensions that may be available and assuming payment of all appropriate maintenance, renewal, annuity or other governmental fees.

U.S. provisional patent applications are not eligible to become issued patents unless and until, among other things, we file one or more non-provisional U.S., foreign, and/or PCT Applications within 12 months of the first-filed provisional application to which these non-provisional applications claim priority. With regard to such U.S. provisional patent applications, if we do not timely file any non-provisional patent applications, we will lose our priority date with respect to subject matter and inventions disclosed in these provisional patent applications. Provided no statutory bars to patentability have occurred during the 12-month pendency of the provisional patent application, the option to refile and obtain a later filing date remains open. While we intend to timely file non-provisional patent applications related to our provisional patent applications, we cannot predict whether any such patent applications will result in the issuance of patents that provide us with any competitive advantage. Further, our PCT Applications are not eligible to become patents until, among other things, we timely file national stage patent applications in jurisdictions that are party to the Patent Cooperation Treaty, and in which we seek patent protection. If we do not timely file any national stage patent applications, we may lose our priority date with respect to our PCT Applications and any patent protection on inventions disclosed in such PCT Applications.

The proprietary nature of, and protection for, our product candidates and their methods of use are an important part of our strategy to develop and commercialize novel medicines. We have filed for or licensed patents rights relating to certain of our product candidates and are pursuing additional patent protection for them and for our other product candidates and technologies. In addition to patent protection, we also rely on trade secrets, know-how, trademarks, confidential information, other proprietary information and continuing technological innovation to develop, strengthen and maintain our competitive position. We seek to protect and maintain the confidentiality of proprietary information to protect aspects of our business that are not amenable to, or that we do not consider appropriate for, patent protection. Although we take steps to protect our proprietary information and trade secrets, including through contractual means with our employees, consultants, contractors and collaborators, third parties may independently develop substantially equivalent proprietary information and techniques or otherwise gain access to our trade secrets or disclose our technology. Thus, we may not be able to meaningfully protect our trade secrets. It is our policy to require our employees, consultants, outside scientific collaborators, sponsored researchers and other advisors to execute confidentiality and invention assignment agreements upon the commencement of employment or consulting relationships with us. However, such

confidentiality agreements can be breached, and we may not have adequate remedies for any such breach. For more information regarding the risks related to our intellectual property, see the section titled “Risk factors—Risks related to intellectual property.”

License and collaboration agreements

Institute for Protein Innovation License Agreement

On November 1, 2021, we and the Institute for Protein Innovation, Inc., or IPI, entered into an Exclusive License Agreement, as amended on July 26, 2022, the IPI Agreement, pursuant to which IPI granted us an exclusive, worldwide license, with the right to sublicense (subject to certain conditions), under certain of IPI’s patents and know-how related to certain binder proteins, targeting up to 14 target proteins, including Nectin-4, to research, develop, make, have made, and commercialize certain products. Pursuant to the IPI Agreement, IPI also granted us a non-exclusive license to certain intellectual property rights required to research, develop, make, have made, and commercialize certain products.

Upon execution of the IPI Agreement, we paid an upfront license fee of $0.2 million and are required to pay an annual license fee of less than $0.1 million until the first commercial sale of the first licensed product, pursuant to which we have paid an aggregate of $0.2 million through December 31, 2025. The IPI Agreement requires us to pay up to an aggregate of $24.0 million upon achievement of certain regulatory and development milestones. In addition, if we successfully commercialize a licensed product under the IPI Agreement, we are required to pay low single-digit royalties on net sales, on a product-by-product and country-by-country basis, subject to specified reductions, until the later of (a) the expiration of the last to expire valid claim covering the manufacture, use or sale of such licensed product in such country or (b) ten years after the first licensed product sale in such country. The royalties are subject to specified and capped reductions for payments owed to third parties for additional rights necessary to commercialize licensed products.

The IPI Agreement requires us to use diligent and commercially reasonable efforts to develop and commercialize a licensed product.

At any time after the fifth year anniversary of the IPI Agreement, if IPI receives a third-party request to license certain rights granted to us pursuant to the IPI Agreement for which we are not actively developing or commercializing a licensed product, we must either (i) submit a commercially reasonable development plan for such undeveloped field to IPI that we will put into effect within a certain number of days, (ii) substantiate why granting a license to such rights in such undeveloped field to the third party is not in our best business interest or (iii) enter into good faith negotiations with such third party for such rights in such undeveloped field.

Unless earlier terminated, the IPI Agreement will expire at the end of the last to expire royalty term. IPI may, at its election, either terminate the IPI Agreement, convert any of our exclusive license rights into non-exclusive rights, or choose to reduce the field or territory, if (a) the first commercial sale of a licensed product does not occur by January 1, 2035 or the payment of earned royalties, once begun, ceases for more than eight consecutive calendar quarters; (b) we default in the timely payment of any amount due or are otherwise in breach of the IPI Agreement and fail to remedy such default or breach within 30 days after written notice thereof; (c) we are found, on more than one examination, to have underreported or underpaid any royalty payment by more than five percent in any three calendar quarters in the period under examination; (d) we cease to carry on our business related to the subject matter of the licensed patents or (e) we become insolvent or file a petition regarding bankruptcy or insolvency or other certain insolvency or bankruptcy-related events occur. We may terminate the IPI Agreement in its entirety, with or without cause, upon 60 days’ written notice.

TRIUMF License Agreement

On July 21, 2022, we and TRIUMF Inc., a Canadian non-profit, or TRIUMF, TRIUMF Innovations, Inc., a Canadian non-profit, the University of British Columbia, and BC Cancer, a provincial health services authority, entered into a License Agreement, the TRIUMF License. Pursuant to the TRIUMF License, TRIUMF, the University of British Columbia and BC Cancer, or the Licensors, granted us a non-exclusive, worldwide license, with right to sublicense (subject to certain conditions), under certain patents and know-how related to the Licensors’ chelator technology to make, use, sell, offer for sale, import, and export certain radiopharmaceutical products for the diagnosis, treatment, amelioration, and prevention of human diseases and conditions. None of our product candidates currently incorporate, or rely on, the licensed patents and know-how from the TRIUMF License.

We paid an initial license fee of $0.1 million upon execution of the TRIUMF License. The TRIUMF License requires us to pay up to an aggregate of $2.0 million upon achievement of certain regulatory and development milestones. We are also obligated to pay low single digit royalties on net sales of licensed products, on a product-by-product basis.

For licensed products not covered by a valid claim of a licensed patent, our royalty obligation terminates on the tenth anniversary of the first commercial use of such licensed product in each country.

Unless earlier terminated, the TRIUMF License will expire on the later of the twelfth-year anniversary of the TRIUMF License or the expiry of the last patent subject to the TRIUMF License. We may terminate the TRIUMF License for convenience upon 60 days’ written notice. The Licensor may, at its option, terminate the TRIUMF License if (i) we become insolvent, cease to carry on business or other certain insolvency or bankruptcy-related events occur, (ii) we breach certain provisions (including those related to sublicenses, confidentiality, and insurance), (iii) the licensed patents and know-how become subject to any security interest, lien,

charge or encumbrance in favor of a third party through our action or (iv) there is an uncured breach by our sublicensee and we do not terminate the respective sublicense agreement. Either party may terminate the TRIUMF License for uncured breach, subject to specified cure periods.

University of Minnesota License Agreement

On March 3, 2023, we and the Regents of the University of Minnesota, or the University of Minnesota, entered into an Exclusive License Agreement, the Minnesota License, pursuant to which the University of Minnesota and the Stanford University, or Stanford, granted us, solely for human and veterinary uses, an exclusive license under the University of Minnesota’s and Stanford’s rights in certain patents related to certain binding proteins to make, use, sell, offer for sale, and import certain therapeutic and diagnostic products in the countries where there are licensed patents and a non-exclusive license to use licensed technical information. None of our product candidates incorporate, or rely on, the patents and know-how from the Minnesota License.

We paid an upfront fee of $0.1 million upon entering into the Minnesota License and paid an annual license fee of less than $0.1 million throughout the term of the Minnesota License, pursuant to which we have paid an aggregate of $0.4 million through September 30, 2025. No milestones were achieved under the Minnesota License prior to the termination of this agreement.

In July 2025, we provided notice to the University of Minnesota to terminate the Minnesota License and paid the $10,000 early termination fee, with an effective termination date of September 9, 2025.

Eli Lilly and Company License, Research and Collaboration Agreement

On May 16, 2024, we and Eli Lilly entered into a License, Research and Collaboration Agreement, the Collaboration Agreement. Pursuant to the Collaboration Agreement, we granted Eli Lilly an exclusive (even as to us and our affiliates), royalty-bearing, worldwide license, with the right to sublicense, to certain of our patents and other intellectual property rights to exploit certain compounds and therapeutic or diagnostic products that contain such compounds solely as products that contain a radioactive isotope. We also granted Eli Lilly a non-exclusive, royalty-bearing, worldwide license, with the right to sublicense, to the intellectual property necessary or useful to exploit the licensed compounds and licensed products solely as products that contain a radioactive isotope and a non-exclusive, fully paid-up license, with the right to sublicense, to exploit certain other intellectual property developed under the Collaboration Agreement for any and all purposes (subject to certain limitations). In addition, we and Eli Lilly agreed to negotiate in good faith to enter into a separate agreement in the event the parties agree that the clinical development of a licensed compound requires, or would be benefited by, a license to one of our other compounds.

Under the Collaboration Agreement, Eli Lilly may designate a specified number of initial collaboration targets, with the right to substitute other targets. We will be responsible for research activities through initial human imaging studies for a lead candidate for each selected target, and Eli Lilly will thereafter be responsible for regulatory filings, clinical development and commercialization activities worldwide. There is a separate research plan for each collaboration target, and our development costs are capped, on a research plan-by-research plan basis. Eli Lilly will reimburse our reasonable out-of-pocket costs and full-time equivalent costs incurred in excess of the cap.

Eli Lilly paid us an upfront license fee of $60.0 million upon execution of the Collaboration Agreement. The Collaboration Agreement requires Eli Lilly to pay up to an aggregate of $525.0 million upon achievement of certain research, development, regulatory and commercial launch milestones and up to an aggregate of $630 million upon achievement of certain sales milestones. In addition, if Eli Lilly successfully commercializes a therapeutic or diagnostic product under the Collaboration Agreement, Eli Lilly is required to pay us tiered royalties of up to 10% based on annual net sales, on a product-by-product and country-by-country basis, subject to specified reductions, until the later of the expiration of licensed patent rights in a country, expiration of regulatory exclusivity, or ten years after the first product sale in such country. The Collaboration Agreement requires Eli Lilly to use commercially reasonable efforts to develop and commercialize a licensed product from a research program in certain markets and through satisfaction of certain criteria.

Unless earlier terminated, the Collaboration Agreement will continue on a licensed product-by-licensed product and country-by-country basis until the expiration of the applicable royalty term for such licensed product. Either party may terminate the Collaboration Agreement for uncured material breach, subject to specified cure periods. In certain instances, if Eli Lilly has the right to terminate the Collaboration Agreement for our uncured material breach, Eli Lilly may, at its option, continue the Collaboration Agreement where all payments due from Eli Lilly to us, on a prospective basis, will be reduced by a specified percentage and Eli Lilly diligence and reporting obligations will end. Eli Lilly may, at any time and without cause, terminate the Collaboration Agreement in its entirety or on a collaboration target-by-collaboration target or region-by-region basis upon sixty days’ notice.

In connection with the Collaboration Agreement, we and Eli Lilly entered into a Series A-1 redeemable convertible preferred stock purchase agreement pursuant to which we issued and sold an aggregate of 2,500,000 shares of our Series A-1 redeemable convertible preferred stock at a purchase price of $4.00 per share for aggregate net proceeds of $10.0 million.

Government regulation

Government authorities in the U.S., including federal, state, and local authorities, and in other countries, extensively regulate, among other things, the manufacturing, research and clinical development, marketing, labeling and packaging, storage, distribution, post-approval monitoring and reporting, advertising and promotion, and export and import of biological products, such as those we are developing. In addition, some government authorities regulate the pricing of such products. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local, and foreign statutes and regulations require the expenditure of substantial time and financial resources.

Review and approval for licensing biologics in the U.S.

In the U.S., the FDA regulates biological products under the Federal Food, Drug, and Cosmetic Act, or the FDCA, the Public Health Service Act, or the PHSA, and their implementing regulations. FDA approval is required before any biological product can be marketed in the U.S. Biological products are also subject to other federal, state, and local statutes and regulations. If we fail to comply with applicable FDA or other requirements at any time during the product development process, clinical testing, the approval process or after approval, we may become subject to administrative or judicial sanctions or other consequences, including the FDA’s refusal to allow us to proceed with clinical testing, issuance of clinical holds for planned or ongoing studies, refusal to approve pending applications, license suspension or revocation, withdrawal of an approval, issuance of untitled or warning letters, product recalls, product seizures, import detentions or refusals, total or partial suspension of manufacturing or distribution, injunctions, fines, civil penalties or criminal prosecution. Any such action could have a material adverse effect on us.

The process required by the FDA before product candidates may be marketed in the U.S. generally involves the following:

The nonclinical and clinical testing and approval process requires substantial time, effort, and financial resources, and we cannot be certain that any approvals for our product candidates will be granted on a timely basis, if at all.

Nonclinical studies and investigational New Drug Application

Before testing any biological product in humans, a product candidate must undergo rigorous preclinical testing. Preclinical studies include laboratory evaluations of product chemistry, formulation, and stability, as well as in vitro and animal studies to assess safety and in some cases to establish the rationale for therapeutic use. The conduct of preclinical studies is subject to federal and state regulation and requirements, including GLP requirements for safety/toxicology studies. The results of the preclinical studies, together with manufacturing information and analytical data, must be submitted to the FDA as part of an IND.

An IND is a request for authorization from the FDA to administer an investigational biological product to humans in clinical trials in the U.S. The central focus of an IND submission is on the general investigational plan, the protocol(s) for human trials and the safety of trial participants. The IND also includes results of animal and in vitro studies assessing the toxicology, pharmacokinetics, pharmacology, and pharmacodynamic characteristics of the product; chemistry, manufacturing and controls

information; and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. An IND will automatically become effective 30 days after receipt by the FDA, unless before that time the FDA raises concerns or questions related to the proposed clinical trials. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before clinical trials can begin. Accordingly, submission of an IND may or may not result in the FDA allowing clinical trials to commence.

At any time during the initial 30 day IND review period or while clinical trials are ongoing under the IND, the FDA may impose a partial or complete clinical hold. Clinical holds may be imposed by the FDA when there is concern for patient safety, and may be a result of new data, findings, or developments in clinical, nonclinical, and/or chemistry, manufacturing and controls or where there is non-compliance with regulatory requirements. A clinical hold would delay either a proposed clinical trial or cause suspension of an ongoing trial, until all outstanding concerns have been adequately addressed and the FDA has notified the company that investigations may proceed. A separate submission to an existing IND must also be made for each successive clinical trial to be conducted, and the FDA must grant permission, either explicitly or implicitly by not objecting, before each clinical trial can begin.

Clinical trials

Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCPs, which include the requirement that all research subjects provide their informed consent for their participation in any clinical trial. Clinical trials are conducted under protocols detailing, among other things, the objectives of the trial, the inclusion and exclusion criteria, the parameters to be used in monitoring safety, and the efficacy criteria to be evaluated. A protocol for each clinical trial and any subsequent protocol amendments must be submitted to the FDA as part of the IND.

Additionally, approval must also be obtained from each clinical trial site’s IRB, before the trials may be initiated and the IRB must monitor the trial until completed. The IRB will consider, among other things, clinical trial design, patient informed consent, ethical factors, the safety of human subjects and the possible liability of the institution. There are also requirements governing the reporting of ongoing clinical trials and clinical trial results to public registries, including on clinicaltrials.gov.

The clinical investigation of a biological product is generally divided into three or four phases. Although the phases are usually conducted sequentially, they may overlap or be combined.

Phase 1. The investigational product is initially introduced into healthy human subjects or, in the case of some products designed to address severe or life-threatening diseases, patients with the target disease or condition. These trials are designed to evaluate the safety, dosage tolerance, metabolism and pharmacologic actions of the investigational product in humans, the side effects associated with increasing doses, and if possible, to gain early evidence on effectiveness.

Phase 2. The investigational product is administered to a limited patient population to evaluate dosage tolerance and optimal dosage, identify possible adverse side effects and safety risks, and preliminarily evaluate efficacy.

Phase 3. The investigational product is administered to an expanded patient population, generally at geographically dispersed clinical trial sites to generate enough data to statistically evaluate safety, purity and potency, to evaluate the overall benefit-risk profile of the investigational product, and to provide an adequate basis for physician labeling.

Phase 4. In some cases, the FDA may condition approval of a BLA for a product candidate on the sponsor’s agreement to conduct additional clinical trials after approval or a sponsor may voluntarily conduct additional clinical trials after approval to gain more information about the biological product. Such post-approval trials are typically referred to as Phase 4 clinical trials.

Sponsors must also report to the FDA, within certain timeframes, serious and unexpected adverse reactions, any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator’s brochure, or any findings from other studies or animal or in vitro testing that suggest a significant risk in humans exposed to the product candidate. The FDA, the IRB, or the clinical trial sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research subjects are being exposed to an unacceptable health risk. Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data and safety monitoring board or committee. This group provides authorization for whether or not a trial may move forward at designated check points based on access to certain data from the trial. We may also suspend or terminate a clinical trial based on evolving business objectives or competitive climate.

A sponsor of an investigational biological product for a serious disease or condition is required to make available, such as by posting on its website, its policy on evaluating and responding to requests for individual patient access to such investigational biological product. This requirement applies on the earlier of the first initiation of a Phase 2 or Phase 3 trial of the investigational biological product or, as applicable, 15 days after the biological product receives a designation as a breakthrough therapy or fast track product.

Concurrent with clinical trials, sponsors usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product candidate and finalize a process for manufacturing the drug product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and manufacturers must develop, among other things, methods for testing the identity, strength, quality, and purity of the final drug product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

During the development of a new biologic, sponsors are given opportunities to meet with the FDA at certain points. These points may be prior to submission of an IND, at the end of Phase 1, at the end of Phase 2, and before a BLA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the sponsor to share information about the data gathered to date, for the FDA to provide advice, and for the sponsor and the FDA to reach agreement on the next phase of development.

Submission of a BLA to the FDA

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, detailed investigational product information is submitted to the FDA in the form of a BLA requesting approval to market the product for one or more indications. Under federal law, the submission of most BLAs is subject to an application user fee, and the sponsor of an approved BLA is also subject to an annual program fee for each approved biological product on the market. Applications for orphan drug products are exempted from the BLA application fee and may be exempted from program fees, unless the application includes an indication for other than a rare disease or condition.

A BLA must include all relevant data available from pertinent nonclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls, and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of a use of a product, or from a number of alternative sources, including trials initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety and effectiveness of the investigational product to the satisfaction of the FDA.

The FDA conducts a preliminary review of all BLAs within the first 60 days after submission before accepting them for filing to determine whether they are sufficiently complete to permit substantive review. The FDA may request additional information rather than accept an application for filing. Under the performance goals and policies implemented by the FDA under PDUFA, once a BLA has been submitted, the FDA’s goal for novel biological products generally is to review the application within ten months after it accepts the application for filing, or, if the application is granted priority review, six months after the FDA accepts the application for filing. The FDA does not always meet its PDUFA goal dates, and the review process may be extended. For example, the review process and the PDUFA goal date may be extended by three months if the FDA requests or if the applicant otherwise provides additional data, analysis or information that FDA deems a major amendment.

Before approving a BLA, the FDA typically will inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA will typically inspect the sponsor and one or more clinical sites to assure compliance with GCPs. Material changes in manufacturing equipment, location, or process post-approval, may result in additional regulatory review and approval.

The FDA is required to refer an application for a novel biological product to an advisory committee or explain why such referral was not made. An advisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

The FDA’s decision on a BLA

On the basis of the FDA’s evaluation of the application and accompanying information, including the results of the inspection of the manufacturing facilities and any FDA inspections of nonclinical and clinical trial sites to assure compliance with GLPs or GCPs, the FDA may approve the BLA or issue a complete response letter. Under the PHSA, the FDA may approve a BLA if it determines the product is safe, pure, and potent, and that the facility in which the product will be manufactured, processed, packaged or held meets standards designed to assure the product’s continued safety, purity and potency. If the FDA determines the product meets those standards, it may issue an approval letter authorizing commercial marketing of the biological product with specific prescribing information for specific indications. If the application is not approved, FDA will issue a complete response letter, which indicates that the review cycle of the application is complete and the application is not ready for approval. A complete response letter will identify the deficiencies that prevent the FDA from approving the application and may require additional clinical data or an additional Phase 3 clinical trial(s), or other significant, expensive and time-consuming requirements related to clinical trials, nonclinical studies or manufacturing. Even if such additional information is submitted, the FDA may ultimately decide that the BLA does not satisfy the criteria for approval and issue a denial.

The FDA could also approve the BLA with a Risk Evaluation and Mitigation Strategy, or REMS, program to mitigate risks, which could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling, development of adequate controls and specifications, or a commitment to conduct one or more post-market studies or clinical trials. Such post-market testing may include Phase 4 clinical trials and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization.

Orphan drug designation

Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biological product intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the U.S., or more than 200,000 individuals in the U.S. and for which there is no reasonable expectation that the cost of developing and making a drug or biological product available in the U.S. for this type of disease or condition will be recovered from sales of the product. Orphan product designation must be requested before submitting a BLA. After the FDA grants orphan product designation, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. Orphan product designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.

Orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers. Additionally, if a product that has orphan designation subsequently receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications to market the same drug or biological product for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan exclusivity.

The period of exclusivity begins on the date that the marketing application is approved by the FDA and applies only to the indication for which the product has been designated. The FDA may approve a second application for the same product for a different use or a second application for a clinically superior version of the product for the same use. The FDA cannot, however, approve the same product made by another manufacturer for the same indication during the market exclusivity period unless it has the consent of the sponsor, or the sponsor is unable to provide sufficient quantities. If a drug or biological product designated as an orphan product receives marketing approval for an indication broader than what is designated, it may not be entitled to orphan product exclusivity. Orphan drug status in the European Union has similar, but not identical, benefits.

The FDA has historically taken the position that the scope of orphan exclusivity aligns with the approved indication or use of a product, rather than the disease or condition for which the product received orphan designation. However, in Catalyst Pharms., Inc. v. Becerra, 14 F.4th 1299 (11th Cir. 2021), the court disagreed with this position, holding that orphan-drug exclusivity blocked the FDA’s approval of the same drug for all uses or indications within the same orphan-designated disease. On January 24, 2023, the FDA published a notice in the Federal Register to clarify that the FDA intends to continue to apply its longstanding interpretation of the regulations to all matters outside of the scope of the Catalyst order and will continue tying the scope of orphan-drug exclusivity to the uses or indications for which a drug is approved. It is unclear how future litigation, legislation, agency decisions, and administrative actions will impact the scope of orphan drug exclusivity.

Expedited review programs

The FDA offers a number of expedited development and review programs for qualifying product candidates. New biological products are eligible for fast track designation if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a new biologic may request that the FDA designate the biologic as a fast track product at any time during the clinical development of the product. The sponsor of a fast track product has opportunities for more frequent interactions with the applicable FDA review team during product development and, once a BLA is submitted, the product candidate may be eligible for priority review. A fast track product may also be eligible for rolling review, where the FDA may consider for review sections of the BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the BLA, the FDA agrees to accept sections of the BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the BLA.

A product candidate intended to treat a serious or life-threatening disease or condition may also be eligible for breakthrough therapy designation to expedite its development and review. A product candidate can receive breakthrough therapy designation if preliminary clinical evidence indicates that the product candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product candidate, including involvement of senior managers.

Any marketing application for a biologic submitted to the FDA for approval, including a product candidate with a fast track designation and/or breakthrough therapy designation, may be eligible for other types of FDA programs intended to expedite development and review, such as priority review. An application for a biological product will receive priority review designation if it is for a biological product that treats a serious condition and, if approved, would provide a significant improvement in safety or effectiveness. The FDA will attempt to direct additional resources to the evaluation of an application for a new biological product designated for priority review in an effort to facilitate the review. For original BLAs, priority review designation means the FDA’s goal is to take action on the marketing application within six months of the 60-day filing date (as compared to ten months under standard review).

Fast track designation, breakthrough therapy designation, and priority review do not change the standards for approval but may expedite the development or approval process. Even if a product candidate qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.

Accelerated approval

Product candidates studied for their safety and effectiveness in treating serious conditions may receive accelerated approval upon a determination that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA will generally require the sponsor to perform adequate and well-controlled post-marketing clinical studies to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. Under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA may require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a biologic or indication approved under accelerated approval if, for example, the sponsor fails to conduct the required post-marketing studies or if such studies fail to verify the predicted clinical benefit. In addition, for products being considered for accelerated approval, the FDA generally requires, unless otherwise informed by the FDA, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to FDA for review during the pre-approval period. After 120 days following marketing approval, unless otherwise informed by the FDA, advertising and promotional materials must be submitted at least 30 days prior to the intended time of initial dissemination or publication.

Project Optimus

In 2021, the FDA’s Oncology Center of Excellence launched Project Optimus, an initiative to reform the dose optimization and dose selection paradigm in oncology drug development to emphasize selection of an optimal dose, which is a dose that maximizes not only the efficacy of a drug but also its safety and tolerability.

Project Optimus was driven by the FDA’s concerns that the historical approach to dose selection, which generally determined the maximum tolerated dose, may have resulted in doses and schedules of molecularly targeted therapies that were inadequately characterized before the initiation of pivotal trials.

Project Optimus requires the implementation of strategies for dose finding and dose optimization that leverage nonclinical and clinical data in dose selection, including randomized evaluations of a range of doses in trials. This initiative emphasizes the performance of dose finding and dose optimization studies as early and efficiently as possible in development programs. In support of this initiative, the FDA may request sponsors of oncology product candidates to conduct dose optimization studies.

Post-approval requirements

Biological products manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to recordkeeping, periodic reporting, product sampling and distribution, advertising and promotion and reporting of adverse experiences with the product. After approval, most changes to the approved product, such as adding new dosage forms, indications or other labeling claims, are subject to prior FDA review and approval.

Biological product manufacturers are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections for compliance with cGMPs. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirements upon us and any third-party manufacturers that we may decide to use. Manufacturers and manufacturers’ facilities are also required to comply with applicable product tracking and tracing requirements and notify the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the U.S. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance.

A biological product may also be subject to official lot release, meaning that the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. If the product is subject to official lot release, the manufacturer must submit samples of each lot, together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot, to the FDA. The FDA may perform certain confirmatory tests on lots of some products before releasing the lots for distribution.

Until we are able to establish our own cGMP manufacturing facility, we expect to continue to rely on third parties for the production of clinical quantities of our product candidates, and expect to rely in the future on third parties for the production of commercial quantities. Future FDA and state inspections may identify compliance issues at our facilities or at the facilities of our contract manufacturers that may disrupt production, or distribution, or may require substantial resources to correct. In addition, discovery of previously unknown problems with a product or the failure to comply with applicable requirements may result in restrictions on a product, manufacturer or holder of an approved BLA, including withdrawal or recall of the product from the market or other voluntary, FDA-initiated or judicial action that could delay or prohibit further marketing.

The FDA may suspend or revoke product license approvals if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical trials to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program.

FDA has authority to require post-market studies, in certain circumstances, on reduced effectiveness of a biological product and FDA may require labeling changes related to new reduced effectiveness information. Other potential consequences of a failure to maintain regulatory compliance include, among other things:

The FDA strictly regulates marketing, labeling, advertising, and promotion of prescription drug products, including biological products. These regulations include, among other things, standards and regulations for direct-to- consumer advertising, communications regarding unapproved uses, industry-sponsored scientific and educational activities and promotional activities involving the internet and social media. Promotional claims about a drug’s safety or effectiveness are prohibited before the BLA is approved. Once a BLA is approved, the sponsor can only make those claims relating to safety, efficacy, purity and potency that are consistent with the biological product’s approved label. Additionally, promotional materials for prescription drug products must be submitted to the FDA in conjunction with their first use.

In the U.S., healthcare professionals are generally permitted to prescribe legally available drugs for uses that are not described in the product’s labeling and that differ from those approved by the FDA. The FDA does not regulate the practice of medicine or healthcare providers’ choice of treatments; however, FDA restricts manufacturers’ communications of off-label uses. If a company, including any agent of the company or anyone speaking on behalf of the company, is found to have promoted off-label uses, the company may become subject to adverse public relations and administrative and judicial enforcement by the FDA, the DOJ, or the Office of the Inspector General of HHS, as well as state authorities. This could subject a company to a range of penalties that could have a significant commercial impact, including civil and criminal fines and agreements that materially restrict the manner in which a company promotes or distributes drug products. The federal government has levied large civil and criminal fines against companies for alleged improper promotion and has also requested that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed.

Pediatric trials and exclusivity

Under the Pediatric Research Equity Act of 2003, a BLA (or BLA supplement thereto) must contain data that are adequate to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. A sponsor who is planning to submit a marketing application for a biological product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration must submit an initial Pediatric Study Plan, or PSP, within sixty days of an end of Phase 2 meeting or as may be agreed between the sponsor and FDA. The initial PSP must include an outline of the pediatric study or studies that the sponsor plans to conduct, including study objectives and design, age groups, relevant endpoints and statistical approach, or a justification for not including such detailed information, and any request for a deferral of pediatric assessments or a full or partial waiver of the requirement to provide data from pediatric studies along with supporting information. Generally, development program candidates designated as orphan drugs are exempt from the above requirements. FDA and the sponsor must reach agreement on the PSP. A sponsor can submit amendments to an agreed upon initial PSP at any time if changes to the pediatric plan need to be considered based on data collected from nonclinical studies, early phase clinical trials, and/or other clinical development programs.

The FDA may, on its own initiative or at the request of the applicant, grant deferrals for submission of some or all pediatric data until after approval of the product for use in adults, or full or partial waivers from the pediatric data requirements. The FDA may send a non-compliance letter to any sponsor that fails to submit the required assessment, keep a deferral current or fails to submit a request for approval of a pediatric formulation. Unless otherwise required by regulation, the pediatric data requirements do not apply to products with orphan designation.

Pediatric exclusivity is another type of non-patent exclusivity in the U.S. and, if granted for a biologic, provides for the attachment of an additional six months of marketing protection to the term of any existing regulatory exclusivity for all formulations, dosage forms, and indications of the biologic, including the five-year and three-year non-patent and orphan exclusivity. This six-month exclusivity may be granted if a BLA sponsor submits pediatric data that fairly respond to a written request from the FDA for such data, provided that at the time pediatric exclusivity is granted there is not less than nine months of term remaining. The data do not need to show the product to be effective in the pediatric population studied; rather, if the clinical trial is deemed to fairly respond to the FDA’s request, the additional protection is granted. If reports of FDA-requested pediatric trials are submitted to and accepted by the FDA within the statutory time limits, whatever statutory or regulatory periods of exclusivity or patent protection covering the product are extended by six months. This is not a patent term extension, but it effectively extends the regulatory period during which the FDA cannot accept or approve another application relying on the BLA sponsor’s data.

Patent term restoration

Depending upon the timing, duration, and specifics of the FDA approval of the use of our product candidates, some of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, commonly referred to as the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of a BLA, plus the time between the submission date and the approval of that application. Only one patent applicable to an approved product is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent and within 60 days of the product’s approval. The U.S. Patent and Trademark Office, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may apply for restoration of patent term for one of our currently owned or licensed patents to add patent life beyond its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant BLA.

Regulation of diagnostic patient selection tool

We believe that the success of certain of our product candidates may depend, in part, on the development and commercialization of an imaging agent that will serve, where needed, as a patient selection tool. This diagnostic imaging agent is subject to FDA regulation, review, and approval in the same manner as the therapeutic biological products we are seeking to develop and commercialize and are subject to the same risks.

Other regulatory matters

Manufacturing, sales, promotion and other activities of product candidates following product approval, where applicable, or commercialization are also subject to regulation by numerous regulatory authorities in the U.S. in addition to the FDA, which may include the Centers for Medicare & Medicaid Services, or CMS, other divisions of the Department of Health and Human Services, or HHS, the Department of Justice, the Drug Enforcement Administration, the Consumer Product Safety Commission, the Federal Trade Commission, the Occupational Safety & Health Administration, the Environmental Protection Agency and state and local governments and governmental agencies.

European Union/rest of world government regulation

In addition to regulations in the U.S., we will be subject to a variety of regulations in other jurisdictions governing, among other things, clinical trials and any commercial sales and distribution of our products. The cost of establishing a regulatory compliance system for numerous varying jurisdictions can be very significant. Although many of the issues discussed above with respect to the United States apply similarly in the context of the European Union and in other jurisdictions, the approval process varies between countries and jurisdictions and can involve additional product testing and additional administrative review periods. The time required to obtain approval in other countries and jurisdictions might differ from and be longer than that required to obtain FDA approval. Regulatory approval in one country or jurisdiction does not ensure regulatory approval in another, but a failure or delay in obtaining regulatory approval in one country or jurisdiction may negatively impact the regulatory process in others.

Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application much like the IND prior to the commencement of human clinical trials. In the European Union, for example, a clinical trial authorization application must be submitted for each clinical protocol to each country’s national health authority and an independent ethics committee, much like the FDA and IRB, respectively. Under the EU Clinical Trials Regulation, this is now done through a single application submitted through the Clinical Trials Information System, or CTIS, as described in more detail below.

The requirements and process governing the conduct of clinical trials vary from country to country. In all cases, the clinical trials are conducted in accordance with GCP, the applicable regulatory requirements, and the ethical principles that have their origin in the Declaration of Helsinki.

To obtain regulatory approval of a medicinal product under European Union regulatory systems, we must submit a marketing authorization application. The content of the BLA filed in the U.S. is similar to that required in the European Union, with the exception of, among other things, country-specific document requirements.

For other countries outside of the European Union, such as countries in Eastern Europe, Latin America or Asia, the requirements governing product licensing, pricing, and reimbursement vary from country to country.

Countries that are part of the European Union, as well as countries outside of the European Union, have their own governing bodies, requirements, and processes with respect to the approval of biological products. If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

Clinical trial approval in the European Union

In April 2014, the European Union adopted the Clinical Trials Regulation (EU) No 536/2014, which replaced the Clinical Trials Directive 2001/20/EC on January 31, 2022. The Clinical Trials Regulation is directly applicable in all European Union Member States meaning no national implementing legislation in each European Union Member State is required. The Clinical Trials Regulation aims to simplify and streamline the approval of clinical trials in the European Union. The main characteristics of the regulation include: a streamlined application procedure via a single-entry point, through the CTIS; a single set of documents to be prepared and submitted for the application as well as simplified reporting procedures for clinical trial sponsors; and a harmonized procedure for the assessment of applications for clinical trials, which is divided in two parts (Part I contains scientific and medicinal product documentation and Part II contains the national and patient-level documentation). Part I is assessed by a coordinated review by the competent authorities of all European Union Member States in which an application for authorization of a clinical trial has

been submitted (Member States concerned) of a draft report prepared by a reference Member State. Part II is assessed separately by each Member State concerned. Strict deadlines have also been established for the assessment of clinical trial applications.

Marketing authorization procedures in the European Union

Medicines can be authorized in the European Union by using either the centralized authorization procedure or national authorization procedures.

The European Commission implemented the centralized procedure for the approval of human medicines to facilitate marketing authorizations that are valid throughout the European Economic Area, or the EEA, which is comprised of the Member States of the European Union plus Norway, Iceland, and Lichtenstein. The centralized procedure is administered by the European Medicines Agency, or EMA, and is compulsory for human medicines that are: derived from certain biotechnology processes, such as genetic engineering, contain a new active substance indicated for the treatment of certain diseases, such as HIV, AIDS, cancer, diabetes, neurodegenerative disorders or autoimmune diseases and other immune dysfunctions, advanced therapy medicines (gene therapy, somatic cell therapy or tissue-engineered medicines), and officially designated orphan medicines.

For medicines that do not fall within these categories, an applicant has the option of submitting an application for a centralized marketing authorization to the EMA, as long as the medicine concerned contains a new active substance not yet authorized in the European Union, is a significant therapeutic, scientific or technical innovation, or if its authorization would be in the interest of public health in the European Union.

Under the centralized procedure, the EMA’s Committee for Medicinal Products for Human Use, or the CHMP, is responsible for conducting the initial assessment of a product and for several post-authorization and maintenance activities, such as the assessment of modifications or extensions to an existing marketing authorization. Under the centralized procedure in the European Union, the maximum timeframe for the evaluation of a marketing authorization application is 210 days (excluding clock stops, when additional written or oral information is to be provided by the applicant in response to questions asked by the CHMP). Clock stops may extend the timeframe of evaluation of a marketing authorization application considerably beyond 210 days. Where the CHMP gives a positive opinion, it provides the opinion together with supporting documentation to the European Commission, who makes the final decision to grant a marketing authorization, which is issued within 67 days of receipt of the EMA’s recommendation. Accelerated evaluation might be granted by the CHMP in exceptional cases, when a medicinal product is expected to be of a major public health interest, particularly from the point of view of therapeutic innovation. In this circumstance, the EMA ensures that the opinion of the CHMP is given within 150 days, excluding clock stops, but it is possible that the CHMP can revert to the standard time limit for the centralized procedure if it considers that it is no longer appropriate to conduct an accelerated assessment.

Prior to obtaining a marketing authorization in the European Union, applicants must demonstrate compliance with all measures included in an EMA-approved pediatric investigation plan, or PIP, covering all subsets of the pediatric population, unless the EMA has granted a product-specific waiver, a class waiver, or a deferral for one or more of the measures included in the PIP. The Pediatric Committee of the EMA, or the PDCO, may grant deferrals for some medicines, allowing a company to delay development of the medicine for children until there is enough information to demonstrate its effectiveness and safety in adults. The PDCO may also grant waivers when development of a medicine for children is not needed or is not appropriate, such as for diseases that only affect the elderly population.

Data and market exclusivity in the European Union

In the European Union, innovative medicinal products approved on the basis of a complete and independent data package qualify for eight years of data exclusivity upon marketing authorization and an additional two years of market exclusivity. This data exclusivity, if granted, prevents regulatory authorities in the European Union from referencing the innovator’s pre-clinical and clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar marketing authorization in the European Union, during a period of eight years from the date on which the reference product was first authorized in the European Union.

Reform of the regulatory framework in the European Union

The European Commission introduced legislative proposals in April 2023 that, if implemented, will replace the current regulatory framework in the European Union for all medicines (including those for rare diseases and for children). The European Commission has provided the legislative proposals to the European Parliament and the European Council for their review and approval and, in April 2024, the European Parliament proposed amendments to the legislative proposals. Once the European Commission’s legislative proposals are approved (with or without amendment), they will be adopted into European Union law.

The aforementioned European Union rules are generally applicable in the EEA.

Brexit and the Regulatory Framework in the United Kingdom

The United Kingdom, or UK, formally left the European Union on January 31, 2020, and the European Union and the UK have concluded a trade and cooperation agreement, or TCA, which was provisionally applicable since January 1, 2021 and has been formally applicable since May 1, 2021. The TCA includes specific provisions concerning pharmaceuticals, which include the mutual recognition of cGMP, inspections of manufacturing facilities for medicinal products and cGMP documents issued, but does not provide for wholesale mutual recognition of UK and EU pharmaceutical regulations. At present, Great Britain has implemented European Union legislation on the marketing, promotion and sale of medicinal products through the Human Medicines Regulations 2012 (as amended) (under the Northern Ireland Protocol, the European Union regulatory framework currently continues to apply in Northern Ireland). The regulatory regime in Great Britain therefore aligns in many ways with current European Union regulations, however it is likely that these regimes will diverge significantly in the future now that Great Britain’s regulatory system is independent from the European Union and the TCA does not provide for mutual recognition of UK and European Union pharmaceutical legislation. However, notwithstanding that there is no wholesale recognition of European Union pharmaceutical legislation under the TCA, under a new international recognition procedure which was put in place by the Medicines and Healthcare products Regulatory Agency, or the MHRA, on January 1, 2024, the MHRA may take into account decisions on the approval of a marketing authorization from the EMA (and certain other regulators) when considering an application for a Great Britain marketing authorization.

On February 27, 2023, the UK government and the European Commission announced a political agreement in principle to replace the Northern Ireland Protocol with a new set of arrangements, known as the “Windsor Framework”. This new framework fundamentally changes the existing system under the Northern Ireland Protocol, including with respect to the regulation of medicinal products in the UK. In particular, the MHRA will be responsible for approving all medicinal products destined for the UK market (i.e., Great Britain and Northern Ireland), and the EMA will no longer have any role in approving medicinal products destined for Northern Ireland. A single UK-wide marketing authorization will be granted by the MHRA for all medicinal products to be sold in the UK, enabling products to be sold in a single pack and under a single authorization throughout the UK. The Windsor Framework was approved by the EU-UK Joint Committee on March 24, 2023, so the UK government and the European Union will enact legislative measures to bring it into law. On June 9, 2023, the MHRA announced that the medicines aspects of the Windsor Framework will apply from January 1, 2025.

Pharmaceutical coverage, pricing and reimbursement

In the U.S. and foreign markets, sales of any products for which we may receive regulatory approval for commercial sale will depend in part on the availability of coverage and reimbursement for our products from third-party payors, such as government healthcare programs (e.g., Medicare, Medicaid), managed care organizations, private health insurers, health maintenance organizations, and other organizations. These third-party payors decide which medications they will pay for and will establish reimbursement levels. The availability of coverage and extent of reimbursement by governmental and other third-party payors is essential for patients depending on government or commercial insurance to pay for the costs of prescription medications and other medical products.

In the U.S., the principal decisions about reimbursement for new medicines are typically made by the CMS, an agency within the HHS. CMS decides whether and to what extent products will be covered and reimbursed under Medicare and private payors tend to follow CMS to a substantial degree. Third-party payors may also limit coverage to specific products on an approved list, or formulary, which might not include all of the FDA-approved products for a particular indication.

Factors payors consider in determining reimbursement are based on whether the product is:

Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from third-party payors, including government healthcare programs (e.g., Medicare, Medicaid), managed care organizations, private health insurers, health maintenance organizations, and other organizations. Moreover, a payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved.

In the U.S., no uniform policy of coverage and reimbursement for drug products exists among third-party payors. Therefore, coverage and reimbursement for drug products can differ significantly from payor to payor. One payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage and reimbursement for the product, and the level of coverage and reimbursement can differ significantly from payor to payor. Third-party payors are increasingly challenging pharmaceutical prices and examining the medical necessity and cost- effectiveness of medical products and services, in addition to their safety and efficacy. In order to secure coverage and reimbursement for any product that might be approved for sale, we may need to conduct expensive pharmacoeconomic studies in order to demonstrate the medical necessity and cost-effectiveness of our

products, in addition to the costs required to obtain FDA or comparable regulatory approvals. Additionally, we may also need to provide discounts to purchasers, private health plans or government healthcare programs. Our product candidates may nonetheless not be considered medically necessary or cost-effective. If third-party payors do not consider a product to be cost-effective compared to other available therapies, they may not cover the product after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow a company to sell its products at a profit. A decision by a third-party payor not to cover a product could reduce utilization once the product is approved and have a material adverse effect on sales, our operations and financial condition.

Further, the process for determining whether a payor will provide coverage for a product may be separate from the process for setting the reimbursement rate that the payor will pay for the product. A payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved. Even if we obtain coverage for a given product, the resulting reimbursement payment rates might not be adequate for us to achieve or sustain profitability or may require co-payments that patients find unacceptably high. There is significant uncertainty related to insurance coverage and reimbursement of newly approved products. It is difficult to predict at this time what third-party payors will decide with respect to the coverage and reimbursement for our product candidates.

Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and impacted by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the U.S. In addition, many pharmaceutical manufacturers must calculate and report certain price reporting metrics to the government, such as average sales price and best price. Penalties may apply in some cases when such metrics are not submitted accurately and timely.

The marketability of any product candidates for which we receive regulatory approval for commercial sale may suffer if third-party payors fail to provide adequate coverage and reimbursement. In addition, emphasis on managed care in the U.S. has increased and could increase the pressure on pharmaceutical pricing. Coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

Other U.S. Healthcare Laws

Healthcare providers, physicians, and third-party payors will play a primary role in the recommendation and prescription of drug products for which we obtain marketing approval. Arrangements with third-party payors, healthcare providers and physicians, as well as patients and other third parties, in connection with the clinical research, sales, marketing and promotion of products, once approved, and related activities, may expose a pharmaceutical manufacturer to broadly applicable fraud and abuse and other healthcare laws and regulations. In the U.S., these laws include, without limitation, state and federal anti-kickback, false claims, transparency, consumer protection, and patient data privacy and cybersecurity laws and regulations, including but not limited to those described below:

Because of the breadth of these laws and the narrowness of the statutory exceptions and safe harbors available, it is possible that some of our business activities could be subject to challenge under one or more of such laws in the future. If our operations are found to be in violation of any of such laws or any other governmental regulations that apply to us, we may be subject to, on a corporate or individual basis, penalties, including civil and criminal penalties, damages, fines, the curtailment or restructuring of our operations, the exclusion from participation in federal and state healthcare programs and even imprisonment, any of which could materially adversely affect our ability to operate our business and our financial results. In addition, the cost of implementing sufficient systems, controls, and processes to ensure compliance with all of the aforementioned laws could be significant. Any action for violation of these laws, even if successfully defended, could cause us to incur significant legal expenses and divert management’s attention from the operation of the company’s business. If any of the physicians or other healthcare providers or entities with whom we expect to do business is found noncompliant with applicable laws, that person or entity may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs.

It is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent inappropriate conduct may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. Efforts to ensure that our business arrangements will comply with applicable healthcare laws may involve substantial costs. It is

possible that governmental and enforcement authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law interpreting applicable fraud and abuse or other healthcare laws and regulations. If any such actions are instituted against us and we are not successful in defending ourselves or asserting our rights those actions, our business may be impaired.

In the ordinary course of our business, we and the third parties upon which we rely collect, receive, store, or otherwise process personal data, including information we may collect about participants in our clinical trials. Our data processing activities subject us to numerous, evolving data privacy and cybersecurity obligations, such as various laws, regulations, guidance, industry standards, external and internal privacy and security policies, contractual requirements, and other obligations relating to data privacy and cybersecurity.

The legislative and regulatory framework for the processing of personal data worldwide is rapidly evolving in a manner that is increasingly stringent and, globally, this legal and regulatory framework is likely to remain uncertain for the foreseeable future. In the U.S., numerous federal, state and local laws and regulations, including federal health information privacy laws, state information security and data breach notification laws, federal consumer protection laws (e.g., Section 5 of the Federal Trade Commission Act), state consumer protection and privacy laws, and other similar laws (e.g., wiretapping and communications interception laws) govern the processing of health-related and other personal data.

At the state level, numerous U.S. states have enacted comprehensive privacy laws that impose certain obligations on covered businesses, including providing specific disclosures in privacy notices and affording individuals certain rights concerning their personal data. Similar laws are being considered in several other states, as well as at the federal and local levels, and we expect more states to pass similar laws in the future. While existing state comprehensive privacy laws exempt some data processed in the context of clinical trials, these developments may further complicate compliance efforts, and increase legal risk and compliance costs for us and the third parties upon whom we rely.

Additionally, a smaller number of states have passed or are considering laws governing the privacy of consumer health data. For example, Washington’s My Health My Data Act broadly defines consumer health data, creates a private right of action to allow individuals to sue for violations of the law, imposes stringent consent requirements, and grants consumers certain rights with respect to their health data, including to request deletion of their information. Connecticut and Nevada have also passed similar laws regulating consumer health data. These various data privacy and cybersecurity laws may impact our business activities, including our identification of research subjects, relationships with business partners and ultimately the marketing and distribution of our products.

Additionally, to the extent we collect personal information from individuals outside of the United States, through clinical trials or otherwise, we are, or may become, subject to foreign data privacy and security laws, such as the European Union’s General Data Protection Regulation 2016/679 (or EU GDPR) and other national data protection legislation in force in relevant EEA Member States, and the EU GDPR as it forms part UK law by virtue of section 3 of the European Union (Withdrawal) Act 2018 (or UK GDPR). Foreign data privacy and cybersecurity laws impose significant and complex compliance obligations on entities that are subject to those laws, as more fully discussed in the section titled “Risk Factors—Risks related to government regulation”.

Current and Future U.S. Healthcare Reform Legislation

Payors, whether domestic or foreign, or governmental or private, are developing increasingly sophisticated methods of controlling healthcare costs and those methods are not always specifically adapted for new and innovative technologies, such as pharmaceutical products like [225Ac]Ac-AKY-1189. In both the U.S. and certain foreign jurisdictions, there have been a number of legislative and regulatory changes to the health care system that could impact our ability to sell products profitably.

By way of example, the U.S. and state governments continue to propose and pass legislation designed to reduce the cost of healthcare. In March 2010, the ACA, was enacted, which, among other things, increased the minimum Medicaid rebates owed by most manufacturers under the Medicaid Drug Rebate Program; extended the Medicaid Drug Rebate program to utilization of prescriptions of individuals enrolled in Medicaid managed care organizations; subjected manufacturers to new annual fees and taxes for certain branded prescription drugs; created the Medicare Part D coverage gap discount program, in which manufacturers agree to provide 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; and provided incentives to programs that increase the federal government’s comparative effectiveness research. Current laws, as well as other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price for any approved products.

Since its enactment, there have been, and continue to be, numerous judicial, administrative, executive, and legislative challenges to certain aspects of the ACA, and there could be additional amendments to the ACA in the future. It is unclear whether the ACA will be overturned, repealed, replaced, or further amended. We cannot predict what effect further changes to the ACA would have on our business.

Additionally, there have been several U.S. congressional inquiries and proposed federal and proposed and enacted state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient support programs, reduce the costs of drugs under Medicare and reform government program reimbursement

methodologies for drug products. For example, on August 16, 2022, the Inflation Reduction Act of 2022, or IRA, was signed into law by President Biden. The IRA includes several provisions that may impact pharmaceutical companies to varying degrees, including provisions that create a $2,000 out-of-pocket cap for Medicare Part D beneficiaries; impose new manufacturer financial liability on all drugs in Medicare Part D; allow the U.S. government to negotiate Medicare Part B and Part D pricing caps for certain high-cost drugs and biologics without generic or biosimilar competition; require companies to pay rebates to Medicare for drug prices that increase faster than inflation; and delay the rebate rule that would require pass through of pharmacy benefit manager rebates to beneficiaries. Generally, these government prices can apply as soon as nine years (for small-molecule drugs) or 13 years (for biological products) from their FDA approval and will be capped at a statutory ceiling price that is likely to represent a significant discount from average prices to wholesalers and direct purchasers. The implementation of the IRA is currently subject to ongoing litigation that challenges the constitutionality of the IRA’s Medicare drug price negotiation program. The full impact of the IRA on our business and the pharmaceutical and healthcare industry in general is not yet known.

At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.

Employees and Human Capital Resources

As of December 31, 2025, we had 79 full-time employees. Of these employees, 67 are engaged in research and development and 12 are engaged in business development, finance, legal, and general management and administration. Our human capital resources objectives include identifying, recruiting, retaining, incentivizing and integrating our existing and new employees, advisors and consultants. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

Corporate Information

We were originally incorporated under the laws of the State of Delaware in August 2020 under the name HotKnot Therapeutics, Inc. We changed our name to Aktis Oncology, Inc. in April 2021. Our principal executive offices are located at 17 Drydock Avenue, Suite 17-401, Boston, Massachusetts 02210 and our telephone number is (617) 461-4023.

Available Information

We file electronically with the Securities and Exchange Commission, the SEC, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, proxy statements and other information. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Our website address is https://www.aktisoncology.com. We make available on our website, under “Investors,” free of charge, copies of these reports as soon as reasonably practicable after filing or furnishing these reports with the SEC. The information contained in, or accessible through, our website does not constitute a part of this Annual Report. All statements made in any of our securities filings, including all forward-looking statements or information, are made as of the date of the document in which the statement is included, and we do not assume or undertake any obligation to update any of those statements or documents unless we are required to do so by law.

Item 1A. Risk Factors.

You should carefully consider the risks and uncertainties described below, as well as the other information in this Annual Report, including our consolidated financial statements and the related notes appearing elsewhere in this Annual Report and the sections of this Annual Report titled “Special Note Regarding Forward-Looking Statements” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” before you make an investment decision in our common stock. The risks described below are not the only risks that we face. The occurrence of any of the following risks, or of additional risks and uncertainties not presently known to us or that we currently believe to be immaterial, could materially and adversely affect our business, financial condition, results of operations and prospects.

Risks related to our limited operating history, financial condition and need for additional capital

We have incurred significant losses since our inception, have no products approved for sale, and we expect to incur losses for the foreseeable future.

Development of radiopharmaceutical product candidates is a highly speculative undertaking and involves a substantial degree of risk. We are still in the early stages of development of our product candidates and our lead product candidate, [225Ac]Ac-AKY-1189, is being evaluated in a Phase 1b clinical trial for locally advanced or metastatic urothelial cancer, or UC, and other Nectin-4 expressing tumors. We have no products licensed for commercial sale and have not generated any revenues from product sales to date, and we continue to incur significant research and development and other expenses related to our ongoing operations. As such, we have incurred significant losses since inception, and have financed our operations principally through equity financings. We expect that it will be several years, if ever, before we have a commercialized product candidate and generate revenue from sales.

Our net losses for the years ended December 31, 2025 and 2024 were $63.7 million and $44.0 million, respectively. As of December 31, 2025, we had an accumulated deficit of $156.6 million. We anticipate that our expenses and operating losses will increase substantially as we:

Because of the numerous risks and uncertainties associated with the development of radiopharmaceutical therapies, we are unable to accurately predict the timing or amount of increased expenses. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenue. Our prior losses and expected future losses have had and will continue to have an adverse effect on our stockholders’ equity and working capital. Even if we succeed in commercializing one or more of our product candidates, we will continue to incur substantial research and development and other expenditures to develop, seek regulatory approval for, and market additional product candidates. We may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. For example, if we are required by the United States Food and Drug Administration, or FDA, or comparable foreign regulatory authorities to perform studies or clinical trials in addition to those we currently anticipate, or if there are any delays in commencing or completing our clinical trials or the development of any product candidates, our expenses could increase and commercial revenue could be further delayed and more uncertain, which will adversely affect our business. We may not be successful in navigating these challenges, which may adversely affect our business, results of operations and prospects.

Our limited operating history may make it difficult for you to evaluate our prospects and likelihood of success.

We have a limited operating history upon which you can evaluate our business and prospects. Since our inception in August 2020, we have devoted substantially all our resources and efforts to organizing and staffing our company, business planning, raising capital, conducting discovery and research activities, filing patent applications, identifying potential product candidates, undertaking preclinical studies, in-licensing technology, building out our manufacturing facility and establishing arrangements with third parties for the supply and manufacture of our product candidates and component materials. We have commenced a multi-site Phase 1b clinical trial in the United States to evaluate our lead product candidate, [225Ac]Ac-AKY-1189, for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors. We have not yet demonstrated our ability to successfully complete any clinical trials, obtain regulatory approvals, manufacture a commercial scale product supply, or arrange for a third party to do so on our behalf, or conduct sales and marketing activities necessary for successful commercialization. Additionally, we expect our financial condition and operating results to continue to fluctuate significantly from period to period due to a variety of factors, many of which are beyond our control. Such factors include, among other things, the timing of, cost of, and level of investment in, research, development, and commercialization activities, which could vary over time. Consequently, any predictions you may make about our future success or viability may not be as accurate as they could be if we had a longer operating history.

In addition, as a young business, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors. We will need to transition at some point from a company with a research and development focus to a company capable of supporting commercial activities. We may not be successful in such a transition.

We will require additional funding to finance operations. If we are unable to raise capital when needed, or on acceptable terms, we would be forced to delay, reduce, or eliminate our research and product candidate development programs.

Developing radiopharmaceutical product candidates, including conducting preclinical studies and clinical trials, is a very time-consuming, capital-expensive, and uncertain process that takes years to complete. We have commenced a multi-site Phase 1b clinical trial in the United States to evaluate our lead program, [225Ac]Ac-AKY-1189, for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors and are preparing to commence a Phase 1b clinical trial for [225Ac]Ac-AKY-2519. We are also evaluating multiple current product candidates in preclinical studies. We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we continue the research and development of, advance the preclinical and clinical activities of, and seek regulatory approval for, [225Ac]Ac-AKY-1189 for Nectin-4 expressing tumors from the FDA and other foreign regulatory authorities, as well as our other product candidates. In addition, if we obtain regulatory approval for [225Ac]Ac-AKY-1189 for any Nectin-4 expressing tumor or our other product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution to the extent that such sales, marketing, manufacturing and distribution are not the responsibility of our collaborators. We may also need to raise additional funds sooner if our preclinical and clinical activities take longer than expected, as a result of regulatory approvals or otherwise, or if we choose to pursue additional indications and geographies for any of our product candidates or otherwise expand more rapidly than we presently anticipate.

Furthermore, we expect to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on attractive terms, we will be forced to delay, reduce, or eliminate programs, and may be unable to expand our operations or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition, results of operations and prospects.

As of December 31, 2025, we had $226.8 million in cash, cash equivalents and marketable securities. Based on our current business plans, we believe that our existing cash, cash equivalents and marketable securities, together with the net proceeds of approximately $335.3 million from our initial public offering completed in January 2026, will be sufficient to fund our operating expenses and capital expenditure requirements into 2029. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect, requiring us to seek additional funds sooner than planned, through public or private equity or debt financings or other sources, such as strategic collaborations. Our failure to raise capital or enter into such other arrangements when needed would have a negative impact on our financial condition and could force us to

delay, limit, reduce or terminate clinical trials, our research and development programs or other operations, or lead us to grant rights to third parties to develop and market product candidates that we would otherwise prefer to develop and market ourselves. In addition, we may seek additional capital opportunistically due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. Attempting to secure additional financing may divert our management from our day-to-day activities. See “Management’s discussion and analysis of financial condition and results of operations—Liquidity and capital resources.”

Our future capital requirements will depend on, and could increase significantly because of many factors including:

We cannot be certain that additional funding will be available on acceptable terms, or at all. If we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may have to significantly delay, scale back or discontinue the development or commercialization of our product candidates or other research and development initiatives. Any of our current or future license agreements may also be terminated if we are unable to meet the payment or other obligations under the agreements.

We have not generated any revenue to date and may never be profitable.

Our ability to become profitable depends upon our ability to generate revenue. To date, we have not generated any revenue. We do not expect to generate significant product revenue unless or until we successfully complete clinical development and obtain regulatory approval of, and then successfully commercialize, at least one of our product candidates. Other than [225Ac]Ac-AKY-1189, which is in a Phase 1b clinical trial for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors, all of our product candidates are in the preclinical stages of development and will require additional preclinical studies and clinical development as well as regulatory review and approval, substantial investment, access to sufficient commercial manufacturing capacity and significant marketing efforts before we can generate any revenue from product sales. We will face significant development risk as our product candidates, including [225Ac]Ac-AKY-1189, advance through clinical development. Our ability to generate revenue depends on a number of factors, including, but not limited to:

Many of the factors listed above are beyond our control, and could cause us to experience significant delays or prevent us from obtaining regulatory approvals or commercialize our product candidates. Even if we are able to commercialize our product candidates, we may not achieve or maintain profitability. If we are unable to generate sufficient revenue through the sale of our product candidates or any future product candidates, we may be unable to continue operations without continued funding.

Raising additional capital may cause dilution to our stockholders restrict our operations or require us to relinquish rights to our technologies or product candidates.

We expect our expenses to increase in connection with our planned operations. Unless and until we can generate a substantial amount of revenue from our product candidates, we expect to finance our future cash needs through public or private equity offerings, debt financings, collaborations, licensing arrangements or other sources, or any combination of the foregoing. In addition, we may seek additional capital due to favorable market conditions or strategic considerations, even if we believe that we have sufficient funds for our current or future operating plans. Disruptions in the financial markets in general may make equity and debt financing more difficult to obtain and may have a material adverse effect on our ability to meet our fundraising needs.

To the extent that we raise additional capital through the sale of common stock, convertible securities or other equity securities, your ownership interest may be diluted, and the terms of these securities could include liquidation or other preferences and anti-dilution protections that could adversely affect your rights as a common stockholder. In addition, debt financing, if available, may result in fixed payment obligations and may involve agreements that include restrictive covenants that limit our ability to take specific actions, such as incurring additional debt, making capital expenditures, creating liens, redeeming shares or declaring dividends, that could adversely impact our ability to conduct our business. In addition, securing financing could require a substantial amount of time and attention from our management and may divert a disproportionate amount of their attention away from day-to-day activities, which may adversely affect our management’s ability to oversee the development of our product candidates.

If we raise additional funds through collaborations, strategic alliances, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds when needed, we would be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves. Any additional fundraising efforts we undertake may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize our product candidates.

Risks related to our business and development of our product candidates

We are early in our development efforts. If we are unable to develop, and commercialize, any of our current or future product candidates through clinical development, obtain regulatory approval and ultimately commercialize our product candidates, or if we experience significant delays in doing so, our business will be materially harmed.

We are early in our development efforts. The success of our business depends upon our ability to identify, develop, and commercialize targeted radiopharmaceuticals across a range of oncology indications. [225Ac]Ac-AKY-1189, our most advanced product candidate, is in a Phase 1b clinical trial for the treatment of locally advanced or metastatic UC and other Nectin-4 expressing tumors. Commencing clinical trials for our current or future product candidates in the United States is subject to clearance by the FDA of an IND application and finalizing the trial design based on discussions with the FDA. In the event that the FDA requires us to complete additional preclinical studies or we are required to satisfy other FDA requests prior to commencing clinical trials, the start of our planned future clinical trials may be delayed or we may be unsuccessful obtaining clearance to proceed into clinical development. In addition, clinical trials conducted in one country, may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not guarantee regulatory approval in any other country. Although the FDA may accept data from clinical trials conducted outside the United States, acceptance of these data is subject to conditions imposed by the FDA, and there can be no assurance that the FDA will accept data from trials conducted outside of the United States. If the FDA does not

accept the data from any trial that we conduct outside the United States, it would likely result in the need for additional trials, which would be costly and time-consuming and could delay or permanently halt our development of the applicable product candidates. Our ability to generate product revenues, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of one or more of our product candidates.

The success of our product candidates will depend on several factors, including the following:

If we do not achieve one or more of these factors in a timely manner, or at all, we could experience significant delays or be unable to successfully commercialize our product candidates, which would materially harm our business.

Our business is highly dependent on our lead product candidate, [225Ac]Ac-AKY-1189, for the treatment of Nectin-4 expressing tumors. We must complete clinical trials before we can seek regulatory approval and begin commercialization of [225Ac]Ac-AKY-1189. If we are unable to obtain regulatory approval for, and successfully commercialize, [225Ac]Ac-AKY-1189, our business may be materially harmed, and such failure may affect our other current or future product candidates.

The process for obtaining marketing approval for any product candidate, including [225Ac]Ac-AKY-1189, is very long and risky and there will be significant challenges for us to address to obtain marketing approval as planned, if at all. There is no guarantee that the results obtained in our ongoing and planned clinical trials of [225Ac]Ac-AKY-1189 will be sufficient to obtain regulatory approval. Furthermore, success in an early-stage trial does not necessarily mean a later stage trial will be successful. In addition, because our other product candidates are based on similar technology of our lead product candidate, if [225Ac]Ac-AKY-1189

encounters safety or efficacy problems, manufacturing or supply interruptions, developmental delays, regulatory issues, or other problems, our development plans and business related to other product candidates could be significantly harmed.

Preclinical and clinical development is a lengthy and expensive process with uncertain timelines and uncertain outcomes. If preclinical studies or clinical trials of a product candidate are prolonged or delayed, we may be unable to obtain required regulatory approvals, and therefore be unable to commercialize [225Ac]Ac-AKY-1189, [225Ac]Ac-AKY-2519 or any of our future product candidates on a timely basis or at all.

We, and any future collaborators, are not permitted to commercialize, market, promote or sell any product candidate in the United States without obtaining regulatory approval from the FDA. Foreign regulatory authorities, such as the European Medicines Agency, or EMA, impose similar requirements. The time required to obtain approval by the FDA and comparable foreign authorities is unpredictable, but typically takes many years following the commencement of clinical trials and depends upon numerous factors, including substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions. We, and any future collaborators, must complete additional preclinical studies and clinical trials to demonstrate the safety and efficacy of our product candidates in humans before we will be able to obtain these approvals.

For our current and future product candidates, we may not be able to file IND applications, or similar applications outside the United States, on the timelines we expect. For example, we may experience supply or manufacturing delays or other delays with IND-enabling, or equivalent foreign preclinical studies. Moreover, we cannot be sure that submission of an IND application, or similar applications outside the United States, will result in the FDA, or comparable foreign regulatory authorities, allowing clinical trials to begin, or that, once begun, issues will not arise that suspend or terminate clinical trials. Additionally, even if such regulatory authorities agree with the design and implementation of the clinical trials set forth in an IND application, or similar applications outside the United States, we cannot guarantee that such regulatory authorities will not change their requirements in the future. We also cannot predict that approval of an IND application or similar application by the FDA or comparable foreign regulatory authority will result in approval of similar applications to conduct clinical trials. These considerations also apply to new clinical trials we may submit as amendments to existing INDs or similar approvals outside the United States. We do not know whether planned clinical trials will begin on time, need to be redesigned, enroll patients on time, or be completed on schedule, if at all.

Clinical trials can be delayed, suspended, or terminated for a variety of reasons, including the following:

Moreover, clinical trials must be conducted in accordance with the FDA and comparable foreign regulatory authorities’ legal requirements, regulations, and guidelines, and are subject to oversight by regulatory authorities and IRBs or ethics committees at the medical institutions where the clinical trials are conducted.

Safety or tolerability concerns could cause us or regulatory authorities, as applicable, to suspend or terminate a clinical trial if it is found that the participants are being exposed to unacceptable health risks, undesirable side effects, or other unfavorable characteristics of the product candidate, or if such undesirable effects or risks are found to be caused by a chemically or mechanistically similar therapeutic or therapeutic candidate. We could encounter delays if a clinical trial is suspended or terminated by us, by the IRBs or ethics committees of the institutions in which such trials are being conducted, by the data review committee or data safety monitoring board for such trial or by the FDA, or comparable foreign regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a product, changes in governmental regulations or administrative actions, or lack of adequate funding to continue the clinical trial.

In 2021, the FDA launched Project Optimus as an initiative to reform the dose optimization and dose selection paradigm in oncology drug development with the goal of advancing an oncology dose-finding and dose optimization paradigm that emphasizes dose selections that maximize efficacy as well as safety and tolerability. In support of this initiative, the FDA may request sponsors of oncology product candidates to conduct dose optimization studies before permitting sponsors to initiate a pivotal study. In early 2023, the FDA issued a draft guidance intended to assist sponsors in identifying the optimal dosages for these products during clinical development and prior to applying for approval for a new indication and usage as well as another draft guidance intended to provide recommendations to sponsors of anticancer drugs or biological products on considerations for designing trials intended to support accelerated approval. In August 2004, the FDA issued final guidance on optimizing the dosage of oncology drugs and biologics, which noted that while the guidance did not contain specific recommendations for radiopharmaceuticals, some of the recommendations in the guidance may be applicable to these products. If we are required to conduct dose optimizing studies, such studies may delay our product development activities.

If we or our collaborators are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials, our development plans may be impacted. For example, in December 2022, with the passage of Food and Drug Omnibus Reform Act, or FDORA, Congress required sponsors to develop and submit a diversity action plan for each Phase 3 clinical trial or any other “pivotal study” of a new drug or biological product. These plans are meant to encourage the enrollment of more diverse patient populations in late-stage clinical trials of FDA-regulated products. In June 2024, as mandated by FDORA, the FDA issued draft guidance outlining the general requirements for Diversity Action Plans, or DAPs. Unlike most guidance documents issued by the FDA, the DAP guidance when finalized will have the force of law because FDORA specifically dictates that the form and manner for submission of DAPs are specified in FDA guidance. On January 27, 2025, in response to an Executive Order issued on January 21, 2025, on Diversity, Equity and Inclusion programs, the FDA removed this draft guidance from its website. This action raises questions about the applicability of statutory obligations to submit DAPs and the agency’s current thinking on best practices for clinical development.

Furthermore, even if we are able to complete our manufacturing facility, we will continue to rely on contract manufacturing organizations, or CMOs, and contract development and manufacturing organization, or CDMOs, for the proper and timely manufacturing of our product candidates in accordance with cGMP requirements. We also intend to continue to rely on CROs and clinical trial sites to ensure the proper and timely conduct of our clinical trials in compliance with good clinical practice, or GCP, requirements. While we have agreements governing their committed activities, we will have limited influence over their actual performance. To the extent our CMOs fail to comply with cGMP or to perform their manufacturing obligations in a timely manner, or our CROs fail to enroll participants for our clinical trials, fail to conduct the study in accordance with GCP, or are delayed for a significant time in the execution of trials, including achieving full enrollment, we may be affected by increased costs, program delays, or both, which may harm our business.

Moreover, any clinical trials that we may conduct in countries outside the United States may subject us to further delays and expenses because of increased shipment and distribution costs, additional regulatory requirements, and the engagement of non-U.S. CROs, as well as expose us to risks associated with clinical investigators who are unknown to the FDA, and different standards of diagnosis, screening, and medical care. The FDA may decline to accept the data we obtain from these clinical studies in support of an IND application or a biologics license application, or BLA, in the United States, which may require us to repeat or conduct additional preclinical studies or clinical trials that we did not anticipate in the United States, and therefore we may be unable to commercialize our current or future product candidates, on a timely basis or at all in the United States. Foreign regulatory authorities may also decline to accept data obtained from clinical studies conducted in the United States in support of a related marketing authorization application which may lead to similar risks in countries outside the United States.

If we experience delays in the completion of, or termination of, any clinical trial, the commercial prospects of [225Ac]Ac-AKY-1189 for Nectin-4 expressing tumors, or our other product candidates will be harmed, and our ability to generate revenue from sales

of any products will be delayed. In addition, any delays in completing our clinical trials will increase our costs, slow down our development and approval process, and jeopardize our ability to commence sales and generate revenue. Significant clinical trial delays could also allow our competitors to bring products to market before we do or shorten any periods during which we have the exclusive right to commercialize our product candidates and impair our ability to commercialize our product candidates and may harm our business, financial condition, results of operations and prospects.

Our clinical trials may fail to demonstrate substantial evidence of the safety and efficacy of [225Ac]Ac-AKY-1189, [225Ac]Ac-AKY-2519, or any of our future product candidates, which would prevent or delay or limit the scope of regulatory approval and commercialization.

To obtain the requisite regulatory approvals to market and sell [225Ac]Ac-AKY-1189, [225Ac]Ac-AKY-2519, or any of our future product candidates, we must demonstrate through clinical trials that such product candidates are safe and effective for use in each targeted indication. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization. Unforeseen side effects could arise either during clinical development or, if such side effects are more rare, after our products have been approved by regulatory authorities and the approved product has been marketed, resulting in the exposure of additional patients than if such side effect had arisen during a clinical trial. Furthermore, the results of our Phase 1b clinical trial may not demonstrate the clinical utility of [225Ac]Ac-AKY-1189, or reveal an unacceptable safety profile. Additionally, assessments of the long-term safety of targeted alpha-emitting isotope therapies in humans have been limited, and there may be long-term effects from treatment with [225Ac]Ac-AKY-1189 or any of our other current or future product candidates that we cannot predict at this time. Further, we may be unable to establish clinical endpoints that applicable regulatory authorities would consider clinically meaningful, and a clinical trial can fail at any stage of testing.

Clinical trials that we conduct may not demonstrate the efficacy and safety necessary to obtain regulatory approval to market [225Ac]Ac-AKY-1189, [225Ac]Ac-AKY-2519 or any of our future product candidates. In some instances, there can be significant variability in safety or efficacy results between different clinical trials of the same product candidate due to numerous factors, including changes in trial procedures set forth in protocols, differences in the size and type of the patient populations, changes in and adherence to the clinical trial protocols, and the rate of dropout among clinical trial participants. Additionally, our Phase 1b clinical trial for [225Ac]Ac-AKY-1189 is, and we expect future trials of our product candidates to be, open-label trials, meaning both the patient and investigator know whether the patient is receiving the investigational product candidate. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect, as patients in open-label clinical trials are aware when they are receiving treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. Therefore, it is possible that positive results observed in an open-label trial would not be replicated in a controlled trial. Moreover, if unacceptable toxicities, undesirable side effects or adverse product-product interactions arise in the development of our product candidates alone or in combination with other therapies, we could suspend or terminate or trials, or the FDA or comparable foreign regulatory authorities could order us to cease clinical trials, deny approval of the product candidate for any or all targeted indications or require a more restrictive label. If the results of our clinical trials are inconclusive with respect to the efficacy of product candidates, if we do not meet the clinical endpoints with statistical and clinically meaningful significance, if there are safety concerns associated with our product candidates, or if the results observed cannot be replicated, we may be delayed in obtaining regulatory approval, if at all. Additionally, any safety concerns observed in our clinical trials, or in the clinical experience of others using our product candidates in “compassionate use” scenarios outside of the United States, or investigating similar products or modalities could impact our prospects for regulatory approval in those and other indications.

Even if the trials are successfully completed, clinical data is often susceptible to varying interpretations and analyses, and we cannot guarantee that the FDA or comparable foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit any future BLA or comparable foreign application. We cannot guarantee that the FDA or comparable foreign regulatory authorities will view our product candidates as having efficacy even if positive results are observed in clinical trials. Moreover, results acceptable to support approval in one jurisdiction may be deemed inadequate by another regulatory authority to support regulatory approval in that other jurisdiction. To the extent that the results of the clinical trials are not satisfactory to the FDA or comparable foreign regulatory authorities for support of a regulatory application, approval of our product candidates may be significantly delayed, or we may be required to expend significant additional resources, which may not be available to us, to conduct additional development work. Even if regulatory approval is secured for a product candidate, the terms of such approval may limit the scope and use of the specific product candidate, which may also limit its commercial potential.

Our approach to the discovery and development of product candidates using our miniprotein radioconjugate platform represents a novel approach to radiation therapy, which may create significant and potentially unpredictable challenges for us.

Our future success depends on leveraging our miniprotein radioconjugate platform to successfully develop product candidates which are designed to treat advanced solid tumors, utilizing a novel approach to directed-radiation therapy. There are currently few approved radiopharmaceutical therapeutic products. In addition, there has been limited historical clinical trial experience, generally, for the development of radiopharmaceutical therapeutics. As a result, the design and conduct of clinical trials for these product candidates is uncertain and subject to increased risk.

While external beam radiation as a therapy for cancers has existed for decades, oncology treatment using systemic delivery of targeted radiopharmaceuticals in general, and alpha emitting isotopes specifically, is relatively new. Only one alpha emitting isotope therapy, Xofigo, which uses the isotope radium-223, or 223radium, has been approved in the United States or the European Union, or EU, and only a limited number of clinical trials of products based on alpha emitting isotope therapies have commenced. Approved therapies containing beta emitting isotopes have also been limited. As such, it is difficult to accurately predict the developmental challenges we may incur for our product candidates as they proceed through discovery or identification, preclinical studies, and clinical trials. In addition, beyond the limited universe of patients treated with Xofigo, assessments of the long-term safety of targeted alpha emitting isotope therapies in humans have been limited, and there may be long-term effects from treatment with our product candidates that we cannot predict at this time.

It is difficult for us to predict the time and cost of the development of our product candidates, and we cannot predict whether the application of our technology, or any similar or competitive technologies, will result in the identification, development, and regulatory approval of any products. There can be no assurance that any development problems we experience in the future related to our technology or any of our research programs will not cause significant delays or unanticipated costs, or that such development problems can be solved at all. Any of these factors may prevent us from completing our preclinical studies and clinical trials that we may initiate or commercializing any product candidates we may develop on a timely or profitable basis, if at all.

Our product candidates may cause adverse events, undesirable side effects or have other properties that could halt their preclinical or clinical development, prevent, delay, or cause the withdrawal of their regulatory approval, limit their commercial potential, or result in significant negative consequences, including death of patients. If any of our product candidates receive marketing approval and we, or others, later discover that the product is less effective than previously believed or causes undesirable side effects that were not previously identified, our ability, or that of any potential future collaborators, to market the product could be compromised.

As with most biological products, use of our product candidates could be associated with undesirable side effects or adverse events which can vary in severity from minor reactions to death and in frequency from infrequent to prevalent. Undesirable side effects or unacceptable toxicities caused by our product candidates could cause us or regulatory authorities to interrupt, delay, or halt clinical trials.

Treatment-related undesirable side effects or adverse events could also affect patient recruitment or the ability of enrolled subjects to complete the trial, or could result in potential product liability claims. In addition, these side effects may not be appropriately or timely recognized or managed by the treating medical staff, particularly outside of the research institutions that collaborate with us. We have, and will need to continue to, educate and train medical personnel using our product candidates to understand their side effect profiles, for our ongoing Phase 1b clinical trial of [225Ac]Ac-AKY-1189 and any future clinical trials, and upon any commercialization of any product candidates. Inadequate training in recognizing or managing the potential side effects of our product candidates could result in adverse events to patients, including death. Any of these occurrences may materially and adversely harm our business, financial condition, results of operations and prospects.

Clinical trials of our product candidates must be conducted in carefully defined subsets of patients who have agreed to enter into clinical trials. Consequently, it is possible that our clinical trials, or those of any potential future collaborator, may indicate an apparent positive effect of a product candidate that is greater than the actual positive effect, if any, or alternatively fail to identify undesirable side effects. If one or more of our product candidates receives marketing approval and we, or others, discover that it is less effective than previously believed or causes undesirable side effects that were not previously identified, including during any long-term follow-up observation period recommended or required for patients who receive treatment using our products, a number of potentially significant negative consequences could result, including:

Any of the foregoing could prevent us from achieving or maintaining market acceptance of the particular product candidate, if approved, and could significantly harm our business, results of operations, and prospects, and could adversely impact our financial condition, results of operations or the market price of our common shares.

Results of preclinical studies, dosimetry assessments, and early-stage clinical trials may not be predictive of the results of future preclinical studies or clinical trials.

Success in preclinical studies does not ensure that later preclinical studies or clinical trials will be successful. Several companies in the biotechnology industry have suffered significant setbacks in clinical trials, even after positive results in preclinical and earlier clinical trials. These setbacks have been caused by, among other things, negative preclinical findings identified after clinical trials have already commenced and safety or efficacy observations made in clinical trials, including previously unanticipated adverse events. We cannot predict if the FDA or comparable foreign regulatory authority will consider the data from our future preclinical studies sufficient to support approval of an IND application or similar application. In addition, preclinical data is often susceptible to varying interpretations and analyses, which could require us to repeat or conduct additional preclinical studies. Notwithstanding any potential promising results in earlier studies, we cannot be certain that we will not face similar setbacks. In addition, the results of our preclinical animal studies, may not be predictive of the results of outcomes in subsequent clinical trials on human subjects. Product candidates in clinical trials may fail to show the desired pharmacological properties or safety and efficacy traits despite having progressed through preclinical studies.

The dosimetry assessments conducted using radioconjugates of our product candidates used may not be predictive of the anticancer effect or safety profile of our product candidates and we have had limited control and input over the conduct of this assessment and the reported results. The ability of our miniproteins to localize on tumors does not ensure that our product candidates will be successful at eradicating the tumor with an acceptable risk and safety profile, if at all. Likewise, the results of any early-stage clinical trials may not be predictive of the results of the later-stage clinical trials, which tend to enroll substantially larger numbers of patients. The preliminary results of clinical trials with smaller sample sizes can be disproportionately influenced by various biases associated with the conduct of small clinical trials, such as the potential failure of the smaller sample size to accurately depict the features of the broader patient population, which limits the ability to generalize the results across a broader community, thus making the clinical trial results less reliable than clinical trials with a larger number of patients. We plan to enroll larger patient populations in later trials of [225Ac]Ac-AKY-1189. With significantly more patients in future phases of the trial, we may not achieve statistically significant results or the same level of statistical significance, if any, that are observed in any earlier trials. Differences in trial design between early-stage clinical trials and later-stage clinical trials make it difficult to extrapolate the results of earlier clinical trials to later clinical trials. In addition, results in one indication may also not be predictive of results to be expected for the same product candidate in another indication.

If we fail to receive positive results in preclinical studies or early-stage clinical trials, or those results are not replicated in later-stage clinical trials of any product candidate or across indications for that product candidate, the development timeline and regulatory approval and commercialization prospects for that product candidate, and, correspondingly, our business, financial condition, results of operations and prospects, would be harmed.

The administration of AKY-1189 to patients in South Africa pursuant to Section 21 of the Medicines and Related Substances Act, or MRSA, as authorized by the South African Health Products Regulatory Authority, or SAPHRA, was conducted by a third-party physician. We had limited control and input with respect to the collection of the data from the patients in South Africa conducted pursuant to Section 21 of the MRSA and the manner in which it was conducted and will have limited control with respect to the human imaging data being gathered pursuant to Section 21 of the MSRA. We have relied on the results of the assessment to inform our development of [225Ac]Ac-AKY-1189, and these results may turn out to be incorrect or unreliable. Similarly, we will be relying on the investigator to conduct the human imaging studies in accordance with the applicable protocol, legal, regulatory and scientific standards, and accurately report the results and correctly collect the data. If these results prove to be unreliable, the development of [225Ac]Ac-AKY-1189 may be adversely affected.

Interim, topline, or preliminary data from our preclinical studies and clinical trials that we announce or publish from time to time may change as more patient data becomes available or as we make changes to our manufacturing processes and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publicly disclose interim, topline, or preliminary data from our preclinical studies and clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the study or trial. Preliminary or interim data from clinical trials are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data becomes available. We also make assumptions, estimations, calculations, and conclusions as part of our analyses of data, and we may not have received or had the opportunity to evaluate all data fully and carefully. Further, modifications or improvements to our manufacturing processes for a therapy may result in changes to the characteristics or behavior of the product candidate that could cause our future product candidates to perform differently and affect the results of our ongoing clinical trials. As a result, other current or the topline results that we report may differ from future results of the same preclinical studies or clinical trials, or different conclusions or considerations may qualify such topline results, once additional data have been received and fully evaluated. Topline data also remain subject to audit and verification procedures that may result in the final data being materially

different from the preliminary data we previously published. As a result, topline data should be viewed with caution until the final data are available.

Adverse differences between preliminary or interim data and final data could significantly harm our business, financial condition, results of operations and prospects. Additionally, disclosure of preliminary or interim data by us or by our competitors could result in volatility in the price of our common stock.

Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions, or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate, and our company in general. If the interim, topline, or preliminary data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, any of our current or future product candidates may be harmed, which could harm our business, financial condition, results of operations and prospects.

Due to the radioactive nature of our product candidates, once manufactured, our product candidates will have time-limited stability, and as a result, we may encounter difficulties with fulfilment and logistics.

[225Ac]Ac-AKY-1189 is designed to provide at least four days of stability following radiolabeling, meaning that the patient must intravenously receive our product candidate within four days of its radiolabeling. We anticipate that our future products candidates utilizing 225Ac, including [225Ac]Ac-AKY-2519, will have similar, limited stable life-span. As such, our product candidates must be manufactured on an as-needed basis, and shipped almost immediately thereafter. Because our product candidates, including [225Ac]Ac-AKY-1189, cannot be “stock-piled” and stored for even a small number of days ahead of shipment, we or any third-party manufacturer must be able to manufacture our product candidates on a rolling basis, and any delays, could result in an immediate and substantial impact on our ability to deliver the product candidate to patients. Any significant delays in delivering product candidates to patients could damage our reputation and result in deviations from our clinical trial protocols, which in turn could affect our ability to advance the clinical development of our product candidates on a timely basis, or at all.

In addition, once manufactured, our product candidates must be quickly and safely transported to the applicable clinical trial site. As we scale our operations and enroll larger clinical trials, and prepare for potential commercialization, we will need to scale our shipping abilities. Labor disputes, government restrictions, work stoppages, pandemics, derailments, damage or loss events, adverse weather conditions, other events beyond our control could interrupt or delay transportation, which could result in the loss or damage of our product candidates. Although, we carry insurance to cover material loss or damage to supplies in transit, any insurance policy claims awarded to us may be insufficient to cover our losses or damages.

We depend on enrollment and retention of patients in our clinical trials. If we experience delays or difficulties enrolling or retaining patients in our clinical trials, our research and development efforts and business, financial condition, results of operations and prospects could be materially adversely affected.

Successful and timely completion of clinical trials will require that we enroll and retain a sufficient number of patient candidates. Any clinical trials we conduct may be subject to delays for a variety of reasons, including as a result of patient enrollment taking longer than anticipated, patient withdrawal, or adverse events. These types of developments could cause us to delay the trial or halt further development.

Our clinical trials will compete with other clinical trials that are in the same therapeutic areas as our product candidates, and this competition reduces the number and types of patients available to us, as some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. In addition, in the future, we may evaluate our product candidates as first-in-line treatments for which there are other approved treatment alternatives, which may present enrollment challenges. Because the number of qualified clinical investigators and clinical trial sites capable of administering radiopharmaceutical therapies is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which will reduce the number of patients who are available for our clinical trials at such clinical trial sites.

Enrollment may also depend in part on the medical community and public’s perception of our product candidates or those of our competitors. Adverse events in our preclinical studies or clinical trials or those of our competitors or of academic researchers or other clinicians utilizing our product candidates under “compassionate use” pathways outside the United States, or similar technologies, even if not ultimately attributable to product candidates we may discover and develop, and the resulting publicity could result in unfavorable public perception and adversely impact our ability to enroll clinical trials.

Delays in the completion of any clinical trial of [225Ac]Ac-AKY-1189 for Nectin-4 expressing tumors or our other current or future product candidates will increase our costs, slow down the development and approval process, and delay or potentially jeopardize our ability to commence sales and generate revenue. In addition, some of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of [225Ac]Ac-AKY-1189 or any other current or future product candidates.

The commercial success of [225Ac]Ac-AKY-1189, or any of our other current or future products, if approved, will depend upon public perception of radiopharmaceuticals and the degree of their market acceptance by physicians, patients, healthcare payors and others in the medical community.

Adverse events in clinical trials of our product candidates, or in clinical trials or other studies conducted by others involving similar products, which may include the same radioisotopes as our product candidates, and the resulting negative publicity, as well as any other adverse events in the field of radiopharmaceuticals that may occur in the future, could result in a decrease in demand for [225Ac]Ac-AKY-1189 for any approved indication or any future product candidates that we may develop. If public perception is influenced by claims that radiopharmaceuticals or specific therapies within radiopharmaceuticals are unsafe, [225Ac]Ac-AKY-1189 or any other current or future product candidates may not be accepted by the general public or the medical community.

In particular, the commercial success of our products, if approved, will depend upon, among other things, these products gaining and maintaining acceptance by physicians, patients, third-party payors, and other members of the medical community as efficacious and cost-effective alternatives to competing products and treatments. Even if [225Ac]Ac-AKY-1189, or any other product candidates we develop receive marketing approval by the FDA or other foreign regulatory authority, they may not achieve the level of commercial acceptance and sales experienced by approved beta-emitting therapies, Pluvicto and Lutathera. If any of our products, once approved, do not achieve and maintain an adequate level of acceptance, we may not generate material sales or be able to successfully commercialize such product.

The degree of market acceptance of our candidates products, if approved, will depend on a number of factors, including:

We may develop [225Ac]Ac-AKY-1189, and potentially future product candidates, in combination with other therapies, which exposes us to additional risks.

We may develop [225Ac]Ac-AKY-1189, and may develop future product candidates, for use in combination with one or more currently approved cancer therapies. Even if any product candidate we develop was to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risks that the FDA or similar foreign regulatory authorities could revoke approval of the therapy used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues could arise with these existing therapies. Combination therapies are commonly used for the treatment of cancer, and we would be subject to similar risks if we develop any of our product candidates for use in combination with other products or for indications other than cancer. This could result in our own products being removed from the market or being less successful commercially.

We may also evaluate [225Ac]Ac-AKY-1189 or any other current or future product candidates in combination with one or more other cancer therapies that have not yet been approved for marketing by the FDA or similar foreign regulatory authorities. We will not be able to market and sell [225Ac]Ac-AKY-1189 or any product candidate we develop in combination with any such unapproved cancer therapies that do not ultimately obtain marketing approval.

If the FDA or similar foreign regulatory authorities do not approve these other products or revoke their approval of, or if safety, efficacy, manufacturing, or supply issues arise with, the products we choose to evaluate in combination with [225Ac]Ac-AKY-1189 or any product candidate we develop, we may be unable to obtain approval of or market [225Ac]Ac-AKY-1189 or any other current or future product candidate we develop.

We may expend our limited resources to pursue a particular product candidate or indication and fail to capitalize on product candidates or indications that may be more profitable or for which there is a greater likelihood of success.

A key element of our strategy is to apply our development pipeline to address a broad array of cancer targets and new therapeutic areas. The therapeutic discovery activities that we are conducting may not be successful in identifying product candidates that are useful in treating targets in oncology. Our research programs may be unsuccessful in identifying potential

product candidates, or our potential product candidates may be shown to have harmful side effects or may have other characteristics that may make the products unmarketable or unlikely to receive regulatory approval.

Because we have limited financial and managerial resources, we focus on research programs, therapeutic platforms, and product candidates that we identify for specific indications. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs, therapeutic platforms, and product candidates for specific indications may not yield any commercially viable products. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may need to relinquish valuable rights to that product candidate through collaboration, licensing, or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights.

We face substantial competition, which may result in others discovering, developing, or commercializing products before or more successfully than we do.

The development and commercialization of new radiopharmaceutical products is highly competitive. We face and will continue to face competition from third parties that use radioisotopes and from companies focused on more traditional therapeutic modalities. Potential competitors also include academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection, and establish collaborative arrangements for research, development, manufacturing, and commercialization of new products.

We consider our most direct competitors to be companies developing targeted alpha-based radiopharmaceuticals for the treatment of cancer. There are several companies developing targeted alpha-based radiopharmaceuticals for the treatment of cancer, including Abdera Therapeutics, Actinium Pharmaceuticals, Inc., Alpha9 Oncology, Inc., Artbio AS, Bayer AG, Convergent Therapeutics, Fusion Pharmaceuticals Inc. (acquired by AstraZeneca), Johnson & Johnson, Mariana Oncology, Inc. (acquired by Novartis AG), Perspective Therapeutics, POINT Biopharma Global Inc. (acquired by Eli Lilly), RadioMedix, Inc., RayzeBio, Inc. (acquired by Bristol Myers Squibb) and Telix Pharmaceuticals Limited. These companies are targeting a wide range of solid and hematologic malignancies using various alpha emitting isotopes, including 223radium, lead-212 and 225Ac. The first and only approved alpha particle-based therapy is Bayer’s Xofigo (223radium) which is a salt of radium that cannot easily and robustly be attached to a targeting molecule, but naturally localizes to regions where cancer cells are infiltrating bone. Xofigo was approved in 2013 for the treatment of prostate cancer with symptomatic bone metastases.

There are several companies with approved beta-emitting radiopharmaceuticals, including Lantheus Holdings, Novartis, Bayer, Sirtex, Boston Scientific and Q BioMed Inc. and other companies developing beta-emitting radiopharmaceuticals, including POINT Biopharma Global, ITM Isotope Technologies Munich SE, Y-Mabs and Telix Pharmaceuticals Limited. The beta emitting isotopes used by these companies include iodine-131, lutetium-177, strontium-89 and yttrium-90. A recently approved beta particle-based radiopharmaceutical is Novartis’ Pluvicto, which was approved by the FDA in 2022 for the treatment of patients with metastatic prostate cancer.

Our competitors will also include companies that are or will be developing other treatment methods as well as therapies for the same indications in oncology that we are targeting. In addition to the competitors we face in developing radiopharmaceuticals, we will also face competition in the indications we expect to pursue. In order to compete effectively with these existing therapies, we will need to demonstrate that our therapies are favorable to existing therapeutics and obtain comparable coverage and reimbursement for our product candidates.

Many of our current or future competitors have significantly greater financial resources and expertise in research and development, isotope supply chain logistics, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, obtaining reimbursement for and marketing of approved products than we do. Mergers and acquisitions in the biotechnology, pharmaceutical and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we or our collaborators may develop. Our competitors also may obtain FDA or other foreign regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we or our collaborators are able to enter the market. Even if the product candidates we may develop in the future achieve regulatory approval, they may be priced at a significant premium over competitive products if any have been approved by then, resulting in reduced competitiveness. Moreover, technological advances or products developed by our competitors may render our technologies or product candidates we may develop in the future obsolete, less competitive, or not economical. The key competitive factors affecting the success of [225Ac]Ac-AKY-1189 and our other current and future product candidates, if approved, are likely to be their efficacy, safety, convenience, price, the level of generic competition and the availability of reimbursement from government and other third-party payors.

The market opportunities for our product candidates may be smaller than we anticipated or may be limited to those patients who are ineligible for or have failed prior treatments. If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

Our current and future target patient populations are based on our beliefs and estimates regarding the incidence or prevalence of certain types of cancers that may be addressable by our product candidates, which is derived from a variety of sources, including scientific literature and surveys of clinics. Our projections may prove to be incorrect and the number of potential patients may turn out to be lower than expected. Even if we obtain significant market share for our product candidates, because the potential target populations could be small, we may never achieve profitability without obtaining regulatory approval for additional indications, including use of our product candidates for front-line and second-line therapy.

We expect to initially seek approval of some of our product candidates, including [225Ac]Ac-AKY-1189 and [225Ac]Ac-AKY-2519, as second-or third-line therapies for patients who have failed other approved treatments.

Subsequently, for those product candidates that prove to be sufficiently beneficial, if any, we would expect to seek approval as a second-line therapy and potentially as a front-line therapy, but there is no guarantee that our product candidates, even if approved for third-line therapy, would be approved for second-line or front-line therapy. In addition, we may have to conduct additional clinical trials prior to gaining approval for second-line or front-line therapy.

Our company has never commercialized a product candidate and may experience delays or unexpected difficulties in obtaining regulatory approval for our current and future product candidates.

Our company has never obtained regulatory approval for, or commercialized, a product. It is possible that the FDA may refuse to accept any or all of our planned BLAs for substantive review or may conclude after review of our data that our application is insufficient to obtain regulatory approval for any product candidates. If the FDA does not approve any of our planned BLAs, it may require that we conduct additional costly clinical trials, preclinical studies or manufacturing validation studies before it will reconsider our applications. Depending on the extent of these or any other FDA-required studies, approval of any BLA or other application that we submit may be significantly delayed, possibly for several years, or may require us to expend more resources than we have available. Any failure or delay in obtaining regulatory approvals would prevent us from commercializing our product candidates, generating revenues and achieving and sustaining profitability. It is also possible that additional studies, if performed and completed, may not be considered sufficient by the FDA to approve any BLA or other application that we submit. If any of these outcomes occur, we may be forced to abandon the development of our product candidates, which would materially adversely affect our business and could potentially cause us to cease operations. We face similar risks for our applications in foreign jurisdictions.

We currently have no marketing and sales organization and have no experience in marketing products. If we are unable to establish marketing and sales capabilities or enter into agreements with third parties to market and sell our product candidates, if approved for commercial sale, we may not be able to generate product revenue.

We currently have no sales, marketing or distribution capabilities and have no experience in marketing products. We intend to develop an in-house marketing organization and sales force, which will require significant capital expenditures, management resources and time. We will have to compete with other pharmaceutical and biotechnology companies to recruit, hire, train and retain marketing and sales personnel.

If we are unable to, or decide not to, establish internal sales, marketing and distribution capabilities, we will pursue collaborative arrangements regarding the sales and marketing of our products, if licensed. However, there can be no assurance that we will be able to establish or maintain such collaborative arrangements, or if we are able to do so, that they will have effective sales forces. Any revenue we receive will depend upon the efforts of such third parties, which may not be successful. We may have little or no control over the marketing and sales efforts of such third parties and our revenue from product sales may be lower than if we had commercialized our product candidates ourselves. We also face competition in our search for third parties to assist us with the sales and marketing efforts of our product candidates.

There can be no assurance that we will be able to develop in-house sales and distribution capabilities or establish or maintain relationships with third-party collaborators to commercialize any product in the United States or overseas for which we are able to obtain regulatory approval.

We may become exposed to costly and damaging liability claims, either when testing [225Ac]Ac-AKY-1189 or our other current or future product candidates in the clinic or at the commercial stage, and our product liability insurance may not cover all damages from such claims.

We are exposed to potential product liability and professional indemnity risks that are inherent in the research, development, manufacturing, marketing, and use of pharmaceutical products. We currently have no products that have been approved for commercial sale, the use of product candidates by us in clinical trials, and the sale of any approved products in the future, may expose us to liability claims, including third-party claims against any of our collaboration partners, some of which we could be contractually obligated to indemnify. These claims might be made by patients that use the product, healthcare providers, pharmaceutical companies, or others selling such products. Any claims against us, regardless of their merit, could be difficult and

costly to defend and could materially adversely affect the market for [225Ac]Ac-AKY-1189 or our other current or future product candidates or any prospects for commercialization.

Although the clinical trial process is designed to identify and assess potential side effects, it is always possible that a product, even after regulatory approval, may exhibit unforeseen side effects. If [225Ac]Ac-AKY-1189 or any of our other current or future product candidates were to cause adverse side effects during clinical trials or after approval of the product candidate, we may be exposed to substantial liabilities. Physicians and patients may not comply with any warnings that identify known potential adverse effects and patients who should not use [225Ac]Ac-AKY-1189 or our other current or future product candidates.

Even successful defense against product liability claims would require significant financial and management resources. Regardless of the merits or eventual outcome, liability claims may result in:

Although we maintain product liability insurance in the United States, and in other jurisdictions where we have ongoing clinical trials, it is possible that our liabilities could exceed our insurance coverage. We intend to expand our insurance coverage to include the sale of commercial products if we obtain regulatory approval for [225Ac]Ac-AKY-1189 or any of our other current or future product candidates. However, we may be unable to maintain insurance coverage at a reasonable cost or obtain insurance coverage that will be adequate to satisfy any liability that may arise. If a successful product liability claim or series of claims is brought against us for uninsured liabilities or in excess of insured liabilities, our assets may not be sufficient to cover such claims, and our business operations could be impaired.

We are party to multiple license and collaboration agreements with significant payment obligations that are contingent upon the occurrence of future events, the timing and likelihood of which are difficult to predict. If we fail to comply with our obligations under these license and collaboration agreements, we could lose rights that are important to our business.

Under our license and collaboration agreements, we have payment obligations that are contingent upon future events, such as the achievement of specified development, regulatory and commercial milestones, and in some cases, we are required to make royalty payments in connection with the sales of products developed under those agreements. Although we could be required to make substantial milestone payments under our license and collaboration agreements, we are currently unable to estimate the timing or likelihood of achieving the milestones or making future sales. For further discussion of our obligations under these agreements, see “Business—License and collaboration agreements.”

We may be unable to meet our obligations as they become due, especially in the event that multiple milestones are achieved in a short amount of time. If we are unable to meet our obligations when due, it may result in the delay or termination of the research, development or commercialization of the relevant product candidate, and may result in costly litigation or arbitration that diverts management attention and resources away from our day-to-day activities, which may adversely affect our business, financial condition, results of operations and prospects.

Risks related to government regulation

The development and commercialization of pharmaceutical products is subject to extensive regulation, and the regulatory approval processes of the FDA and comparable foreign authorities are lengthy, time-consuming, and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for [225Ac]Ac-AKY-1189 or any other current or future product candidates, on a timely basis if at all, our business will be substantially harmed.

Commencing clinical trials in the United States is subject to acceptance by the FDA of an IND application and finalizing the trial design based on discussions with the FDA. Even after we receive and incorporate guidance from the FDA, the FDA could

disagree that we have satisfied their requirements to commence any clinical trial or change their position on the acceptability of our trial design or the clinical endpoints selected, which may require us to complete additional preclinical studies or clinical trials, delay the enrollment of our clinical trials, abandon our clinical development plans or meet stricter approval conditions than we currently expect. There are equivalent processes and risks applicable to clinical trial applications in other countries, including countries in the EU.

Furthermore, we have not previously submitted a BLA to the FDA or similar marketing applications to similar foreign regulatory authorities. An BLA must include extensive preclinical and clinical data and supporting information to establish the product candidate’s safety, purity and potency for each desired indication. The BLA must also include significant information regarding the manufacturing controls for the product. We expect the novel nature of our product candidates to create further challenges in obtaining regulatory approval.

A BLA must be supported by extensive clinical and preclinical data, as well as extensive information regarding pharmacology, chemistry, manufacturing and controls. Outside the United States, many comparable foreign regulatory authorities employ similar approval processes.

[225Ac]Ac-AKY-1189 and any of our current or future product candidates could fail to receive regulatory approval for many reasons, including the following:

This lengthy approval process, as well as the unpredictability of clinical trial results, may result in our failing to obtain regulatory approval to market [225Ac]Ac-AKY-1189 or any other current or future product candidates, which would significantly harm our business, financial condition, results of operations and prospects. The FDA and comparable foreign regulatory authorities have substantial discretion in the approval process and determining when or whether regulatory approval will be obtained for [225Ac]Ac-AKY-1189 or any other current or future product candidates. For example, regulatory authorities in various jurisdictions may have differing requirements for, interpretations of and opinions on our preclinical and clinical data. As a result, we may be required to conduct additional preclinical studies, alter our proposed clinical trial designs, or conduct additional clinical trials to satisfy the regulatory authorities in each of the jurisdictions in which we hope to conduct clinical trials and develop and market our products, if approved. Further, even if we believe the data collected from clinical trials of [225Ac]Ac-AKY-1189 or our other current or future product candidates is promising, such data may not be sufficient to support approval by the FDA or any comparable foreign regulatory authority.

In addition, even if we were to obtain approval, regulatory authorities may approve [225Ac]Ac-AKY-1189 or any other current or future product candidates for fewer or more limited indications than we request, may not approve the price we intend to charge for our products, may grant approval contingent on the performance of costly post-marketing clinical trials, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate. Any of the foregoing scenarios could materially harm the commercial prospects for [225Ac]Ac-AKY-1189 or any other current or future product candidates.

We may seek orphan drug designation for the product candidates we develop, and we may be unsuccessful or may be unable to maintain the benefits associated with orphan drug designation, including the potential for market exclusivity.

As part of our business strategy, we may seek orphan drug designation for the product candidates we develop, and we may be unsuccessful. Regulatory authorities in some jurisdictions, including the United States and Europe, may designate drugs and biologics for relatively small patient populations as orphan drugs. Under the Orphan Drug Act, the FDA may designate a drug or biologic as an orphan drug if it is a drug or biologic intended to treat a rare disease or condition, which is defined as a patient

population of fewer than 200,000 individuals annually in the United States, or a patient population greater than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug or biologic will be recovered from sales in the United States. In the United States, orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers.

Similarly, in Europe, the European Commission grants orphan drug designation after receiving the opinion of the EMA Committee for Orphan Medicinal Products on an orphan drug designation application. Orphan drug designation is intended to promote the development of drugs and biologics that are intended for the diagnosis, prevention or treatment of life-threatening or chronically debilitating conditions affecting not more than five in 10,000 persons in Europe and for which no satisfactory method of diagnosis, prevention or treatment has been authorized (or the product would be a significant benefit to those affected). Additionally, designation is granted for drugs and biologics intended for the diagnosis, prevention or treatment of a life-threatening, seriously debilitating or serious and chronic condition and when, without incentives, it is unlikely that sales of the drug or biologic in Europe would be sufficient to justify the necessary investment in developing the drug or biologic. In Europe, orphan drug designation entitles a party to a number of incentives, such as protocol assistance and scientific advice specifically for designated orphan medicines, and potential fee reductions depending on the status of the sponsor.

Generally, if a drug or biologic with an orphan drug designation subsequently receives the first marketing approval for the indication for which it has such designation, the drug or biologic is entitled to a period of marketing exclusivity, which precludes the EMA, or the FDA from approving another marketing application for the same drug and for the same indication during the period of exclusivity, except in limited circumstances. The applicable period is seven years in the United States and 10 years in Europe. The European exclusivity period can be reduced to six years if a drug or biologic no longer meets the criteria for orphan drug designation or if the drug or biologic is sufficiently profitable such that market exclusivity is no longer justified.

Even if we obtain orphan drug exclusivity for a product candidate, that exclusivity may not effectively protect such product candidate from competition because different therapies can be approved for the same condition and the same therapies can be approved for different conditions but used off-label. Even after an orphan drug is approved, the FDA can subsequently approve the same drug for the same condition if the FDA concludes that the later drug or biologic is clinically superior in that it is shown to be safer, more effective or makes a major contribution to patient care. In addition, a designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which it received orphan designation. Moreover, orphan drug exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the drug or biologic to meet the needs of patients with the rare disease or condition. Orphan drug designation neither shortens the development time or regulatory review time of a drug or biologic nor gives the drug or biologic any advantage in the regulatory review or approval process. While we may seek orphan drug designation for applicable indications for our current and any future product candidates, we may never receive such designations. Even if we do receive such designation, there is no guarantee that we will enjoy the benefits of that designation.

We may seek one or more designations or expedited programs for one or more of our product candidates, but we might not receive such designations or be allowed to proceed on expedited program pathways, and even if we do and proceed on such expedited program pathways in the future, such designations or expedited programs may not lead to a faster development or regulatory review or approval process, and each designation does not increase the likelihood that any of our product candidates will receive marketing approval in the United States.

We have received fast track designation for [225Ac]Ac-AKY-1189 for the treatment of adult patients with locally advanced or metastatic UC who had progressed on or after prior systemic therapies and may seek fast track designation for certain of our other product candidates. If a drug is intended for the treatment of a serious or life-threatening condition and nonclinical or clinical data for the drug demonstrates the potential to address an unmet medical need for such a condition, the drug sponsor may apply for fast track designation. The FDA has broad discretion whether or not to grant this designation, so even if we believe a particular product candidate is eligible for this designation, we cannot assure you that the FDA would decide to grant it for any of our other product candidates. Even with fast track designation, we may not experience a faster development process, review or approval compared to conventional FDA procedures. The FDA may withdraw fast track designation if it believes that the designation is no longer supported by data from our clinical development program. Fast track designation alone does not guarantee qualification for the FDA’s priority review procedures.

A breakthrough therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life threatening disease or condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For product candidates that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Product candidates designated as breakthrough therapies by the FDA may also be eligible for priority review and accelerated approval. Designation as a breakthrough therapy is within the discretion of the FDA.

Accordingly, even if we believe one of our future product candidates meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of a breakthrough therapy designation for a product candidate may not result in a faster development process, review or approval compared to therapies considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our product candidates qualify as breakthrough therapies, the FDA may later decide that such product candidates no longer meet the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.

If the FDA determines that a product candidate offers a treatment for a serious condition and, if approved, the product would provide a significant improvement in safety or effectiveness, the FDA may designate the product candidate for priority review. A priority review designation means that the goal for the FDA to review an application is six months, rather than the standard review period of ten months. We may request priority review for our product candidates. The FDA has broad discretion with respect to whether or not to grant priority review status to a product candidate, so even if we believe a particular product candidate is eligible for such designation or status, the FDA may decide not to grant it. Moreover, a priority review designation does not necessarily result in an expedited regulatory review or approval process or necessarily confer any advantage with respect to approval compared to conventional FDA procedures. Receiving priority review from the FDA does not guarantee approval within the six-month review cycle or at all.

Even if [225Ac]Ac-AKY-1189 or any of our other current or future product candidates obtains regulatory approval, we will be subject to ongoing obligations and continued regulatory review, which may result in significant additional expense. Additionally, [225Ac]Ac-AKY-1189 or any of our other current or future product candidates, if approved, could be subject to labeling and other restrictions and market withdrawal and we may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our products.

If the FDA or a comparable foreign regulatory authority approves [225Ac]Ac-AKY-1189 for any Nectin-4 expressing tumor or any of our other current or future product candidates, the manufacturing facilities and processes, testing, labeling, packaging, distribution, import, export, adverse event reporting, storage, advertising, promotion, and recordkeeping for the product will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as continued compliance with cGMP and GCPs for any clinical trials that we conduct post-approval, all of which may result in significant expense and limit our ability to commercialize such products. In addition, any regulatory approvals that we or our partners receive a product candidate may also be subject to limitations on the approved indicated uses for which the product may be marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing testing, including Phase 4 clinical trials, and surveillance to monitor the safety and efficacy of the product candidate.

Manufacturers and manufacturers’ facilities are required to comply with extensive FDA and comparable foreign regulatory authority requirements, including ensuring that quality control and manufacturing procedures conform to cGMP regulations. As such, we and our CMOs will be subject to continual review and inspections to assess compliance with cGMP and adherence to commitments made in any approved regulatory application. Accordingly, we and others with whom we work must continue to expend time, money, and effort in all areas of regulatory compliance, including manufacturing, quality control, and distribution.

If there are changes in the application of legislation or regulatory policies, or if problems are discovered with a product or our manufacture of a product, or if we or one of our distributors, licensees or co-marketers fails to comply with regulatory requirements, the regulators could take various actions. These include issuing warning letters or untitled letters, imposing fines on us, imposing restrictions on the product or its manufacture, and requiring us to recall or remove the product from the market. The regulators could also suspend any of our preclinical studies and clinical trials or suspend or withdraw our regulatory approvals, requiring us to conduct additional clinical trials, change our product labeling, or submit additional applications for marketing authorization. If any of these events occurs, our ability to sell such product may be impaired, and we may incur substantial additional expense to comply with regulatory requirements, which could materially adversely affect our business, financial condition, results of operations and prospects.

In addition, if we have any product candidate approved, our product labeling, advertising, and promotion will be subject to regulatory requirements and continuing regulatory review. In the United States, the FDA and the Federal Trade Commission, or the FTC, strictly regulate the promotional claims that may be made about pharmaceutical products to ensure that any claims about such products are consistent with regulatory approvals, not misleading or false, and adequately substantiated by clinical data. Physicians may use pharmaceutical products off-label in their professional medical judgment, as the FDA does not restrict or regulate a physician’s choice of diagnostic or treatment within the practice of medicine. However, the promotion of a product in a manner that is false, misleading, unsubstantiated, or for unapproved, or off-label, uses may result in enforcement letters, inquiries and investigations, and civil and criminal sanctions by the FDA or the FTC. In particular, a product may not be promoted for uses that are not approved by the FDA as reflected in the product’s approved labeling. If we receive regulatory approval for a product candidate, physicians may nevertheless prescribe it to their patients in a manner that is inconsistent with the approved label. If we are found to have promoted such off-label uses, we may become subject to significant liability. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant sanctions and may result in false claims litigation under federal and state statutes, which can lead to consent decrees, civil monetary penalties, restitution, criminal fines and imprisonment, and exclusion

from participation in Medicare, Medicaid, and other federal and state healthcare programs. The federal government has levied large civil and criminal fines against companies for alleged improper promotion and has enjoined several companies from engaging in off-label promotion. The FDA has also requested that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed.

Equivalent limitations and penalties are provided in the European Economic Area, or EEA, both at the supranational level and at the national level in the individual EEA countries.

Any government investigation of alleged violations of law could require us to expend significant time and resources in response and could generate negative publicity. Any failure to comply with ongoing regulatory requirements may significantly and adversely affect our ability to commercialize and generate revenue from our products, if approved. Failure to comply with EU and EEA countries’ laws that apply to the conduct of clinical trials, manufacturing approval, marketing authorization of medicinal products and marketing of such products, both before and after grant of the marketing authorization, or with other applicable regulatory requirements may result in administrative, civil or criminal penalties. These penalties could include delays or refusal to authorize the conduct of clinical trials, or to grant marketing authorization, product withdrawals and recalls, product seizures, suspension, withdrawal or variation of the marketing authorization, total or partial suspension of production, distribution, manufacturing or clinical trials, operating restrictions, injunctions, suspension of licenses, fines and criminal penalties. If regulatory sanctions are applied or if regulatory approval is withdrawn, the value of our company and our operating results will be adversely affected.

Moreover, the policies of the FDA and of comparable foreign regulatory authorities may change and additional government regulations may be enacted that could prevent, limit, or delay regulatory approval of [225Ac]Ac-AKY-1189 or any of our other or future product candidates. As an example, the regulatory landscape related to clinical trials in the EEA recently evolved. The EU Clinical Trials Regulation, or CTR, which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. The CTR allows sponsors to make a single submission to both the competent authority and an ethics committee in each EEA country, leading to a single decision for each EEA country. The assessment procedure for the authorization of clinical trials has been harmonized as well, including a joint assessment by all EEA countries concerned, and a separate assessment by each EEA country with respect to specific requirements related to its own territory, including ethics rules. Each EEA country’s decision is communicated to the sponsor via the centralized EU portal. Once the clinical trial approved, clinical study development may proceed. The CTR foresees a three-year transition period. The extent to which ongoing and new clinical trials will be governed by the CTR varies. For clinical trials in relation to which application for approval was made on the basis of the Clinical Trials Directive before January 31, 2022, the Clinical Trials Directive will continue to apply on a transitional basis for three years. Additionally, sponsors could choose to submit a clinical trial application under either the Clinical Trials Directive or the CTR until January 31, 2023. Where these trials were authorized on the basis of the Clinical Trials Directive, they will be governed by the Clinical Trials Directive until January 31, 2025. Commencing on February 1, 2025, all ongoing trials are subject to the provisions of the CTR. The CTR will apply to clinical trials from an earlier date if the clinical trial has already transitioned to the CTR framework. Compliance with the CTR requirements by us and our third-party service providers, such as CROs, may impact our developments plans.

We cannot predict the likelihood, nature, or extent of government regulation that may arise from future legislation or administrative or executive action, either in the United States or abroad. In addition, if we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any regulatory approval that we may have obtained and we may not achieve or sustain profitability.

Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not mean that we will be successful in obtaining regulatory approval of our product candidates in other jurisdictions.

Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction, while a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA grants marketing approval of a product candidate, similar foreign regulatory authorities must also approve the manufacturing, marketing and promotion of the product candidate in those countries. Approval and licensure procedures vary among jurisdictions and can involve requirements and administrative review periods different from, and greater than, those in the United States, including additional preclinical studies or clinical trials as clinical trials conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our products is also subject to approval.

We may also submit marketing applications in other countries. Regulatory authorities in jurisdictions outside of the United States have requirements for approval of product candidates with which we must comply prior to marketing in those jurisdictions. Obtaining similar foreign regulatory approvals and compliance with similar foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. If we fail to comply with the regulatory requirements in international markets and/or receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed.

Disruptions at the FDA and other government agencies and foreign regulatory authorities, including those caused by funding shortages or global health concerns could hinder their ability to hire, retain, or deploy key leadership and other personnel, or otherwise prevent new or modified drugs from being developed, approved, or commercialized in a timely manner or at all, which could negatively impact our business.

The ability of the FDA or comparable foreign regulatory authorities to review and approve new drugs can be affected by a variety of factors, including government budget reductions in force, and funding levels, statutory, regulatory, and policy changes, the FDA’s or comparable foreign regulatory authorities’ ability to hire and retain key personnel and accept the payment of user fees, pandemics and other public health crises, and other events that may otherwise affect the FDA’s or comparable foreign regulatory authorities’ ability to perform routine functions. Average review times at the FDA have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Recent disruptions at the FDA and other agencies may also slow the time necessary for new drugs or modifications to approved drugs to be reviewed and/or approved by necessary regulatory authorities, which would adversely affect our business.

For example, in recent years, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical employees and stop critical activities. In addition, the current U.S. presidential administration has issued certain policies and executive orders directed towards reducing the employee headcount and costs associated with U.S. administrative agencies, including the FDA, and it remains unclear the degree to which these efforts may limit or otherwise adversely affect the FDA’s ability to conduct routine activities.

Separately, in response to the COVID-19 pandemic, the FDA postponed most inspections of domestic and foreign manufacturing facilities at various points. If any future prolonged government shutdown occurs, or if renewed global health concerns, funding shortages or staffing limitations prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews or other regulatory activities, it could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

We are currently, and may in the future, conduct clinical trials for product candidates outside the United States, and the FDA and comparable foreign regulatory authorities may not accept data from such trials.

We may in the future choose to conduct one or more additional clinical trials outside the United States, including in the EU, South Africa, Australia and/or Asia. The acceptance of study data from clinical trials conducted outside the United States or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. In cases where data from foreign clinical trials are intended to serve as the basis for regulatory approval in the United States, the FDA will generally not approve the application based on foreign data alone unless: (i) the data is applicable to the U.S. population and U.S. medical practice; and (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations.

Additionally, the FDA’s clinical trial requirements, including sufficient size of patient populations and statistical powering, must be met. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the United States or the applicable jurisdiction. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in product candidates that we may develop not receiving approval for commercialization in such jurisdiction.

Our business operations and current and future relationships with healthcare professionals, principal investigators, consultants, vendors, customers, and third-party payors in the United States and elsewhere are subject, directly or indirectly, to applicable anti-kickback, fraud and abuse, false claims, physician payment transparency, health information privacy and security and other healthcare laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm, administrative burdens, diminished profits and future earnings.

Healthcare providers, healthcare facilities and institutions, and third-party payors in the United States and elsewhere will play a primary role in the recommendation and prescription of any product candidates for which we obtain regulatory approval. Our future arrangements with healthcare professionals, healthcare facilities and institutions, principal investigators, consultants, customers, and third-party payors may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations, including, without limitation, the federal Anti-Kickback Statute and the federal False Claims Act, or the FCA, which may constrain

the business or financial arrangements and relationships through which we research, sell, market, and distribute any product candidates for which we obtain regulatory approval. In addition, we may be subject to physician payment transparency laws and regulation by the federal government and by the states and foreign jurisdictions in which we conduct our business. The applicable federal, state, and foreign healthcare laws and regulations that affect our ability to operate include, but are not limited to, the following:

Outside the United States, interactions between pharmaceutical companies and healthcare professionals are also governed by strict laws, such as national anti-bribery laws of European countries, national sunshine rules, regulations, industry self-regulation codes of conduct and physicians’ codes of professional conduct. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.

Ensuring that our internal operations and future business arrangements with third parties comply with applicable healthcare laws and regulations will involve substantial costs. It is not always possible to identify and deter employee misconduct or business non-compliance, and the precautions we take to detect and prevent inappropriate conduct may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. Efforts to ensure that our business arrangements will comply with applicable healthcare laws may involve substantial costs. We have entered into consulting and scientific advisory board arrangements with physicians and other healthcare providers, including some who could influence the use of [225Ac]Ac-AKY-1189 of any of our other current or future product candidates, if approved. Compensation under some of these arrangements includes the provision of stock or stock options in addition to cash consideration. Because of the complex and far-reaching nature of these laws, it is possible that if our products are commercialized, governmental authorities could conclude that our business practices do not comply with current or future statutes, regulations, agency guidance or case law involving applicable fraud and abuse or other healthcare laws and regulations.

If our operations are found to be in violation of any of the laws described above or any other governmental laws and regulations that may apply to us, we may be subject to significant penalties, including civil, criminal, and administrative penalties, damages, fines, exclusion from government-funded healthcare programs, such as Medicare and Medicaid, or similar programs in other countries or jurisdictions, integrity oversight and reporting obligations to resolve allegations of non-compliance, disgorgement, imprisonment, contractual damages, reputational harm, diminished profits, and the curtailment or restructuring of our operations. If any of the physicians or other providers or entities with whom we expect to do business are found to be in violation of applicable laws, they may be subject to significant criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs and imprisonment, which could affect our ability to operate our business. Further, defending against any such actions can be costly, time-consuming and may require significant personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired.

Healthcare policy changes may have a material adverse effect on our business, financial condition, results of operations and prospects.

The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, or collectively, the ACA, enacted in March 2010, made several substantial changes in the way healthcare is financed by both governmental and private insurers, and significantly impacted the U.S. pharmaceutical industry. Some ways in which the ACA may significantly impact our business include provisions regarding coordination and promotion of research on comparative clinical effectiveness of different technologies and procedures, initiatives to revise Medicare payment methodologies, and initiatives to promote quality indicators in payment methodologies.

There have been legal and political challenges to certain aspects of the ACA. For example, on June 17, 2021, the U.S. Supreme Court dismissed a challenge on procedural grounds that argued the ACA is unconstitutional in its entirety because the “individual mandate” was repealed by Congress. Prior to the U.S. Supreme Court ruling, on January 28, 2021, President Biden issued an executive order to initiate a special enrollment period from February 15, 2021, through August 15, 2021 for purposes of obtaining health insurance coverage through the ACA marketplace. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. Further, on August 16, 2022, President Biden signed the Inflation Reduction Act of 2022, or IRA, into law, which among other things, extends enhanced subsidies for individuals purchasing health insurance coverage in ACA marketplaces through plan year 2025. The IRA also eliminates the “donut hole” under the Medicare Part D program beginning in 2025 by significantly lowering the beneficiary maximum out-of-pocket cost and creating a new manufacturer discount program. It is possible that the ACA will be subject to judicial or Congressional challenges in the future. It is unclear how any such challenges and current or evolving federal policies regarding healthcare reform measures will impact the ACA or our business.

Since the ACA’s passage, legislative changes to the ACA have been proposed and adopted. On July 4, 2025, the annual reconciliation bill, the “One Big Beautiful Bill Act,” or OBBBA, was signed into law which is expected to reduce Medicaid spending and enrollment by implementing work requirements for some beneficiaries, capping state-directed payments, reducing federal funding, and limiting provider taxes used to fund the program. OBBBA also narrows access to ACA marketplace exchange enrollment and declines to extend the ACA’s enhanced advanced premium tax credits, set to expire in 2025, which, among other provisions in the law, are anticipated to reduce the number of Americans with health insurance. Additionally, under the sequestration required by the Budget Control Act of 2011, beginning April 1, 2013, Medicare payments to providers were reduced, which will remain in effect through 2032 unless additional Congressional action is taken. On March 11, 2021, the American Rescue Plan Act of 2021 was signed into law, which eliminated the statutory cap on the Medicaid drug rebate effective January 1, 2024. The rebate was previously capped at 100% of a drug’s average manufacturer price.

Recently, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed drugs, which has resulted in several presidential executive orders, Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products. At the federal level, in July 2021, the Biden administration released an executive order, “Promoting Competition in the American Economy,” with multiple provisions aimed at prescription drugs. In response to Biden’s executive order, on September 9, 2021, the U.S. Department of Health and Human Services, or HHS, released a Comprehensive Plan for Addressing High Drug Prices that outlines principles for drug pricing reform and sets out a variety of potential legislative policies that Congress could pursue as well as potential administrative actions HHS can take to advance these principles. Further, the IRA, among other things (i) directs HHS to negotiate the price of certain high-expenditure, single-source drugs and biologics covered under Medicare and (ii) imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation. These provisions began to take effect progressively in fiscal year 2023, although the drug price negotiation program is currently subject to legal challenges. HHS has and will continue to issue and update guidance as these programs are implemented. It is currently unclear how the IRA will be implemented but is likely to have a significant impact on the pharmaceutical industry. In addition, in response to the Biden administration’s October 2022 executive order, on February 14, 2023, HHS released a report outlining three new models for testing by the Center for Medicare and Medicaid Innovation which will be evaluated on their ability to lower the cost of drugs, promote accessibility, and improve quality of care. It is unclear whether the models will be utilized in any health reform measures in the future. At the state level, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biological drug pricing, including price or patient reimbursement constraints, discounts, restrictions on certain drug access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.

Our ability to develop and market new drug products may be impacted if litigation challenging the FDA’s approval of another company’s drug continues. In April 2023, the U.S. District Court for the Northern District of Texas invalidated the approval by the FDA of mifepristone, a drug product, which was originally approved in 2000, and whose distribution is governed by various measures adopted under a REMS. The Court of Appeals for the Fifth Circuit declined to order the removal of mifepristone from the market but did hold that plaintiffs were likely to prevail in their claim that changes allowing for expanded access of mifepristone, which the FDA authorized in 2016 and 2021, were arbitrary and capricious. In June 2024, the Supreme Court reversed and remanded that decision after unanimously finding that the plaintiffs did not have standing to bring this legal action against the FDA. Depending on the outcome of this litigation, if it continues, our ability to develop [225Ac]Ac-AKY-1189 or future product candidates we may develop may be at risk and could be delayed, undermined or subject to protracted litigation. Finally, we could be adversely affected by several significant administrative law cases decided by the U.S. Supreme Court in 2024. In Loper Bright Enterprises v. Raimondo, for example, the court overruled Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., which for 40 years required federal courts to defer to permissible agency interpretations of statutes that are silent or ambiguous on a particular topic. The U.S. Supreme Court stripped federal agencies of this presumptive deference and held that courts must exercise their independent judgment when deciding whether an agency such as FDA acted within its statutory authority under the Administrative Procedure Act, or the APA. Additionally, in Corner Post, Inc. v. Board of Governors of the Federal Reserve System, the court held

that actions to challenge a federal regulation under the APA can be initiated within six years of the date of injury to the plaintiff, rather than the date the rule is finalized. The decision appears to give prospective plaintiffs a personal statute of limitations to challenge longstanding agency regulations. These decisions could introduce additional uncertainty into the regulatory process and may result in additional legal challenges to actions taken by federal regulatory agencies, including the FDA and the CMS that we rely on. In addition to potential changes to regulations as a result of legal challenges, these decisions may result in increased regulatory uncertainty and delays and other impacts, any of which could adversely impact our business and operations. Furthermore, recent changes to the leadership of federal agencies like HHS, CMS and FDA can lead to new policies and regulations that can have a material impact on our industry and business operations.

Many EEA countries periodically review their reimbursement procedures for medicinal products, which could have an adverse impact on reimbursement status. We expect that legislators, policymakers and healthcare insurance funds in the EEA countries will continue to propose and implement cost-containing measures, such as lower maximum prices, lower or lack of reimbursement coverage and incentives to use cheaper, usually generic, products as an alternative to branded products, and/or branded products available through parallel import to keep healthcare costs down. Moreover, in order to obtain reimbursement for our products in some European countries, including some EEA countries, we may be required to compile additional data comparing the cost-effectiveness of our products to other available therapies. Health Technology Assessment, or HTA, of medicinal products is becoming an increasingly common part of the pricing and reimbursement procedures in some EEA countries, including those representing the larger markets. The HTA process is the procedure to assess therapeutic, economic and societal impact of a given medicinal product in the national healthcare systems of the individual country. The outcome of an HTA will often influence the pricing and reimbursement status granted to these medicinal products by the competent authorities of individual EEA countries. The extent to which pricing and reimbursement decisions are influenced by the HTA of the specific medicinal product currently varies between EEA countries.

In December 2021, Regulation No 2021/2282 on HTA amending Directive 2011/24/EU, was adopted in the EU. This Regulation, which entered into force in January 2022 and will apply as of January 2025, is intended to boost cooperation among EEA countries in assessing health technologies, including new medicinal products, and providing the basis for cooperation at EEA level for joint clinical assessments in these areas. The Regulation foresees a three-year transitional period and will permit EEA countries to use common HTA tools, methodologies, and procedures across the EEA, working together in four main areas, including joint clinical assessment of the innovative health technologies with the most potential impact for patients, joint scientific consultations whereby developers can seek advice from HTA authorities, identification of emerging health technologies to identify promising technologies early, and continuing voluntary cooperation in other areas. Individual EEA countries will continue to be responsible for assessing non-clinical (e.g., economic, social, ethical) aspects of health technologies, and making decisions on pricing and reimbursement. If we are unable to maintain favorable pricing and reimbursement status in EEA countries for product candidates that we may successfully develop and for which we may obtain regulatory approval, any anticipated revenue from and growth prospects for those products in the EEA could be negatively affected.

Legislators, policymakers and healthcare insurance funds in the EEA may continue to propose and implement cost-containing measures to keep healthcare costs down; particularly due to the financial strain that the COVID-19 pandemic placed on national healthcare systems of the EEA countries. These measures could include limitations on the prices we would be able to charge for product candidates that we may successfully develop and for which we may obtain regulatory approval or the level of reimbursement available for these products from governmental authorities or third-party payors. Further, an increasing number of EEA and other foreign countries use prices for medicinal products established in other countries as “reference prices” to help determine the price of the product in their own territory. Consequently, a downward trend in prices of medicinal products in some countries could contribute to similar downward trends elsewhere.

We cannot predict whether future healthcare initiatives will be implemented at the federal or state level, supranational or national level, or how any future legislation or regulation may affect us, any of which may have a materially adverse effect on our business, financial condition, results of operations and prospects.

Even if we are able to commercialize a product candidate, coverage and adequate reimbursement may not be available or such product candidate may become subject to unfavorable pricing regulations or third-party coverage and reimbursement policies, which would harm our business.

The regulations that govern regulatory approvals, pricing, and reimbursement for product products vary widely from country to country. Some countries require approval of the sale price of a drug product before it can be marketed or may require us or our collaborators to conduct clinical trials that compare the cost-effectiveness of our product candidates to other therapies to obtain reimbursement or pricing approval. In many countries, the pricing review period begins after regulatory approval is granted. In some foreign markets, prescription drug product pricing remains subject to continuing governmental control even after initial approval is granted. As a result, we might obtain regulatory approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, and negatively impact the revenue we are able to generate from the sale of the product in that country. Adverse pricing limitations may hinder our ability to

recoup our investment in one or more product candidates, even if [225Ac]Ac-AKY-1189 or any of our future product candidates obtain regulatory approval.

Our ability to commercialize any products successfully also will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from third-party payors, such as government authorities, private health insurers, and other organizations. Even if we succeed in bringing one or more products to market, these products may not be considered cost-effective, and the amount reimbursed for any products may be insufficient to allow us to sell our products on a competitive basis. Because our programs are in the early stages of development, we are unable at this time to determine their cost effectiveness or the likely level or method of coverage and reimbursement. Increasingly, the third-party payors who reimburse patients or healthcare providers are requiring that drug companies provide them with predetermined discounts from list prices, and are seeking to reduce the prices charged or the amounts reimbursed for drug products. Moreover, no uniform policy requirement for coverage and reimbursement for drugs exists among third-party payors in the United States, which may result in significant variations in coverage and reimbursement from payor to payor. Even if favorable coverage and reimbursement status is attained for one or more drug products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future. If the price we are able to charge for any products we develop, or the coverage and reimbursement provided for such products, is inadequate in light of our development and other costs, our return on investment could be affected adversely.

The continuing efforts of the government, insurance companies, managed care organizations, and other payors of healthcare services to contain or reduce costs of healthcare and/or impose price controls may adversely affect:

Our inability to promptly obtain and maintain coverage and adequate reimbursement from both third-party payors for the product candidates that we may develop and for which we obtain regulatory approval could adversely affect our business, financial condition, results of operations, and prospects.

We and our collaborators and our third-party service providers are subject to a variety of stringent and evolving U.S. and foreign laws, regulations, rules, contractual obligations, policies and industry standards related to data privacy and cybersecurity, which could increase compliance costs, and our actual or perceived failure to comply therewith could subject us to regulatory investigations or actions, litigation, fines or penalties, disruptions of our business operation, reputational harm, loss of revenue or profits, and other adverse business consequences.

We process a large quantity of sensitive information, including proprietary and confidential business information and other personal information, and we and our collaborators and third-party service providers are subject to various federal, state, local and foreign data privacy and cybersecurity laws, rules and regulations relating to the privacy, security and processing of personal information.

The global data privacy and cybersecurity landscape is rapidly evolving, and we and our collaborators and third-party service providers may be affected by or subject to new, amended, or existing laws, rules and regulations, including as our operations continue to expand or if we operate in foreign jurisdictions. These laws, rules and regulations may be subject to differing interpretations, which adds to the complexity of processing personal information. Guidance on implementation and compliance practices are often updated or otherwise revised. This evolution may create uncertainty in our business, affect our ability to operate in certain jurisdictions or to collect, store, transfer, use, share or otherwise process personal information, necessitate the acceptance of more onerous obligations in our contracts, result in liability or impose additional costs on us. If we fail or are perceived to have failed to comply with these laws, rules and regulations, we may be subject to litigation, regulatory investigations, enforcement notices, enforcement actions, fines, imprisonment of company officials and public censure, claims for damages by affected individuals, and criminal or civil penalties, as well as negative publicity, reputational harm, loss of goodwill and a potential loss of business, any of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

In the United States, numerous federal, state and local laws, rules and regulations, including state data breach notification laws and federal and state data privacy laws, rules and regulations that govern the collection, use, disclosure, protection, transfer and other processing of health information and other personal information apply to our operations and the operations of our collaborators and third-party service providers. Each of these laws, rules and regulations is subject to varying interpretations and constantly evolving.

For example, HIPAA, as amended by HITECH, and regulations promulgated thereunder impose certain obligations with respect to safeguarding the privacy, security, transmission and other processing of individually identifiable health information on “covered entities,” and their respective “business associates,” as well as their covered subcontractors, that perform services for them. Depending on the facts and circumstances, we could be subject to significant penalties if we violate HIPAA. For example, under HIPAA, we could potentially face substantial criminal or civil penalties if we knowingly receive protected health information from a HIPAA-covered healthcare provider or research institution that has not satisfied HIPAA’s requirements for disclosure of such protected health information, or otherwise violate applicable HIPAA requirements related to the protection of such information. Moreover, determining whether protected health information has been handled in compliance with applicable privacy standards and our contractual obligations with third parties can be complex and may be subject to changing interpretation. If we are unable to properly protect the privacy and security of protected health information, we could be found to have breached our contracts. The HHS has the discretion to impose penalties without attempting to first resolve violations. HHS enforcement activity can result in financial liability and reputational harm, and responses to such enforcement activity can consume significant internal resources.

Even when HIPAA does not apply, failing to take appropriate steps to keep consumers’ personal information secure may constitute a violation of the Federal Trade Commission Act. The FTC expects a company’s data security measures to be reasonable and appropriate in light of the sensitivity and volume of consumer information it holds, the size and complexity of its business and the cost of available tools to improve security and reduce vulnerabilities. Individually identifiable health information is considered sensitive data that merits stronger safeguards. In connection with our clinical trials, we may maintain sensitive identifiable personal information, including health information, that we receive throughout the clinical trial process, during our research collaborations, and directly from individuals (or their healthcare providers) who enroll in our patient assistance programs. As such, we may become subject to further obligations under HIPAA.

In addition, our collection of personal information generally may subject us and our collaborators and third-party service providers to state data privacy laws governing the processing of personal information, including requiring us to reasonably protect certain types of personal information we hold or to otherwise comply with certain specified cybersecurity requirements with respect to personal information and requiring notification of affected individuals and state regulators in the event of a breach of such personal information in certain instances. For example, these state laws include the California Consumer Privacy Act, as amended by the California Privacy Rights Act, or collectively the CCPA, and applies to personal information of consumers, business representatives and employees that are California residents and requires covered businesses to make disclosures to consumers about their data collection, use and sharing practices, allows consumers to opt out of certain data sharing with third parties and provides a cause of action for data breaches. The CCPA provides for significant civil penalties of up to $7,500 per violation as well as a private right of action for certain data breaches and statutory damages. Although there are limited exemptions for clinical trial data and some other health data under the CCPA, the CCPA and other similar laws may impact our business activities and increase our compliance costs. Additionally, the California Privacy Rights Act, effective in most material respects as of January 1, 2023, expanded data privacy and cybersecurity compliance requirements and consumers’ rights under the CCPA including by, among other things, giving California residents the ability to correct their personal information and limit use of certain sensitive personal information, establishing restrictions on the retention of personal information, expanding the types of data breaches subject to the CCPA’s private right of action, and establishing a new California Privacy Protection Agency to implement and enforce the law. Other states, including but not limited to Virginia, Colorado, Utah, and Connecticut, have also passed comprehensive privacy laws, and similar laws are being considered in several other states (including Washington, which enacted the My Health, My Data Act in 2023), as well as at the federal and local levels. While many of these states, like California, also exempt some data processed in the context of clinical trials, these laws could have potentially conflicting requirements that further complicate compliance efforts, and increase legal risk and compliance costs for us, and the third parties upon whom we rely.

In addition, all 50 U.S. states and the District of Columbia have enacted breach notification laws that may require us to notify patients, employees or regulators in the event of unauthorized access to or disclosure of personal or confidential information experienced by us or our collaborators or third-party service providers. These laws are not consistent, and compliance in the event of a widespread data breach is difficult and may be costly. Moreover, states have been frequently amending existing laws, requiring attention to changing regulatory requirements. We also may be contractually required to notify patients or other counterparties of a security breach. In addition to government regulation, privacy advocates and industry groups have and may in the future propose self-regulatory standards from time to time. These and other industry standards may legally or contractually apply to us, or we may elect to comply with such standards.

Any clinical trial programs and research collaborations that we engage in outside the United States may implicate international data protection laws, including, in Europe, the General Data Protection Regulation, or GDPR, and the United Kingdom’s GDPR, combining the GDPR and the UK’s Data Protection Act of 2018, or the UK GDPR. The GDPR and UK GDPR govern the collection, use, disclosure, transfer or other processing of personal data of individuals within the EEA and UK and impose stringent operational requirements for data processors and controllers of personal data. For example, the GDPR and UK GDPR impose onerous

accountability obligations requiring data controllers and processors to maintain a record of their data processing and policies. The GDPR and UK GDPR also impose certain other onerous obligations, including obligations for controllers and processors to appoint data protection officers in certain circumstances, increased transparency obligations to data subjects for controllers, obligations to honor increased rights for data subjects, and obligations to implement certain technical and organizational safeguards to protect the security and confidentiality of personal data. The GDPR and UK GDPR also provide that EEA member states and the UK make their own further laws, rules and regulations to introduce specific requirements related to the processing of “special categories of personal data,” including personal data related to health, biometric data used for unique identification purposes and genetic information, as well as personal data related to criminal offences or convictions. This fact may lead to greater divergence on the law that applies to the processing of such data types across the EEA and the UK, compliance with which, as and where applicable, may increase our costs and could increase our overall compliance risk. Such member state specific regulations could limit our ability to collect, use and share data in the context of any future EEA or UK establishments (regardless of where any processing in question occurs). Among other things, the GDPR and UK GDPR require detailed notices for clinical trial subjects and investigators as well as the security of personal information, and notification of data processing obligations or security incidents to appropriate data protection authorities or data subjects. In addition, the GDPR and UK GDPR materially expanded the definition of what constitutes personal data (including, for example, by expressly clarifying that the GDPR applies to “pseudonymized” and key-coded data).

Since January 1, 2021, when the transitional period following the exit of the UK from the EU, or Brexit, expired, companies required to comply with the GDPR are also required to comply with the UK GDPR, which exposes these companies to two parallel regimes, each of which authorizes similar fines and may subject them to increased compliance risk based on differing, and potentially inconsistent or conflicting, interpretation and enforcement by regulators and authorities (particularly, if the laws are amended in the future in divergent ways). While the GDPR and the UK GDPR remain substantially similar for the time being, the government of the UK has adopted reforms to its data privacy and cybersecurity legal framework in its Data Use and Access Act 2025, which became law on June 19, 2025 (phasing in between June 2025 and June 2026) and will introduce significant changes from the GDPR. This may lead to additional compliance costs and could increase overall risk exposure as businesses may no longer be able to take a unified approach across the EEA and the UK, and such businesses may need to amend their processes and procedures to align with the new framework. Implementing mechanisms to endeavor to ensure compliance with the GDPR and the UK GDPR may be onerous and expose businesses to divergent parallel regimes that may be subject to potentially different interpretations and enforcement actions for certain violations and related uncertainty. With respect to transfers of personal data from the EEA, on June 28, 2021, the European Commission issued an adequacy decision in respect of the UK’s data protection framework, enabling data transfers from EU member states to the UK to continue without requiring organizations to put in place contractual or other measures in order to lawfully transfer personal data between the territories. However, the UK adequacy decision will automatically expire in December 2031 unless the European Commission re-assesses and renews or extends that decision and remains under review (and may be modified or revoked) by the Commission during this period. In addition, transfers of personal data from the UK to other countries, including the EEA, are subject to specific transfer rules under the UK regime.

The GDPR and UK GDPR impose substantial fines for breaches and violations (up to the greater of €20 million or 4% of consolidated annual worldwide gross revenue under the GDPR or GBP 17.5 million under the UK GDPR). In addition to administrative fines, a wide variety of other potential enforcement powers are available to competent supervisory authorities in respect of potential and suspected violations of the GDPR or the UK GDPR, including extensive audit and inspection rights, and powers to order temporary or permanent bans on all or some processing of personal data carried out by non-compliant actors The GDPR and UK GDPR also confer a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies and obtain compensation for damages resulting from violations of the GDPR or the UK GDPR. Further, the exit of the UK from the EU and ongoing developments in the UK have created uncertainty regarding data protection regulation in the UK.

Certain legal developments in Europe have created complexity and uncertainty regarding transfers of personal data from the EEA to the United States, which will affect us if we begin to transfer personal data from the EEA to other jurisdictions. In July 2023, the European Commission adopted an adequacy decision in relation to the new EU-U.S. Data Privacy Framework, or DPF, rendering the DPF effective as a GDPR transfer mechanism for personal data transferred from the EEA to the United States by United States entities self-certified under the DPF. However, the DPF adequacy decisions do not foreclose, and are likely to face, future legal challenges and the ongoing legal uncertainty with respect to international data transfers may increase our costs and our ability to efficiently process personal data from the EEA. Other data transfer mechanisms such as the Standard Contractual Clauses approved by the European Commission have faced challenges in European courts, may require additional risk analysis and supplemental measures to be used, and may be challenged, suspended or invalidated. Loss of our ability to lawfully transfer personal data out of the EEA and UK to the United States or any other jurisdictions may require us to increase our data processing capabilities in the EEA and UK at significant expense. If we are otherwise unable to transfer personal data between and among countries and regions in which we operate, it could affect the manner in which we perform our operations or provide our services, the geographical location or segregation of our relevant systems and operations, and adversely affect our financial results. These international laws, rules and regulations may apply not only to us, but also to our collaborators, vendors or other third-party service providers that store

or otherwise process personal data on our behalf, such as information technology vendors, and any of the foregoing limitations could impact our ability to work with such collaborators or third-party service providers in certain jurisdictions.

We are bound by contractual obligations related to data privacy and cybersecurity, and our efforts to comply with such obligations may not be successful. For example, certain data privacy laws, such as the EU GDPR, the UK GDPR and the CCPA, require our customers to impose specific contractual restrictions on their service providers. We publish privacy policies, marketing materials and other statements, such as compliance with certain certifications or self-regulatory principles, regarding data privacy and cybersecurity. If these policies, materials or statements are found to be deficient, lacking in transparency, deceptive, unfair, or misrepresentative of our practices, we may be subject to investigation, enforcement actions by regulators or other adverse consequences.

Obligations related to data privacy and cybersecurity are quickly changing, becoming increasingly stringent, and creating regulatory uncertainty. Additionally, these obligations may be subject to differing applications and interpretations, which may be inconsistent or conflicting among jurisdictions. We are likely to be required to expend significant capital and other resources to ensure ongoing compliance with applicable data privacy and cybersecurity laws. Claims that we have violated individuals’ privacy rights or breached our contractual obligations or policies, even if we are not found liable, could be expensive and time-consuming to defend, and could result in adverse publicity that could harm our business. Moreover, even if we take all necessary action to comply with legal and regulatory requirements, we could be subject to data breaches or other unauthorized access of personal information or other sensitive or confidential information, which could subject us to fines and penalties, as well as litigation and reputational damage and other adverse consequences.

If we or our collaborators or our third-party service providers fail to keep apprised of and comply with applicable international, federal, state, or local regulatory requirements, we could be subject to a range of regulatory actions that could affect our or any collaborators’ ability to seek to commercialize our product candidates. Any threatened or actual governmental enforcement action or litigation where private rights of action are available could also generate adverse publicity, damage our reputation, result in liabilities, fines, and loss of business, and require that we devote substantial resources that could otherwise be used in other aspects of our business.

With laws, rules, regulations, and other obligations relating to data privacy and cybersecurity imposing new and relatively burdensome obligations, and with the substantial uncertainty over the interpretation and application of these and other obligations, we may face challenges in addressing their requirements and making necessary changes to our policies and practices and may incur significant costs and expenses in an effort to do so. We are currently in the process of developing and updating our policies and procedures in accordance with requirements under applicable data privacy and cybersecurity laws, rules and regulations and have not completed formal assessments of whether we are in compliance with all applicable data privacy and cybersecurity laws, rules and regulations. Additionally, if third parties with which we work, such as our collaborators, vendors or other third-party service providers, violate applicable laws, rules or regulations or our policies, such violations may also put our or our clinical trial and employee data, including personal or other sensitive or confidential information, at risk, and our business, financial condition, results of operations, and prospects may be adversely affected.

We are subject to certain U.S. and foreign export and import controls, sanctions, embargoes, anti-corruption laws, and anti-money laundering laws and regulations. Compliance with these legal standards could impair our ability to compete in domestic and international markets. We can face criminal liability and other serious consequences for violations, which can harm our business.

We are subject to export control and import laws and regulations, including the U.S. Export Administration Regulations, U.S. Customs regulations, various economic and trade sanctions regulations administered by the U.S. Treasury Department’s Office of Foreign Assets Controls, the U.S. Foreign Corrupt Practices Act of 1977, as amended, or FCPA, the U.S. domestic bribery statute contained in 18 U.S.C. § 201, the U.S. Travel Act, the USA PATRIOT Act, and other state and national anti-bribery and anti-money laundering laws in the countries in which we conduct activities. Anti-corruption laws are interpreted broadly and prohibit companies and their employees, agents, contractors, and other collaborators from authorizing, promising, offering, or providing, directly or indirectly, improper payments or anything else of value to recipients in the public or private sector.

We expect to have direct or indirect interactions with officials and employees of government agencies or government-affiliated hospitals, universities, and other organizations, and we expect our international activities to increase in time. We may engage third parties to conduct clinical trials, obtain necessary permits, licenses, patent registrations and other regulatory approvals or sell our products outside the United States, to conduct clinical trials, and/or to obtain necessary permits, licenses, patent registrations, and other regulatory approvals. We can be held liable for the corrupt or other illegal activities of our employees, agents, contractors, and other collaborators, even if we do not explicitly authorize or have actual knowledge of such activities. Any violations of the laws and regulations described above may result in substantial civil and criminal fines and penalties, imprisonment, the loss of

export or import privileges, debarment, tax reassessments, breach of contract and fraud litigation, reputational harm, and other consequences.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on our business.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes, including radioactive materials and gas. Our operations involve the use of hazardous and flammable materials, including chemicals and biological and radioactive materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties.

Our use of facilities that use and produce radioactive materials subjects us to compliance with decommissioning and decontamination, or D&D, requirements when we close those facilities, exposing us to potentially significant costs. Our product candidates are manufactured using radioactive components, such as the radioisotope 225Ac. When one of such facilities reaches the end of its useful life or if we need to abandon such facility for any other reason, we are obligated under the laws and regulatory rules of the various jurisdictions in which we operate to decommission and decontaminate such facility. We have no experience with D&D, and the costs of such D&D may be substantial. Estimating the amount and timing of such future D&D costs includes, among other factors, country-specific requirements and projections as to when a facility will retire or the useful life of a facility. If we do not conduct D&D properly at any of our sites, we may suffer significant additional costs to remediate any D&D deficiencies, fines, regulatory or criminal charges or other sanction or legal action, any of which could have a material adverse effect upon our business, financial condition and results of operations. Although we have estimated our future D&D costs and recorded a liability for such costs, there can be no assurances that we will not incur material D&D costs beyond such estimates or our provisions.

Although we maintain workers’ compensation insurance to cover us for costs and expenses, we may incur due to injuries to our employees resulting from the use of hazardous materials, and this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of biological, hazardous, or radioactive materials. In addition, we may incur substantial costs to comply with current or future environmental, health and safety laws and regulations. Current or future environmental laws and regulations may impair our research, development, and production efforts, which could harm our business, financial condition, results of operations or prospects.

Risks related to manufacturing

We intend to build and operate our own manufacturing facility for preclinical and clinical supply needs, which will require significant resources, and we may fail to successfully establish and operate our facility, which could adversely affect our clinical trials and the commercial viability of our product candidates.

We are currently establishing and building a manufacturing facility, in addition to our reliance on CDMOs for the manufacture of our product candidates for preclinical and clinical needs. We expect that construction of our own manufacturing facility will provide us with enhanced control of material supply for preclinical studies and clinical trials, enable the more rapid implementation of process changes, and allow for better long-term cost efficiencies. However, we have no experience as a company in construction of a manufacturing facility and may never be successful in building our own manufacturing facility or capability. As a result, we will also need to hire additional personnel to manage our operations and facilities and develop the necessary infrastructure to continue the research and development and manufacture of our product candidates. We, as a company, have no experience in setting up, building, or eventually managing a manufacturing facility. If we fail to complete the planned construction and buildout in an efficient manner, or fail to recruit the required personnel and generally manage our growth effectively, the development and production of our product candidates could be curtailed or delayed. Even if we are successful, our manufacturing capabilities could be affected by cost-overruns, unexpected delays, equipment failures, labor shortages, natural disasters, power failures and numerous other factors that could prevent us from realizing the intended benefits of our manufacturing strategy and have a material adverse effect on our business. Furthermore, if we are successful in building our own manufacturing facility, we will continue to be reliant on our CDMOs for clinical and commercial supply, if our product are approved, and their continued compliance with relevant regulations.

In addition, the FDA, the EMA, and other foreign regulatory authorities may require us to submit samples of any lot of any approved product together with the protocols showing the results of applicable tests at any time. Under some circumstances, the FDA, the EMA, or other foreign regulatory authorities may require that we not distribute a lot until the relevant agency authorizes its release. Slight deviations in the manufacturing process, including those affecting quality attributes and stability, may result in unacceptable changes in the product that could result in lot failures or product recalls. Lot failures or product recalls could cause us to delay product launches or clinical trials, which could be costly to us and otherwise harm our business, financial condition, results

of operations, and prospects. Problems in our manufacturing process could restrict our ability to meet clinical and market demand for our products.

Any problems in our manufacturing process or facilities could make us a less attractive collaborator for potential partners, including larger pharmaceutical companies and academic research institutions, which could limit our access to additional attractive development programs.

Our product candidates are biologics and the manufacture of our product candidates is complex. Even after our planned manufacturing facility is operating, we will continue to rely on third parties to manufacture our product candidates. Our business could be harmed if those third parties fail to provide us with sufficient quantities of product supplies or product candidates, or fail to do so at acceptable quality levels or prices.

Our product candidates are biologics and the process of manufacturing them is complex, highly regulated and subject to multiple risks. As a result of these complexities, the cost to manufacture biologics is generally higher than traditional small molecule chemical compounds, and the manufacturing process for biologics is less reliable and is more difficult to reproduce. In addition, manufacturing our product candidates will require many reagents, which are substances used in our manufacturing processes to bring about chemical or biological reactions, and other specialty materials and equipment, some of which are manufactured or supplied by small companies with limited resources and experience to support commercial biologics production. Even minor deviations from normal manufacturing processes could result in reduced production yields, product defects, and other supply disruptions. If microbial, viral or other contaminations are discovered in our product candidates or in the manufacturing facilities in which our product candidates are made, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination. We have experienced manufacturing deviations and similar issues in the past, and may experience similar issues in the future. We cannot assure you that any stability failures or other issues relating to the manufacture of our product candidates will not occur in the future. Any such issues could cause delays in our development plans. Further, as product candidates are developed through preclinical to late-stage clinical trials towards approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods, are altered along the way in an effort to optimize processes and results. Such changes carry the risk that they will not achieve these intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials.

Even if we are able to complete our manufacturing facility, we will continue to rely on U.S.-based third-party manufacturers or third-party collaborators for the manufacture of our product candidates and for commercial supply of any of our product candidates for which we or any of our potential future collaborators obtain marketing approval. We may be unable to maintain agreements with our existing third-party manufacturers, or to establish additional agreements with third-party manufacturers or to do so on acceptable terms. Even if we are able to establish agreements with third-party manufacturers, reliance on third-party manufacturers entails additional risks, including:

Our third-party manufacturers and clinical reagent suppliers may be subject to regulatory requirements or sanctions, as well as damage or interruption from, among other things, fire, natural or man-made disaster, power loss, telecommunications failure, unauthorized entry, computer viruses, denial-of-service attacks, acts of terrorism, human error, vandalism or sabotage, financial insolvency, bankruptcy and similar events.

We currently engage WuXi Biologics (Hong Kong) Limited, or WuXi, with respect to the manufacture of miniprotein variants and recombinant production and pharmacokinetic studies unrelated to [225Ac]Ac-AKY-1189 and [225Ac]Ac-AKY-2519. Certain Chinese biotechnology companies and CMOs, including WuXi, may in the future become subject to trade restrictions, sanctions, and other regulatory requirements by the U.S. government, which could restrict or even prohibit our ability to work with such entities, thereby potentially disrupting the supply of material to us. The recently proposed BIOSECURE Act would have banned U.S. government contracts, grants, and loans from being used towards biotechnology equipment and services produced or provided by certain named Chinese biotechnology companies, including WuXi, and would authorize the U.S. government to name additional Chinese biotechnology companies of concern. The legislation did not pass the U.S. Congress in 2024; however, on December 18, 2025, the BIOSECURE Act was passed as part of the final Fiscal Year 2026 National Defense Authorization Act. Although the newly passed act does not explicitly name WuXi, or any other companies in the statute, the BIOSECURE Act bans federal procurement or funding associated with “biotechnology companies of concern” and restricting use of their equipment and services in federal contracts, grants, and loans. The implementation of the act will be phased in over a period of years, and could severely restrict the ability of companies to work with certain Chinese biotechnology companies of concern without losing the ability to contract with, or otherwise receive funding from, the U.S. government.

The new administration has substantially altered prior U.S. government international trade policy and has commenced activities to renegotiate, or potentially terminate, certain existing bilateral or multi-lateral trade agreements and treaties with foreign countries. In addition, the new administration has initiated or is considering imposing tariffs on certain foreign goods. Related to this action, certain foreign governments, including China, have instituted or are considering imposing tariffs on certain U.S. goods. It remains unclear what the new policies by the U.S government or foreign governments will or will not do with respect to tariffs or other international trade agreements and policies. A trade war or other governmental action related to tariffs or international trade agreements or policies has the potential to disrupt our research activities, affect our suppliers, increase the cost of materials purchased to manufacture our products, impact our ability to sell our products outside the U.S. or to sell our products outside the U.S. at competitive prices and/or to affect the U.S. or global economy or certain sectors thereof and, thus, could adversely impact our business.

If the third parties we engage to supply materials or manufacture product candidates or products for preclinical testing or clinical or commercial supply should cease to do so for any reason, we would likely experience delays in advancing these preclinical tests and clinical trials and/or interruptions in commercial supply while we identify and qualify replacement suppliers or manufacturers, and we may be unable to obtain replacement supplies on terms that are favorable to us, or at all. If we are not able to obtain adequate supplies of our product candidates or products or the substances used to manufacture them, it could materially and adversely impact our business, prospects, operating results or financial condition.

Each of these risks could delay or prevent the completion of our ongoing and future clinical trials or the approval of any of our product candidates by the FDA, result in higher costs or adversely impact commercialization of our product candidates. Any shortages in the supply of such raw materials used in the manufacture of our product candidates could delay or prevent the completion of our clinical trials or the approval of any of our product candidates by the FDA, result in higher costs or adversely impact commercialization of our product candidates. In addition, we may rely on third parties to perform certain specification tests on our product candidates prior to delivery to patients. If these tests are not appropriately done and test data are not reliable, patients could be put at risk of serious harm and the FDA could place significant restrictions on our company until deficiencies are remedied.

The facilities used by our contract manufacturers to manufacture our product candidates may be subject to inspections that will be conducted after we submit our BLA to the FDA. We do not have complete control over all aspects of the manufacturing process of, and are dependent on, our contract manufacturing partners for compliance with cGMP regulations. Any product candidates that we may develop may compete with product candidates of other companies for access to manufacturing facilities. There are a limited number of manufacturers that operate under cGMP regulations and that might be capable of manufacturing for us. Our failure, or the failure of our third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on us, including fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of product candidates or products, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of our products and harm our business and results of operations.

Our contract manufacturers’ failure to achieve and maintain high manufacturing standards, in accordance with applicable regulatory requirements, or the incidence of manufacturing errors, could result in patient injury or death, product shortages, product recalls or withdrawals, delays or failures in product testing or delivery, cost overruns or other problems that could seriously harm our business. Contract manufacturers often encounter difficulties involving production yields, quality control and quality assurance, as well as shortages of qualified personnel.

We may be unable to obtain a sufficient supply of 225Ac or other radioisotopes to support clinical development or manufacturing at commercial scale.

225Ac is a key component of [225Ac]Ac-AKY-1189 and [225Ac]Ac-AKY-2519 and, as a radiopharmaceutical company, we expect our future product candidates to include 225Ac or other isotopes. Although we believe our present suppliers have adequate quantities of 225Ac and labeling isotopes available to meet our current needs, we may encounter supply shortages which could affect our business operations and results of operations. There can be no assurance that our suppliers will renew the contracts on acceptable terms, or at all. Further, long-term suppliers are not yet producing beyond minimal research quantities and there is no guarantee they will come online in the time frame we expect. Even when a contract exists, we have very limited recourse under our current supply contracts if a supplier is unable to meet its obligations. Suppliers may be unable to meet their obligations for a number of reasons, for example, the U.S. Department of Energy has reserved its ability to cancel private orders when the supply is instead needed for national defense, environmental safety or there is a lack of capacity, and the likelihood of any such cancellation may be increased for a number of reasons. There are not many alternatives to our current suppliers, and finding any replacement suppliers would divert management resources. Failure to acquire enough medical-grade 225Ac would make it impossible to effectively complete clinical trials, especially as we scale up for later-stage clinical trials, and to commercialize any 225Ac-based product candidates that we may develop and would materially harm our business.

To date, we have obtained the 225Ac for our ongoing Phase 1b clinical trial of [225Ac]Ac-AKY-1189 from several United States and foreign-based suppliers pursuant to long-term supply agreements. In the event we are unable to source 225Ac from our current suppliers, we may seek to source 225Ac from other sources, including those located in Russia. This could expose us to additional environmental and geopolitical risks, including restrictions on trade of certain items between the United States and Russia, and other unforeseen geopolitical factors that limit our ability to access our supply of raw material. For example, any Russian supplier may become designated on export-or sanctions-related restricted party lists maintained by the U.S. government. Our ability to conduct clinical trials to advance our product candidates is dependent on our ability to obtain these radioisotopes and other isotopes we may choose to utilize in the future. We expect to remain dependent on third-party manufacturers and suppliers for our isotopes. These parties may not perform their contracted services or may breach or terminate their agreements with us. Our suppliers are subject to regulations and standards that are overseen by regulatory and government agencies and we have no control over our suppliers’ compliance to these standards. Failure to comply with regulations and standards may result in their inability to supply isotope could result in delays in our clinical trials, which could have a negative impact on our business. Our inability to build out and establish our own manufacturing facilities would require us to continue to rely on third-party suppliers, as we currently do.

Changes in the methods of manufacturing or formulation of our product candidates may result in additional costs or delay.

As our product candidates progress through clinical trials to regulatory approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods and formulation, may be altered along the way in an effort to optimize safety, efficacy, yield, and manufacturing batch size, minimize costs, and achieve consistent quality and results. There can be no assurance that any future manufacturing or formulation changes will achieve their intended objectives. These changes and any future changes we may make to our product candidates may also cause such candidates to perform differently and affect the results of future clinical trials conducted with the altered materials. Such changes or related unfavorable clinical trial results could delay initiation or completion of additional clinical trials, require the conduct of bridging studies or clinical trials or the repetition of one or more studies or clinical trials, increase development costs, delay or prevent potential regulatory approval, and jeopardize our ability to commercialize our product candidates, if approved, and generate revenue.

Risks related to related to our dependence on third parties

We rely on third parties to conduct the Phase 1b clinical trial of [225Ac]Ac-AKY-1189 and plan to rely on third parties to conduct our future clinical trials. If these third parties do not properly and successfully carry out their contractual duties or meet expected deadlines, we may not be able to obtain regulatory approval of or commercialize our product candidates.

We depend and will continue to depend on independent investigators and collaborators, such as medical institutions, CROs, CMOs, CDMOs, and strategic partners to conduct our preclinical studies and clinical trials, including with respect to our ongoing Phase 1b clinical trial for [225Ac]Ac-AKY-1189. We expect to have to negotiate budgets and contracts with CROs, CDMOs, CMOs and trial sites which may result in delays to our development timelines and increased costs. We will rely heavily on these third parties over the course of our clinical trials, and we control only certain aspects of their activities. As a result, we will have less direct control over the conduct, timing and completion of these clinical trials and the management of data developed through clinical trials than would be the case if we were relying entirely upon our own staff. Nevertheless, we are responsible for ensuring that each of our studies is conducted in accordance with applicable protocol, legal and regulatory requirements and scientific standards, and our reliance on third parties does not relieve us of our regulatory responsibilities. We and these third parties are required to comply with GCPs. Regulatory authorities enforce these GCPs through periodic inspections of trial sponsors, principal investigators and trial sites. If we or any of these third parties fail to comply with applicable GCP regulations, the clinical data generated in our clinical trials may be deemed unreliable and the FDA or similar foreign regulatory authorities may require us to perform additional clinical trials before approving our marketing applications. We cannot assure you that, upon inspection, such regulatory authorities will determine that any of our clinical trials comply with the GCP regulations. In addition, our clinical trials must be conducted with biologic product produced under cGMP regulations, and will require a large number of patients. Our failure or any failure by these third parties to comply with these regulations or to recruit a sufficient number of patients may require us to repeat clinical trials, which would delay the regulatory approval process. Moreover, our business may be implicated if any of these third parties violates federal or state fraud and abuse or false claims laws and regulations or healthcare privacy and security laws.

Any third parties conducting our clinical trials are not and will not be our employees and, except for remedies available to us under our agreements with such third parties, we cannot control whether or not they devote sufficient time and resources to our ongoing, clinical and preclinical product candidates. These third parties may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical trials or other product development activities, which could affect their performance on our behalf. If these third parties do not successfully carry out their contractual duties or obligations or meet expected deadlines, if they need to be replaced or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to our clinical protocols or regulatory requirements or for other reasons, our clinical trials may be extended, delayed or terminated and we may not be able to complete development of, obtain regulatory approval of or successfully commercialize our product candidates. As a result, our financial results and the commercial prospects for our product candidates would be harmed, our costs could increase and our ability to generate revenue could be delayed.

As a result of the bankruptcy of one our CROs in 2025, we migrated to another provider. Switching or adding third parties to conduct our clinical trials or preclinical studies involves substantial cost and requires extensive management time and focus and may ultimately be unsuccessful. In addition, there is a natural transition period when a new third party commences work. As a result, delays occur, which can materially impact our ability to meet our desired clinical development timelines.

We have in place certain collaboration and licensing arrangements, and may form or seek collaborations, strategic alliances or licensing arrangements in the future, and we may not realize the benefits of such collaborations, alliances or licensing arrangements.

We have in place certain collaboration and licensing arrangements, and in the future, we may form or seek strategic alliances, create joint ventures or collaborations, or enter into additional licensing arrangements with third parties that we believe will complement or augment our development and commercialization efforts with respect to our product candidates and any future product candidates that we may develop. For example, in May 2024, we entered into a research, collaboration and license agreement with Eli Lilly to discover and generate novel tumor-targeting radiopharmaceuticals. For more information on this and other arrangements, see “Business—License and collaboration agreements.” Any of these current or future relationships may require us to incur non-recurring and other charges, increase our near and long-term expenditures, issue securities that dilute our existing shareholders or disrupt our management and business. We cannot guarantee you that our current or future partners will not terminate their collaboration, or seek to change terms of the collaboration, with us.

In addition, we face significant competition in seeking appropriate strategic partners and the negotiation process is time-consuming and complex. Whether we reach a definitive agreement for a collaboration will depend, among other things, upon our assessment of the collaborator’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator’s evaluation of a number of factors. These factors may include the design or results of clinical trials, the likelihood of approval by the FDA or applicable foreign regulatory authorities, the potential market for the subject product candidate, the costs and complexities of manufacturing and delivering such product candidate to patients, the potential of competing products and the existence of uncertainty with respect to its ownership of technology, which can exist if there is a challenge to such ownership without regard to the merits of the challenge and industry and market conditions generally. Moreover, we may not be successful in our efforts to establish a strategic partnership or other alternative arrangements for our product candidates because they may be deemed to be at too early of a stage of development for collaborative effort and third parties may not view our product candidates

as having the requisite potential to demonstrate safety, potency and purity and obtain marketing approval. In certain cases, when we collaborate with a third party for the development and commercialization of a product candidate, we can expect to relinquish some or all of the control over the future success of that product candidate to the third party.

Collaborations are complex and time-consuming to negotiate and document. In addition, there have been a significant number of business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators.

Further, collaborations involving our product candidates are subject to numerous risks, which may include the following:

As a result, we may not be able to realize the benefit of our current or future collaborations, joint ventures, strategic partnerships or licensing arrangements if we are unable to successfully integrate them with our existing operations and company culture, which could delay our timelines or otherwise adversely affect our business. If our existing or future collaborations are terminated or suspended, we may not be able to identify other suitable collaborators or reach agreement with other suitable collaborators on a timely basis, on acceptable terms or at all. If we are unable to continue our current or future collaborations or are unable to identify or reach agreement with other suitable collaborators, we may have to curtail the development of a product candidate, reduce or delay its development program or one or more of our other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, increase our expenditures or needs for additional capital to pursue further development or commercialization of the applicable product candidates or undertake development or commercialization activities at our own expense. If we fail to enter into collaborations and do not have sufficient funds or expertise to undertake the necessary development and commercialization activities, we may not be able to further develop our product candidates or bring them to market and generate product sales revenue, which would harm our business prospects, financial condition and results of operation. We also cannot be certain that, following a strategic transaction or license, we will achieve the revenue or specific net income that justifies such transaction. Any delays in entering into new collaborations or strategic partnership agreements related to our product candidates could delay the development and commercialization of our product candidates in certain geographies for certain indications. Any of the foregoing could have a material adverse effect on our business, prospects, financial condition and results of operations.

If we or third parties, such as CROs, CDMOs, CMOs, use hazardous and biological materials in a manner that causes injury or violates applicable law, we may be liable for damages.

Our research and development activities may involve the controlled use of potentially hazardous substances, including chemicals and biological and radioactive materials, by us or third parties, such as CROs, CDMOs and CMOs. The use of 225Ac-labeled miniproteins treatments involves the inherent risk of exposure from gamma ray emissions, which can alter or harm healthy cells in the body. We and such third parties are subject to federal, state, provincial and local laws and regulations in the United States and other foreign jurisdictions governing the use, manufacture, storage, handling, and disposal of medical and hazardous materials. Although we believe that our and such third-parties’ procedures for using, handling, storing and disposing of these materials comply with legally prescribed standards, we cannot completely eliminate the risk of contamination or injury resulting from medical or hazardous materials. As a result of any such contamination or injury, we may incur liability or local, city, state, provincial or federal authorities may curtail the use of these materials and interrupt our business operations. In the event of an accident, we could be held liable for damages or penalized with fines, and the liability could exceed our resources. Compliance with applicable environmental laws and regulations is expensive, and current or future environmental regulations may impair our research, development and production efforts, which could harm our business, prospects, financial condition, or results of operations. We currently maintain insurance coverage for injuries resulting from the hazardous materials we use; however, future claims may exceed the amount of our coverage. Also, we do not have insurance coverage for pollution cleanup and removal. Currently the costs of complying with such federal, state, provincial, local and foreign environmental regulations are not significant, and consist primarily of waste disposal expenses. However, they could become expensive, and current or future environmental laws or regulations may impair our research, development, production and commercialization efforts.

Our employees, independent contractors, principal investigators, consultants, commercial partners, and vendors may engage in misconduct or other improper activities, including non-compliance with regulatory standards and requirements.

We are exposed to the risk of employee fraud or other misconduct. We cannot ensure that our compliance controls, policies, and procedures will in every instance protect us from acts committed by our employees, agents, contractors, directors or collaborators that would violate the laws or regulations of the jurisdictions in which we operate, including, without limitation, employment, foreign corrupt practices, trade restrictions and sanctions, environmental, competition, securities, and patient privacy and other privacy laws and regulations. Misconduct by employees could include failures to comply with FDA regulations and equivalent foreign regulations, provide accurate information to the FDA or competent foreign regulatory authorities, comply with manufacturing standards we may establish, comply with federal and state or national healthcare fraud and abuse laws and regulations, report financial information or data accurately, or disclose unauthorized activities to us. Sales, marketing, and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing, and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, labeling, marketing and promotion, sales commission, customer incentive programs, and other business arrangements. Employee misconduct could also involve the improper use of information obtained during clinical trials, which could result in regulatory sanctions and serious harm to our reputation. In addition, our reputation may be harmed if any of our employees, directors, independent contractors, principal investigators or consultants are found to have been involved in similar misconduct outside of their services to our Company. It is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with such laws or regulations.

If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a material and adverse effect on our business, financial condition, results of operations and prospects, including the imposition of significant civil, criminal and administrative penalties, damages, monetary fines, individual imprisonment, disgorgement of profits, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs or equivalent foreign programs, contractual damages, reputational harm, diminished profits and future earnings, additional reporting or oversight obligations if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with the law, and curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business or pursue our strategy.

Risks related to intellectual property

We do not own or expect to own any issued patents relating to the radioactive payload, 225Ac, used in our product candidates, including [225Ac]Ac-AKY-1189 and [225Ac]Ac-AKY-2519.

We do not own or license, and do not expect to own or license, any patents or patent applications that cover the radioactive payload, 225Ac, in our product candidates. Composition-of-matter patent claims in pharmaceutical products are generally considered to be the favored form of intellectual property protection for products because such patents may provide protection without regard to any particular method of use or manufacture or formulation of the composition of matter used. For example, formulation and method-of-use patent claims do not prevent a competitor or other third party from marketing an identical radioactive payload for an indication that is outside the scope of the method claims or from developing a different formulation that is outside the scope of the formulation claims.

With respect to AKY-1189, as of March 1, 2026, we own one patent family, including one pending Patent Cooperation Treaty, or PCT, Application, one issued U.S. patent, one pending U.S. non-provisional application, and two pending ex-US non-provisional patent applications directed to composition of matter of AKY-1189 and methods of use. With respect to AKY-2519, as of March 1, 2026, we own one patent family, including one pending PCT Application, one pending U.S. non-provisional application, and two pending ex-U.S. non-provisional patent applications directed to composition of matter of AKY-2519 and methods of use. We cannot predict whether our patent applications will result in the issuance of any patents that provide us with any competitive advantage. We have one issued patent relating to our product candidates, in particular, AKY-1189, and do not currently have any issued patents relating to AKY-2519. It is also possible that others will design around any future patents we may obtain. Further, any future patents we obtain may not be sufficiently broad to prevent others from using our technology or from developing competing products and technologies. In addition, any future patents we obtain may be narrowed or found to be invalid or unenforceable.

Any patent that issues from national stage entries of the aforementioned pending PCT application or either of the two foreign patent applications and any future non-provisional patent applications that we may file claiming priority to these patent applications are expected to expire in 2044, excluding any patent term adjustments and extensions that may be available. We cannot be certain that we will obtain issued patents based on our current and future patent applications, and if obtained, whether they can provide meaningful protection for our product candidates or any future product candidates or whether they will remain in force through their expected expiration date. If we do not obtain and maintain meaningful patent coverage for our product candidates, their respective components, formulations, combination therapies, methods of manufacture, and methods of treatment, competitors may be able to erode or negate any competitive advantage we may have, which would likely harm our business and ability to achieve profitability. Any of the foregoing events could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Our success depends on our ability to obtain, maintain, enforce, defend and protect our intellectual property and our proprietary technologies, and conduct our business without infringing, misappropriating or otherwise violating intellectual property or proprietary rights of others.

Our commercial success depends, in part, on our ability to obtain, maintain, enforce, defend and protect our intellectual property rights, including patent protection and trade secret protection for our product candidates, proprietary technologies and their uses as well as our ability to operate without infringing upon, misappropriating or otherwise violating the proprietary rights of others. We generally seek to protect our proprietary position by filing patent applications in the United States and abroad related to our product candidates, proprietary technologies and their uses that are important to our business. We may also seek to protect our proprietary position by acquiring or in-licensing relevant issued patents or pending patent applications or other intellectual property or proprietary rights from third parties. If we or our current or future licensors are unable to obtain or maintain patent protection with respect to our product candidates and other proprietary technologies we may develop, it could have a material adverse effect on our business, financial condition, results of operations and prospects.

Pending patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless, and until, patents issue from such applications, and then only to the extent the issued claims cover the technology. Our owned and in-licensed patent portfolio is at an early stage. We currently own one issued patent relating to one of our product candidates, [225Ac]Ac-AKY-1189. We do not currently own or in-license any other issued patents relating to any product candidates, including [225Ac]Ac-AKY-1189, or otherwise. There can be no assurance that our patent applications or the patent applications of our current or future licensors will result in patents being issued or that issued patents will afford sufficient protection against competitors or other third parties with similar technology, nor can there be any assurance that the patents issued will not be infringed, designed around or invalidated by third parties.

Even issued patents may later be found invalid or unenforceable or may be modified or revoked in proceedings instituted by third parties before various patent offices or in courts in the United States and abroad. The degree of future protection for our and our licensors’ intellectual property or other proprietary rights is uncertain. Only limited protection may be available and may not adequately protect our rights or permit us to gain or keep any competitive advantage. These uncertainties and/or limitations in our ability to properly protect the intellectual property or other proprietary rights relating to our product candidates could have a material adverse effect on our business, financial condition, results of operations and prospects.

As of June 1, 2023, European applications have the option, upon grant of a patent, of becoming a Unitary Patent which will be subject to the jurisdiction of the Unitary Patent Court, or UPC. This is a significant change in European patent practice. As the UPC is a new court system, there is no precedent for the court, increasing the uncertainty of any litigation.

We cannot be certain that the claims in our U.S. pending patent applications, our pending international patent applications and any patent applications that we may file in the future in the United States or foreign territories, or those of our current or future licensors, will be considered patentable by the United States Patent and Trademark Office, or USPTO, courts in the United States or by the patent offices and courts in foreign countries, nor can we be certain that the claims in our future issued patents will not be found invalid or unenforceable if challenged. Even if they are unchallenged, our owned and licensed patent applications, and any patents we obtain, may not provide us with any meaningful protection or prevent competitors from designing around our patent claims to circumvent our owned or licensed patents by developing similar or alternative technologies in a non-infringing manner. If the patent protection provided by the patent applications we own or license and any patents we obtain is not sufficiently broad to

impede such competition, our ability to successfully commercialize our product candidates could be negatively affected, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

The patent application process is subject to numerous risks and uncertainties, and there can be no assurance that we or any of our potential future collaborators will be successful in protecting our product candidates by obtaining, maintaining, enforcing, protecting and defending patents. These risks and uncertainties include the following:

The patent prosecution process is expensive, time-consuming and complex, and we and any current or future licensors may not be able to file, prosecute, maintain, enforce, protect, defend or license all necessary or desirable patent applications at a reasonable cost or in a timely manner or in all jurisdictions where protection may be commercially advantageous. We may not be able to obtain or maintain patent applications and patents due to the subject matter claimed in such patent applications and patents being in disclosures in the public domain. It is also possible that we or any current or future licensors will fail to identify patentable aspects of our research and development output before it is too late to obtain patent protection.

In addition, although we enter into non-disclosure and confidentiality agreements with parties who have access to confidential or patentable aspects of our research and development output, such as our employees, outside scientific collaborators, CROs, third-party manufacturers, consultants, advisors and other third parties, any of these parties may breach such agreements and disclose such output before a patent application is filed, thereby jeopardizing our ability to obtain or maintain valid and enforceable patent protection. Furthermore, publications of discoveries in the scientific literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing or until issuance, or in some cases not at all. Therefore, we cannot be certain that we or our licensors were the first to make the inventions claimed in any of our owned or licensed patents or pending patent applications, or that we or our licensors were the first to file for patent protection of such inventions. If a third party can establish that we or our licensors were not the first to make or the first to file for patent protection of such inventions, our owned or licensed patent applications may not issue as patents and even if issued, may be challenged and invalidated or rendered unenforceable.

In addition, given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, our intellectual property may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours. Any of the foregoing events could have a material adverse effect on our business, financial condition, results of operations, and prospects.

If the scope of any patent protection we obtain is not sufficiently broad, or if we lose any of our patent protection, our ability to prevent our competitors from commercializing similar or identical product candidates would be adversely affected.

The patent position of biotechnology and pharmaceutical companies generally is highly uncertain, involves complex legal and factual questions, and has been the subject of much litigation in recent years. As a result, the issuance, scope, validity, enforceability, and commercial value of our patent rights are highly uncertain. Our pending and future patent applications and those of our current or future licensors may not result in patents being issued which protect our product candidates and other proprietary technologies we may develop, or which effectively prevent others from commercializing competitive technologies and product candidates.

Moreover, the coverage claimed in a patent application can be significantly reduced before the corresponding patent is issued, and its scope can be reinterpreted after issuance. Even if patent applications we own or in-license issue as patents in the future, they may not issue in a form that will provide us with any meaningful protection, prevent competitors or other third parties from competing with us, or otherwise provide us with any competitive advantage. Any patents that we in the future own, or in-license,

may be challenged or circumvented by third parties or may be narrowed or invalidated as a result of challenges by third parties. Consequently, we do not know whether our product candidates or other proprietary technology will be protectable or remain protected by valid and enforceable patents. Even if a patent issues, our competitors or other third parties may be able to circumvent our patents or the patents of our current or future licensors by developing similar or alternative technologies or products in a non-infringing manner which could materially adversely affect our business, financial condition, results of operations and prospects.

The issuance of a patent is not conclusive as to its inventorship, scope, validity or enforceability, and our patents, if issued, or the patents of our current or future licensors may be challenged in the courts or patent offices in the United States and abroad. We or any of our licensors may be subject to a third-party pre-issuance submission of prior art to the USPTO, or become involved in opposition, derivation, revocation, reexamination, post-grant review, or PGR, and inter partes review, or IPR, or other similar proceedings challenging our patent rights. An adverse determination in any such submission, proceeding or litigation could reduce the scope of, or invalidate or render unenforceable, our patent rights, allow third parties to commercialize our product candidates and compete directly with us, without payment to us, or result in our inability to manufacture or commercialize products without infringing, misappropriating or otherwise violating third-party patent rights. Moreover, our future patents or the patents of our current or future licensors may become subject to post-grant challenge proceedings, such as oppositions in a foreign patent office, that challenge our priority of invention or other features of patentability with respect to our patents, if issued, and patent applications or those of our current or future licensors. Such challenges may result in loss of patent rights, loss of exclusivity or in patent claims being narrowed, invalidated, or held unenforceable, which could limit our ability to stop others from using or commercializing similar or identical technology and products, or limit the duration of the patent protection of our product candidates. Such proceedings also may result in substantial cost and require significant time from our scientists and management, even if the eventual outcome is favorable to us. In addition, if the breadth or strength of protection provided by our patents, if issued, and patent applications or those of our current or future licensors is threatened, regardless of the outcome, it could dissuade companies from collaborating with us to license, develop or commercialize current or future product candidates.

Moreover, some of our patent applications and future patents are, and may in the future be, co-owned with third parties. If we are unable to obtain an exclusive license to any such third-party co-owners’ interest in such patents and patent applications, such co-owners may be able to license their rights to other third parties, including our competitors, and our competitors could market competing products and technology. In addition, we may need the cooperation of any such co-owners of such patents in order to enforce such patents against third parties, and such cooperation may not be provided to us. Any of the foregoing, could have a material adverse effect on our competitive position, business, financial condition, results of operations and prospects.

We may not be able to obtain and protect our intellectual property rights throughout the world.

Patents are of national or regional effect. Filing, prosecuting, maintaining, enforcing, protecting and defending patent rights and other proprietary rights on all of our research programs and product candidates in all countries throughout the world would be prohibitively expensive, and our intellectual property rights in some countries outside the United States can be less extensive than those in the United States. In some cases, we or our licensors may not be able to obtain patent protection for certain technology outside the United States. In addition, the laws of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the United States. Consequently, we may not be able to prevent third parties from practicing our or our licensors’ inventions in all countries outside the United States, even in jurisdictions where we or our licensors do pursue patent protection, or from selling or importing products made using our or our licensors’ inventions in and into the United States or other jurisdictions. Competitors or other third parties may use our technologies in jurisdictions where we and our licensors have not pursued and obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the United States. These products may compete with our product candidates, and our and our licensors’ patent applications, if issued, or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Various companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of many countries do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to pharmaceuticals and biotechnology products, which could make it difficult for us to stop the infringement of our patents, if issued, or marketing of competing products in violation of our intellectual property and proprietary rights. In addition, some jurisdictions, such as the Europe, Japan, and China, may have a higher standard for patentability than in the United States, including, for example, the requirement of claims having literal support in the original patent filing and the limitation on using supporting data that is not in the original patent filing. Under those heightened patentability requirements, we may not be able to obtain sufficient patent protection in certain jurisdictions even though the same or similar patent protection can be secured in the United States and other jurisdictions.

Proceedings to enforce our or our licensors’ intellectual property and proprietary rights in the United States and foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patent rights at risk of being invalidated or interpreted narrowly, could put our owned or in-licensed patent applications at risk of not issuing and could provoke third parties to assert claims against us. We or our licensors may not prevail in any lawsuits that we or our licensors initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property and proprietary rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

Various countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In addition, many countries limit the enforceability of patents against government agencies or government contractors. As a result, a patent owner in these countries may have limited remedies in certain circumstances, which could materially diminish the value of such patent. If we or any of our licensors are forced to grant a license to third parties with respect to any patent rights relevant to our business, our competitive position may be impaired, and our business, financial condition, results of operations and prospects may be adversely affected. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

Geo-political actions in the United States and in foreign countries could increase the uncertainties and costs surrounding the prosecution or maintenance of our patent applications or those of any current or future licensors and the maintenance, enforcement or defense of our future issued patents or those of any current or future licensors. For example, the United States and foreign government actions related to Russia’s invasion of Ukraine may limit or prevent filing, prosecution and maintenance of patent applications in Russia. Government actions may also prevent maintenance of issued patents in Russia. These actions could result in abandonment or lapse of any future patents or patent applications in Russia, resulting in partial or complete loss of patent rights in Russia. In addition, a decree was adopted by the Russian government in March 2022, allowing Russian companies and individuals to exploit inventions owned by patentees that have citizenship or nationality in, are registered in, or have predominately primary place of business or profit-making activities in the United States and other countries that Russia has deemed unfriendly without consent or compensation. Consequently, we would not be able to prevent third parties from practicing our inventions in Russia or from selling or importing products made using our inventions in and into Russia. Accordingly, our competitive position may be impaired, and our business, financial condition, results of operations and prospects may be adversely affected.

Further, the standards applied by the USPTO and foreign patent offices in granting patents are not always applied uniformly or predictably. As such, we do not know the degree of future protection that we will have on our technologies and product candidates. While we will endeavor to try to protect our technologies and product candidates with intellectual property rights such as patents, as appropriate, the process of obtaining patents is time consuming, expensive, and unpredictable. Any of the foregoing events could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Obtaining, maintaining, enforcing, protecting and defending our patent protection depends on compliance with various procedural, documentary, fee payment and other requirements imposed by regulations and governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance fees, renewal fees, annuity fees and various other governmental fees on patents and patent applications will be due to be paid to the USPTO and various foreign patent agencies at various stages over the lifetime of our owned or licensed patent rights. We have systems in place to remind us to pay these fees, and we rely on our outside counsel and its outside patent annuity service to pay these fees when due. In addition, the USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. We are also dependent on our licensors to take the necessary action to comply with these requirements with respect to our licensed intellectual property. We seek to employ reputable law firms and other professionals to help us comply with these provisions. In many cases, an inadvertent lapse can be cured by payment of a late fee or by other means in accordance with the applicable rules. However, there are situations in which non-compliance can result in abandonment or lapse of a patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction, including as a result of failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. In such an event, potential competitors might be able to enter the market. Our ability to comply with the various procedural, documentary, fee payment and other requirements imposed by regulations and governmental patent agencies could also be reduced or eliminated in the event of natural disasters, pandemics, or other catastrophic events. If such an event were to occur, including with respect to the patent rights covering our research programs and product candidates, as well as their respective methods of use, manufacture, and formulations thereof, it could have a material adverse effect on our business, financial condition, results of operations and prospects, as for example, competitors might be able to enter the market earlier than would otherwise have been the case.

Patent terms may be inadequate to protect our competitive position on our product candidates for an adequate amount of time.

Patents have a limited lifespan. In the United States, if all maintenance fees are timely paid, the natural expiration of a patent is generally 20 years from its earliest U.S. non-provisional application filing date. Various extensions may be available, but the life of a patent, and the protection it affords, is limited. Even if patents covering our product candidates are obtained, once the patent life has expired, we may be open to competition from competitive products. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, our owned or licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours, which would have a material adverse effect on our business, financial condition, results of operations, and prospects.

Changes in U.S. patent law, or laws in other countries, could diminish the value of patents in general, thereby impairing our ability to protect our product candidates.

As is the case with other biotechnology and pharmaceutical companies, our success is heavily dependent on intellectual property and other proprietary rights, particularly patents. Obtaining, maintaining, enforcing, defending and protecting intellectual property and other proprietary rights, including patent rights in the biotechnology and pharmaceutical industries involve a high degree of technological and legal complexity. Therefore, obtaining, maintaining, enforcing, defending and protecting biotechnology and pharmaceutical patents is costly, time consuming and inherently uncertain. Changes in either the patent laws or in the interpretations of patent laws in the United States and other countries may diminish the value of our intellectual property and may increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of issued patents. We cannot predict the breadth of claims that may be allowed or enforced in our future patents or in third-party patents. In addition, Congress or other foreign legislative bodies may pass patent reform legislation that is unfavorable to us.

The patent positions of companies engaged in the development and commercialization of biologics and pharmaceuticals are particularly uncertain. For example, the U.S. Supreme Court has ruled on several patent cases in recent years, either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. In addition to increasing uncertainty regarding our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on decisions by the U.S. Congress, the U.S. federal courts, the USPTO, or similar authorities in foreign jurisdictions, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain patents or to enforce the patents we might obtain or license in the future. Any of the foregoing could have a material adverse effect on our owned and in-licensed patent portfolio and our ability to protect and enforce our intellectual property in the future, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Patent reform legislation could increase the uncertainties and costs surrounding the prosecution of our patent applications or those of our current or future licensors and the enforcement or defense of our future issued patents or those of our current or future licensors.

On September 16, 2011, the Leahy-Smith America Invents Act, or the Leahy-Smith Act, was signed into law. The Leahy-Smith Act includes several significant changes to U.S. patent law. These include provisions that affect the way patent applications will be prosecuted and may also affect patent litigation. In particular, under the Leahy-Smith Act, the United States transitioned in March 2013 to a “first inventor to file” system in which, assuming that other requirements of patentability are met, the first inventor to file a patent application will be entitled to the patent regardless of whether a third party was first to invent the claimed invention. A third party that files a patent application in the USPTO after March 2013, but before us, could therefore be awarded a patent covering an invention of ours even if we had made the invention before it was made by such third party. This will require us to be cognizant going forward of the time from invention to filing of a patent application. Furthermore, our ability to obtain and maintain valid and enforceable patents depends on whether the differences between our technology and the prior art allow our technology to be patentable over the prior art. Since patent applications in the United States and most other countries are confidential for a period after filing or until issuance, we may not be certain that we or our current or future licensors are the first to either (i) file any patent application related to our product candidates or (ii) invent any of the inventions claimed in the patents or patent applications.

The Leahy-Smith Act also includes several significant changes that affect the way patent applications will be prosecuted and also may affect patent litigation. These include allowing third-party submission of prior art to the USPTO during patent prosecution and additional procedures to attack the validity of a patent by USPTO administered post-grant proceedings, including PGR, IPR, and derivation proceedings. An adverse determination in any such submission or proceeding could reduce the scope or enforceability of, or invalidate, our patent rights, which could adversely affect our competitive position.

Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in U.S. federal courts necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though the same evidence would be insufficient to invalidate the claim if first presented in a district court action. Accordingly, a third party may attempt to use the USPTO procedures to invalidate our patent claims that would not have been invalidated if first challenged by the third party as a defendant in a district court action. Thus, the Leahy-Smith Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our patent applications or those of

our current or future licensors and the enforcement or defense of our future issued patents or those of our current or future licensors, all of which could have a material adverse effect on our business, financial condition, results of operations and prospects.

If we do not obtain patent term extension for our product candidates, our business may be materially harmed.

Depending upon the timing, duration, and specifics of FDA regulatory approval of our product candidates, one or more patents issued from U.S. patent applications that we file or those of our current or future licensors may be eligible for limited patent term restoration under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during the FDA regulatory review process based on the first regulatory approval for a particular drug or biologic. A maximum of one patent may be extended per FDA-approved drug as compensation for the patent term lost during the FDA regulatory review process. A patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of drug approval, and only those claims covering such approved drug product, a method for using it or a method for manufacturing it may be extended. Patent term extension may also be available in certain foreign countries upon regulatory approval of our product candidates.

However, we may not be granted an extension for which we apply in the United States or any other jurisdiction because of, for example, failing to exercise due diligence during the testing phase or regulatory review process, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents, or otherwise failing to satisfy applicable requirements. Moreover, the applicable time or the scope of patent protection afforded could be less than we request. In addition, to the extent we wish to pursue patent term extension based on a patent that we in-license from a third party, we would need the cooperation of that third party.

If we are unable to obtain patent term extension or restoration, or the foreign equivalent, or the term of any such extension is less than we request, our competitors or other third parties may obtain approval of competing products following our patent expiration, and our revenue could be reduced, possibly materially. Further, if this occurs, our competitors or other third parties may take advantage of our investment in development and trials by referencing our clinical and preclinical data and launch their product earlier than might otherwise be the case. Any of the foregoing could materially harm our business, financial condition, results of operations and prospects.

We may license technology from third parties that may be subject to retained rights, including certain intellectual property discovered through government funded programs that is subject to federal regulations such as “march-in” rights, certain reporting requirements and a preference for U.S.-based companies.

Certain of our current licensors, and certain of our future licensors may retain, certain rights under the relevant agreements with us, including the right to use the underlying technology for noncommercial academic and research use, to publish general scientific findings from research related to the technology, and to make customary scientific and scholarly disclosures of information relating to the technology. It is difficult to monitor whether our licensors limit their use of the technology to these uses, and we could incur substantial expenses to enforce our rights to our licensed technology in the event of misuse.

In addition, the U.S. federal government retains certain rights in inventions produced with its financial assistance under the Patent and Trademark Law Amendments Act, or the Bayh-Dole Act. The federal government retains a “nonexclusive, nontransferable, irrevocable, paid-up license” for its own benefit. The Bayh-Dole Act also provides federal agencies with “march-in rights.” March-in rights allow the government, in specified circumstances, to require the contractor or successors in title to the patent to grant a “nonexclusive, partially exclusive, or exclusive license” to a “responsible applicant or applicants.” If the patent owner refuses to do so, the government may grant the license itself.

We currently collaborate, and our current and future licensors may also collaborate, with academic institutions to accelerate our research or development. We may acquire or license in the future intellectual property rights that have been generated with U.S. government funding or grants. If the U.S. government exercises its march-in rights in our existing or future intellectual property rights that are generated with U.S. government funding or grants, we could be forced to license or sublicense intellectual property developed by us or that we license on terms unfavorable to us, and there can be no assurance that we would receive compensation from the U.S. government for the exercise of such rights. The U.S. government also has the right to take title to these inventions if the grant recipient fails to disclose the invention to the government or fails to file an application to register the intellectual property within specified time limits. Intellectual property generated under a government funded program is also subject to certain reporting requirements, compliance with which may require us to expend substantial resources. In addition, the U.S. government requires that any products embodying any of these inventions or produced through the use of any of these inventions be manufactured substantially in the United States. This preference for U.S. industry may be waived by the federal agency that provided the funding if the owner or assignee of the intellectual property can show that reasonable but unsuccessful efforts have been made to grant licenses on similar terms to potential licensees that would be likely to manufacture substantially in the United States or that under the circumstances domestic manufacture is not commercially feasible. This preference for U.S. industry may limit our ability to

contract with non-U.S. drug manufacturers for drugs covered by such intellectual property. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations, and prospects.

Intellectual property rights do not necessarily address all potential threats to our competitive advantage.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations and may not adequately protect our business or permit us to maintain our competitive advantage. For example:

Should any of these events occur, it could have a material adverse effect on our business, financial condition, results of operations and prospects.

We cannot ensure that patent rights relating to inventions described and claimed in our and our licensors’ pending patent applications will issue or that patents based on our or our licensors’ patent applications will not be challenged and rendered invalid and/or unenforceable.

We have pending provisional patent applications in the United States and pending patent applications under the PCT and in foreign countries in our portfolio relating to our research programs and product candidates. However, we cannot predict:

We cannot be certain that the claims in our current or future patent applications directed to our product candidates, as well as technologies relating to our research programs, will be considered patentable by the USPTO or by patent offices in foreign countries. One aspect of the determination of patentability of our inventions depends on the scope and content of the “prior art,” information that was or is deemed available to a person of skill in the relevant art prior to the priority date of the claimed invention. The

biotechnology and pharmaceutical industries, including the fields of targeted radiopharmaceuticals, are intense, fast-moving and highly competitive. There may be prior art of which we are not aware that may affect the patentability of our patent claims or, if issued, affect the validity or enforceability of a patent claim relevant to our business. There is no assurance that there is not prior art of which we are aware, but which we do not believe is relevant to our business, which may, nonetheless, ultimately be found to limit our ability to make, use, sell, offer for sale or import our products that may be approved in the future, or impair our competitive position.

Even if the patents do issue based on our or our licensors’ patent applications, third parties may challenge the validity, enforceability or scope thereof, which may result in such patents being narrowed, invalidated or held unenforceable. Furthermore, even if they are unchallenged, patents in our portfolio may not adequately exclude third parties from practicing relevant technology or prevent others from designing around our claims. If the breadth or strength of our intellectual property position with respect to our product candidates is threatened, it could dissuade companies from collaborating with us to develop and threaten our ability to commercialize our product candidates. In the event of litigation or administrative proceedings, we cannot be certain that the claims in any of our or our licensors’ future issued patents will be considered valid by courts in the United States or foreign countries. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

We may be involved in lawsuits to protect or enforce any patents we obtain in the future or our future licensors’ patents, which could be expensive, time consuming and unsuccessful. Further, any future issued patents we obtain or our current or future licensors’ patents could be found invalid or unenforceable if challenged in court.

Competitors or other third parties may infringe, misappropriate or otherwise violate our intellectual property rights. To prevent such infringement or unauthorized use, we may be required to file infringement and other claims, which can be expensive and time-consuming. In addition, in a patent infringement proceeding, a court may decide that a patent we own or in-license is not valid, is unenforceable or is not infringed. If we or any of our current or potential future collaborators were to initiate legal proceedings against a third party to enforce a patent directed at one of our product candidates, the defendant could counterclaim that such patent is invalid or unenforceable in whole or in part. In patent litigation in the United States, defendant counterclaims alleging invalidity or unenforceability are commonplace. Grounds for a validity challenge include an alleged failure to meet any of several statutory requirements, including lack of novelty, obviousness, lack of sufficient written description, non-enablement, or obviousness-type double patenting. Grounds for an unenforceability assertion could include an allegation that someone connected with prosecution of the patent withheld relevant information from the USPTO or made a misleading statement during prosecution.

Third parties may also raise similar invalidity claims before the USPTO or patent offices abroad, even outside the context of litigation. Such mechanisms include re-examination, PGR, IPR, derivation proceedings, and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings). The outcome following legal assertions of invalidity or unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we, our current or future licensors, and the patent examiners are unaware during prosecution. There is also no assurance that there is not prior art of which we are aware, but which we do not believe affects the validity or enforceability of a claim in our or our licensors’ patent applications or any patents or patent applications we may obtain or license in the future, which may, nonetheless, ultimately be found to affect the validity or enforceability of a claim. If a third party were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on our technology or platform, or any product candidates that we may develop. Such a loss of patent protection would have a material adverse impact on our business, financial condition, results of operations and prospects. Even if we establish infringement, the court may decide not to grant an injunction against further infringing activity and instead award only monetary damages, which may or may not be an adequate remedy.

Derivation proceedings provoked by third parties or brought by us or declared by the USPTO may be necessary to determine the priority of inventions with respect to our future patents or patent applications or those of our current or future licensors. An unfavorable outcome could require us to cease using the related technology or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer us a license on commercially reasonable terms or at all.

In addition, if the breadth or strength of protection provided by our or our licensors’ patent applications or the patents and patent applications we may obtain or in-license in the future is threatened, it could dissuade companies from collaborating with us to license, develop or commercialize current or future product candidates.

Even if resolved in our favor, litigation or other legal proceedings relating to our intellectual property rights may cause us to incur significant expenses, and could distract our technical and management personnel from their normal responsibilities. In addition, there could be public announcements of the results of hearings, rulings, motions and other interim proceedings or developments, and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock. Such litigation or proceedings could substantially increase our operating losses and reduce the resources available for development activities or any future sales, marketing or distribution activities. We may not have sufficient financial or other resources to conduct such litigation or proceedings adequately. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their greater financial resources and more mature and developed intellectual property portfolios. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could compromise our ability to compete in the marketplace.

Because of the expense and uncertainty of litigation, we may conclude that even if a third party is infringing any one of our future issued patents or other intellectual property rights, the risk-adjusted cost of bringing and enforcing such an infringement claim or action may be too high or not in the best interest of our company or our stockholders. In such cases, we may decide that the more prudent course of action is to simply monitor the situation or initiate or seek some other non-litigious action or solution.

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation or other legal proceedings relating to our intellectual property rights, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation or other proceedings.

In addition, the issuance of a patent does not give us the right to practice the patented invention. Third parties may have blocking patents that could prevent us from marketing our own patented product and practicing our own patented technology.

The occurrence of any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

Our commercial success depends significantly on our ability to operate without infringing, misappropriating or otherwise violating the intellectual property and other proprietary rights, including patents, of third parties. Claims by third parties that we infringe, misappropriate, or otherwise violate their intellectual property or other proprietary rights, may result in liability for damages or prevent or delay our developmental and commercialization efforts.

Our commercial success depends in part on avoiding infringement, misappropriation or other violation of the intellectual property and proprietary rights of third parties. However, our research, development and commercialization activities may be subject to claims that we infringe, misappropriate, or otherwise violate patents, trade secrets or other intellectual property rights owned or controlled by third parties. Third parties may assert infringement claims against us based on existing patents or patents that may be granted in the future, regardless of their merit. If our defenses to such claims are unsuccessful, we could be liable for damages, which could be significant. Other entities may have or obtain patents, intellectual property rights or other proprietary rights that could limit our ability to make, use, sell, offer for sale, or import our product candidates and products that may be approved in the future, or impair our competitive position. There is a substantial amount of litigation, both within and outside the United States, involving patent and other intellectual property rights in the biotechnology and pharmaceutical industries, including patent infringement lawsuits, oppositions, reexaminations, IPR proceedings and PGR proceedings before the USPTO and/or corresponding foreign patent offices. Numerous third-party U.S. and foreign-issued patents and pending patent applications exist in the fields in which we are developing product candidates. There may be third-party patents or patent applications with claims to materials, formulations, methods of manufacture or methods for treatment related to the use or manufacture of our product candidates. The intellectual property landscape around our radiopharmaceutical product candidates is crowded, complex, and fast-moving, and third parties may initiate legal proceedings alleging that we are infringing, misappropriating, or otherwise violating their intellectual property.

As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our product candidates may be subject to claims of infringement, misappropriation or other violation of the patents or other intellectual property rights and proprietary rights of third parties. There could be certain third-party patent applications in this landscape we are unaware of that may, if issued as patents, be asserted to encompass aspects of our technology. Because patent applications are maintained as confidential for a certain period of time, until the relevant application is published, we may be unaware of third-party patents that may be infringed by commercialization of any of our product candidates, and we cannot be certain that we were the first to file a patent application related to a product candidate or technology. Moreover, because patent applications can take many years to issue, may be confidential for 18 months or more after filing and can be revised before issuance, there may be currently pending patent applications that may later result in issued patents that our product candidates may infringe. Furthermore, certain applications may remain confidential until a patent issues. In addition, identification of third-party patent rights that may be relevant to our technology is difficult because patent searching is imperfect due to differences in terminology among patents, incomplete databases and the difficulty in assessing the meaning of patent claims. There is also no assurance that there is not prior art of which we are aware, but which we do not believe is relevant to our business, which may, nonetheless, ultimately be found to limit our ability to make, use, sell, offer for sale or import our products that may be approved in the future, or impair our competitive position. In addition, third parties may obtain patents in the future and claim that use of our technologies infringes upon these patents. If a patent holder believes the manufacture, use, sale or importation of any of our product candidates infringes its patent, the patent holder may sue us even if we have licensed other patent protection for our technology. Moreover, we may face patent infringement claims from nonpracticing entities that have no relevant product revenue and against whom our owned or licensed patent portfolio may therefore have no deterrent effect. Any claims of patent infringement asserted by third parties would be time consuming and could:

We may choose to challenge the enforceability or validity of claims in a third party’s U.S. patent by requesting that the USPTO review the patent claims in an ex-parte re-exam, IPR or PGR proceedings. We may also choose to challenge the validity of a third party’s U.S. patent in federal court proceedings, however, to be successful, we would need to overcome a presumption of validity. As this burden is a high one requiring us to present clear and convincing evidence as to the invalidity of any such U.S. patent claim, there is no assurance that a court of competent jurisdiction would invalidate the claims of any such U.S. patent. Both USPTO and federal proceedings are expensive and may consume our time or other resources. We may choose to challenge a third party’s patent in patent opposition proceedings in the European Patent Office, or EPO, or other foreign patent office. The costs of these opposition proceedings could be substantial and may consume our time or other resources. If we fail to obtain a favorable result at the USPTO, EPO or other patent office, then we may be exposed to litigation by a third party alleging that the patent may be infringed by our product candidates or proprietary technologies.

It is possible that a third party may assert a claim of patent infringement directed at any of our product candidates. Any patent-related legal action against us claiming damages and seeking to enjoin commercial activities relating to our product candidates, treatment indications, or processes could subject us to significant liability for damages, including treble damages and attorneys’ fees if we were determined to willfully infringe, and require us to obtain a license to manufacture or market our product candidates. Defense of these claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee resources from our business. We cannot predict whether we would prevail in any such actions or that any license required under any of these patents would be made available on commercially acceptable terms, if at all. Moreover, even if we or our future strategic partners were able to obtain a license, the rights may be nonexclusive, which could result in our competitors or other third parties gaining access to the same intellectual property. In addition, we cannot be certain that we could redesign our product candidates, treatment indications, or processes to avoid infringement, if necessary. Accordingly, an adverse determination in a judicial or administrative proceeding, or the failure to obtain necessary licenses, could prevent us from developing and commercializing our product candidates, which could harm our business, financial condition, results of operations and prospects. In addition, intellectual property litigation, regardless of its outcome, may cause negative publicity and could prohibit us from marketing or otherwise commercializing our product candidates and technology.

Parties making claims against us may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation or administrative proceedings, there is a risk that some of our confidential information could be compromised by disclosure. In addition to any of the foregoing events, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on our ability to raise additional funds or otherwise have a material adverse effect on our business, results of operations, financial condition, and prospects.

Intellectual property litigation may lead to unfavorable publicity that harms our reputation and causes the market price of our common shares to decline.

During any intellectual property litigation, there could be public announcements of the initiation of the litigation as well as results of hearings, rulings on motion, and other interim proceedings or developments in the litigation. If securities analysts or investors regard these announcements as negative, the perceived value of our existing product candidates, approved products, programs, or intellectual property could be diminished. Accordingly, the market price of shares of our common stock may decline. Such announcements could also harm our reputation or the market for our future products, which could have a material adverse effect on our business, results of operations, financial condition and prospects.

If we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.

In addition, we rely on the protection of our trade secrets, including unpatented or unpatentable know-how, technology and other proprietary information to maintain our competitive position. Trade secrets and know-how can be difficult to protect. Although we have taken steps to protect our trade secrets and unpatented or unpatentable know-how, including entering into confidentiality agreements with third parties, and confidential information and invention assignment agreements with employees, consultants and advisors, we cannot provide any assurances that all such agreements have been duly executed, and any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. Further, we cannot guarantee that we have entered into such agreements with each party that may have or have had access to our trade secrets or proprietary technology and process. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems; however, such systems and security measures may be breached, and we may not have adequate remedies for any breach. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult,

expensive, and time-consuming, and the outcome is unpredictable. In addition, some courts inside and outside the United States are less willing or unwilling to protect trade secrets.

Competitors or third parties could attempt to replicate some or all of the competitive advantages we derive from our development efforts, willfully infringe our intellectual property rights, design around our protected technology or develop their own competitive technologies that fall outside the scope of our intellectual property rights. Moreover, third parties may still lawfully obtain this information or may come upon this or similar information independently, and we would have no right to prevent them from using that technology or information to compete with us. If any of these events occurs or if we otherwise lose protection for our trade secrets, the value of this information may be greatly reduced, and our competitive position would be harmed. If we do not apply for patent protection prior to such publication or if we cannot otherwise maintain the confidentiality of our proprietary technology and other confidential information, then our ability to obtain patent protection or to protect our trade secret information may be jeopardized. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

Our reliance on third parties requires us to share our trade secrets, which increases the possibility that a competitor or other third party will discover them or that our trade secrets will be misappropriated or disclosed.

In addition to seeking patent protection for some of our technology and product candidates, we also rely on trade secrets, including unpatented know-how, technology, and other proprietary information, to maintain our competitive position. Elements of our product candidates, including processes for their preparation and manufacture, may involve proprietary know-how, information, or technology that is not covered by patents, and thus for these aspects we may consider trade secrets and know-how to be our primary intellectual property. Any disclosure, either intentional or unintentional, by our employees, the employees of third parties with whom we share our facilities or third-party consultants and vendors that we engage to perform research, clinical trials or manufacturing activities, or misappropriation by third parties (such as through a cybersecurity breach or other security incident) of our trade secrets or proprietary information could enable competitors to duplicate or surpass our technological achievements, thus eroding our competitive position in our market.

Trade secrets and unpatented know-how can be difficult to trace, protect and enforce. We require our employees to enter into written employment agreements containing provisions of confidentiality and obligations to assign to us any inventions generated in the course of their employment. We seek to protect our potential trade secrets, proprietary know-how and information in part, by entering into non-disclosure and confidentiality agreements with parties who are given access to them, such as our corporate collaborators, outside scientific collaborators, CROs, CMOs, consultants, advisors and other third parties. With our consultants, contractors and outside scientific collaborators, these agreements typically include invention assignment obligations. Although we have taken steps to protect our trade secrets and unpatented know-how, we cannot provide any assurances that all such agreements have been duly executed, and any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets and unpatented know-how, and we may not be able to obtain adequate remedies for such breaches. Monitoring unauthorized uses and disclosures is difficult, and we do not know whether the steps we have taken to protect our proprietary technologies will be effective. Unauthorized parties may also attempt to copy or reverse engineer certain aspects of our products that we consider proprietary. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time consuming, and the outcome is unpredictable. In addition, some courts inside and outside the United States are less willing or unwilling to protect trade secrets.

Trade secrets may be independently developed by others in a manner that could prevent legal recourse by us. Trade secrets will over time be disseminated within the industry through independent development, the publication of journal articles and the movement of skilled personnel from company to company or academic to industry scientific positions. Though our agreements with third parties typically restrict the ability of our advisors, employees, collaborators, licensors, suppliers, third-party contractors, and consultants to publish data potentially relating to our trade secrets, our agreements may contain certain limited publication rights. Because from time to time we expect to rely on third parties in the development, manufacture and distribution of our products and provision of our services, we must, at times, share trade secrets with them. Despite employing the contractual and other security precautions described above, the need to share trade secrets increases the risk that such trade secrets become known by our competitors, are inadvertently incorporated into the technology of others, or are disclosed or used in violation of these agreements. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor or other third party, we would have no right to prevent them from using that technology or information to compete with us. If any of our trade secrets were to be disclosed to or independently developed by a competitor or other third party, our competitive position would be harmed, and our business, financial condition, results of operations and prospects could be materially adversely affected.

We may be subject to claims that we or our employees, consultants, or collaborators have wrongfully used or disclosed alleged confidential information or trade secrets of their former employers or claims asserting ownership of what we regard as our own intellectual property.

Some of our employees, consultants, advisors and collaborators are currently or were previously employed at universities or other biotechnology or pharmaceutical companies, including our competitors or potential competitors. We have sought to enter into, and may in the future seek to enter into, non-disclosure and confidentiality agreements to protect the proprietary positions of third parties, such as outside scientific collaborators, CROs, CDMOs, consultants, advisors, potential partners, and other third

parties. Although we try to ensure that our employees, consultants, advisors and collaborators do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or these individuals have used or disclosed intellectual property, including trade secrets or other proprietary information, of any such individual’s current or former employer. We may become subject to litigation where a third party asserts that we or our employees inadvertently or otherwise breached the agreements and used or disclosed trade secrets or other information proprietary to the third parties. Defense of such matters, regardless of their merit, could involve substantial litigation expense and be a substantial diversion of employee resources from our business. We cannot predict whether we would prevail in any such actions.

Moreover, intellectual property litigation, regardless of its outcome, may cause negative publicity and could prohibit us from marketing or otherwise commercializing our product candidates and technology. Failure to defend against any such claim could subject us to significant liability for monetary damages, lead to a loss of valuable intellectual property rights or otherwise prevent or delay our developmental and commercialization efforts, which could adversely affect our business. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to our management team and other employees. In addition, we may lose personnel as a result of such claims and any such litigation, or the threat thereof may adversely affect our ability to hire employees or contract with independent contractors. A loss of key personnel or their work product could hamper or prevent our ability to commercialize our product candidates, which would have a material adverse effect on our business, results of operations, financial condition and prospects.

In addition, while it is our policy to require our employees and contractors who may be involved in the conception or development of intellectual property to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who, in fact, conceives or develops intellectual property we regard as ours. Moreover, even when we obtain agreements assigning intellectual property to us, the assignment of intellectual property rights may not be self-executing, or the assignment agreements may be breached, and we may be forced to bring claims against third parties to determine the ownership of what we regard as our intellectual property, or defend claims that they may bring against us. Such claims could have a material adverse effect on our business, financial condition, results of operations and prospects. Furthermore, individuals executing agreements with us may have preexisting or competing obligations to a third party, such as an academic institution, and thus an agreement with us may be ineffective in perfecting ownership of inventions developed by that individual.

In addition, we or our licensors may in the future be subject to claims by former employees, collaborators, consultants or other third parties asserting an ownership right in our owned or licensed patent applications or future patents, patent applications, trade secrets or other intellectual property. For example, one of our licensors has inquired into whether they should be named as co-inventors for our pending patent applications relating to our Nectin-4 program, including [225Ac]Ac-AKY-1189. Although we do not believe that anyone from the licensor made any contributions that rise to the level of inventorship on any of the claims that we are pursuing or plan to pursue, and we have had discussions with them regarding their inquiry, we cannot guarantee the final resolution of the matter. In some instances, litigation may be necessary to defend against claims challenging inventorship or ownership of our patent rights, trade secrets or other intellectual property. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights. Such an outcome could have a material adverse effect on our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and distraction to management and other employees. An adverse determination in any such submission or proceeding may result in loss of exclusivity or freedom to operate or in patent claims being narrowed, invalidated or held unenforceable, in whole or in part, which could limit our ability to stop others from using or commercializing similar product candidates and technology, without payment to us, or could limit the duration of the patent protection covering our product candidates and proprietary technology. Such challenges may also result in our inability to develop, manufacture or commercialize our product candidates and proprietary technology without infringing third-party patent rights. In addition, if the breadth or strength of protection provided by our owned or licensed patent rights, trade secrets or other intellectual property is threatened, it could dissuade companies from collaborating with us to license, develop or commercialize current or future product candidates.

Parties making claims against us may be able to sustain the costs of complex intellectual property litigation more effectively than we can because they have substantially greater resources. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure. Any of the foregoing have a material adverse effect on our business, financial condition, results of operations, and prospects.

Our rights to develop and commercialize our technology and product candidates may be subject, in part, to the terms and conditions of licenses granted to us by others.

We have entered into and may enter into in the future license agreements with others to advance our existing or future research or allow commercialization of our existing or future product candidates. If we fail to comply with our obligations under our intellectual property licenses, if the licenses are terminated, or if disputes regarding these licenses arise, we could lose significant rights that are important to our business. These licenses may not provide exclusive rights to use such intellectual property and technology in all relevant fields of use and in all territories in which we may wish to develop or commercialize our technology and products in the future.

In addition, subject to the terms of any such license agreements, we may not have the right to control the preparation, filing, prosecution, maintenance, enforcement, or defense of patent rights covering the technology that we license from third parties now

or in the future. In such an event, we cannot be certain that these patents and patent applications will be prepared, filed, prosecuted, maintained, enforced, and defended in a manner consistent with the best interests of our business or in compliance with applicable laws and regulations, or will result in valid and enforceable patents and other intellectual property rights. It is also possible that our licensors’ infringement proceedings or defense activities may be less vigorous than had we conducted them ourselves or may not be conducted in accordance with our best interest. If we or our current or future licensors fail to prosecute, maintain, enforce, and defend such patents or patent applications, or lose rights to those patents or patent applications, the rights we have licensed may be reduced or eliminated, and our right to develop and commercialize any of our product candidates that are the subject of such licensed rights could be adversely affected.

Our current or future licensors may rely on third-party consultants or collaborators or on funds from third parties such that our licensors are not the sole and exclusive owners of the patent rights we in-license. If other third parties have ownership rights to our current or future in-licensed patent rights, they may be able to license such patent rights to our competitors, and our competitors could market competing products and technology. This could have a material adverse effect on our competitive position, business, financial condition, results of operations, and prospects.

It is possible that we may be unable to obtain licenses at a reasonable cost or on reasonable terms, if at all. Even if we can obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us. If we are unable to do so, we may be unable to develop or commercialize the affected product candidates, which could harm our business, financial condition, results of operations, and prospects significantly. We cannot provide any assurances that third-party patents do not exist which might be enforced against our current technology, manufacturing methods, product candidates, or future methods or products resulting in either an injunction prohibiting our manufacture or future sales, or, with respect to our future sales, an obligation on our part to pay royalties and/or other forms of compensation to third parties, which could be significant. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations, and prospects.

If we fail to comply with our obligations in the agreements under which we license intellectual property rights to or from third parties or otherwise experience disruptions to our business relationships with our current and future licensors or licensees, we could lose license rights that are important to our business.

We are heavily reliant upon licenses from third parties to certain patent rights and proprietary technology that are important or necessary to the development of our proprietary technology. Further development of our proprietary technology may require us to enter into additional license or collaboration agreements. Our future licenses may not provide us with exclusive rights to use the licensed intellectual property and technology, or may not provide us with exclusive rights to use such intellectual property and technology in all relevant fields of use and in all territories in which we may wish to develop or commercialize our product candidates and proprietary technology in the future. Additionally, our current license agreements impose, and future agreements may impose, various development, diligence, commercialization and other obligations on us and require us to meet development timelines, or to exercise commercially reasonable efforts to develop and commercialize licensed products, in order to maintain the licenses.

Disputes may arise between us and our current or future licensors or licensees regarding intellectual property subject to a license agreement, including:

In addition, we may seek to obtain additional licenses from our licensors and, in connection with obtaining such licenses, we may agree to amend our existing licenses in a manner that may be more favorable to the licensors, including by agreeing to terms that could enable third parties, including our competitors, to receive licenses to a portion of the intellectual property that is subject to our existing licenses and to compete with our proprietary technologies and product candidates.

The agreements under which we license intellectual property or technology from third parties are complex, and certain provisions in such agreements may be susceptible to multiple interpretations. The resolution of any contract interpretation disagreement that may arise could narrow what we believe to be the scope of our rights to the relevant intellectual property or

technology or increase what we believe to be our financial or other obligations under the relevant agreement, either of which could have a material adverse effect on our business, financial condition, results of operations, and prospects. Moreover, if disputes over intellectual property that we have licensed, or license in the future, prevent or impair our ability to maintain our licensing arrangements on commercially acceptable terms, we may be unable to successfully develop and commercialize the affected product candidates, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Despite our best efforts, our current or future licensors or licensees might conclude that we materially breached our license agreements and might therefore terminate the license agreements, thereby removing our ability to develop and commercialize products and technology covered by these license agreements. If these licenses are terminated, or if the underlying patent rights fail to provide the intended exclusivity, competitors will have the freedom to seek regulatory approval of, and to market, products identical to ours, and we may be required to cease our development and commercialization of certain of our product candidates and proprietary technology. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations, and prospects.

We may not be successful in obtaining or maintaining necessary rights to our product candidates through acquisitions and in-licenses.

Because our development programs may require or in the future require the use of additional intellectual property or proprietary rights held by third parties, the growth of our business may depend in part on our ability to acquire, in-license, or use these third-party intellectual property or proprietary rights. We may be unable to acquire or in-license any compositions, methods of use, processes, or other third-party intellectual property rights from third parties that we identify as necessary for our product candidates on commercially reasonable terms or at all. Even if we are able to in-license any such necessary intellectual property, it could be on nonexclusive terms, thereby giving our competitors and other third parties access to the same intellectual property licensed to us, and it could require us to make substantial licensing and royalty payments. The licensing and acquisition of third-party intellectual property rights is a competitive area, and several more established companies may pursue or are already pursuing strategies to license or acquire third-party intellectual property rights that we may consider attractive or necessary.

More established companies may have a competitive advantage over us due to their size, capital resources and greater clinical development and commercialization capabilities. In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. We also may be unable to license or acquire third-party intellectual property rights on terms that would allow us to make an appropriate return on our investment or at all. If we are unable to successfully obtain rights to required third-party intellectual property rights or maintain the existing intellectual property rights we have, we may be required to expend significant time and resources to redesign our product candidates, or to develop or license replacement candidates, all of which may not be feasible on a technical or commercial basis, and we may have to abandon development of the relevant program or product candidate, any of which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.

We intend to use registered or unregistered trademarks or trade names to brand and market ourselves and our products. Our current and future trademarks and trade names, including our future registered trademarks and current or future unregistered trademarks, may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks. Moreover, our current or future trademark applications may not be allowed or may subsequently be opposed. We may not be able to protect our rights to these trademarks and trade names, which we need to build name recognition among potential partners or customers in our markets of interest. At times, competitors may adopt trade names or trademarks similar to ours, thereby impeding our ability to build brand identity and possibly leading to market confusion. In addition, there could be potential trade name or trademark infringement claims brought by owners of other registered trademarks or trademarks that incorporate variations of our trademarks or trade names. As a means to enforce our trademark rights and prevent infringement, we may be required to file trademark claims against third parties or initiate trademark opposition proceedings. This can be expensive and time-consuming, particularly for a company of our size. If we assert trademark infringement claims, a court may determine that the trademarks we have asserted are invalid or unenforceable, or that the party against whom we have asserted trademark infringement has superior rights to the marks in question. In this case, we could ultimately be forced to cease use of such trademarks.

During trademark registration proceedings, we may receive rejections of our applications by the USPTO or in other foreign jurisdictions. Although we would be given an opportunity to respond to those rejections, we may be unable to overcome such rejections. In addition, in the USPTO and in comparable agencies in many foreign jurisdictions, third parties are given an opportunity to oppose pending trademark applications and to seek to cancel registered trademarks. Opposition or cancellation proceedings may be filed against our trademarks, and our trademarks may not survive such proceedings. If we are unable to establish name recognition based on our trademarks and trade names, we may not be able to compete effectively and our business may be adversely affected. We may license our trademarks and trade names to third parties, such as distributors. Although these license agreements may provide guidelines for how our trademarks and trade names may be used, a breach of these agreements or misuse of our trademarks and trade names by our licensees may jeopardize our rights in or diminish the goodwill associated with our trademarks and trade names.

Moreover, any name we may propose to use with our product candidates in the United States must be approved by the FDA, regardless of whether we have registered it, or applied to register it, as a trademark. Similar requirements exist in Europe. The FDA typically conducts a review of proposed product names, including an evaluation of potential for confusion with other product names. If the FDA (or an equivalent administrative body in a foreign jurisdiction) objects to any of our proposed proprietary product names, it may be required to expend significant additional resources in an effort to identify a suitable substitute name that would qualify under applicable trademark laws, not infringe the existing rights of third parties and be acceptable to the FDA. Furthermore, in many countries, owning and maintaining a trademark registration may not provide an adequate defense against a subsequent infringement claim asserted by the owner of a senior trademark.

Over the long term, if we are unable to establish name recognition based on our trademarks and trade names, then we may not be able to compete effectively, and our business may be adversely affected. Our efforts to enforce or protect our proprietary rights related to trademarks, trade secrets, domain names, copyrights or other intellectual property may be ineffective and could result in substantial costs and diversion of resources and could adversely affect our business, financial condition, results of operations and prospects.

The use of new and evolving technologies, such as AI, in our operations may require us to expend material resources and may present risks and challenges that can impact our business, including by posing security and other risks to our confidential information, proprietary information and personal information, any of which may result in reputational harm and liability, or otherwise adversely affect our business.

We may choose to integrate AI into our operations, and this innovation presents risks and challenges that could affect its adoption, and therefore our business. There are significant risks involved in utilizing AI and no assurance can be provided that the usage of AI will enhance our business or assist our business in becoming more efficient or profitable. The use of certain AI technology can give rise to intellectual property risks, including compromises to proprietary intellectual property and intellectual property infringement and misappropriation. Other known risks of AI currently include inaccuracy, bias, toxicity, data privacy and cybersecurity issues, and data provenance disputes. In addition, AI may have errors or inadequacies that are not easily detectable. AI may also be subject to data herding and interconnectedness (i.e., multiple market participants utilizing the same data), which may adversely impact our business. If the data used to train AI or the content, analyses, or recommendations that AI applications assist in producing are or are alleged to be deficient, inaccurate, incomplete, overbroad or biased, our business, financial condition, and results of operations may be adversely affected.

Additionally, we expect to see increasing government and supranational regulation and ethical concerns related to AI use, which may also significantly increase the burden and cost of research, development and compliance in this area. For example, the EU’s Artificial Intelligence Act, or the AI Act,—the world’s first comprehensive AI law—entered into force on August 1, 2024 and, with some exceptions, will become effective 24 months thereafter. This legislation imposes significant obligations on providers and deployers of AI systems, and encourages providers and deployers of AI systems to account for certain ethical principles in their design, development and use of these systems. The rapid evolution of AI will require the application of significant resources to design, develop, test and maintain our technology and products to help ensure that AI is implemented in accordance with applicable laws and regulations and in a socially responsible manner and to minimize any real or perceived unintended harmful impacts. The legal landscape and subsequent legal protection for the use of AI remains uncertain, and development of the law in this area could impact our ability to enforce our proprietary rights or protect against infringing uses. If we do not have sufficient rights to use the data on which AI relies or to the outputs produced by AI applications, we may incur liability through the violation of certain laws, third-party privacy or other rights or contracts to which we are a party. Our use of AI applications may also, in the future, result in cybersecurity incidents that implicate the personal data of customers or patients. Any such cybersecurity incidents related to our use of AI applications could adversely affect our reputation and results of operations.

Our collaborators or other third-party service providers may also incorporate AI tools into their own offerings, and the providers of these AI tools may not meet existing or rapidly evolving regulatory or industry standards, including with respect to intellectual property, data privacy and cybersecurity. Further, bad actors around the world use increasingly sophisticated methods, including the use of AI, to engage in illegal activities involving the theft and misuse of personal information, confidential information and intellectual property. Any of these effects could damage our reputation, result in the loss of valuable property and information, cause us to breach applicable laws and regulations, or otherwise adversely impact our business.

Risks related to Employee Matters and Managing Growth

Our ability to develop our future product candidates for our future growth depends on retaining our key personnel and recruiting additional qualified personnel.

Our success depends upon the continued contributions of our key management, scientific, and technical personnel, many of whom have been instrumental for us and have substantial experience with our radiopharmaceuticals, our discovery engine and development processes and capabilities, underlying technologies, and related product candidates. In particular, we are highly dependent on Matthew Roden, PhD, our Chief Executive Officer, Kyle D. Kuvalanka, our Chief Financial Officer, Shulamit Ron-Bigger, PhD, our Chief Operating Officer, Paul L. Feldman, PhD, our Chief Scientific Officer, Akos Czibere, MD, PhD, our Chief Medical Officer and Tyler Benedum, PhD, our Chief Technical Officer, as well as the other principal members of our management

and scientific teams. The loss of the services of any of these persons could impede the achievement of our research, development and commercialization objectives.

For us to successfully compete and grow, we must recruit, retain, and develop talent who can provide the necessary expertise across a broad spectrum of disciplines. In addition, we must develop, maintain and, as necessary, implement appropriate succession plans to ensure we have the necessary human capital capable of maintaining continuity in our business. Given the fact that these are novel and emerging fields, there is an inherent scarcity of experienced personnel in these fields. As we continue developing our pipeline, we will require personnel with medical, scientific, or technical qualifications specific to each program. The loss of key managers and senior scientists could delay our research and development activities. Despite our efforts to retain valuable employees, members of our management, scientific, and development teams may terminate their employment with us on short notice. Although we have employment agreements with our key employees, these employment agreements provide for at-will employment, which means that any of our employees could leave our employment at any time, with or without notice. We do not maintain “key person” insurance for any of our executives or other employees. The competition for qualified personnel in the biotechnology industry is intense, and our future success depends upon our ability to attract, retain, and motivate highly skilled scientific, technical, and managerial employees. We face competition for personnel from other companies, universities, public and private research institutions, and other organizations. If our recruitment and retention efforts are unsuccessful in the future, it may be difficult for us to implement our business strategy, which could have a material adverse effect on our business.

In addition, our research and development programs, clinical operations and sales and marketing efforts depend on our ability to attract and retain highly skilled scientists, engineers, and sales professionals.

Competition for skilled personnel in our market is intense, and we have from time to time experienced, and we expect to continue to experience, difficulty in hiring and retaining employees with appropriate qualifications on acceptable terms, or at all. Many of the companies with which we compete for experienced personnel have greater resources than we do, and any of our employees may terminate their employment with us at any time. Failure to succeed in preclinical studies, clinical trials or applications for regulatory approval may make it more difficult to recruit or retain qualified personnel. Moreover, if we hire employees from competitors or other companies, their former employers may attempt to assert that these employees or we have breached legal obligations, resulting in a diversion of our time and resources and, potentially, damages. In addition, job candidates and existing employees often consider the value of the stock awards they receive in connection with their employment. If the perceived benefits of our stock awards decline, it may harm our ability to recruit and retain highly skilled employees. If we fail to attract new personnel or fail to retain and motivate our current personnel, our business, financial condition, results of operations and prospects would be harmed.

We expect to continue to expand our development and regulatory capabilities, and as a result, we may encounter difficulties in managing our growth, which could disrupt our operations.

We have experienced rapid growth since our inception in August 2020. We expect continued growth in the number of our employees and the scope of our operations, particularly to continue our planned clinical operations, preclinical and IND-enabling studies or studies approved by comparable foreign authorities, establish regulatory, quality, and manufacturing supply chain logistics and facility operations.

To manage our anticipated future growth, we will continue to seek to implement and improve our managerial, operational, and financial systems, expand our facilities, and continue to recruit and train additional qualified personnel. Due to our limited financial resources and the complexity in managing a company with such anticipated growth, we may not be able to effectively manage the expansion of our operations or recruit and train additional qualified personnel. The expansion of our operations may lead to significant costs and may divert our management and business development resources. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.

In addition, future growth imposes significant added responsibilities on members of management, including: identifying, recruiting, integrating, maintaining, and motivating new employees; managing our internal development efforts effectively, including the clinical and FDA, or comparable foreign regulatory authority, review process for [225Ac]Ac-AKY-1189 and any current or future product candidates, while complying with our contractual obligations to third parties; and improving our operational, financial and management controls, reporting systems, and procedures.

We currently rely, and for the foreseeable future will continue to rely, in substantial part on certain independent organizations, advisors, and consultants to provide certain services, including strategic, financial, business development, and research and development services, as well as certain aspects of regulatory approval and manufacturing. There can be no assurance that the services of independent organizations, advisors, and consultants will continue to be available to us on a timely basis when needed or on reasonable terms, or that we can find qualified replacements. In addition, if we are unable to effectively manage our outsourced activities or if the quality or accuracy of the services provided by consultants, CROs, CDMOs or CMOs is compromised for any reason, our preclinical or clinical trials may be extended, delayed, or terminated, and we may not be able to obtain regulatory approval of [225Ac]Ac-AKY-1189 or any of our other current or future product candidates or otherwise advance our business. We cannot assure you that we will be able to manage our existing consultants or find other competent outside contractors and consultants on economically reasonable terms, or at all.

If we are not able to effectively expand our organization by hiring new qualified employees and expanding our groups of consultants and contractors, we may experience delays or may not be able to successfully implement the tasks necessary to further develop and commercialize [225Ac]Ac-AKY-1189 for any Nectin-4 expressing tumor and any future product candidates we develop and, accordingly, we may not achieve our research, development, and commercialization goals.

Business disruptions could seriously harm our future revenue and financial condition and increase our costs and expenses.

Our operations, and those of our CROs, CDMOs, CMOs and other contractors and consultants, could be subject to earthquakes, power shortages, telecommunications failures, water shortages, floods, hurricanes, typhoons, fires, extreme weather conditions, medical epidemics and other natural or man-made disasters or business interruptions, for which we are predominantly self-insured. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses. We rely on third-party manufacturers to produce and process our product candidates on a patient-by-patient basis. Our ability to obtain clinical supplies of our product candidates could be disrupted if the operations of these suppliers are affected by a man-made or natural disaster or other business interruption.

Our insurance policies are expensive and protect us from only some business risks, which will leave us exposed to significant uninsured liabilities.

We do not carry insurance for all categories of risk that our business may encounter. Some of the policies we currently maintain include property, general liability, employee benefits liability, workers’ compensation, clinical trial liability, cyber liability, and directors’ and officers’ insurance. We do not know, however, if we will be able to maintain insurance with adequate levels of coverage. No assurance can be given that an insurance carrier will not seek to cancel or deny coverage after a claim has occurred. Any significant uninsured liability may require us to pay substantial amounts, which would adversely affect our financial position and results of operations.

Risks related to our common stock

Our stock price may be volatile or may decline regardless of our operating performance, resulting in substantial losses for investors.

Our stock price has been, and is likely to remain, volatile and may fluctuate substantially as a result of a variety of factors, some of which are related in complex ways. The market price of our common stock may fluctuate significantly in response to numerous factors, many of which are beyond our control, including the factors listed below and other factors describe in this “Risk factors” section:

In addition, the stock market in general and biotechnology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

Future sales of our common stock in the public market could cause our common stock price to fall.

Our common stock price could decline as a result of sales of a large number of shares of common stock or the perception that these sales could occur. These sales, or the possibility that these sales may occur, might also make it more difficult for us to sell equity securities in the future at a time and price that we deem appropriate. The lock-up agreements entered into in connection with our initial public offering in January 2026 will expire at the close of business on July 7, 2026. J.P. Morgan Securities LLC, BofA Securities, Inc., Leerink Partners LLC and TD Securities (USA) LLC, in their sole discretion, may permit our equity holders who are subject to these lock-up agreements to sell shares prior to the expiration of the lock-up agreements. After the lock-up agreements expire, the shares of common stock will be eligible for sale in the public market. As of March 10, 2026, we had outstanding a total of 53,403,173 shares of common stock. Of these shares, 20,297,500 shares of our common stock were sold in the initial public offering, substantially all of which are freely tradable, without restriction, in the public market.

In addition, the holders of approximately 34,057,218 shares of our common stock, which includes all of the shares of common stock issuable upon the conversion of our outstanding shares of Class A common stock, or approximately 61.6% of our outstanding capital stock, have rights, subject to some conditions, to require us to file registration statements covering the sale of their shares or to include their shares in registration statements that we may file for ourselves or our other stockholders, subject to the lock-up agreements described above. Registration of these shares under the Securities Act of 1933, as amended, or the Securities Act, would result in the shares becoming freely tradable without restriction under the Securities Act, except for shares purchased by affiliates. Any sales of securities by these stockholders could have a material adverse effect on the market price of our common stock.

In addition, in the future, we may issue additional shares of common stock, or other equity or debt securities convertible into common stock, in connection with a financing, acquisition, employee arrangement, or otherwise. Any such issuance could result in substantial dilution to our existing stockholders and could cause the price of our common stock to decline.

Our principal stockholders and management own a significant percentage of our stock and will be able to exert significant control over matters subject to stockholder approval.

Our Class A common stock has no voting rights. As a result, all matters submitted to our stockholders will be decided by the vote of holders of our common stock. Based on the beneficial ownership of our common stock as of March 10, 2026, our executive officers, directors, holders of 5% or more of our capital stock and their respective affiliates beneficially owned approximately 56.2% of our outstanding voting stock. Therefore, these stockholders have the ability to influence us through this ownership position. These stockholders, if acting together, may be able to determine all matters requiring stockholder approval and they may have interests that differ from yours and may be adverse to your interests. For example, these stockholders may be able to control elections of directors, amendments of our organizational documents, or approval of any merger, sale of assets, or other major corporate transaction.

We may not be able to satisfy listing requirements of Nasdaq or obtain or maintain a listing of our common stock on Nasdaq.

Since our common stock is listed on Nasdaq, we must meet certain financial and liquidity criteria to maintain such listing. If we violate Nasdaq’s listing requirements, our common stock may be delisted. If we fail to meet any of Nasdaq’s listing standards, our common stock may be delisted. In addition, our board of directors may determine that the cost of maintaining our listing on a national securities exchange outweighs the benefits of such listing. A delisting of our common stock from Nasdaq may materially impair our stockholders’ ability to buy and sell our common stock and could have an adverse effect on the market price of, and the efficiency of the trading market for, our common stock. The delisting of our common stock could significantly impair our ability to raise capital and the value of our stockholders' investment.

We do not currently intend to pay dividends on our common stock and, consequently, our stockholders’ ability to achieve a return on their investment will depend on appreciation of the value of our common stock.

We have never declared or paid cash dividends on our common stock. We currently intend to retain all available funds and any future earnings to support operations and to finance the growth and development of our business. We do not intend to declare or pay any cash dividends on our capital stock in the foreseeable future. As a result, any investment return on our common stock will depend upon increases in the value for our common stock, which is not certain.

If securities or industry analysts either do not publish research about us or publish inaccurate or unfavorable research about us, our business or our market, or if they change their recommendations regarding our common stock adversely, the trading price or trading volume of our common stock could decline.

The trading market for our common stock is influenced in part by the research and reports that securities or industry analysts may publish about us, our business, our market, or our competitors. If one or more of these analysts initiate research with an unfavorable rating or downgrade our common stock, provide a more favorable recommendation about our competitors, or publish inaccurate or unfavorable research about our business, our common stock price would likely decline. If any analyst who may cover us were to cease coverage of us or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause the trading price or trading volume of our common stock to decline. In addition, if we fail to the meet the forecasts published by these analysts, the trading price of our common stock would likely decline.

We are an “emerging growth company,” and a “smaller reporting company,” and any decision on our part to comply only with certain reduced reporting and disclosure requirements applicable to emerging growth companies and smaller reporting companies could make our common stock less attractive to investors.

We are an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended, or the JOBS Act. We are also a “smaller reporting company,” as defined in Rule 12b-2 under the Securities Exchange Act of 1934, or the Exchange Act. For as long as we continue to be an “emerging growth company,” and a “smaller reporting company” we may choose to take advantage of exemptions from various reporting requirements applicable to other public companies but not to emerging growth companies and smaller reporting companies, including:

We could be an “emerging growth company” for up to five years following the completion of our initial public offering in January 2026. Our status as an “emerging growth company” will end as soon as any of the following takes place:

Even after we no longer qualify as an emerging growth company, we may continue to qualify as a smaller reporting company, which would allow us to take advantage of many of the same exemptions from disclosure requirements, including reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements. In addition, if we are a smaller reporting company with less than $100.0 million in annual revenue, we would not be required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act. We would cease to be a smaller reporting company if the market value of our common stock that is held by non-affiliates exceeds $250.0 million and we had annual revenues in excess of $100.0 million or if the market value of our common stock that is held by non-affiliates exceeds $700.0 million, each as determined on an annual basis.

If some investors find our common stock less attractive because we rely on any of these exemptions, there may be a less active trading market for our common stock and the market price of our common stock may be more volatile.

Under the JOBS Act, emerging growth companies can also delay adopting new or revised accounting standards until such time as those standards apply to private companies. We have elected to use this extended transition period for any new or revised accounting standards during the period in which we remain an “emerging growth company” (or we affirmatively and irrevocably opt out of the extended transition period); however, we may adopt certain new or revised accounting standards early. As a result, our consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Unstable market and economic conditions may have serious adverse consequences on our business, financial condition and stock price.

Global credit and financial markets have experienced extreme volatility and disruptions in the past several years, including severely diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability, including most recently in connection with the ongoing war between Russia and Ukraine and the political, economic and social instability in Venezuela. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. Our general business strategy may be adversely affected by any such economic downturn, volatile business environment or continued unpredictable and unstable market conditions. If the current equity and credit markets deteriorate, or do not improve, it may make any debt or equity financing more difficult, more costly, and more dilutive. Furthermore, our stock price may decline due in part to the volatility of the stock market and the general economic downturn.

Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay, scale back or discontinue the development and commercialization of [225Ac]Ac-AKY-1189 or one or more of our future product candidates or delay our pursuit of potential in-licenses or acquisitions. In addition, there is a risk that one or more of our current service providers, manufacturers and other partners may not succeed or survive these difficult economic times, which could directly affect our ability to attain our operating goals on schedule and on budget.

Our amended and restated certificate of incorporation designates the state courts in the State of Delaware or, if no state court located within the State of Delaware has jurisdiction, the federal court for the District of Delaware, as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by our stockholders, which could discourage lawsuits against us or our directors, officers, or employees.

Our amended and restated certificate of incorporation provides that, to the fullest extent permitted by law, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, any state court located within the State of Delaware, or if all such state courts lack jurisdiction, the federal district court for the District of Delaware) and any appellate court therefrom is the sole and exclusive forum for the following types of claims or causes of action under Delaware statutory or common law: (i) any derivative claim or cause of action brought on our behalf; (ii) any claim or cause of action asserting a breach of a fiduciary duty owed by any current or former director, officer or other employee, to us or our stockholders; (iii) any claim or cause of action against us or any of our current or former directors, officers or other employees, arising out of or pursuant to any provisions of the Delaware General Corporation Law, our amended and restated certificate of incorporation, or our amended and restated bylaws; (iv) any claim or cause of action seeking to interpret, apply, enforce or determine the validity of our amended and restated certificate of incorporation or our amended and restated bylaws; (v) any claim or cause of action as to which the Delaware General Corporation Law confers jurisdiction on the Court of Chancery of the State of Delaware; and (vi) any claim or cause of action against us, or any of our directors, officers or other employees, that is governed by the internal affairs doctrine, or otherwise related to our internal affairs, in all cases to the fullest extent permitted by law and subject to the court’s having personal jurisdiction over the indispensable parties named as defendants. Our amended and restated certificate of incorporation states that these choice of forum provisions do not apply to claims or causes of action brought to enforce a duty or liability created by the Securities Act, the Exchange Act, or any other claim for which the federal courts have exclusive jurisdiction. Furthermore, Section 22 of the

Securities Act creates concurrent jurisdiction for federal and state courts over all such Securities Act actions. Accordingly, both state and federal courts have jurisdiction to entertain such claims. To prevent having to litigate claims in multiple jurisdictions and the threat of inconsistent or contrary rulings by different courts, among other considerations, our amended and restated certificate of incorporation further provides that the federal district courts of the United States are the exclusive forum for resolving any complaint asserting a cause or causes of action arising under the Securities Act, including all causes of action asserted against any defendant to such complaint. While the Delaware courts have determined that such choice of forum provisions are facially valid, a stockholder may nevertheless seek to bring a claim in a venue other than those designated in the exclusive forum provisions. In such instance, we would expect to vigorously assert the validity and enforceability of the exclusive forum provisions of our amended and restated certificate of incorporation. This may require significant additional costs associated with resolving such action in other jurisdictions, which costs could be borne by investors, and there can be no assurance that the provisions will be enforced by a court in those other jurisdictions.

These choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers, or other employees and may discourage these types of lawsuits. Furthermore, if a court were to find the choice of forum provisions contained in our amended and restated certificate of incorporation to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, and such costs could be borne by investors.

Delaware law and provisions in our amended and restated certificate of incorporation and amended and restated bylaws could make a merger, tender offer, or proxy contest difficult, thereby depressing the trading price of our common stock.

Provisions of our amended and restated certificate of incorporation and amended and restated bylaws may delay or discourage transactions involving an actual or potential change in our control or change in our management, including transactions in which stockholders might otherwise receive a premium for their shares or transactions that our stockholders might otherwise deem to be in their best interests. Therefore, these provisions could adversely affect the price of our common stock. Among other things, our amended and restated certificate of incorporation and amended and restated bylaws:

The amendment of any of these provisions, with the exception of the ability of our board of directors to issue shares of preferred stock and designate any rights, preferences and privileges thereto, requires approval by the holders of at least two-thirds of our then-outstanding capital stock entitled to vote thereon, voting together as a single class.

In addition, as a Delaware corporation, we are subject to Section 203 of the Delaware General Corporation Law. These provisions may prohibit large stockholders, in particular those owning 15% or more of our outstanding voting stock, from merging or combining with us for a certain period of time. A Delaware corporation may opt out of this provision by express provision in its original certificate of incorporation or by amendment to its certificate of incorporation or bylaws approved by its stockholders. However, we have not opted out of this provision.

These and other provisions in our amended and restated certificate of incorporation, amended and restated bylaws and Delaware law could make it more difficult for stockholders or potential acquirors to obtain control of our board of directors or initiate actions that are opposed by our then-current board of directors, including delay or impede a merger, tender offer or proxy contest involving

our company. The existence of these provisions could negatively affect the price of our common stock and limit opportunities for you to realize value in a corporate transaction.

General risk factors

We will incur significantly increased costs as a result of operating as a public company, and our management will be required to devote substantial time to new compliance initiatives and corporate governance practices.

As a public company, and particularly after we are no longer an emerging growth company or smaller reporting company, we will incur significant legal, accounting and other expenses that we did not incur as a private company. The Securities Act, the Exchange Act, Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Consumer Protection Act, the listing requirements of Nasdaq and other applicable securities rules and regulations impose various requirements on public companies, including establishment and maintenance of effective disclosure and financial controls and corporate governance practices. Our management and other personnel will need to devote a substantial amount of time to these compliance initiatives. Moreover, we expect these rules and regulations to substantially increase our legal and financial compliance costs and to make some activities more time consuming and costly. For example, we expect that these rules and regulations may make it more difficult and more expensive for us to obtain director and officer liability insurance and we may be required to incur substantial costs to maintain sufficient coverage. We cannot predict or estimate the amount or timing of additional costs we may incur to respond to these requirements. The impact of these requirements could also make it more difficult for us to attract and retain qualified persons to serve on our board of directors, our board committees or as executive officers. The increased costs may require us to reduce costs in other areas of our business. Moreover, these rules and regulations are often subject to varying interpretations, in many cases due to their lack of specificity, and, as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies. This could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices.

Unfavorable global economic conditions could adversely affect our business, financial condition or results of operations.

Our results of operations could be adversely affected by general conditions in the global economy, geopolitical tensions, including heightened risk of military conflict, political instability and escalation of hostilities in the Middle East, and in the global financial markets. A severe or prolonged economic downturn or additional global financial and political crises could result in a variety of risks to our business, including weakened demand for any product candidates we develop or our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could also strain our suppliers or other third parties and create import and export issues, possibly resulting in supply disruption. Any of the foregoing could harm our business and we cannot anticipate all of the ways in which the current economic climate and financial market conditions could adversely impact our business.

We face risks related to health epidemics, pandemics and other widespread outbreaks of contagious disease, which could significantly disrupt our operations, impact our financial results or otherwise adversely impact our business.

Significant outbreaks of contagious diseases and other adverse public health developments could have a material impact on our business operations and operating results. As a result of public health crises that may arise, we may experience disruptions that could adversely impact our operations, research and development, and as we continue developing, any preclinical studies, clinical trials and manufacturing activities we may conduct, some of which may include: 

In addition, the trading prices for biopharmaceutical companies have been highly volatile as a result of the COVID-19 pandemic and we may face similar volatility in our stock price. If we or any of the third parties with whom we engage were to experience shutdowns or other business disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially and negatively affected, which could have a material adverse impact on our business, financial condition, our results of operations and prospects.

Our operations are vulnerable to interruption by disasters, terrorist activity, pandemics and other events beyond our control, which could harm our business.

We have not undertaken a systematic analysis of the potential consequences to our business and financial results from a major flood, power loss, terrorist activity, pandemics or other regional or global disasters and generally do not have a recovery plan for such events. In addition, we do not carry sufficient insurance to compensate us for actual losses from interruption of our business that may occur, and any losses or damages incurred by us could harm our business. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses.

We could be subject to securities class action litigation.

In the past, securities class action litigation has often been instituted against companies following periods of volatility in the market price of a company’s securities. This type of litigation, if instituted, could result in substantial costs and a diversion of management’s attention and resources, which would harm our business, operating results, or financial condition. Additionally, the dramatic increase in the cost of directors’ and officers’ liability insurance may cause us to opt for lower overall policy limits or to forgo insurance that we may otherwise rely on to cover significant defense costs, settlements, and damages awarded to plaintiffs.

Failure to establish and maintain effective internal control over financial reporting could adversely affect our business and if investors lose confidence in the accuracy and completeness of our financial reports, the market price of our common stock could be negatively affected.

As a public company, we are required to comply with the SEC’s rules implementing Sections 302 and 404 of the Sarbanes-Oxley Act, which requires management to certify financial and other information in our quarterly and annual reports and provide an annual management report on the effectiveness of internal control over financial reporting. Although we are required to disclose changes made in our internal control over financial reporting on a quarterly basis, we are not required to make our first annual assessment of our internal control over financial reporting until our annual report on Form 10-K for the year ending December 31, 2026. However, as an emerging growth company and smaller reporting company, our independent registered public accounting firm will not be required to formally attest to the effectiveness of our internal control over financial reporting until the later of the year following our first annual report required to be filed with the SEC or the date we are no longer an emerging growth company or smaller reporting company. At such time, our independent registered public accounting firm would need to issue a report that is adverse in the event that there are material weaknesses in our internal control over financial reporting.

As a private company, we did not have any internal audit function. To comply with the requirements of being a public company, we have undertaken various actions, and will need to take additional actions, such as implementing numerous internal controls and procedures and hiring additional accounting or internal audit staff or consultants. Testing and maintaining internal controls can divert our management’s attention from other matters that are important to the operation of our business and failure to establish and maintain effective internal control over financial reporting could adversely affect our business and if investors lose confidence in the accuracy and completeness of our financial reports, the market price of our common stock could be negatively affected.

Our disclosure controls and procedures or internal controls and procedures may not prevent or detect all errors or acts of fraud.

As a public company, we must design our disclosure controls and procedures to reasonably assure that information we must disclose in reports we file or submit under the Exchange Act is accumulated and communicated to management, and recorded, processed, summarized, and reported within the time periods specified in the rules and forms of the SEC. We believe that any disclosure controls and procedures or internal controls and procedures, no matter how well-conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. For example, our directors or executive officers could inadvertently fail to disclose a new relationship or arrangement causing us to fail to make a required related party transaction disclosure. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements due to error or fraud may occur and not be detected.

Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

We have incurred losses during our history and do not expect to become profitable in the near future, and we may never achieve profitability. Under current law, U.S. federal net operating losses, or NOLs, incurred in taxable years beginning after December 31, 2017, can be carried forward indefinitely, but the deductibility of such U.S. federal NOLs in taxable years beginning after December 31, 2020, is limited to 80% of taxable income. It is uncertain if and to what extent various states will conform to the federal law.

As of December 31, 2025, we had $45.8 million of U.S. federal NOLs and $40.8 million of state NOLs. Our U.S. federal NOLs can be carried forward indefinitely under current laws and the state NOLs begin to expire in 2041. Additionally, we continue to generate U.S. federal research and development, or R&D, credits, which generally may be carried forward to offset a portion of future tax liabilities, if any, subject to expiration of such credit carryforwards. Our NOL carryforwards and R&D credits are subject to review and possible adjustment by the U.S. and state tax authorities.

In addition, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a cumulative change (by value) in its equity ownership by “5-percent shareholders” that is greater than 50 percentage points over a rolling three-year period, the corporation’s ability to use its pre-change NOL carryforwards, R&D credits and certain other pre-change tax attributes to offset its post-change income or taxes may be limited. This could limit the amount of NOLs, R&D credit carryforwards or other applicable tax attributes that we can utilize annually to offset future taxable income or tax liabilities. Our recently completed initial public offering, together with private placements and other transactions that have occurred since our inception, may trigger such an ownership change. Subsequent ownership changes, some of which may be outside our control, and changes to the U.S. tax rules in respect of the utilization of NOLs, R&D credits and other applicable tax attributes carried forward may further affect the limitation in future years. We have not conducted any studies to determine annual limitations, if any, that could result from such ownership changes.

In addition, at the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. As a result, we may be unable to use all or a material portion of our NOL carryforwards and other tax attributes, which could adversely affect our future cash flows.

Changes in tax laws or regulations that are applied adversely to us or our customers may have a material adverse effect on our business, cash flow, financial condition or results of operations.

New income, sales, use or other tax laws, statutes, rules, regulations, or ordinances could be enacted at any time, which could adversely affect our business operations and financial performance. Further, existing tax laws, statutes, rules, regulations, or ordinances could be interpreted, changed, modified or applied adversely to us. For example, the Tax Cuts and Jobs Act, the Coronavirus Aid, Relief, and Economic Security Act, and the IRA have all made many significant changes to the U.S. tax laws. Future guidance from the Internal Revenue Service and other tax authorities with respect to such legislation may affect us, and certain aspects of such legislation could be repealed or modified in future legislation. It is also possible that future legislation could have an adverse effect on our operations, cash flows and results of operations and contribute to overall market volatility. In addition, it is uncertain if and to what extent various states will conform to recent or newly enacted federal tax legislation. Changes in corporate tax rates, the realization of net deferred tax assets relating to our operations, the taxation of foreign earnings, and the deductibility of expenses could have a material impact on the value of our deferred tax assets, could result in significant one-time charges, and could increase our future U.S. tax expense.

If our information technology systems or data, or those of third parties upon which we rely, are or were compromised, we could experience adverse consequences resulting from such compromise, including but not limited to regulatory investigations or actions, litigation, fines and penalties, disruptions of our business operations, reputational harm, loss of revenue or profits, and other adverse consequences. Our internal computer systems, or those of our third-party CROs, manufacturers, contractors or consultants, or current or future collaborators or other third parties, may fail or suffer security breaches or other unauthorized or improper access, which could result in a material disruption of our development programs or other adverse consequences.

We are increasingly dependent upon information technology systems, infrastructure and data to operate our business. In the ordinary course of business, we collect, store, handle, share, use, retain, safeguard, transmit, analyze and otherwise process large amounts of data, including, without limitation, proprietary business information, intellectual property, health information, personal information and other confidential information, or collectively, confidential information. We have also outsourced elements of our operations to third parties, and as a result we manage a number of CROs, manufacturers, third-party vendors and other contractors, consultants and collaborators who have access to such information. It is critical that we and these third parties process such confidential information in a manner to maintain the confidentiality and integrity of such information.

Despite the implementation of security measures, given the size and complexity of our internal information technology systems and those of our current and future CROs, manufacturers, third-party vendors and other contractors, consultants and collaborators, and the increasing amounts of confidential information that we and such parties maintain, such internal information technology systems are potentially vulnerable to breakdown or other damage, interruption or incident, including from service interruptions, system failures or malfunctions, information security threats, such as data breaches, damage from computer viruses, cyberattacks (such as the deployment of malware, denial-of-service attacks, ransomware attacks, supply chain attacks, and phishing and other social engineering attacks), unauthorized access, intentional or accidental actions or inaction by our employees, third-party vendors, contractors, consultants, business partners or other third parties that introduce vulnerabilities, natural disasters, terrorism, war, telecommunication and electrical failures and other compromises or disruptions.

While we have not experienced any material system failures, accidents, security breaches, intrusions or other incidents to date, if such an event were to occur, or be perceived to occur, and cause interruptions in our operations or result in any inadvertent or unauthorized disclosure of or access to personal information, protected health information, or other sensitive, confidential or proprietary information, it could compel us to comply with breach notification laws, subject us to mandatory remedial action or otherwise result in a material disruption of our programs and/or material liability and reputation harm. For example, the loss of data from preclinical studies or clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. Undetected security breaches of our information technology systems could result in the theft of our proprietary chemical structures and fraudulent filing of patent claims by competitors that could limit our freedom to operate in

the future. To the extent that any disruption, security breach or other incident results in a loss of or damage to our data or applications, other data or applications relating to our technology, [225Ac]Ac-AKY-1189 or other current or future product candidates, or those of our third-party vendors and other contractors and consultants, or inappropriate disclosure of confidential or proprietary information, we could incur liabilities and the further development of [225Ac]Ac-AKY-1189 or other current or future product candidates could be compromised or delayed. Any of the foregoing could result in significant legal and financial exposure and reputational damage that could potentially have a material adverse effect on our business, financial condition, results of operations, and prospects. We may be unable to adequately protect our information systems from cyberattacks, which could result in the disclosure of confidential or proprietary information, including personal data, damage our reputation, and subject us to significant financial and legal exposure.

We rely on information technology systems that we or our third-party service providers operate to collect, store, handle, share, use, retain, safeguard, transmit, analyze and otherwise process electronic information in our day-to-day operations. In connection with our discovery efforts, we may collect, store, handle, use or otherwise process a variety of personal information and data, such as name, mailing address, email addresses, phone number and clinical trial information. A successful cyberattack could result in the theft or destruction of intellectual property, data (such as personal information) or other misappropriation of assets, or otherwise compromise our confidential or proprietary information and disrupt our operations. Cyberattacks are increasing in their frequency, sophistication and intensity, and have become increasingly difficult to detect. Cyberattacks could include wrongful conduct by computer hackers, hostile foreign governments or agencies, industrial espionage, cyber criminals, organized crime affiliates, terrorist organizations, wire fraud and other forms of cyber fraud, the deployment of harmful malware, denial-of-service, social engineering fraud, ransomware, loss of data or other information technology assets, adware, telecommunications failures, earthquakes, fires, floods, and other similar threats or other means to threaten data security, confidentiality, integrity and availability. We may not be able to anticipate all types of security threats, and we may not be able to implement preventive measures effective against all such security threats. A successful cyberattack could cause serious negative consequences for us, including, without limitation, the disruption of operations, the misappropriation of confidential business information, including financial information and trade secrets, financial loss and the disclosure of corporate strategic plans. Although we devote resources to protect our information systems, we realize that cyberattacks are a threat, and there can be no assurance that our efforts will prevent information security breaches that would result in business, legal, financial or reputational harm to us, or would have a material adverse effect on our results of operations and financial condition. Any failure to prevent or mitigate security breaches or improper access to, use of, or disclosure of our clinical data or patients’ personal data could result in significant liability under state (e.g., state breach notification laws), federal (e.g., HIPAA, as amended by HITECH), and international law (e.g., the EU GDPR or the UK GDPR) and may cause a material adverse impact to our reputation, affect our ability to use collected data, conduct new studies and potentially disrupt our business.

Some actors now engage and are expected to continue to engage in cyberattacks, including without limitation nation-state actors for geopolitical reasons and in conjunction with military conflicts and defense activities. During times of war and other major conflicts, we and the third parties upon which we rely may be vulnerable to a heightened risk of these attacks, including retaliatory cyberattacks, that could materially disrupt our systems and operations, supply chain, and ability to produce, sell and distribute our services. Extortion payments may alleviate the negative impact of a ransomware attack, but we may be unwilling or unable to make such payments due to, for example, applicable laws or regulations prohibiting such payments.

Remote work has become more common and has increased risks to our information technology systems and data, as more of our employees utilize network connections, computers, and devices outside our premises or network, including working at home, while in transit and in public locations. Additionally, future or past business transactions (such as acquisitions or integrations) could expose us to additional cybersecurity risks and vulnerabilities, as our systems could be negatively affected by vulnerabilities present in acquired or integrated entities’ systems and technologies. Furthermore, we may discover security issues that were not found during due diligence of such acquired or integrated entities, and it may be difficult to integrate companies into our information technology environment and security program.

We rely on third-party service providers and technologies to operate critical business systems to process confidential information in a variety of contexts, including, without limitation, cloud-based infrastructure, data center facilities, encryption and authentication technology, employee email, content delivery to customers, and other functions. We also rely on third-party service providers to provide other products, services, parts, or otherwise to operate our business. Our ability to monitor these third parties’ information security practices is limited, and these third parties may not have adequate information security measures in place. If our third-party service providers experience a security incident, breach or other interruption, including as described above, we could experience adverse consequences. Although we may have contractual protections with our service providers, any actual or perceived security breach or other incident could harm our reputation and brand, expose us to potential liability or require us to expend significant resources on data security and in responding to any such actual or perceived breach. Any contractual protections we may have from our service providers may not be sufficient to adequately protect us from any such liabilities and losses, and we may be unable to enforce any such contractual protections.

We may expend significant resources or modify our business activities to try to protect against security incidents. Additionally, certain data privacy and cybersecurity obligations may require us to implement and maintain specific security measures or industry-standard or reasonable security measures to protect our information technology systems and confidential information. While we have implemented security measures designed to protect against security incidents, there can be no assurance that these measures have been or will be effective.

We rely on our CROs, manufacturers, contractors, consultants, collaborators and other third-party providers to implement effective security measures and identify and correct for any such failures, deficiencies, breaches or other incidents. We also rely on our employees and consultants to safeguard their security credentials and follow our policies and procedures regarding use, access and protection of computers and other devices that may contain our confidential information. There can be no assurances that these measures have been or will be effective. If we or our third-party providers fail to maintain or protect our information technology systems and data integrity effectively or fail to anticipate, plan for or manage significant disruptions to our information technology systems, we or our third-party providers could have difficulty preventing, detecting and controlling such cyberattacks or other security incidents described above which could result in losses described above, as well as disputes with physicians, patients and our partners, regulatory sanctions or penalties, increases in operating expenses, lost revenue or other adverse consequences. Any failure by such third parties to prevent or mitigate security breaches or improper access to or other unauthorized disclosure of such information could have similarly adverse consequences for us. If we are unable to prevent or mitigate the impact of such security or data privacy breaches or other incidents, we could be exposed to litigation and governmental investigations, which could lead to a potential disruption to our business.

Our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our data privacy and cybersecurity obligations and related practices. We cannot be sure that our insurance coverage will be adequate or sufficient to protect us from or to mitigate liabilities arising out of our privacy and cybersecurity practices, or any event that affects our systems or third-party systems where information important to our business operations or commercial development is stored or otherwise processed, that such coverage will continue to be available on commercially reasonable terms or at all, or that such coverage will pay future claims. Further, our insurance may not cover all claims made against us and could have high deductibles in any event, and defending a suit, regardless of its merit, could be costly and divert management attention.

In addition to experiencing a security incident, third parties may gather, collect, infer or otherwise obtain confidential information about us from public sources, data brokers, or other means that reveals competitively sensitive details about our organization and could be used to undermine our competitive advantage or market position. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

Item 1B. Unresolved Staff Comments.

Not applicable.

Item 1C. Cybersecurity.

Risk Management and Strategy

We have developed and maintain an information security program designed to assess, identify, and manage risks from cybersecurity threats. As part of this program, we conduct periodic assessments of our assets to evaluate the effectiveness of applicable security controls. These assessments are informed by industry standard frameworks and include a review of our information security controls to assess cybersecurity maturity compared to our peers and other security awareness trainings.

We engage security technology vendors to assist with detecting potential threats to our information assets. In addition, we have implemented a cybersecurity third party risk management process to assess mission and business critical third parties for cyber risks and to assist the business in making risk-informed technology product and services decisions. Our practice is to perform due diligence, including the completion of security questionnaires and risk assessments, as appropriate, on third parties who maintain material data or information to help us evaluate and verify third party information security capabilities.

Our process designed to detect and respond to cybersecurity incidents that may represent a threat to the confidentiality, integrity or availability of our information assets is based on industry standards and best practices of peer companies. Our technology, procedures and key vendors with security responsibilities are designed to help contain, eradicate and recover from cybersecurity incidents in a timely manner. Senior management is informed about incidents that may have a significant impact on the business. Incidents are reviewed once they are resolved, and policies and controls are updated to help mitigate gaps. We have not identified risks from known cybersecurity threats, including as a result of any prior cybersecurity incidents, that have materially affected us, including our operations, business strategy, results of operations, or financial condition. We face risks from cybersecurity threats that, if realized, are reasonably likely to materially affect us, including our operations, business strategy, results of operations, or financial condition. There can be no assurance, however, that our cybersecurity risk management program and processes, including our policies, controls or procedures, will be fully implemented, complied with or effective in protecting our systems and information. For more information, see Part I, Item 1A “Risk Factors— If our information technology systems or data, or those of third parties upon which we rely, are or were compromised, we could experience adverse consequences resulting from such compromise, including but not limited to regulatory investigations or actions, litigation, fines and penalties, disruptions of our business operations, reputational harm, loss of revenue or profits, and other adverse consequences. Our internal computer systems, or those of our third-party CROs, manufacturers, contractors or consultants, or current or future collaborators or other third parties, may fail or suffer security breaches or other unauthorized or improper access, which could result in a material disruption of our development programs or other adverse consequences."

Governance

Our board of directors, in coordination with the audit committee, oversees our cybersecurity risk management. On a regular basis, the audit committee discusses our cybersecurity risk management program with our Chief Operating Officer and other members of senior management. The audit committee receives regular reports from the Chief Operating Officer regarding cybersecurity and information technology matters, including recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, the threat environment, technology trends, and information security considerations relating to our peers and third parties. The full board of directors receives reports from the audit committee on its cybersecurity risk management activities, as well as updates from management regarding the Company’s cybersecurity program.

Our management team, led by our Chief Operating Officer, has primary responsibility for developing and managing our overall cybersecurity risk management program. The Chief Operating Officer oversees our internal information technology functions and supervises third-party cybersecurity vendors and consultants.

The Chief Operating Officer works collaboratively across the Company to implement and maintain a program designed to protect our information systems from cybersecurity threats and to respond promptly to cybersecurity incidents in accordance with our incident response and recovery plans. Cross-functional teams throughout the Company support these efforts by addressing cybersecurity risks and responding to incidents as they arise. Through ongoing communication with these teams and our third-party service providers, the Chief Operating Officer monitors the prevention, detection, escalation, mitigation, and remediation of cybersecurity threats and incidents and reports significant matters to the audit committee, as appropriate.

Item 2. Properties.

Our principal facilities consist of office and laboratory space. Our corporate headquarters is located in Boston, Massachusetts, where we lease and occupy approximately 17,944 square feet of such laboratory and office space at 17 Drydock Avenue, Suite 17-401, Boston, Massachusetts 02210. The current term of our lease expires in January 2033. We also lease an aggregate of 12,089 square feet of laboratory and office space in two facilities in Durham, North Carolina, under leases that expire in April 2027 and September 2026. We sublease approximately 1,332 square feet of such laboratory and office space.

We believe these facilities are adequate for the foreseeable future and that suitable additional space will be available as and when needed. To meet the future needs of our business, we may lease additional or alternate space. We believe that suitable additional or substitute space at commercially reasonable terms will be available as needed to accommodate any future expansion of our operations.

Item 3. Legal Proceedings.

From time to time, we may become involved in legal proceedings arising from the ordinary course of business. We record a liability for such matters when it is probable that future losses will be incurred and that such losses can be reasonably estimated. Significant judgment by us is required to determine both probability and the estimated amount. We are not currently subject to any material legal or arbitration proceedings.

Item 4. Mine Safety Disclosures.

Not applicable.

PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Market Information

Our common stock began trading on the Nasdaq Global Select Market under the symbol "AKTS" on January 9, 2026. Prior to that time, there was no public market for our common stock.

Holders of our Common Stock

As of March 10, 2026, there were approximately 69 stockholders of record of shares of our common stock and 4 holders of shares of our Class A common stock. The actual number of stockholders is greater than this number of record holders, and includes stockholders who are beneficial owners, but whose shares are held in street name by brokers and other nominees. This number of holders of record also does not include stockholders whose shares may be held in trust by other entities.

Dividend Policy

We have never declared or paid any cash dividends on our capital stock and do not anticipate paying any cash dividends in the foreseeable future. Payment of cash dividends, if any, in the future will be at the discretion of our board of directors and will depend on then-existing conditions, including our financial condition, operating results, contractual restrictions, capital requirements, business prospects and other factors our board of directors may deem relevant.

Recent Sales of Unregistered Equity Securities

Between January 1, 2025 and December 31, 2025, we issued to certain of our employees and directors options to purchase an aggregate of 784,343 shares of our common stock at a weighted average exercise price of $10.59 per share under our 2020 Equity Incentive Plan, or the 2020 Plan. On January 8, 2026, we issued to certain of our employees and directors options to purchase an aggregate of 1,720,277 shares of our common stock at an exercise price per share equal to $18.00 under our 2026 Equity Incentive Plan, or the 2026 Plan. The offers, sales and issuances of the securities described in this paragraph were deemed to be exempt from registration either under Rule 701 promulgated under the Securities Act, or Rule 701, in that the transactions were under compensatory benefit plans and contracts relating to compensation. The recipients of such securities were our employees, directors or consultants and received the securities under the 2020 Plan or the 2026 Plan, as applicable. Appropriate legends were affixed to the securities issued in these transactions. Each of the recipients of securities in these transactions had adequate access, through employment, business or other relationships, to information about our company. We filed a registration statement on Form S-8 (File No. 333-292679) under the Securities Act on January 12, 2026 to register all of the shares of our common stock subject to outstanding options and all shares of our common stock otherwise issuable pursuant to the 2020 Plan and 2026 Plan.

On January 12, 2026, immediately prior to the closing of our initial public offering, or the IPO, all of our outstanding shares of convertible preferred stock automatically converted into 34,057,218 shares of our common stock and 1,872,829 shares of our Class A common stock. The issuance of such common stock and Class A common stock upon conversion of the convertible preferred stock was exempt from the registration requirements of the Securities Act pursuant to Section 3(a)(9) thereof, involving an exchange of securities exchanged by the issuer with its existing security holders exclusively where no commission or other remuneration is paid or given directly or indirectly for soliciting such exchange.

Securities Authorized for Issuance Under Equity Compensation Plans

Information about securities authorized for issuance under our equity compensation plans is incorporated herein by reference to Part III, Item 12 of this Annual Report

Use of Proceeds from our Initial Public Offering

On January 8, 2026, the SEC declared effective our registration statement on Form S-1 (File No. 333-292283), as amended, or the Registration Statement, filed in connection with our IPO. Pursuant to the Registration Statement, we registered the offer and sale of 20,297,500 shares of our common stock with a maximum aggregate offering price of approximately $365.4 million. J.P. Morgan Securities LLC, BofA Securities, Inc., Leerink Partners LLC and TD Securities (USA) LLC acted as representatives of the underwriters for the IPO. We received net proceeds of $335.3 million from the sale of 20,297,500 share of common stock at a price of $18.00 per share, which included 2,647,500 shares of common stock sold pursuant to the underwriters' full exercise of their option to purchase additional shares, after deducting offering costs payable by us of $4.5 million. None of the expenses associated with the IPO were paid to directors, officers, persons owning 10% or more of any class of equity securities, or to our affiliates.

There has been no material change in the expected use of the net proceeds from our IPO as described in our final prospectus filed with the SEC pursuant to Rule 424(b) of the Securities Act on January 9, 2026. We are holding a significant portion of the balance of the net proceeds in money market funds.

Issuer Repurchases of Equity Securities

None.

Item 6. [Reserved]

Not applicable.

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and related notes and other financial information included elsewhere in this Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. See “Special Note Regarding Forward-Looking Statements.” As a result of many factors, including those factors set forth in the "Risk Factors" section of this Annual Report and "Cautionary Note Regarding Forward-Looking Statements", our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. Our historical results are not necessarily indicative of the results that may be expected for any period in the future.

Overview

We are a clinical-stage oncology company focused on expanding the breakthrough potential of targeted radiopharmaceuticals to large patient populations, including those not addressed by existing platform technologies. The field of targeted radiopharmaceuticals is currently led by two marketed products that illustrated transformative survival outcomes and quality of life benefits can be conferred by delivering radioisotopes to solid tumors. These leading products, which target prostate specific membrane antigen or somatostatin-2 receptor, are each currently approved in only one tumor type, but in those indications, have seen considerable commercial uptake and have become fundamental pillars of cancer treatment. Despite these advances, we believe that the field of radiopharmaceuticals is still in its infancy, with many emerging companies still primarily focused on these same two targets. In contrast, we see a significant opportunity to broaden the cancer patient populations benefiting from targeted radiopharmaceuticals by developing next-generation technologies that expand the scope of tumor targets for which it is possible to safely deliver a powerful payload of an alpha-emitting radioisotope. To ensure patient demand is reliably met, we are also establishing efficient end-to-end supply, with a combination of critical internal capabilities paired with experienced external vendors. Through these efforts, we seek to maximize clinical utility across multiple indications in multiple tumor types, and to expand the commercial uptake of radiopharmaceuticals beyond the traditional nuclear medicine setting and into the more expansive clinical oncology setting.

Since our inception in August 2020, we have devoted substantially all of our resources to developing our miniprotein radioconjugate platform, identifying and developing our product candidates and programs, establishing and protecting our intellectual property, conducting research and development activities, building our supply chain and manufacturing capabilities, organizing and staffing our company, raising capital and providing general and administrative support for these operations. We do not have any products approved for commercial sale and have not generated any revenues from product sales. We have funded our operations primarily with proceeds from the issuance and sale of our redeemable convertible preferred stock and upfront payments from a Research and Collaboration Agreement, the Collaboration Agreement, with Eli Lilly and Company, or Eli Lilly, and have received aggregate net proceeds of $345.5 million from the sale of our redeemable convertible preferred stock, $60.0 million in upfront payments upon entering into the Collaboration Agreement, and $1.0 million upon achieving the first development milestone under the Collaboration Agreement. In January 2026, we completed our initial public offering, or the IPO, and raised aggregate net proceeds of $335.3 million from the sale of 20,297,500 shares of common stock, which included 2,647,500 shares of common stock sold pursuant to the underwriters' full exercise of their option to purchase additional shares.

We have incurred significant operating losses in every year since inception and we expect to continue to incur substantial losses for the foreseeable future. Our ability to generate revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our product candidates. As of December 31, 2025, we had an accumulated deficit of $156.6 million and our net losses were $63.7 million and $44.0 million for the years ended December 31, 2025 and 2024, respectively. We expect our expenses and operating losses will increase substantially as we:

In addition, we have several clinical development, regulatory, and commercial milestones, as well as royalty payment obligations under our licensing arrangements. Our net losses may fluctuate significantly from quarter to quarter and year to year, depending on the timing of our ongoing and planned clinical trials and our expenditures on other research and development activities.

We do not have any products approved for sale and have not generated any revenue from product sales. We will not generate revenue from product sales unless and until we successfully complete clinical development and obtain regulatory approval for our current and any future product candidates, which we expect will take a number of years or may never occur. As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings or other capital sources, including collaborations, licenses or other strategic arrangements. See “—Liquidity and capital resources.” We may be unable to raise additional funds or enter into such other agreements or arrangements when needed on favorable terms, or at all. If we fail to raise capital or enter into such agreements as, and when, needed, we may have to significantly delay, scale back or discontinue the development and commercialization of one or more of our product candidates, or grant rights to develop and market our product candidates even if we would otherwise prefer to develop and market such product candidates ourselves.

Due to the numerous risks and uncertainties associated with the development of radiopharmaceutical candidates, we are unable to accurately predict the timing or amount of increased expenses or the timing of when, or if, we will be able to achieve or maintain profitability. Even if we generate product sales, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce or terminate our operations.

As of December 31, 2025, we had cash, cash equivalents and marketable securities of $226.8 million. Based upon our current operating plans, we believe that our existing cash, cash equivalents and marketable securities, together with the net proceeds of approximately $335.3 million from our IPO completed in January 2026, will be sufficient to fund our operations into 2029. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See the sections titled “—Liquidity and capital resources” and “Risk Factors” included elsewhere in this Annual Report.

License and collaboration agreements

We may incur contingent regulatory and development milestones, commercial milestones and royalty payments that we are required to make under our license and collaboration agreements, in which the amounts to be paid by us are not fixed or determinable at this time. For a more detailed description of these agreements, see the section titled “Business—License and collaboration agreements” and Notes 11 and 12 to our consolidated financial statements included elsewhere in this Annual Report.

Blaze Bioscience license agreement

On July 22, 2021, we entered into a Discovery, License and Option Agreement, or the Blaze Agreement, as amended on March 3, 2022, May 20, 2022 and December 19, 2022, with Blaze Bioscience Inc., or Blaze, pursuant to which we granted to each other certain exclusive and non-exclusive licenses and an option to license Blaze’s platform technology to use in conducting certain research and development activities. We made a one-time non-refundable upfront payment of $1.8 million to Blaze, as partial consideration for the rights and licenses granted to us under the Blaze Agreement. We paid an additional one-time payment of $0.2 million in connection with the December 19, 2022 amendment. The Blaze Agreement required us to make specified non-refundable, non-creditable milestone payments of up to $0.7 million per collaboration target as well as royalty payments on a product-by-product basis until the later of (a) the date of expiration of the last-to-expire valid claim covering such collaboration target, or (b) ten years following the date of the first commercial sale of such collaboration target. None of the milestones had been achieved prior to termination.

Upon execution of the Blaze Agreement, we also issued to Blaze, warrants, or the Preferred Stock Warrants, to purchase 2,000,000 shares of partner preferred stock, or the Partner Preferred Stock, as a partial consideration for the rights granted by Blaze to us. The Preferred Stock Warrants represent an additional upfront payment and the initial fair value of the Preferred Stock Warrants was $0.6 million. See Note 11 to our consolidated financial statements included elsewhere in this Annual Report. In connection with the amendment on May 20, 2022, we replaced the original terms of the Preferred Stock Warrants with revised vesting criteria, related to the achievement of development and regulatory milestones. As of December 31, 2023, 250,000 shares of the Preferred Stock Warrants were vested.

In March 2024, we notified Blaze of our decision to terminate the Blaze Agreement and Blaze exercised the Preferred Stock Warrants for 250,000 shares of Partner Preferred Stock upon payment of nominal consideration. The remaining unvested Preferred Stock Warrants were cancelled upon the notice of termination.

Institute for Protein Innovation, Inc. license agreement

On November 1, 2021, we entered into an exclusive license agreement, the IPI Agreement, with the Institute for Protein Innovation, Inc., or IPI, pursuant to which IPI granted us an exclusive, worldwide license, with the right to sublicense (subject to certain conditions), under certain of IPI’s patents and know-how related to certain binder proteins, targeting up to 14 target proteins, including Nectin-4, to research, develop, make, have made, and commercialize certain products. We made an initial upfront payment of $0.2 million and will make annual payments of less than $0.1 million on each anniversary up to the date of the first commercial sale of the first licensed product in order to retain the licenses, pursuant to which we have paid an aggregate of $0.2 million through December 31, 2025. The IPI Agreement requires us to pay up to an aggregate of $24.0 million upon achievement of certain regulatory and development milestones. In addition, if we successfully commercialize a licensed product under the IPI Agreement, we are required to pay low single-digit royalties on net sales on a product-by-product and country-by-country basis, subject to specified reductions, until the later of (a) the expiration of the last to expire valid claim covering the manufacture, use or sale of such licensed product in such country or (b) ten years after the first licensed product sale in such country. The royalties are subject to specified and capped reductions for payments owed to third parties for additional rights necessary to commercialize licensed products and will terminate upon the last to expire royalty term. As of December 31, 2025, no such milestones have been achieved. For further details see the sections titled “Business—License and collaboration agreements” included elsewhere in this Annual Report.

TRIUMF license agreement

On July 21, 2022, we and TRIUMF Inc., a Canadian non-profit, or TRIUMF, TRIUMF Innovations, Inc., a Canadian non-profit, the University of British Columbia, and BC Cancer, a provincial health services authority, entered into a License Agreement, the TRIUMF License. Pursuant to the TRIUMF License, TRIUMF, the University of British Columbia and BC Cancer, or the Licensors, granted us a non-exclusive, worldwide license, with the right to sublicense (subject to certain conditions), under certain patents and know-how related to the Licensors’ chelator technology to make, use, sell, offer for sale, import, and export certain radiopharmaceutical products for the diagnosis, treatment, amelioration, and prevention of human diseases and conditions. None of our product candidates currently incorporate, or rely on, the licensed patents and know-how from the TRIUMF License.

We paid an initial license fee of $0.1 million upon execution of the TRIUMF License. The TRIUMF License requires us to pay up to an aggregate of $2.0 million upon achievement of certain regulatory and development milestones. We are also obligated to pay low single digit royalties on net sales of licensed products, on a product-by-product basis. For licensed products not covered by a valid claim of a licensed patent, our royalty obligation terminates on the tenth anniversary of the first commercial use of such licensed product in each country. As of December 31, 2025, no such milestones have been achieved. For further details see the sections titled “Business—License and collaboration agreements” included elsewhere in this Annual Report.

University of Minnesota license agreement

On March 3, 2023, we entered into an exclusive license agreement, the Minnesota License, with Regents of the University of Minnesota, or the University of Minnesota, under which we licensed certain rights to the licensed patents of a known target-binding miniprotein, the Licensed Patents, for commercialization. We made an initial payment of $0.1 million and paid an annual license fee of less than $0.1 million throughout the term of the Minnesota License, pursuant to which we have paid an aggregate of $0.4 million through December 31, 2025. In July 2025, we provided notice to the University of Minnesota to terminate the Minnesota License and paid the $10,000 early termination fee, with an effective termination date of September 9, 2025. None of our product candidates incorporate, or rely on, the patents and know-how from the Minnesota License. For further details see the sections titled “Business—License and collaboration agreements” included elsewhere in this Annual Report.

Eli Lilly and Company research and collaboration agreement

In May 2024, we entered into the Collaboration Agreement with Eli Lilly to generate anticancer radiopharmaceuticals using our novel miniprotein technology platform. Pursuant to the Collaboration Agreement, we granted Eli Lilly an exclusive (even as to us and our affiliates), royalty-bearing, worldwide license, with the right to sublicense, to certain of our patents and other intellectual property rights to exploit certain compounds and therapeutic or diagnostic products that contain such compounds solely as products that contain a radioactive isotope. We also granted Eli Lilly a non-exclusive, royalty-bearing, worldwide license, with the right to sublicense, to the intellectual property necessary or useful to exploit the licensed compounds and licensed products solely as products that contain a radioactive isotope and a non-exclusive, fully paid-up license, with the right to sublicense, to exploit certain other intellectual property developed under the Collaboration Agreement for any and all purposes (subject to certain limitations). In addition, we and Eli Lilly agreed to negotiate in good faith to enter into a separate agreement in the event the parties agree that the clinical development of a licensed compound requires, or would be benefited by, a license to one of our other compounds. Eli Lilly may, at any time in its sole discretion and without cause, terminate the Collaboration Agreement on a collaboration target-by-collaboration target or region-by- region basis (or any combination thereof) upon 60 days’ prior written notice to us.

Under the Collaboration Agreement, Eli Lilly may designate a specified number of initial collaboration targets, with the right to substitute other targets. We will be responsible for research activities through initial human imaging studies for a lead candidate for each selected target, and Eli Lilly will thereafter be responsible for regulatory filings, clinical development and commercialization activities worldwide. There is a separate research plan for each collaboration target, and our development costs are capped, on a research plan-by-research plan basis. Eli Lilly will reimburse our reasonable out-of-pocket costs and full-time equivalent costs incurred in excess of the cap.

Eli Lilly paid us an upfront license fee of $60.0 million as a nonrefundable cash payment upon execution of the Collaboration Agreement. The Collaboration Agreement requires Eli Lilly to pay up to an aggregate of $525.0 million upon achievement of certain research development, regulatory and commercial launch milestones and up to an aggregate of $630.0 million upon achievement of certain sales milestones. As of December 31, 2025, one development milestone under the Collaboration Agreement totaling $1.0 million was achieved. In addition, if Eli Lilly successfully commercializes a therapeutic or diagnostic product under the Collaboration Agreement, Eli Lilly is required, unless earlier terminated, to pay us tiered royalties of up to 10% based on annual net sales, on a product-by-product and country-by-country basis, subject to specified reductions, until the later of the expiration of licensed patent rights in a country, expiration of regulatory exclusivity, or ten years after the first product sale in such country. The Collaboration Agreement requires Eli Lilly to use commercially reasonable efforts to develop and commercialize a licensed product from a research program in certain markets and through satisfaction of certain criteria. For further details see the sections titled “Business—License and collaboration agreements” included elsewhere in this Annual Report.

Components of results of operations

Revenue

To date, we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products in the near future, if ever. Substantially all of our revenue to date has been derived from the work performed under the Collaboration Agreement.

If our development efforts for our current or future product candidates are successful and result in regulatory approval or if we enter into additional license or collaboration agreements with third parties, we may generate revenue in the future from product sales, payments from such license or collaboration agreements, or any combination thereof. We cannot predict if, when or to what extent we will generate revenue as we may never succeed in obtaining regulatory approval for any of our product candidates. If we fail to complete preclinical and clinical development of our current or future product candidates or fail to obtain regulatory approval for any that successfully complete clinical trials, our ability to generate future revenues, and our results of operations and financial position would be adversely affected.

Operating expenses

Research and development expenses

We recognize research and development expenses in the periods in which they are incurred. Research and development expenses consist primarily of employee-related costs and other internal and external costs associated with our discovery and development efforts and the preclinical development of our current and future product candidates. In particular, our research and development expenses include:

We track direct external research and development expenses by stage of program, clinical or preclinical. We expect to report external research and development expenses for each clinical drug candidate following development candidate designation. Our internal research and development expenses are deployed across multiple programs and, as such, are not separately tracked. Significant judgments and estimates are made in determining the accrued, or prepaid expense balances at the end of any reporting period.

Research and development activities are central to our business model. We expect that our research and development expenses will continue to increase for the foreseeable future as we advance our product candidates into and through clinical development and as we continue to develop additional product candidates. We expect to fund our research and development expenses from our current cash, cash equivalents, investments in marketable securities, and a combination of public and private equity offerings, debt financings, or other sources of capital, which may include additional collaborations with other companies, marketing, distribution, or licensing arrangements with third parties, or other similar arrangements.

General and administrative expenses

General and administrative expenses consist primarily of employee-related costs, including salaries, bonuses, benefits, and stock-based compensation expenses for personnel in executive, finance, accounting, human resources, and other administrative functions. General and administrative expenses also include professional and consulting expenses, including legal fees relating to patent, intellectual property, and corporate matters, professional fees for accounting, audit, and consulting services, and facility and depreciation expenses, including expenses for rent, insurance expenses, and other operating costs not included in research and development. We recognize general and administrative expenses in the periods in which they are incurred.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our expansion of the business. We also anticipate that we will incur significantly increased accounting, audit, legal, regulatory, compliance, and director and officer insurance costs as well as investor and public relations expenses associated with operating as a public company.

Other income, net

Interest income

Other income, net consists of interest earned, the accretion or amortization of discount or premiums on our cash equivalents and investments in marketable securities, income (expense) associated with the change in fair value of the Preferred Stock Warrant Liability, and realized and unrealized foreign currency transaction losses.

Income taxes

Since our inception, we have not recorded any income tax benefits or expense for the net losses we have incurred in each period or for our earned research and development tax credits, as we believe, based upon the weight of available evidence, that it is more likely than not that all of our net operating loss carryforwards and tax credits will not be realized. As of December 31, 2025, we had net operating loss carryforwards, or NOLs, for federal and state income tax purposes of $45.8 million and $40.8 million, respectively. The federal NOLs are not subject to expiration and the state NOLs begin to expire in 2041. These loss carryforwards are available to reduce future federal taxable income, if any. As of December 31, 2025 and 2024, we have recorded a full valuation allowance against our net deferred tax assets.

Results of operations

Comparison of the years ended December 31, 2025 and 2024

The following table summarizes our results of operations (in thousands):

Revenue

Collaboration revenue was $6.5 million and $1.5 million for the years ended December 31, 2025 and 2024, respectively, driven by a full year of revenue recognized in 2025 from our Collaboration Agreement with Eli Lilly, which was entered into in May 2024 and is recognized over time using the cost incurred input method.

Research and development expenses

The following table summarizes our research and development expenses (in thousands):

Research and development expenses were $67.5 million for the year ended December 31, 2025, compared to $41.0 million for the comparable prior year period. The increase of $26.5 million was primarily due to the following:

General and administrative expenses

The following table summarizes our general and administrative expenses (in thousands):

General and administrative expenses were $13.7 million for the year ended December 31, 2025, compared to $12.6 million for the comparable prior year period. The increase of $1.1 million was primarily due to the following:

Other income, net

Other income, net was $11.0 million for the year ended December 31, 2025, compared to $8.1 million for the comparable prior year period. The increase of $2.9 million was primarily driven by an increase in interest income earned due to higher average balances in cash equivalents and marketable securities in the year ended December 31, 2025, compared to the comparable prior year period.

Liquidity and capital resources

Sources of liquidity

Since our inception, we have incurred significant operating losses. We have not generated any revenue from product sales and we do not expect to generate revenue from sales of products in the near term, if at all. We expect to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates into and through clinical development and as we continue to develop additional product candidates. As such, we expect our research and development and general and administrative costs will continue to increase significantly, including the costs associated with operating as a public company. As a result, we will need additional capital to fund our operations, which we may obtain from additional equity or debt financings or strategic agreements.

To date, we have funded our operations primarily with proceeds from the issuance and sale of our redeemable convertible preferred stock and the Collaboration Agreement with Eli Lilly. As of December 31, 2025, we had raised aggregate net proceeds of $345.5 million through the sale and issuance of our redeemable convertible preferred stock and received $60.0 million in upfront payments and $1.0 million from the achievement of the first milestone under the Collaboration Agreement with Eli Lilly. As of December 31, 2025, we had cash, cash equivalents and marketable securities of $226.8 million.

In January 2026, we raised aggregate net proceeds of $335.3 million from the sale of shares of common stock in our initial public offering.

Cash flows

The following table sets forth a summary of the net cash flow activity (in thousands):

Operating activities

Net cash used in operating activities was $64.1 million for the year ended December 31, 2025, primarily consisting of our net loss of $63.7 million and net changes in operating assets and liabilities of $3.4 million, offset by non-cash charges of $2.8 million related to accretion of investment discounts, stock-based compensation and depreciation.

Net cash provided by operating activities was $14.8 million for the year ended December 31, 2024, primarily consisting of net changes in operating assets and liabilities of $59.0 million, primarily driven by an increase in deferred revenue in connection with the Collaboration Agreement of $58.5 million, partially offset by our net loss of $44.0 million, and $0.2 million of non-cash charges related to stock-based compensation, depreciation, and accretion of investment discounts.

Investing activities

Net cash provided by investing activities was $66.0 million for the year ended December 31, 2025, primarily consisting of maturities of marketable securities of $269.4 million, partially offset by purchases of marketable securities and property and equipment of $193.8 million and $9.6 million, respectively.

Net cash used in investing activities was $190.4 million for the year ended December 31, 2024, primarily consisting of the purchases of marketable securities and property and equipment of $288.4 million and $2.9 million, respectively, partially offset by maturities of marketable securities of $100.9 million.

Financing activities

Net cash used in financing activities was $1.2 million during the year ended December 31, 2025, primarily consisting of payments of deferred offering costs of $1.5 million, partially offset by proceeds received from the exercise of common stock options of $0.3 million.

Net cash provided by financing activities was $183.3 million during the year ended December 31, 2024, primarily consisting of proceeds from the issuances of Series A-1 redeemable convertible preferred stock and Series B redeemable convertible preferred stock of $10.0 million and $175.0 million, respectively, and the exercise of common stock options of $0.2 million, partially offset by payments of deferred offering costs of $1.5 million and issuance costs relating to the Series A-1 and Series B financings of $0.3 million.

Future funding requirements

As of December 31, 2025, we had cash, cash equivalents and marketable securities of $226.8 million. Based upon our current operating plans, we believe that the net proceeds from our initial public offering, together with our cash, cash equivalents and marketable securities as of December 31, 2025, will be sufficient to fund our operations into 2029. We have based this estimate on assumptions that may prove to be wrong, and we could expend our capital resources sooner than we expect.

We expect to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates into and through clinical development and as we continue to develop additional product candidates. In addition, we expect to incur additional costs associated with operating as a public company, including significant legal, accounting, investor relations and other expenses that we did not incur as a private company. We may also require additional capital to pursue additional research and collaboration agreements.

Because of the numerous risks and uncertainties associated with research, development, and commercialization of pharmaceutical product candidates, we are unable to estimate the amount of our future working capital requirements. Our future capital requirements will depend on many factors, including:

We have no committed sources of capital. Until such time, if ever, as we can generate substantial product revenue to support our cost structure, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, potentially including collaborations, licenses or other strategic arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing common stockholders. In addition, debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If we raise additional funds through a strategic agreement, we may have to grant rights to develop and market our current and future product candidates even if we would otherwise prefer to develop and market such product candidates ourselves. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional capital or obtain adequate funding when needed or on acceptable terms, we may be required to delay, scale back, or discontinue our research, product development, or future commercialization efforts, or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

Contractual obligations and commitments

Royalty transfer agreement

In August 2020, we entered into a royalty transfer agreement, or the Royalty Transfer Agreement, with MPM Oncology Charitable Foundation, Inc., or MPM Charitable Foundation, an affiliate of a stockholder holding more than 5% of our total outstanding stock, and the UBS Optimus Foundation, or UBS, and together with MPM Charitable Foundation, the Charitable Foundations. Pursuant to the Royalty Transfer Agreement, we will pay 0.5% of our annual global net sales to each of the Charitable Foundations, for a total of 1.0% of net sales, subject to customary reductions, for products that incorporate or utilize intellectual property that was discovered or developed by us prior to our initial public offering. Our payment obligations for each product will continue on a country-by-country basis upon the later of the twelfth anniversary of the first commercial sale of our product in such country or the expiration of the last to expire of certain patents owned or controlled by us covering such products in such country.

Our payment obligations to MPM Charitable Foundation will terminate immediately upon the authorization of the MPM Charitable Foundation’s board of directors (or similar body) or upon the winding up or dissolution of MPM Charitable Foundation. Our payment obligations to UBS will terminate immediately upon the winding up of Oncology Impact Fund 2, L.P., a Cayman Islands exempted limited partnership, which is associated with MPM Charitable Foundation.

Leases

As of December 31, 2025, we had future minimum operating lease payment obligations under non-cancellable leases of $16.3 million related to leases we have recognized on our consolidated balance sheets, which are due over the following 6.87 years.

License agreements

Our agreements with certain third parties to license intellectual property include potential milestone fees, sublicense fees and royalty fees. The milestone fees are dependent upon the development of products using the intellectual property licensed under the arrangements and contingent upon the achievement of development or regulatory approval milestones, as well as commercial milestones. These potential obligations are contingent upon the occurrence of future events and the timing and likelihood of such potential obligations are not known with certainty. For further information regarding these agreements, please see the section titled “Business—License and collaboration agreements,” included elsewhere in this Annual Report.

Purchase and other obligations

We enter into contracts in the normal course of business with CROs and other third-party vendors for preclinical and commercial supply manufacturing, support for pre-commercial activities, research and development activities, and other services and products for our operations. These contracts are generally cancelable upon written notice. For additional information on our contractual obligations and commitments please see Note 13 to our consolidated financial statements included elsewhere in this Annual Report.

Critical accounting estimates

While our significant accounting policies are described in more detail in Note 2 to our consolidated financial statements included elsewhere in this Annual Report, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our consolidated financial statements.

Revenue recognition

In May 2024, we entered into the Collaboration Agreement. We apply the revenue recognition guidance in accordance with the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 606, Revenue Recognition, or ASC 606. Under ASC 606, we recognize revenue following the five steps: (i) identification of the contract(s) with a customer; (ii) identification of the promised goods and services in the contract and determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) we satisfy each performance obligation. We only apply the five-step model once the contract is determined to be within scope of ASC 606 and when we determine that collection of substantially all consideration for goods and services that are transferred is probable based on the customer's intent and ability to pay the promised consideration.

At contract inception, once the contract is determined to be within the scope of ASC 606, we assess the goods or services promised within each contract and determine those that are performance obligations, and whether each promised good or service is distinct and if there are any material rights present. We then recognize as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For each material right identified, if any, the allocated transaction price will be recognized as revenue over the total estimated period of performance upon exercise of the material right, or will be recognized as revenue immediately upon expiration of the replacement right.

As part of the accounting for these arrangements, we must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract as there is not a readily available standalone selling price. Our revenue recognized is related to research services performed for each initial collaboration target whereby revenue was recognized as the underlying services were performed using a costs incurred input method, in which we apply a cost-to-cost method and compare the actual costs incurred to date with the current estimate of total costs to complete, or ETCs, to measure the satisfaction of each performance obligation. We estimate the ETCs utilizing our best knowledge and as there are changes in facts and circumstances, we update our ETCs accordingly for the ongoing and prospective research activities. To the extent the estimates are not appropriate in the circumstances, it could impact the timing of our revenue recognition. We evaluate the measure of progress each reporting period and if estimates related to the measure of progress change, related revenue recognition is adjusted accordingly.

Accrued research and development expenses

In preparing the consolidated financial statements, we are required to estimate our accrued research and development expenses as of each balance sheet date. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period. This process involves reviewing open contracts, communicating with internal personnel to identify services that have been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. We periodically confirm the accuracy of our estimates with our service providers and make adjustments, if necessary. The majority of our service providers invoice in arrears for services performed or when contractual milestones are met. The financial terms of agreements with these service providers are subject to negotiation, vary from contract-to-contract and may result in uneven payment flows. In circumstances where amounts have been paid in excess of costs incurred, we record a prepaid expense.

Although we do not expect our estimates to be materially different from amounts incurred, if our estimates of the status and timing of services performed differ from the actual status and timing of services performed, it could result in us reporting amounts that are too high or too low in any particular period. To date, there have been no material differences between our estimates of such expenses and the amounts incurred.

Stock-based compensation

We account for stock-based compensation under the provisions of ASC Topic 718-10, Compensation-Stock Compensation, ASC 718-10, which requires all stock-based payments to employees, non-employees, and directors, including grants of stock options and restricted stock, which we collectively refer to as stock awards, to be recognized in the consolidated statements of operations and comprehensive loss based on their fair values on the date of grant over the requisite service period, which is generally the vesting period of the respective award. Forfeitures are accounted for as they occur. Generally, we issue stock awards with only service-based vesting conditions and record the expense for these awards using the straight-line method. We classify stock-based compensation expense in the same manner in which the awards recipient’s payroll or service provider’s costs are classified.

We estimate the fair value of each option grant using the Black-Scholes option pricing model and we estimate the fair value of each restricted stock grant using the fair value of common stock. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the award, the risk-free interest rate, expected dividends, and the fair value of common stock. We estimate the expected stock price volatility based on the historical

volatility of publicly traded peer companies. The expected term of our stock options has been determined utilizing the “simplified” method for awards that qualify as “plain vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. There is no expected dividend yield since we have never paid cash dividends on common stock and do not expect to pay any cash dividends in the foreseeable future.

Determination of fair value of common stock valuations

Prior to our initial public offering in January 2026, there was no public market for our common stock to date. As a result, the estimated fair value of our common stock has been determined by our Board of Directors, or the Board, as of the date of each option grant with input from management, considering our most recently available third-party valuations of common stock, and our Boards’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent valuation through the date of the grant. These third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Our common stock valuation was prepared using a market approach to estimate our enterprise value and an option pricing method, OPM, to allocate value to the common stock. The OPM treats common stock and convertible preferred stock as call options on the total equity value of a company, with exercise prices based on the value thresholds at which the allocation among the various holders of a company’s securities changes. Under this method, the common stock has value only if the funds available for distribution to stockholders exceeded the value of the convertible preferred stock liquidation preferences at the time of the liquidity event, such as a strategic sale or a merger. A discount for lack of marketability of the common stock is then applied to arrive at an indication of value for the common stock.

Given the absence of a public trading market, our Board, with input from management considered numerous objective and subjective factors to determine the fair value of common stock. The factors included, but were not limited to:

The assumptions underlying these valuations were highly complex and subjective and represented management’s best estimates, which involved inherent uncertainties and the application of management’s judgment. As a result, if we had used significantly different assumptions or estimates, the fair value of our common stock and our stock-based compensation expense could have been materially different.

In January 2026, we completed our IPO. As such, the fair value of our common stock will be determined based on the quoted market price of our common stock and it is no longer necessary for our board of directors to estimate the fair value of our common stock in connection with our accounting for granted stock options and other such awards we may grant.

Recently issued accounting pronouncements

A description of recently issued accounting pronouncements that may potentially impact our financial position and results of operations is disclosed in Note 2 to our consolidated financial statements included elsewhere in this Annual Report.

Emerging Growth Company and Smaller Reporting Company status

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, as amended, or JOBS Act, and we may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. We may take advantage of these exemptions until we are no longer an emerging growth company. Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. We have elected to use the

extended transition period for complying with new or revised accounting standards and as a result of this election, our consolidated financial statements may not be comparable to companies that comply with public company effective dates. We may take advantage of these exemptions up until the time that we are no longer an “emerging growth company.”

We will remain an emerging growth company until the earlier of (1) the last day of the fiscal year (a) following the fifth anniversary of the completion of our initial public offering, (b) in which we have total annual gross revenue of at least $1.235 billion or (c) in which we are deemed to be a “large accelerated filer” under the rules of the SEC, which means, among other things, the market value of our common stock that is held by non-affiliates exceeds $700.0 million as of the last business day of our most recently completed second fiscal quarter and (2) the date on which we have issued more than $1.0 billion in non-convertible debt during the prior three-year period.

We are also a “smaller reporting company” as defined in the Exchange Act. We may continue to be a smaller reporting company even after we are no longer an emerging growth company. We may take advantage of certain of the scaled disclosures available to smaller reporting companies until for so long as either (i) our voting and non-voting common stock held by non-affiliates is less than $250.0 million measured on the last business day of our second fiscal quarter, or (ii) our annual revenue is less than $100.0 million during the most recently completed fiscal year and our voting and non-voting common stock held by non-affiliates is less than $700.0 million measured on the last business day of our second fiscal quarter.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

As a "smaller reporting company," as defined by Rule 12b-2 of the Exchange Act, and pursuant to Item 305 of Regulation S-K, we are not required to provide quantitative and qualitative disclosures about market risk.

Item 8. Financial Statements and Supplementary Data.

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm

To the stockholders and the Board of Directors of Aktis Oncology, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Aktis Oncology, Inc. and subsidiary (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, redeemable convertible preferred stock and stockholders' deficit, and cash flows for each of the years then ended, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

March 30, 2026

We have served as the Company's auditor since 2021.

AKTIS ONCOLOGY, INC.

CONSOLIDATED BALANCE SHEETS

(In thousands, except shares and par value data)

The accompanying notes are an integral part of these consolidated financial statements.

AKTIS ONCOLOGY, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

(In thousands, except share and per share data)

The accompanying notes are an integral part of these consolidated financial statements.

AKTIS ONCOLOGY, INC.

CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT

(In thousands, except share amounts)