Ionis Pharmaceuticals
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549

FORM 10-K
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934
FOR THE FISCAL YEAR ENDED DECEMBER 31, 2000
COMMISSION FILE NUMBER 0-19125

ISIS PHARMACEUTICALS, INC.
(Exact name of Registrant as specified in its charter)

DELAWARE 33-0336973
State or other jurisdiction of (IRS Employer Identification No.)
incorporation or organization)

2292 FARADAY AVE., CARLSBAD, CA 92008
(Address of principal executive offices, including zip code)

760-931-9200
(Registrant's telephone number, including area code)

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

Securities registered pursuant to Section 12(g) of the Act:
COMMON STOCK, $.001 PAR VALUE

Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities and Exchange Act
of 1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes X No .
--- ---

Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not be contained to
the best of Registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. Yes X No .
--- ---

The approximate aggregate market value of the voting common stock held
by non-affiliates of the Registrant, based upon the last sale price of the
common stock reported on the National Association of Securities Dealers
Automated Quotation National Market System was $299,046,755 as of January 12,
2001.*

The number of shares of voting common stock outstanding as of
January12, 2001 was 40,119,564.

DOCUMENTS INCORPORATED BY REFERENCE
(To the extent indicated herein)

Registrant's definitive Proxy Statement filed on or about February 28,
2001 with the Securities and Exchange Commission in connection with Registrant's
annual meeting of stockholders to be held on April 6, 2001 is incorporated by
reference into Part III of this Report.

- ------------------------

*Excludes 10,584,082 shares of common stock held by directors and
officers and by stockholders whose beneficial ownership is known by the
registrant to exceed 10% of the common stock outstanding at January 12, 2001.
Exclusion of shares held by any person should not be construed to indicate that
such person possesses the power, direct or indirect, to direct or cause the
direction of the management or policies of the Registrant, or that such person
is controlled by or under common control with the Registrant.
THIS FORM 10-K CONTAINS FORWARD-LOOKING STATEMENTS REGARDING THE
COMPANY'S BUSINESS AND THE THERAPEUTIC AND COMMERCIAL POTENTIAL OF ITS
TECHNOLOGIES AND PRODUCTS IN DEVELOPMENT. SUCH STATEMENTS ARE SUBJECT TO CERTAIN
RISKS AND UNCERTAINTIES, PARTICULARLY THOSE RISKS OR UNCERTAINTIES INHERENT IN
THE PROCESS OF DISCOVERING, DEVELOPING AND COMMERCIALIZING DRUGS THAT CAN BE
PROVEN TO BE SAFE AND EFFECTIVE FOR USE AS HUMAN THERAPEUTICS, AND THE ENDEAVOR
OF BUILDING A BUSINESS AROUND SUCH POTENTIAL PRODUCTS. ACTUAL RESULTS COULD
DIFFER MATERIALLY FROM THOSE DISCUSSED IN THIS FORM 10-K. FACTORS THAT COULD
CAUSE OR CONTRIBUTE TO SUCH DIFFERENCES INCLUDE, BUT ARE NOT LIMITED TO, THOSE
DISCUSSED IN THIS FORM 10-K INCLUDING THOSE IDENTIFIED IN THE SECTION OF ITEM 1
ENTITLED "RISK FACTORS." AS A RESULT, THE READER IS CAUTIONED NOT TO RELY ON
THESE FORWARD-LOOKING STATEMENTS.

2
PART I

ITEM 1. BUSINESS

OVERVIEW

The sequencing of the human genome is opening up significant new
opportunities for the treatment of disease. At Isis, we are pioneering
genomics-based drug discovery and development focused on RNA. RNA, or
ribonucleic acid, contains all of the information the cell needs to produce
proteins. Interaction with RNA can keep disease-causing proteins from being
produced. Our goal is to discover and develop novel drugs to treat patients and
to use our proprietary technologies to allow our pharmaceutical company partners
to most efficiently capitalize on the opportunities provided by the genomics
revolution. RNA is a novel target for drug discovery, and we believe we have
established a dominant position in exploiting RNA as a drug target.

We have integrated our expertise in molecular and cellular biology,
medicinal chemistry, RNA biochemistry, bioinformatics, pharmacology and clinical
development to create two exciting technologies. Antisense, our leading
technology, directly uses gene sequencing information to rationally design
drugs. From this technology, we have put one product on the market and built a
robust pipeline of eleven products in development, of which six products are in
late stage clinical trials, either Phase II or Phase III. We have successfully
leveraged our antisense technology through corporate collaborations with Elan
Pharmaceuticals, Inc., Merck & Co., Inc.; AstraZeneca plc; Abbott Laboratories,
Inc.; Aventis S.A., formerly Rhone-Poulenc Rorer; R.W. Johnson Pharmaceutical
Research Institute, a member of the Johnson & Johnson family of companies;
Novartis Ophthalmics, formerly CIBA Vision; Novartis AG and Boehringer Ingelheim
International GmbH. These collaborations increase our financial resources,
improve our technological strength and establish valuable development and
commercial relationships.

Our Ibis Therapeutics-TM- division has created a complementary
technology based on designing small molecule drugs that work by binding to
structured RNA targets that are critical in disease processes. In 2000, Ibis
initiated its first collaboration with a pharmaceutical industry partner,
Agouron Pharmaceuticals, Inc., a Pfizer company, in a research partnership worth
up to $37 million.

Our GeneTrove-TM- division uses our antisense technology as a tool to
provide pharmaceutical companies with vital information about genes that these
companies are interested in targeting for drug discovery. We provide this
information rapidly and efficiently, using the proprietary methods and systems
that we developed to create antisense inhibitors as drugs. We have
collaborations in place with three major pharmaceutical partners for these
services and recently successfully completed a one year collaboration with
another major pharmaceutical company. We plan to grow this business. We expect
to supplement our GeneTrove services business with a subscription database,
which we plan to launch later this year. The database will contain our
proprietary gene function information, which is valuable in designing and
prioritizing genomics-based drug discovery programs.

In addition to our antisense technology, our Ibis program and our
GeneTrove genomics services business, we have a broad patent portfolio covering
inventions in areas such as antisense chemistries, mechanisms by which antisense
inhibitors work, gene sequences, antisense drugs in specific diseases, methods
of performing our Ibis and GeneTrove businesses and manufacturing methods. We
believe we have the largest antisense and RNA-oriented patent estate in the
pharmaceutical industry with more than 700 patents issued or allowed. Beyond our
RNA-based drug discovery patents, we have several other patents that have
contributed substantial revenue to us. These patents include PNA antisense
chemistry, reagents for diagnostics and novel immunogenicity applications of
antisense. In 2000, we generated $12.3 million in revenue from the sale and
license of patents unrelated to our core business.

ANTISENSE THERAPEUTICS

Our antisense drug research programs focus on targets associated with
infectious, inflammatory and metabolic diseases and cancer. Once we have
identified a gene target in one of these areas, we use its precise genetic
sequence, or code, to design short synthetic strands of genetic code that
precisely complement regions



3
of the code of the gene's RNA. Using high throughput methods, we are able to
design and optimize these strands to rapidly identify the most effective
inhibitor of the gene target. The product we've created, the synthetic strand of
DNA, is called an antisense inhibitor to the target gene. We have pioneered and
reduced to practice the design and optimization of antisense inhibitors
targeting the RNA of genes.

Antisense inhibitors may be marketed as drugs because the inhibitor,
once it binds to the target RNA, prevents the production of the disease-causing
protein directly, resulting in a therapeutic benefit to the patient. We believe
Antisense inhibitors are also useful as a tool to understand a gene's function
and its value as a drug target. Understanding the function of a gene helps
prioritize targets for drug discovery. Antisense is an efficient technology to
convert gene sequence information into drugs. In addition, because antisense
inhibitors are very specifically designed to complement the RNA of a gene, and
as a result, do not inhibit unintended gene products, we believe antisense drugs
are safer and more effective than traditional drugs. Our expertise in molecular
biology and drug discovery allows us to rapidly identify potent antisense
inhibitors of disease-causing proteins. Our medicinal chemistry program
continues to focus on improving the properties of antisense drugs. Using
chemical modifications we can design new antisense compounds that are
potentially safer and more effective than current antisense drugs. In addition,
we believe that these chemical modifications will support methods of dosing
drugs that are more convenient for patients, including methods of oral delivery.

We brought the first antisense drug to market, Vitravene-TM-, for
cytomegaloviral, or CMV, retinitis. We have a robust pipeline, including eleven
products in development, seven of which are in human clinical trials and the
remaining four of which we expect to enter clinical trials in the next twelve
months. Our broad research programs continue to identify additional products
that should keep our pipeline full.

GENETROVE GENOMICS

Our GeneTrove division uses antisense as a tool to provide valuable
information about human genes: what they do, how they behave within cells,
whether they are important in disease, and whether they would make good drug
targets. The processes involved in answering these questions are called gene
functionalization and target validation. In our GeneTrove division, we are using
our antisense expertise to provide pharmaceutical companies with gene function
and target validation information about genes that these companies are
interested in targeting for drug discovery. Using our proprietary methods, we
can provide this information rapidly and efficiently.

We currently have collaborations in place with three major
pharmaceutical partners for our GeneTrove division. Our collaboration with
Abbott began in 1998 and was recently extended, Aventis began in 1999, and R.W.
Johnson Pharmaceutical Research Institute began in 2000. We recently completed
our collaboration with AstraZeneca. With the vast amount of gene sequence
information now available to pharmaceutical and biotechnology companies, there
is significant demand for services such as ours in order to understand and
prioritize the gene targets in drug discovery programs and expedite discovery of
genomics-based drugs. We intend to grow our GeneTrove business this year by
marketing the speed, accuracy and efficiency of our genomics capabilities to new
partners. In addition to our functional genomics service business, our GeneTrove
division expects to launch a subscription database later this year. This
database will contain our proprietary gene function information and we expect
that it will provide corporate partners with new methods to evaluate gene
targets that are not currently available.

IBIS THERAPEUTICS

Ibis Therapeutics' drug discovery program targets the structured
regions of RNA as the binding site for small molecule drugs. This novel program
builds upon our substantial experience in RNA-targeted drug discovery and
combines this understanding with innovations in comparative genomics, mass
spectrometry and bioinformatics to discover low molecular weight, orally
bioavailable drugs that work by binding to RNA.

We have developed proprietary algorithms and software to identify RNA
structures that are important in disease to serve as targets for drugs. We can
then use our proprietary molecular modeling techniques to predict the shape of
drug binding pockets in these important RNA structures. With a working
approximation of the shape of the target, our Ibis Therapeutics division is
designing libraries of drug-like molecules that can

4
bind to the RNA targets. We use mass spectrometry to screen large numbers of
small molecules against multiple RNA targets simultaneously. We are applying
this drug discovery approach initially to discover novel antibacterial,
antiviral and antifungal drugs, and we believe that our technology will be
useful in a broad range of diseases such as cancer and central nervous system
diseases. In 2000, Ibis initiated a research partnership with Pfizer worth up to
$37 million. The funding is based on an up-front technology access fee, ongoing
research support, and milestone payments for the first product. In addition,
Pfizer will develop and commercialize drugs discovered through the collaboration
and pay us milestone payments and royalties on the sale of these drugs.

In addition to the Pfizer partnership, Ibis has been funded through
grants from the Defense Advanced Research Projects Agency, or DARPA, and the
National Institute of Standards & Technology's Advanced Technology Program, or
NIST. DARPA continues to invest in Ibis' approach as an opportunity to discover
a universal antibacterial drug.

DRUG DISCOVERY AND DEVELOPMENT

Our work in RNA-based drug discovery and development has produced two
important drug-discovery technologies: antisense and small molecule RNA drugs.
From our progress in antisense we have developed a robust pipeline of promising
new drugs and efficient genomics tools that unlock value from gene sequence
data. Our earlier stage Ibis program holds important potential to become a new
alternative approach to traditional drug discovery.

ANTISENSE TECHNOLOGY PLATFORM

ANTISENSE DRUG DISCOVERY

Genes carry the information that cells need to produce proteins.
Specific genes contain information to produce specific proteins at the genetic
level. The human genome, and its collection of approximately 30,000 genes,
contains the information required for the human body to produce all proteins.
Genes are made up of DNA, a molecule that contains the information about when
and how much of which protein to produce, depending on what function the gene is
to perform. The DNA molecule is a double helix, a duplex of entwined strands. In
each strand, the building blocks of DNA, the nucleotides, are bound or "paired"
with complementary nucleotides on the other strand. The precise sequence of a
nucleotide chain, called the "sense" sequence, is a blueprint for the
information that is used during protein production. The sequence of a nucleotide
chain that is precisely complementary to a given sense sequence is called its
"antisense" sequence.

In the cell nucleus, the information in the gene necessary for the
production of a protein is copied from one strand of DNA into precursor
messenger RNA, or mRNA, through a process called transcription. After processing
into mature mRNA, the mRNA moves from the nucleus of the cell into the cell
cytoplasm, which contains amino acids, the building blocks of proteins. The
information encoded in a single mRNA is then translated into many copies of the
sequence of amino acids that builds the protein.

Using the information contained in mRNA, we design chemical structures,
called oligonucleotides, which resemble DNA and are the complement of mRNA.
These potent antisense oligonucleotides inhibit the production of
disease-causing proteins. This method of drug design is highly productive. In
eleven years we have created a substantial pipeline of drug candidates,
including one product on the market and eleven products currently in
development. We can design antisense drugs to be much more selective than
traditional drugs. Antisense drugs are able to selectively inhibit one protein
among a closely related group of proteins without having an impact on the other
members of the group because antisense drugs interact by binding to mRNA and
not, as traditional drugs do, by binding to proteins. As a result, we are able
to design antisense drugs that selectively inhibit the disease-causing member of
the group without interfering with those members of the group necessary for
normal bodily functions. This unique selectivity means that antisense drugs may
be far less toxic than traditional drugs because they can be designed to
minimize the impact on unintended targets.

Almost all human diseases are a result of inappropriate protein
production or performance. By preventing the production of the disease-causing
protein and acting in the early stage of the disease-causing



5
process, antisense drugs have the potential to provide greater therapeutic
benefit than traditional drugs, which act after the body has produced the
disease-causing protein. Traditional drugs are designed to interact with the
proteins in the body that are supporting or causing a disease. Antisense
technology is different than traditional drug discovery because it targets
disease-causing proteins before the body produces them.

The design of antisense compounds is less complex, more rapid and more
efficient than traditional drug design directed at protein targets. Traditional
drug design usually begins by characterizing the three-dimensional structure of
the protein target in order to design a prototype drug to interact with it.
Proteins are complex molecules with structures that are difficult to predict.
Antisense compounds, on the other hand, are designed to bind to mRNA structures,
which are more easily understood and predicted. Prototype antisense drugs can be
designed as soon as the sequence for the mRNA receptor is identified.

Our early research efforts focused on answering basic questions
regarding antisense-based therapeutics, including their stability, their ability
to be taken up by the target cells, their efficacy and their cost to
manufacture. In the eleven years since our founding, we have made significant
progress in understanding and using antisense technology to develop drug
candidates, and have established a leadership position in this field.

GENETROVE TARGET VALIDATION AND GENE FUNCTIONALIZATION

Historically, the genomics industry has been focused on identifying and
cataloging all of the genes in the human genome. This stage of the process is
now complete. The next steps in the process of making drugs and creating value
from genomics are to identify the functions of the approximately 30,000 human
genes, or gene functionalization, and to identify which genes are good targets
for drugs, or target validation. We have developed our GeneTrove division, which
is responsible for providing our antisense target validation and gene
functionalization information in an efficient and cost effective manner to the
pharmaceutical industry.

We have based GeneTrove's antisense target validation and gene
functionalization program on our expertise in producing highly specific
antisense inhibitors to genes and on a variety of specialized technologies that
we have created and/or integrated. Our antisense inhibitors can be used in
cellular assays and in animal models of disease to rapidly determine the
pharmacological impact of inhibiting the expression of a single gene target and
to determine the role of the targeted gene in human disease. Once we have shown
that a target is important in human disease, traditional drug discovery can be
used to develop drugs to inhibit the target, or the specific antisense inhibitor
used to validate the target can be rapidly developed as a drug.

Specialized technologies employed by our GeneTrove division include:

o A PROPRIETARY AUTOMATED RAPID THROUGHPUT SCREENING PROCESS THAT
STREAMLINES THE CREATION OF OPTIMIZED, TARGET-SPECIFIC ANTISENSE
INHIBITORS. We are using this system to build a large proprietary
database of inhibitors to more than 1,800 gene targets this year and
the capacity can continue to expand. We plan to use this system to
identify antisense inhibitors to approximately 10,000 gene targets
over the next several years. We are rapidly filing patent
applications on the most important of these gene targets, thus
expanding our proprietary position in gene function and antisense.

o LIBRARIES OF ANTISENSE INHIBITORS TO IDENTIFY NOVEL GENE FUNCTION.
With hundreds, and planned thousands, of validated antisense
inhibitors to individual genes in our library, we are able to screen
the library to determine the function of individual genes in
cell-based assays. Results from these screens can provide novel
insights into functions of poorly understood genes, potentially
identifying which genes are involved in disease. This process is
being used to further expand our strong intellectual property
estate.

o IN VIVO VALIDATION OF DRUG TARGETS IN ANIMAL MODELS. GeneTrove's
scientists are testing hundreds of antisense inhibitors in animal
models of disease. This data can provide definitive information on
the role of these genes in models of human disease, identifying
which genes are suitable targets for drug discovery. As part of the
process, we not only identify which genes are therapeutically
important, but also identify at a very early stage potential
toxicological consequences of drugs that inhibit the gene.


6
o  A PROPRIETARY BIOINFORMATICS DATABASE, WHICH WILL PROVIDE ACCESS TO
CELLULAR PHENOTYPIC DATA TO PARTNERS. The data will be derived from
evaluating antisense inhibitors for up to 10,000 genes in 20 or more
cellular physiological tests. Partners may use this data to help to
identify which genes are important drug targets. We expect to launch
this subscription database later this year.

GeneTrove has already achieved many significant accomplishments. We
have identified antisense inhibitors to more than 600 genes, patented many of
these findings and expect to create antisense inhibitors to all important human
genes over the next several years. As we create and test the inhibitors to these
genes we are incorporating the data into our genomic database. We currently have
three target validation and gene functionalization partnerships, with Abbott
Laboratories, Aventis and Johnson & Johnson, and we are pursuing additional
partnerships.

IBIS TECHNOLOGY PLATFORM

Ibis Therapeutics is our program to discover low molecular weight,
potentially orally bioavailable drugs that work by binding to RNA. Ibis uses our
success in pioneering RNA-targeted drug discovery and development and expands
our ability to convert genomics data into drug discovery information. In Ibis,
we have developed proprietary technologies in four key areas:

1) The comparison of gene sequences across and within species to
identify target sites in structured RNA;

2) The prediction of the structure of RNA from genome sequence data;

3) The rapid creation and screening of large libraries of small
molecule compounds designed to bind to RNA; and

4) The screening for RNA-binding molecules using novel mass
spectrometry.

In our Ibis division, we are developing and integrating genome mining
software to identify RNA structural motifs in therapeutic targets of interest.
We can predict the three-dimensional shape of these motifs from biochemical
probes of RNA structure and molecular modeling methods. We have made a
fundamental breakthrough in the development of a parallel high-throughput
screening strategy to identify small molecules that bind to RNA targets using
high resolution mass spectrometry. In a MASS, multitarget affinity/specificity
screening, assay, each compound and each target RNA is labeled by its exact
molecular mass. Since every small molecule is labeled uniquely, a large mixture
can be screened in the presence of several RNA targets simultaneously. The
identity of the small molecule, the RNA target that it binds, its binding
affinity and the location of the binding site on the RNA can be determined in
one rapid set of experiments. Using this technology, we expect to be able to
screen 10,000 compounds per day against ten RNA targets.

Our initial area of focus in Ibis is discovering novel antibacterial,
antiviral and antifungal compounds. We believe the technology has the potential
in diseases such as cancer and central nervous system disease. In 2000, Ibis and
Pfizer entered into a research partnership worth up to $37 million.

PRODUCTS APPROVED AND UNDER DEVELOPMENT

Our antisense drug discovery programs identify compounds to treat
cancer and infectious, inflammatory, and metabolic diseases. The following table
outlines each product under development, its target, disease indication and
development status, as well as our commercial rights.




7
PRODUCTS IN DEVELOPMENT

<TABLE>
<CAPTION>
- --------------------------------------------------------------------------------------------------------------------------

PRODUCT (1) TARGET DISEASE INDICATION DEVELOPMENT STATUS COMMERCIAL RIGHTS
- --------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C>
Vitravene (I) Antiviral CMV Retinitis Approved for marketing in Isis/Novartis Ophthalmics
the U.S., Europe, (2)
Australia and Brazil.

- --------------------------------------------------------------------------------------------------------------------------
ISIS 3521 (P) PKC-(alpha) Cancer - Non-Small Cell Phase III Isis
Lung Cancer, Others
- --------------------------------------------------------------------------------------------------------------------------
ISIS 2302 (P) ICAM-1 Crohn's Disease Phase II/III Isis
- --------------------------------------------------------------------------------------------------------------------------
ISIS 2302 (T) ICAM-1 Psoriasis Phase II Isis
- --------------------------------------------------------------------------------------------------------------------------
ISIS 14803 (P) Antiviral Hepatitis C Phase I/II HepaSense (3)
- --------------------------------------------------------------------------------------------------------------------------
ISIS 2503 (P) Ha-RAS Cancer - Pancreatic, Phase II Isis
Others
- --------------------------------------------------------------------------------------------------------------------------
ISIS 5132 (P) C-RAF kinase Cancer - Ovarian, Others Phase II Isis
- --------------------------------------------------------------------------------------------------------------------------
ISIS 104838 (P, O) TNF-(alpha) Rheumatoid Arthritis Phase I Isis/Orasense (4)
- --------------------------------------------------------------------------------------------------------------------------
ISIS 104838 (T) TNF-(alpha) Psoriasis Preclinical Isis
- --------------------------------------------------------------------------------------------------------------------------
ISIS 113715 (P, O) PTP-1B Diabetes Preclinical Isis
- --------------------------------------------------------------------------------------------------------------------------
ISIS 13650 (I) C-RAF kinase Diabetic Retinopathy, Preclinical Isis
Age-Related Macular
Degeneration
- --------------------------------------------------------------------------------------------------------------------------
ISIS 107248 (P, O) VLA-4 Multiple Sclerosis, Preclinical Isis
Inflammatory Diseases
- --------------------------------------------------------------------------------------------------------------------------

</TABLE>


(1) I = Intravitreal; P = Parenteral; T = Topical; O = Oral

(2) Novartis Ophthalmics has the exclusive right to distribute Vitravene.

(3) HepaSense is a joint venture of Isis and Elan.

(4) Orasense, a joint venture of Isis and Elan, owns the rights to an oral
formulation of ISIS 104838.

The following section provides more detailed descriptions of our
approved product and those products under development and the disease
indications they target. We also have a significant research program with the
potential to yield additional development candidates in the future.

CYTOMEGALOVIRUS, OR CMV, RETINITIS

Individuals with suppressed immune systems, such as those with AIDS
resulting from the HIV virus, are susceptible to opportunistic infections caused
by CMV. In the AIDS population, CMV retinitis is the primary cause of blindness.
There are more than 270,000 active AIDS cases in the United States. The
introduction of new anti-HIV drugs, particularly protease inhibitors and
combination treatment regimens, has prolonged survival in HIV-infected
individuals. Over the last several years, this has resulted in a decline in
mortality from AIDS, accompanied by a decline in the incidence of many
opportunistic infections including



8
CMV retinitis. Currently approved drugs for CMV retinitis are ganciclovir,
foscarnet, cidofovir and fomivirsen. Foscarnet and cidofovir are available in
intravenous dosing forms only. Ganciclovir is available in intravenous and oral
doses, as well as in an intraocular implant form.

VITRAVENE, OR FOMIVIRSEN In August 1998, the FDA approved Vitravene to
treat CMV retinitis in AIDS patients. Vitravene is an antisense compound, which
we discovered and developed. Novartis Ophthalmics, the eye health unit of life
sciences leader Novartis AG and our worldwide distribution partner for this
drug, launched Vitravene in November 1998. For a more detailed discussion of
this collaboration, see "Collaborative Arrangements and Licensing Agreements -
Novartis Ophthalmics." In 1999 Vitravene also received marketing approval in
Europe and Brazil. Vitravene has also received marketing approval in Australia.

HEPATITIS C, OR HCV

HCV continues to represent a major public health challenge. This
potentially deadly disease affects the liver and can eventually cause liver
cancer and death. It is estimated that almost four million people in the United
States are infected with HCV and 8,000 to 10,000 people in the United States are
expected to die from this disease each year. Interferon-(alpha) therapy, used
alone or in combination with the drug ribovirin, is widely used in an attempt to
eradicate this virus from chronically infected individuals, but long-term
remissions are achieved in only about 20% of patients even after six months of
therapy. Better, safer and more effective treatments are urgently needed, as
current therapies have limited efficacy and potentially serious side effects.

ISIS 14803 Our antisense inhibitor of HCV, ISIS 14803, may represent a
significant therapeutic advance in treating this serious viral epidemic. ISIS
14803 is designed to inhibit the replication of HCV. In preclinical studies,
ISIS 14803 demonstrated specific reduction of the HCV RNA expression in both
cell cultures and mouse model systems. We are developing ISIS 14803 under a
joint venture agreement with Elan, which was signed in January 2000. The joint
venture, HepaSense, will develop and commercialize this novel drug for HCV while
investigating delivery of the drug with Elan's proprietary MEDIPAD Drug Delivery
System, a disposable subcutaneous infusion device.

A Phase I/II clinical study of ISIS 14803 began in early 2000. This
study in patients with Hepatitis C virus will evaluate both the safety and the
efficacy of the drug. Patients in this Phase I/II trial receive ISIS 14803
intravenously. We plan to conduct studies of the subcutaneous delivery of ISIS
14803. We also plan to conduct studies of ISIS 14803 using Elan's MEDIPAD, a
minimally invasive microinfusion pump. The MEDIPAD Drug Delivery System combines
the convenience of a transdermal patch with the drug delivery capabilities of an
infusion pump. This system can be self-administrated, is disposable and
inexpensive. It can be used to infuse drug over 24 and 48-hour timeframes. Elan
and its collaborators presently have multiple drugs in clinical trials being
administered using the MEDIPAD System.

CANCER

We focus much of our work in the area of cancer on specific targets
within multigene families believed to be involved in both normal and abnormal
cell differentiation and cell growth. Members of multigene families, called
isotypes, are extremely similar to one another at the protein level but most
likely serve different biological functions. Since traditional drugs are not
specific enough to inhibit one isotype within a family without affecting the
function of the other related isotypes, it has been difficult to determine the
functional differences among them. There is growing evidence that certain
isotypes might be involved in abnormal cell differentiation or proliferation.
Antisense drug discovery technology exploits the differences among the isotypes
at the mRNA level to design drugs that can inhibit specific isotypes. Selective
inhibition of a single isotype may result in less toxicity. Much of our work has
focused on multigene families in the signal transduction pathway, the method by
which various cellular and extra cellular proteins communicate information
necessary for cell function and growth. Disruptions in the production or
behavior of signal transduction proteins are involved in numerous proliferative
disorders, including cancer.

Clinical trials of our anticancer compounds have demonstrated that
antisense drugs appear to be promising cancer therapeutics. In these trials, our
compounds were well tolerated, with none of the serious side effects associated
with standard cancer chemotherapies, such as bone marrow or immune system
suppression, gastrointestinal distress or hair loss.



9
ISIS 3521 ISIS 3521 is an antisense compound in Phase III clinical
development which inhibits the production of one particular isotype, the (alpha)
isotype, of protein kinase C. PKC is a key enzyme in signal transduction, and
PKC isotypes are associated with both normal and abnormal cell growth. In the
laboratory, we have been able to specifically inhibit the production of the
PKC-(alpha) isotype without inhibiting the production of other isotypes, thus
allowing the inhibition of an isotype believed to be involved in abnormal cell
growth without more broadly affecting the PKC isotypes.

We are currently conducting a Phase III clinical trial of ISIS 3521 as
an anticancer agent, using ISIS 3521 in combination with traditional cancer
drugs. We initiated the Phase III trial in late 2000 for patients with non-small
cell lung cancer, based on promising results in an on-going Phase II trial.
Preliminary results from that trial showed a median survival of 19 months in
patients with late stage non-small cell lung cancer. The typical median survival
of these patients receiving standard chemotherapy alone for advanced non-small
cell lung cancer is approximately eight months. In addition, patients treated in
the Phase II study experienced minimal side effects attributable to ISIS 3521.
In November 2000, the FDA granted ISIS 3521 fast track review status.

In Phase I and Phase II studies, ISIS 3521 reduced tumor mass and/or
reduced tumor markers in patients with ovarian cancer and lymphoma, and
stabilized disease in a patient with lung cancer. These results included
complete remissions in two patients with low grade non-Hodgkin's lymphoma, a
disease for which Phase II trials are in progress. In prior trials, ISIS 3521
caused no significant side effects.

ISIS 2503 Substantial evidence exists supporting a direct role for RAS
gene products in the development and maintenance of human cancer. RAS proteins
are involved in passing information between cells. RAS, in both normal and
mutated forms, is associated with abnormal cell growth and, as such, is
associated with cancer. ISIS 2503, a potent selective inhibitor of Harvey RAS,
has been shown to inhibit abnormal cell growth in cell culture and animal
models.

In Phase I studies, ISIS 2503 was well tolerated, with no significant
side effects. We also observed evidence of activity. These results provided a
basis for continuing development of ISIS 2503 in Phase II trials. In Phase II
trials of ISIS 2503, we are evaluating the compound both alone and in
combination with traditional cancer chemotherapies in patients with colon,
breast, pancreatic and lung cancers. The colon cancer trial is near completion
with no significant evidence of activity, while early results in lung cancer
suggest improvement in cancer-related symptoms. We have completed a Phase I
trial of ISIS 2503 plus a traditional chemotherapy drug and we are also planning
a Phase II study in patients with cancer of the pancreas.

ISIS 5132 ISIS 5132 is an antisense compound which inhibits the
expression of c-RAF kinase, another molecular target involved in cell signaling.
C-RAF kinase is a member of the RAF kinase multi-gene family and is associated
with abnormal cell growth. ISIS 5132 selectively inhibits c-RAF kinase without
inhibiting the production of other members of that multigene family. Published
results from a human clinical trial show that ISIS 5132 reduced the levels of
its target RNA, c-RAF-1 after intravenous administration.

In Phase I clinical trials, ISIS 5132 showed evidence of antitumor
activity in patients with ovarian, renal, pancreatic, and colon cancers. In
those trials, ISIS 5132 was well-tolerated and caused no significant side
effects. However, Phase II data in a variety of tumor types have shown minimal
activity. We have limited future investment in this product, pending additional
laboratory studies designed to identify the most promising areas for future
development.

INFLAMMATORY DISEASES

Cell adhesion molecules make up a large family of related proteins and
represent targets for treating inflammatory diseases. Inflammation is a key
component of a large number of acute and chronic diseases. Although inflammation
is part of a normal localized protective response that the human body uses to
destroy infectious agents or repair injured tissue, disruptions of normal
inflammatory responses often lead to inflammatory diseases. These inflammatory
responses result in or contribute to a diverse set of diseases that can affect
many organs of the body ranging from the skin to the brain. Common inflammatory
diseases include rheumatoid arthritis, psoriasis, asthma and inflammatory bowel
disease. Inflammation also occurs as a result of burn, shock or organ
transplantation.



10
We have focused on a number of targets in our cell adhesion molecule
program. Our most advanced cell adhesion research and development effort has
been focused on the intercellular adhesion molecule, or ICAM, family and in
particular, ICAM-1. ICAM-1 facilitates the migration of immune cells involved in
both chronic and acute inflammation, allowing us to target both conditions.
Over-expression of ICAM-1 occurs in a wide variety of inflammatory disorders,
such as rheumatoid arthritis, asthma, psoriasis, organ transplant rejection and
inflammatory bowel diseases. While it is unlikely that over-expression of ICAM-1
is the singular cause of these disorders, experts believe that ICAM-1
contributes to the pathology of these diseases and conditions. We have also
identified lead compounds for other adhesion molecules including CD49d, or
VLA-4.

In addition to cell adhesion molecules, we have active research
programs targeting other steps in the inflammatory process. In particular, we
have identified antisense inhibitors which selectively inhibit the expression of
cytokines such as tumor necrosis factor-(alpha), or TNF-(alpha), interleukin 5,
or IL-5, and the IL-5 receptor. Lead antisense compounds targeting mRNA for
these proteins are showing promising activity in multiple models of inflammatory
diseases.

ISIS 2302 ISIS 2302, the most advanced compound in our cell adhesion
program, selectively inhibits ICAM-1 gene expression. In Phase I testing of ISIS
2302 in healthy volunteers, the compound was well tolerated at all doses. We
conducted Phase II trials of ISIS 2302 in five diseases: Crohn's disease,
psoriasis, ulcerative colitis, prevention of kidney transplant rejection and
rheumatoid arthritis. The Phase II studies involved 20 to 40 patients each and,
in general, were randomized and placebo-controlled.

o CROHN'S DISEASE Crohn's disease is a serious inflammatory disease
that affects the intestines and other parts of the digestive tract.
A patient with Crohn's disease suffers chronic and often severe
episodes of diarrhea, abdominal pain, rectal bleeding and fever.
Crohn's disease afflicts approximately 400,000 people in North
America and a similar number in Europe.

In late 1999, we completed a 300 patient pivotal-quality trial of
ISIS 2302 in Crohn's disease, which we initiated based on
positive results from a Phase II trial. In December 1999, we
announced that the initial analysis of the data from this trial
did not show efficacy and that, as a result, the data did not
support an NDA filing. However, further analysis of the data
indicated that those patients who received higher exposure to
ISIS 2302 were more likely to experience complete clinical
remission of their disease, which was the primary endpoint of the
pivotal trial. We are planning additional clinical trials of ISIS
2302 in Crohn's disease patients using higher doses of ISIS 2302
to reproduce the drug exposure levels that correlated with higher
response rates in the analysis. We expect to initiate patient
enrollment in a Phase III trial in the second half of 2001.

o PSORIASIS In early 2000, we initiated a Phase II trial of ISIS
2302 in a topical cream formulation for psoriasis. We expect to
present data from this trial in mid year 2001. Plaque psoriasis
is the most common form of psoriasis, and is an uncomfortable,
disfiguring and incurable skin disorder that affects two to four
percent of the nation's population. Psoriasis produces recurrent
skin lesions that may involve up to 80-90 percent of the body
surface. A conveniently dosed topical cream formulation that is
safe and effective would represent a significant improvement in
treatment for patients and a significant commercial opportunity.

o OTHER INDICATIONS We have evaluated ISIS 2302 for several other
indications, including rheumatoid arthritis, organ transplant
rejection and ulcerative colitis. We completed a Phase II study
in rheumatoid arthritis, in which we saw evidence of therapeutic
activity. ISIS 2302 was well tolerated and the safety profile of
the drug was attractive. However, we have decided to forego
development of this product in favor of ISIS 104838, our
second-generation antisense inhibitor of TNF-(alpha) for
rheumatoid arthritis.

We have completed a Phase II study for kidney transplant rejection.
However, due to the competitive picture and the cost of development,
we have put the development of ISIS 2302 for organ transplants on
hold. We also plan to limit our investment in the development of
ISIS 2302 as an enema formulation for treatment of ulcerative
colitis.


11
ISIS 104838 ISIS 104838 is a second-generation antisense inhibitor of
TNF-(alpha) and our first product from our proprietary second-generation
chemistry to enter the clinic. In October 2000, we initiated Phase I clinical
trials of ISIS 104838 to treat inflammatory and autoimmune diseases such as
rheumatoid arthritis. We expect to begin Phase II trials of ISIS 104838 in
patients with rheumatoid arthritis later this year. Our clinical program for
ISIS 104838 investigates the safety and efficacy of the drug administered
intravenously and subcutaneously. In addition, we expect to initiate clinical
trials of topically administered ISIS 104838 in patients with psoriasis later
this year. Orasense, a joint venture between Elan and us, is developing oral
formulations of ISIS 104838 for rheumatoid arthritis and plans to test those
solid dosage forms of ISIS 104838 in human clinical trials this year.

ISIS 113715 ISIS 113715 is a second-generation antisense inhibitor of
the PTP-1B gene for Type 2 diabetes. The preclinical data demonstrate compelling
activity in multiple diabetic animal models. The preclinical data package for
ISIS 113715 suggests activity as an insulin sensitizer without causing
hypoglycemia and while reducing cholesterol and weight gain. Potential corporate
partners have replicated these results. We plan to initiate a Phase I trial in
late 2001.

ISIS 13650 ISIS 13650 is an inhibitor of c-RAF kinase for diabetic
retinopathy and age-related macular degeneration. ISIS 13650 is also a
second-generation product in preclinical development. We plan to initiate Phase
I clinical trials near the end of this year.

ISIS 107248 ISIS 107248 is a second-generation antisense inhibitor of
CD49d or VLA-4. This compound, which we expect to evaluate as a possible
treatment for a variety of inflammatory diseases including multiple sclerosis,
is currently undergoing preclinical toxicology and pharmacokinetic studies.

RESEARCH PROGRAMS

We combine our core technology programs in medicinal chemistry, RNA
biochemistry, and molecular and cellular biology with molecular target-focused
drug discovery efforts to design drug candidates. The goal of our target-based
research programs is to identify antisense and small molecule drug candidates to
treat diseases for which there are substantial markets and for which there is a
need for better drugs. In addition, our research programs focus on identifying
next-generation compounds to serve as backup compounds to our current products
in development and development candidates. Our Ibis drug discovery program is
currently focused on identifying broad-spectrum antibacterial agents with a
focus on important drug-resistant infections.

Our core technology programs can support multiple target-based
antisense research programs without significantly increasing costs. Through
these programs, we can efficiently explore numerous disease targets and identify
the best lead compounds to advance into preclinical development. We are
currently pursuing antisense and small molecule drug discovery programs focused
on various anti-viral and anti-bacterial targets, inflammatory disease targets,
and other key molecular targets that might play critical roles in cancer and
metabolic diseases such as diabetes and obesity.

COLLABORATIVE ARRANGEMENTS AND LICENSING AGREEMENTS

Our strategy is to use alliances with other companies and equity-based
financing to increase our financial resources, reduce risk, and retain an
appropriate level of ownership of products currently in development. Through
alliances with major pharmaceutical companies, we can obtain funding, expand
existing programs, learn of new technologies, and gain additional expertise in
developing and marketing products.

ANTISENSE THERAPEUTICS

ELAN - HEPASENSE - HEPATITIS C

In January 2000, we formed with Elan a new subsidiary of Isis,
HepaSense, to develop an antisense drug, ISIS 14803, to treat patients
chronically infected with the Hepatitis C virus or HCV. We are the majority
shareholder in HepaSense. HepaSense will develop and commercialize this novel
therapeutic for HCV while investigating delivery of the drug with Elan's
proprietary MEDIPAD Drug Delivery System, a disposable subcutaneous infusion
device. The combination of a novel drug for HCV with a convenient delivery
method could result in a very attractive product for this international public
health problem. We are


12
currently conducting Phase II trials with ISIS 14803. Elan and we have each
licensed significant technology to HepaSense. As part of the transaction, Elan
purchased $7.5 million of our common stock at a premium to market. Elan may
purchase an additional $7.5 million of common stock at a premium to our market
price upon completion of a mutually agreed milestone. Elan also purchased our
Series B preferred stock which is convertible in the future into either our
stock or stock in HepaSense. As part of the transaction, we also issued warrants
to Elan, which are exercisable in five years. In addition, Elan made available
to us a $12.0 million line of credit for our funding commitment to HepaSense.

ELAN - ORASENSE - ORAL FORMULATION

In April 1999, we formed with Elan a new subsidiary, Orasense, to
develop a platform technology for the oral delivery of antisense drugs. We are
the majority shareholder in Orasense. The first oral drug Orasense is working on
is ISIS 104838, our antisense inhibitor for TNF-(alpha). TNF-(alpha) is a gene
that has been implicated in a wide range of inflammatory diseases. As part of
the agreement, Elan made a $27 million equity investment in us, consisting of
$15 million of common stock purchased at a premium to market and $12 million of
convertible exchangeable preferred stock. Elan also received warrants
exercisable in five years. Elan has the right to convert the preferred stock
into either an ownership interest in us or in Orasense. As part of the
agreement, Elan made available to us an $18.4 million line of credit for our
funding commitment to Orasense.

We have made substantial progress in oral formulations of antisense
drugs, achieving significant oral bioavailability by combining novel chemistries
and formulation approaches. Elan, a world leader in oral drug delivery
technology, has demonstrated the oral delivery and bioavailability of large
macromolecules with properties similar to many antisense drugs. Both companies
are combining existing technologies and expertise with new research efforts
towards the goal of building a proprietary, platform technology for the oral
delivery of antisense drugs.

ASTRAZENECA

In December 1998, we established an antisense collaboration with
AstraZeneca to discover, develop and commercialize novel antisense drugs
targeting specific genes associated with cancer. The initial term of this
collaboration is three years, however AstraZeneca may terminate the agreement at
the end of the second year. We received notice in December 2000 that AstraZeneca
was terminating the agreement.

NOVARTIS OPHTHALMICS

In 1997, we entered into an agreement with Novartis Ophthalmics,
formerly CIBA Vision Corporation, granting them exclusive worldwide distribution
rights for Vitravene. The terms of the agreement allow for us to receive $20
million in pre-commercial fees and milestones. As of December 31, 2000, we have
received $17.5 million of these pre-commercial fees and milestones. While
Novartis Ophthalmics markets and sells Vitravene worldwide, we manufacture and
sell Vitravene to Novartis Ophthalmics, at a price that allows us to share the
commercial value of the product with them. The FDA approved Vitravene for
commercial marketing in August 1998. In 1999 Vitravene received marketing
approval in Europe and Brazil. Vitravene has also been approved for marketing in
Australia. We delivered our first commercial shipment of Vitravene to Novartis
Ophthalmics in August 1998.

OTHER

In June 1998, we established a research collaboration with Merck to
discover small molecule drug candidates to treat patients infected with HCV. Our
chemists are working together with Merck scientists to design, synthesize and
evaluate novel compounds that Merck will screen in its proprietary enzymatic
assays for identifying Hepatitis C virus replication inhibitors. Merck has the
right to commercialize any drugs arising from the collaboration, and we retain
the right to use technology developed in the collaboration in our antisense
program. The three-year collaboration provides us with annual research support
plus a technology access fee, milestone payments and royalties upon
commercialization. The collaboration ends in June 2001, however, we expect to
enter into an extension of this agreement.




13
GENETROVE COLLABORATIONS

ASTRAZENECA

In January 2000, we entered into a target validation collaboration with
AstraZeneca for a one year term. Through the collaboration, we used our target
validation technology to assess and prioritize genes identified within
AstraZeneca's genomics programs. This collaboration enabled AstraZeneca to
determine the function and therapeutic value of novel gene targets and to
potentially use this information about gene function to develop pharmaceutical
products. It also provided us with valuable information on these targets to
assist in our development of novel antisense drugs.

AVENTIS

In September 1999, we entered into a target validation collaboration
with Aventis. Through the collaboration, we are using our target validation
technology to assess genes identified within Aventis' genomics programs. This
collaboration enables Aventis to determine the function and therapeutic value of
numerous novel gene targets and to potentially use this information about gene
function to develop pharmaceutical products. It also provides us with valuable
information on these targets to assist in our development of novel antisense
drugs. The initial term of this collaboration is three years with certain
provisions for early termination or extension of the collaboration. Under the
terms of the agreement, Aventis will pay us research fees and milestone payments
based on the success of the program.

ABBOTT LABORATORIES

In December 1998, we entered into a target validation collaboration
with Abbott Laboratories, Inc. Through the collaboration, we are utilizing our
target validation technology to enable Abbott to validate numerous gene targets,
identify the function of these genes and prioritize the targets. Under the
agreement, Abbott agreed to pay us an up-front fee, research fees, milestone
payments and royalties on net sales of any Abbott non-antisense product arising
from the collaboration. We also received rights to develop drugs targeting
Abbott proprietary genes for Abbott. The initial term of the collaboration was
two years. Under the agreement, Abbott had the ability to extend the term of the
agreement. In December 2000, both parties agreed to extend the term of the
agreement for an additional two years.

R.W. JOHNSON PHARMACEUTICAL RESEARCH INSTITUTE

In July 2000, we entered into a target validation agreement with R.W.
Johnson Pharmaceutical Research Institute, a member of the Johnson & Johnson
family of companies. Under the collaboration, we are using our proprietary
target validation technology to assess and prioritize genes identified within
Johnson & Johnson's genomics programs. This collaboration enables Johnson &
Johnson to determine the function and therapeutic value of novel gene targets
and to potentially use this information about gene function to develop
pharmaceutical products. It also provides us with valuable information on these
targets to assist in our development of novel antisense drugs. The initial term
of this collaboration is one year.

IBIS COLLABORATIONS

PFIZER

In June 2000, our Ibis division and Agouron Pharmaceuticals, Inc., a
Pfizer company, entered into a collaboration for the discovery and development
of small molecule drugs against certain RNA targets. Using Ibis' proprietary
technology and Pfizer's expertise in small molecule drug discovery, the
collaboration focuses on discovering drugs that bind to RNA. Pfizer will fund
collaborative research, pay an up-front technology access fee and make milestone
payments, totaling up to $37 million. In addition, Pfizer will develop and
commercialize drugs discovered by the collaboration and will pay us royalties on
sales of any drugs resulting from the collaboration.


14
LICENSING AGREEMENTS

COLEY PHARMACEUTICAL GROUP

In September 2000, we sold to Coley Pharmaceutical Group our patents
concerning the use of phosphorothioate oligonucleotides for activating the
immune system. The patents were originally licensed to Coley in 1998 for a
limited scope of use, at which time Coley paid us $5 million. In exchange for
all non-antisense rights to this group of immunomodulation patents and in lieu
of any and all future payments that could potentially be owed under the original
agreement, Coley paid us an additional $10.7 million.

PANTHECO

In September 2000, we entered into an agreement to license our novel
antisense chemistry, Peptide Nucleic Acid, or PNA, to Pantheco, on a
nonexclusive basis to treat diabetes and cardiovascular diseases. Pantheco
completed financing to raise funds to support its current business and to fund
this expansion of therapeutic focus on October 18, 2000. Subsequent to the
completion of Pantheco's financing, we received, as a fee for this license, 9
million DKK, or $1.1 million, which was paid in Pantheco shares. In addition,
Pantheco will pay us royalties and milestones on any products developed using
PNA. This is the second license of PNA technology from us to Pantheco. As part
of the first licensing transaction completed in November 1998, we received an
equity position in Pantheco.

ROCHE MOLECULAR SYSTEMS

In October 2000, we completed the licensing of novel chemistry patents
to Roche, a business unit of Roche Diagnostics, for use in the production of
Roche's diagnostic products. The royalty-bearing license grants Roche
non-exclusive worldwide access to certain of our proprietary chemistries, in
exchange for initial and ongoing payments to us.

MANUFACTURING

In the past, production of chemically modified oligonucleotides, like
those used in our research and development programs, was generally expensive and
difficult, except in small quantities. As a result, we have dedicated
significant resources to focus on ways to improve manufacturing capacity.
Because all oligonucleotide compounds are made of variants of the same
nucleotide building blocks and are produced using the same types of equipment,
we found that the same techniques used to efficiently manufacture one
oligonucleotide drug product proved helpful in improving the manufacturing
processes for many other oligonucleotide products. Through the development of
several proprietary chemical processes for scaling up manufacturing
capabilities, we have been able to greatly reduce the cost of producing
oligonucleotide compounds. For example, we have significantly reduced the cost
of raw materials, while at the same time increasing our capacity to make the
compounds. We have both internal programs and outside collaborations with
various industry vendors to allow for even greater production capacity.

We have a 12,000 square foot Good Manufacturing Practices manufacturing
facility located in Carlsbad, California. We believe we have sufficient
manufacturing capacity to meet both current and future research and clinical
needs both for ourselves and for our partners. We also believe that we have, or
will be able to develop or acquire, sufficient supply capacity to meet our
anticipated commercial needs. We also believe that with reasonably anticipated
benefits from increases in scale, we will be able to manufacture antisense
compounds at commercially competitive prices.

In 1998, we established an antisense oligonucleotide manufacturing
collaboration with Avecia Life Science Molecules, a leading supplier of chemical
and biological compounds to the pharmaceutical and biotechnology industries.
Although the collaboration ended in January 2000, we continue to work with
Avecia to establish an oligonucleotide supply relationship. Access to an
alternate manufacturing source will provide us with greater flexibility in
production scheduling and will reduce our risk of dependence on a single
manufacturing site for all of our clinical needs. We are not required to make
any capital investment to create this manufacturing capability.


15
In 1999, we established a commercial-scale manufacturing collaboration
with Abbott Laboratories. This collaboration combines Abbott's process
development expertise and manufacturing capability with our proprietary
oligonucleotide manufacturing technology.


PATENTS AND PROPRIETARY RIGHTS

Our success will depend, in part, on our ability to obtain patent
protection for our products in the United States and other countries. We file
applications, as appropriate, for patents covering our products and processes.
As of January 31, 2001, we had been issued or allowed more than 700 patents
worldwide and had filed more than 635 patent applications in the United States,
and counterparts of many of these applications in other countries. Patents
issued to us or applied for cover the following types of inventions, processes
and products:

o Composition of matter claims to core chemistries for oligonucleotide
structures, which cover our rights to the building blocks of our
compounds;

o Composition of matter claims to antisense compounds targeted to
particular messenger RNA target sequences, which cover our drugs;

o Use claims for using oligonucleotides targeted to particular disease
targets, which cover our right to use oligonucleotide based drugs to
treat specific diseases or inhibit expression of the target gene;

o Method claims for the manufacture of oligonucleotides, which cover
our new, improved and/or more cost effective ways to manufacture
oligonucleotides;

o Composition of matter claims to RNA structural elements, which cover
our rights for discovery of small molecules that bind to these RNA
structural elements;

o Method claims for analyzing the interaction of small molecules with
RNA, which cover our novel discovery methods using mass spectrometry
to analyze the interaction of small molecules with RNA;

o Method claims for optimizing the interaction of drug substances with
their target molecules, which cover our mass spectrometry based
structural activity relationship discovery methods, i.e., SAR by
mass spectrometer; and

o Methods claims for rapidly discovering antisense oligonucleotides,
which cover our rapid through-put method of discovering antisense
oligonucleotides.

GOVERNMENT REGULATION

Our manufacture and potential sale of therapeutics are subject to
extensive regulation by United States and foreign governmental authorities. In
particular, pharmaceutical products are subject to rigorous preclinical and
clinical testing and other approval requirements by the FDA in the United States
under the Federal Food, Drug and Cosmetic Act and by comparable agencies in most
foreign countries. Various federal, state and foreign statutes also govern or
influence the manufacture, safety, labeling, storage, record keeping and
marketing of such products. Pharmaceutical manufacturing facilities are also
regulated by state, local and other authorities.

In conjunction with obtaining approval of Vitravene, we successfully
passed the manufacturing pre-approval inspection by the FDA and European
regulatory authorities. Approval of each new drug will require a rigorous
manufacturing pre-approval inspection by regulatory authorities.

In addition to regulations enforced by the FDA, we are also subject to
regulation under the Occupational Safety and Health Act, the Environmental
Protection Act, the Toxic Substances Control Act, the Resource Conservation and
Recovery Act and other present and potential future federal, state and local
regulations.



16
COMPETITION

For many of their applications, antisense based drugs as well as Ibis
small molecules will be competing with existing therapies for market share. In
addition, a number of companies are pursuing the development of
oligonucleotide-based technology and the development of pharmaceuticals
utilizing such technology. These companies include specialized pharmaceutical
firms and large pharmaceutical companies acting either independently or together
with biopharmaceutical companies. Many of our existing or potential competitors
have substantially greater financial, technical and human resources than we do
and may be better equipped to develop, manufacture and market products. In
addition, many of these companies have extensive experience in preclinical
testing and human clinical trials. These companies may develop and introduce
products and processes competitive with or superior to ours. Furthermore,
academic institutions, government agencies and other public and private
organizations conducting research may seek patent protection and may establish
collaborative arrangements for product and clinical development in the areas of
our business.

Vitravene and our other products under development address numerous
markets. Our competition has been and will continue to be determined in part by
the diseases for which our compounds are developed and ultimately approved by
regulatory authorities. For certain of our products, an important factor in
competition may be the timing of market introduction of competitive products.
Accordingly, the relative speed with which we can develop products, complete the
clinical trials and approval processes and supply commercial quantities of the
products to the market is an important competitive factor. We expect that
competition among products approved for sale will be based, among other things,
on product efficacy, safety, reliability, availability, price and patent
position.

Our competitive position also depends upon our ability to attract and
retain qualified personnel, obtain patent protection or otherwise develop
proprietary products or processes and secure sufficient capital resources for
the often substantial period between technological conception and commercial
sales.

EMPLOYEES

As of January 31, 2001, we employed 303 individuals, of whom 122 hold
advanced degrees. A significant number of our management and professional
employees have had prior experience with pharmaceutical, biotechnology or
medical product companies. None of our employees is covered by collective
bargaining agreements, and management considers relations with its employees to
be good.

EXECUTIVE OFFICERS

The following set forth certain information regarding our executive
officers as of March 6, 2001:



<TABLE>
<CAPTION>
NAME AGE POSITION
- ---- --- --------
<S> <C> <C>
Stanley T. Crooke, M.D., Ph.D. 55 Chairman of the Board, President and Chief Executive Officer

B. Lynne Parshall 45 Executive Vice President, Chief Financial Officer and Secretary

C. Frank Bennett, Ph.D. 44 Vice President, Biology

Douglas L. Cole, Ph.D. 54 Vice President, Development Chemistry & Pharmaceutics

F. Andrew Dorr, M.D. 47 Vice President, Clinical Development & Chief Medical Officer

David J. Ecker, Ph.D. 46 Vice President & Managing Director, Ibis Therapeutics

Arthur A. Levin, Ph.D. 47 Vice President, Toxicology & Pharmacokinetics

Patricia Lowenstam 54 Vice President, Human Resources

Karen S. Lundstedt 36 Vice President, Investor Relations & Corporate Communications

</TABLE>




17
STANLEY T. CROOKE, M.D., PH.D.
CHAIRMAN OF THE BOARD, PRESIDENT AND CHIEF EXECUTIVE OFFICER

Dr. Crooke was a founder of Isis and has been its Chief Executive
Officer and a director since January 1989. He served as our President from
January 1989 to May 1994, and was elected Chairman of the Board in February
1991. SmithKline Beckman Corporation, a pharmaceutical company, employed Dr.
Crooke from 1980 until January of 1989, where his titles included President of
Research and Development of SmithKline and French Laboratories. Dr. Crooke is
Chairman of the Board of Idun Pharmaceuticals, Inc., a pharmaceutical company.
He serves as a director of Valentis, Inc., SYNSORB Biotech Inc., and EPIX
Medical, Inc. He is also an adjunct professor of pharmacology at the Baylor
College of Medicine and the University of California, San Diego.

B. LYNNE PARSHALL
EXECUTIVE VICE PRESIDENT, CHIEF FINANCIAL OFFICER AND SECRETARY

Ms. Parshall has served as a director of Isis since September 2000. She
has served as our Executive Vice President since December 1995, our Chief
Financial Officer since June 1994, and our Secretary since November 1991. From
February 1993 to December 1995, she was a Senior Vice President of Isis, and
from November 1991 to February 1993, she was a Vice President of Isis. Prior to
joining Isis, Ms. Parshall practiced law at Cooley Godward LLP, counsel to Isis,
where she was a partner from 1986 to 1991. Ms. Parshall served as Vice President
of Business Development of Biotrack, Inc., a medical device company, during 1988
and 1989. Ms. Parshall is on the Board of Visitors at Stanford University Law
School. Ms. Parshall is also a member of the Licensing Executives Society and a
member of the American, California and San Diego bar associations.

C. FRANK BENNETT, PH.D.
VICE PRESIDENT, BIOLOGY

Dr. Bennett has served as our Vice President, Biology since June 1995.
From March 1993 to June 1995, he was Director, Molecular Pharmacology, and from
May 1992 to March 1993, he was an Associate Director in our Molecular and
Cellular Biology department. Prior to joining Isis in 1989, Dr. Bennett was
employed by SmithKline and French Laboratories in various research positions.

DOUGLAS L. COLE, PH.D.
VICE PRESIDENT, DEVELOPMENT CHEMISTRY & PHARMACEUTICS

Dr. Cole has served as our Vice President, Development Chemistry and
Pharmaceutics since January 1995. From January 1993 until January 1995, he was
our Executive Director, Development Chemistry and Pharmaceutics and from October
1991 until January 1993, he was a Director in our Development Chemistry
department. Prior to joining Isis in 1991, Dr. Cole was Director of Chemical
Affairs for Marion Laboratories.

F. ANDREW DORR, M.D.
VICE PRESIDENT, CLINICAL DEVELOPMENT & CHIEF MEDICAL OFFICER

Dr. Dorr, a medical oncologist, has served as our Vice President,
Clinical Development and Chief Medical Officer since August 2000. From June 1996
until August 2000, Dr. Dorr was our Vice President, Clinical Development. Prior
to joining Isis in June 1996, Dr. Dorr worked for Eli Lilly and Company where he
was the Medical Research Advisor for strategic planning and implementation of
cancer drug development.

DAVID J. ECKER, PH.D.
VICE PRESIDENT & MANAGING DIRECTOR, IBIS THERAPEUTICS

Dr. Ecker was a founder of the Company and has served as our Vice
President & Managing Director of Ibis Therapeutics, a division of Isis
Pharmaceuticals, since June 1995. He served as our Vice President, Biology from
July 1993 to June 1995, as our Executive Director, Molecular and Cellular
Biology from February 1993 to July 1993, and as our Director, Molecular and
Cellular Biology from February 1989 to February 1993. From



18
1984 until February 1989, he was employed by SmithKline and French Laboratories
in a variety of research positions.

ARTHUR A. LEVIN, PH.D.
VICE PRESIDENT, TOXICOLOGY & PHARMACOKINETICS

Dr. Levin, a toxicologist, has served as our Vice President, Toxicology
and Pharmacokinetics since January 1998. From August 1996 to January 1998, Dr.
Levin was our Executive Director, Toxicology and Pharmacokinetics. Dr. Levin
joined Isis in February 1995 as a Director in our Toxicology department and
served in that capacity until August 1996. Prior to joining Isis in 1995, Dr.
Levin worked for Hoffmann-La Roche Inc. where he was Research Leader in their
Investigative Toxicology Department.

PATRICIA LOWENSTAM
VICE PRESIDENT, HUMAN RESOURCES

Ms. Lowenstam has served as our Vice President, Human Resources since
January 1995. She joined Isis in August 1992 as our Director, Human Resources
and served in that capacity until January 1995. Prior to joining Isis, she held
senior management positions in Human Resources with Quotron Systems, Inc.,
Citicorp, Zales Jewelers, and the May Company.

KAREN S. LUNDSTEDT
VICE PRESIDENT, INVESTOR RELATIONS & CORPORATE COMMUNICATIONS

Ms. Lundstedt has served as our Vice President, Investor Relations and
Corporate Communications since April 2000. Ms. Lundstedt joined Isis in August
1999 as our Executive Director, Investor Relations and Corporate Communications.
From September 1991 until joining Isis, Ms. Lundstedt held various management
positions at Dura Pharmaceuticals, a specialty respiratory pharmaceutical and
pulmonary drug delivery company.

RISK FACTORS

Please consider the following risk factors carefully in addition to the
other information contained in this report.

OUR BUSINESS WILL SUFFER IF WE FAIL TO OBTAIN REGULATORY APPROVAL FOR OUR
PRODUCTS.

We must conduct time-consuming, extensive and costly clinical trials,
in compliance with U.S. Food and Drug Administration regulations, and by
comparable authorities in other countries, to show the safety and efficacy of
each of our drug candidates, as well as the optimum dosage for each, before the
FDA can approve a drug candidate for sale. We may not be able to obtain
necessary regulatory approvals on a timely basis, if at all, for any of our
products under development. Delays in receiving these approvals, failure by us
or our partners to receive these approvals at all or failure to comply with
existing or future regulatory requirements could have a material adverse effect
on our business, financial condition and results of operations.

Significant additional trials may be required, and we may not be able
to demonstrate that our drug candidates are safe or effective. We have only
introduced one commercial product, Vitravene. We cannot guarantee that any of
our other product candidates will obtain required government approvals or that
we can successfully commercialize any products.

OUR BUSINESS WILL SUFFER IF OUR PRODUCTS ARE NOT USED BY DOCTORS TO TREAT
PATIENTS.

We cannot guarantee that any of our products in development, if
approved for marketing, will be used by doctors to treat patients. We currently
have one product, Vitravene, a treatment for CMV retinitis in AIDS patients,
which addresses a small commercial market with significant competition. However,
we may not be successful in commercializing additional products.


19
The degree of market acceptance for any of our products depends upon a
number of factors, including:

o the receipt and scope of regulatory approvals;

o the establishment and demonstration in the medical and patient
community of the clinical efficacy and safety of our product
candidates and their potential advantages over competitive products;
and

o reimbursement policies of government and third-party payors.

In addition, physicians, patients, patient advocates, payors or the medical
community in general may not accept and use any products that we may develop.

OUR BUSINESS WILL SUFFER IF ANY OF OUR COLLABORATIVE PARTNERS FAIL TO DEVELOP,
FUND OR SELL ANY OF OUR PRODUCTS UNDER DEVELOPMENT OR IF WE ARE UNABLE TO OBTAIN
ADDITIONAL PARTNERS.

If any collaborative partner fails to develop or sell any product in
which we have rights, our business may be negatively affected. While we believe
that our collaborative partners will have sufficient motivation to continue
their funding, development and commercialization activities, we cannot be sure
that any of these collaborations will be continued or result in commercialized
products. The failure of a corporate partner to continue funding any particular
program could delay or stop the development or commercialization of any products
resulting from such program.

Collaborative partners may be pursuing other technologies or developing
other drug candidates either on their own or in collaboration with others,
including our competitors, to develop treatments for the same diseases targeted
by our own collaborative programs.

We also may wish to rely on additional collaborative arrangements to
develop and commercialize our products in the future. However, we may not be
able to negotiate acceptable collaborative arrangements in the future, and, even
if successfully negotiated, the collaborative arrangements themselves may not be
successful.

OUR BUSINESS COULD SUFFER IF THE RESULTS OF CLINICAL TESTING INDICATE THAT ANY
OF OUR PRODUCTS UNDER DEVELOPMENT ARE NOT SUITABLE FOR COMMERCIAL USE.

Drug discovery and development involves inherent risks, including the
risk that molecular targets prove unsuccessful and the risk that compounds that
demonstrate attractive activity in preclinical studies do not demonstrate
similar activity in human beings or have undesirable side effects. Most of our
resources are dedicated to applying molecular biology and medicinal chemistry to
the discovery and development of drug candidates based upon antisense
technology, a novel drug discovery tool for designing drugs that work at the
genetic level to block the production of disease-causing proteins.

WE HAVE INCURRED LOSSES AND OUR BUSINESS WILL SUFFER IF WE FAIL TO ACHIEVE
PROFITABILITY IN THE FUTURE.

Because of the nature of the business of drug discovery and
development, our expenses have exceeded our revenues since we were founded in
January 1989. As of December 31, 2000, our accumulated losses were approximately
$311 million. Most of the losses have resulted from costs incurred in connection
with our research and development programs and from general and administrative
costs associated with our growth and operations. These costs have exceeded our
revenues, most of which have come from collaborative arrangements, interest
income and research grants. Our current product revenues are derived solely from
sales of Vitravene. This product has limited sales potential. We expect to incur
additional operating losses over the next several years, and we expect losses to
increase as our preclinical testing and clinical trial efforts continue to
expand. We cannot guarantee that we will successfully develop, receive
regulatory approval for, commercialize, manufacture, market or sell any
additional products, or achieve or sustain future profitability.

OUR BUSINESS WILL SUFFER IF WE FAIL TO OBTAIN TIMELY FUNDING.

Based on our current operating plan, we believe that our available cash
and existing sources of revenue and credit, together with the interest earned on
those funds, will be adequate to satisfy our capital needs for at least the next
three years. We expect that we will need substantial additional funding in the
future. Our future capital requirements will depend on many factors, such as the
following:


20
o  continued scientific progress in our research, drug discovery and
development programs;

o the size of these programs and progress with preclinical and
clinical trials;

o the time and costs involved in obtaining regulatory approvals;

o the costs involved in filing, prosecuting and enforcing patent
claims;

o competing technological and market developments, including the
introduction of new therapies that address our markets; and

o changes in existing collaborative relationships and our ability to
establish and maintain additional collaborative arrangements.

Additional funds will need to be raised through public or private
financing. Additional financing may not be available, or, if available, may not
be available on acceptable terms. If additional funds are raised by issuing
equity securities, the shares of existing stockholders will be subject to
further dilution and share prices may decline. If adequate funds are not
available, we may be required to cut back on one or more of our research, drug
discovery or development programs or obtain funds through arrangements with
collaborative partners or others if available. These arrangements may require us
to give up rights to certain of our technologies, product candidates or
products.

OUR BUSINESS WILL SUFFER IF WE CANNOT MANUFACTURE OUR PRODUCTS OR HAVE A THIRD
PARTY MANUFACTURE OUR PRODUCTS AT LOW COSTS SO AS TO ENABLE US TO CHARGE
COMPETITIVE PRICES TO BUYERS.

To establish additional commercial manufacturing capability on a large
scale, we must improve our manufacturing processes and reduce our product costs.
The manufacture of sufficient quantities of new drugs is typically a
time-consuming and complex process. Pharmaceutical products based on chemically
modified oligonucleotides have never been manufactured on a large commercial
scale. There are a limited number of suppliers for certain capital equipment and
raw materials that we use to manufacture our drugs, and some of these suppliers
will need to increase their scale of production to meet our projected needs for
commercial manufacturing. We may not be able to manufacture at a cost or in
quantities necessary to make commercially successful products.

OUR BUSINESS WILL SUFFER IF WE FAIL TO COMPETE EFFECTIVELY WITH OUR COMPETITORS.

Our competitors are engaged in all areas of drug discovery in the
United States and other countries, are numerous, and include, among others,
major pharmaceutical and chemical companies, specialized biopharmaceutical
firms, universities and other research institutions. Our competitors may succeed
in developing other new therapeutic drug candidates that are more effective than
any drug candidates that we are developing. These competitive developments could
make our technology and products obsolete or non-competitive before we have had
enough time to develop and commercialize our products, or to recover our
research, development or commercialization expenses.

Many of our competitors have substantially greater financial, technical
and human resources than we do. In addition, many of these competitors have
significantly greater experience than we do in conducting preclinical testing
and human clinical trials of new pharmaceutical products and in obtaining FDA
and other regulatory approvals of products for use in health care. Accordingly,
our competitors may succeed in obtaining regulatory approval for products
earlier than we do. We will also compete with respect to manufacturing
efficiency and marketing capabilities, areas in which we have limited or no
experience.

OUR BUSINESS WILL SUFFER IF WE ARE UNABLE TO PROTECT OUR PATENTS OR OUR
PROPRIETARY RIGHTS.

Our success depends to a significant degree upon our ability to develop
proprietary products. However, patents may not be granted on any of our pending
patent applications in the United States or in other countries. In addition, the
scope of any of our issued patents may not be sufficiently broad to offer
meaningful protection. Furthermore, our issued patents or patents licensed to us
could potentially be successfully challenged, invalidated or circumvented so
that our patent rights would not create an effective competitive barrier.

21
INTELLECTUAL PROPERTY LITIGATION COULD HARM OUR BUSINESS.

It is possible that we may have to defend our intellectual property
rights in the future. In the event of an intellectual property dispute, we may
be forced to litigate or otherwise defend our intellectual property assets.
Disputes could involve litigation or proceedings declared by the United States
Patent and Trademark Office or the International Trade Commission. Intellectual
property litigation can be extremely expensive, and this expense, as well as the
consequences should we not prevail, could seriously harm our business.

If a third party claimed an intellectual property right to technology
we use, we might be forced to discontinue an important product or product line,
alter our products and processes, pay license fees or cease certain activities.
We may not be able to obtain a license to such intellectual property on
favorable terms, if at all.

THE LOSS OF KEY PERSONNEL, OR THE INABILITY TO ATTRACT AND RETAIN HIGHLY SKILLED
PERSONNEL, COULD ADVERSELY AFFECT OUR BUSINESS.

We are dependent on the principal members of our management and
scientific staff. We do not have employment agreements with any of our
management. The loss of our management and key scientific employees might slow
the achievement of important research and development goals. It is also critical
to our success that we recruit and retain qualified scientific personnel to
perform research and development work. We may not be able to attract and retain
skilled and experienced scientific personnel on acceptable terms, because of
intense competition for experienced scientists among many pharmaceutical and
health care companies, universities and non-profit research institutions.

OUR STOCK PRICE MAY CONTINUE TO BE HIGHLY VOLATILE.

The market price of our common stock, like that of the securities of
many other biopharmaceutical companies, has been and is likely to continue to be
highly volatile. During the past twelve months, the market price of our common
stock has ranged from $5.75 to $39.00 per share. The market price can be
affected by many factors, including, for example, fluctuations in our operating
results, announcements of clinical trial results, technological innovations or
new drug products being developed by us or our competitors, governmental
regulation, regulatory approval, developments in patent or other proprietary
rights, public concern regarding the safety of our drugs and general market
conditions.

PROVISIONS IN OUR CERTIFICATE OF INCORPORATION, OTHER AGREEMENTS AND DELAWARE
LAW MAY PREVENT STOCKHOLDERS FROM RECEIVING A PREMIUM FOR THEIR SHARES.

Our certificate of incorporation provides for classified terms for the
members of our board of directors. Our certificate also includes a provision
that requires at least 66-2/3% of our voting stockholders to approve a merger or
certain other business transactions with, or proposed by, any holder of 15% or
more of our voting stock, except in cases where certain directors approve the
transaction or certain minimum price criteria and other procedural requirements
are met.

Our certificate of incorporation also requires that any action required
or permitted to be taken by our stockholders must be taken at a duly called
annual or special meeting of stockholders and may not be taken by written
consent. In addition, special meetings of our stockholders may be called only by
the board of directors, the chairman of the board or the president, or by any
holder of 10% or more of our outstanding common stock. These provisions, as well
as Delaware law and other of our agreements including our stockholders' Rights
Plan, may discourage certain types of transactions in which our stockholders
might otherwise receive a premium for their shares over then current market
prices, and may limit the ability of our stockholders to approve transactions
that they think may be in their best interests. In addition, our board of
directors has the authority to fix the rights and preferences of and issue
shares of preferred stock, which may have the effect of delaying or preventing a
change in control of Isis without action by the stockholders.



22
ITEM 2.  PROPERTIES

We occupy approximately 170,000 square feet of laboratory and office
space, including a 12,000 square foot Good Manufacturing Practices manufacturing
suite, in five buildings located on our "campus" in Carlsbad, California. We own
three of these buildings and, as of December 31, 2000, these buildings secured
approximately $7 million of our debt. We lease two of the buildings under lease
agreements expiring in 2007 and 2010. We have also leased 1,600 sq. ft. of
office space in the United Kingdom to accommodate employees supervising European
clinical trials. However, we are in the process of closing our United Kingdom
office. We believe that our facilities will be adequate to meet our needs
through 2001.


ITEM 3. LEGAL PROCEEDINGS

The company is not party to any material legal proceedings.


ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

Not applicable.

PART II

ITEM 5. MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS

Our common stock is traded publicly through the Nasdaq National Market
under the symbol "ISIP." The following table presents quarterly information on
the price range of our common stock. This information indicates the high and low
sale prices reported by the Nasdaq National Market. These prices do not include
retail markups, markdowns or commissions.

<TABLE>
<CAPTION>
HIGH LOW
-------------- ---------------
<S> <C> <C>
1999
First Quarter $ 15.25 $ 8.94
Second Quarter $ 12.19 $ 9.25
Third Quarter $ 13.81 $ 9.16
Fourth Quarter $ 17.38 $ 3.88

2000
First Quarter $ 39.00 $ 5.75
Second Quarter $ 16.25 $ 8.06
Third Quarter $ 15.75 $10.50
Fourth Quarter $ 14.75 $ 8.81

</TABLE>

As of January 12, 2001, there were approximately 1,129 stockholders of
record of our common stock. We have never paid dividends and do not anticipate
paying any dividends in the foreseeable future. Under the terms of certain term
loans, we are restricted from paying cash dividends until the loans are fully
repaid. See Item 7, "Management's Discussion and Analysis of Financial Condition
and Results of Operations - Liquidity and Capital Resources."

RECENT SALES OF UNREGISTERED SECURITIES

On January 14, 2000, in conjunction with the formation of our HepaSense
joint venture, we sold 12,015 shares of our Series B Convertible Preferred Stock
to Elan International Services for $12,015,000. In conjunction with this
transaction, we also sold 297,619 shares of our Common Stock to EIS for
$7,500,000, and issued to EIS a warrant to purchase up to 14,881 shares of our
Common Stock at $50.40 per share. The term of the warrant is



23
5 years. We expect to use the proceeds from the sale of these securities for
general corporate purposes, including, but not limited to, funding the research
and development activities of the HepaSense joint venture.

At any time after June 30, 2002, the Preferred Stock (including accrued
dividends) will be convertible at EIS' option into shares of our Common Stock at
125% of the 60-trading day average closing price of our Common Stock ending two
business days prior to June 30, 2002 (as adjusted for stock splits, stock
dividends and the like). In the event of a liquidation of Isis or certain
transactions involving a change of control of Isis, the agreement provides for
automatic conversion of the Preferred Stock on terms similar to those set forth
above.

At any time after January 14, 2000, the holders of Preferred Stock may
exchange their Preferred Stock with us for preferred shares of HepaSense held by
us that represent 30.1% of the total outstanding capital stock of HepaSense. The
exchange right will terminate if the Preferred Stock is converted into our
Common Stock, unless such conversion occurs as a result of a liquidation or
certain transactions involving a change of control of Isis.

Until July 14, 2002, EIS will, at our request, purchase our convertible
debt in an amount equal to our share of budgeted funding for HepaSense. The
convertible debt will have a term of six years, bear interest at the rate of 12%
and be convertible into our Common Stock at a premium. We may prepay the
convertible debt in cash or in our Common Stock. We will use the proceeds of the
sale of the convertible debt to provide additional development funding to
HepaSense.

The issuance and sale of these securities was intended to be exempt
from registration and prospectus delivery requirements under the Securities Act
of 1933, as amended, by virtue of Section 4(2) thereof due to, among other
things, (i) the limited number of persons to whom the shares were issued, (ii)
the distribution of disclosure documents to the investor, (iii) the fact that
such person represented and warranted to Isis, among other things, that such
person was acquiring the shares for investment only and not with a view to the
resale or distribution thereof, and (iv) the fact that certificates representing
the shares were issued with a legend to the effect that such shares had not been
registered under the Securities Act or any state securities laws and could not
be sold or transferred in the absence of such registration or an exemption
therefrom.

ITEM 6. SELECTED FINANCIAL DATA (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)

<TABLE>
<CAPTION>

YEARS ENDED DECEMBER 31,
-------------------------------------------------------------------------------
2000 1999 1998 1997 1996
------------- ------------- ------------- ------------- -------------
<S> <C> <C> <C> <C> <C>
STATEMENT OF OPERATIONS DATA:
Research and development revenues
(includes license and royalty revenue) $ 37,255 $ 33,925 $ 39,171 $ 32,722 $ 22,663
Research and development expenses $ 57,014 $ 66,413 $ 62,200 $ 55,940 $ 45,653
Net loss applicable to common stock $ (54,699) $ (59,645) $ (42,983) $ (31,066) $ (26,521)
Basic and diluted net loss per share $ (1.48) $ (2.08) $ (1.60) $ (1.17) $ (1.04)
Shares used in computing basic and
diluted net loss per share 37,023 28,703 26,873 26,456 25,585

</TABLE>


<TABLE>
<CAPTION>
DECEMBER 31,
-------------------------------------------------------------------------------
2000 1999 1998 1997 1996
------------- ------------- ------------- ------------- -------------
<S> <C> <C> <C> <C> <C>
BALANCE SHEET DATA:
Cash, cash equivalents and short-term
investments $ 127,262 $ 52,839 $ 58,848 $ 86,786 $ 77,624
Working capital $ 118,568 $ 44,213 $ 40,651 $ 62,573 $ 56,300
Total assets $ 183,256 $ 103,107 $ 96,074 $ 117,881 $ 101,305
Long-term debt and capital lease
obligations, less current portion $ 102,254 $ 87,254 $ 77,724 $ 56,452 $ 19,864
Accumulated deficit $ (311,460) $ (256,761) $ (197,116) $ (154,133) $ (123,067)
Stockholders' equity (deficit) $ 66,366 $ 869 $ (4,186) $ 34,852 $ 58,385
</TABLE>


24
ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS

Since our inception in January 1989, almost all of our resources have
been devoted to our research, drug discovery and drug development programs. We
are not yet profitable and expect to continue to have operating losses for at
least the next several years. Our revenue comes from collaborative research and
development agreements with pharmaceutical companies, the sale and licensing of
our intellectual property, research grants and interest income. The revenue from
the collaboration agreements increases the amount of research and development
activity that we are able to fund and offsets a portion of our research and
development costs. See Item 1, Business - Collaborative Arrangements and
Licensing Agreements. In 1998, we received approval from the U.S. Food and Drug
Administration, or FDA, to begin marketing our first product, Vitravene, a drug
used to treat CMV retinitis.

RESULTS OF OPERATIONS

YEARS ENDED DECEMBER 31, 2000 AND DECEMBER 31, 1999

Total revenue for the year ended December 31, 2000 was $37.3 million,
compared to $33.9 million for 1999. The 10% increase in revenues for the year
was due primarily to our sale of patents to Coley Pharmaceutical Group; the
licensing of our third generation antisense chemistry to Pantheco A/S; our
collaborations with Agouron Pharmaceuticals, Inc., a Pfizer Company and Aventis;
our two joint ventures with Elan Corporation, plc, Orasense and HepaSense, and
certain government grants and contracts. The increase was partially offset by
the conclusion in December 1999 of development funding from Novartis Pharma AG
and Boehringer Ingelheim International GmbH.

Our revenue from collaborative research and development agreements was
$16.9 million for the year ended December 31, 2000, compared with $29.4 million
in 1999, a decrease of 43%. The decrease was principally due to the conclusion
in December 1999 of development funding from Novartis and Boehringer Ingelheim.
We delivered our first commercial shipment of Vitravene to our partner Novartis
Ophthalmics in 1998. Since August 1998 we have earned $674,000 in revenue
related to shipments of Vitravene to Novartis Ophthalmics.

In January 2000, we formed a joint venture with Elan to develop an
antisense drug to treat patients chronically infected with the Hepatitis C
virus. The joint venture, HepaSense, is a Bermuda limited company. This is our
second joint venture with Elan. We formed our first joint venture with Elan,
Orasense, in April 1999. While we own 80.1% of the outstanding common stock of
each of the joint ventures, HepaSense and Orasense, Elan and its subsidiaries
have retained in each of the joint ventures significant minority investor rights
that are considered "participating rights" as defined in EITF 96-16. Therefore,
we do not consolidate the financial statements of HepaSense or Orasense, but
instead account for our investment in HepaSense and Orasense under the equity
method of accounting. During 2000, we recognized $8.0 million in contract
revenue for research and development activities performed for HepaSense and
Orasense. In 1999, we recognized $4.4 million in contract revenue for research
and development activities we performed for Orasense.

Our revenue from licensing and royalty activities was $12.4 million in
2000 of which $10.7 million was from the sale of certain of our patents to Coley
Pharmaceutical Group. Licensing and royalty revenue in 1999 was insignificant.

Research and development expenses decreased by 14% to $57.0 million in
2000, from $66.4 million in 1999. The significant decrease in expenses was
primarily due to our restructuring and staff reductions that occurred earlier in
2000 offset by expenses related to the initiation of Phase III clinical trials
for ISIS 3521 in non-small cell lung cancer. We expect that research and
development expenses will increase from the 2000 levels as we advance our
pipeline into later and more expensive stages of development. Of the eleven
products we currently have in development, six of them are in either Phase II or
Phase III clinical trials.

General and administrative expenses were $8.6 million for 2000,
compared with $10.6 million in 1999. This decrease was primarily due to staff
reductions related to our restructuring earlier in 2000. We expect that



25
general and administrative expenses will increase from the 2000 levels in
support of our increasing research and development activities.

Total operating expenses for 2000 were $67.9 million, compared with
$77.0 million for 1999. Operating expenses for 2000 included $1.6 million in
restructuring costs related to our restructuring and staff reductions that
occurred earlier in the year. Additionally, operating expenses included $0.6
million in non-cash compensation expense related to an option exchange program,
which we offered to non-officer employees in January 2000, and the grant of
stock options to consultants. We granted options to consultants at fair market
value on the date of grant. These options become vested or substantially earned,
these options are required to be accounted for in accordance with EITF 96-18.

Interest income increased to $6.5 million in 2000 from $2.5 million in
1999. This increase was principally due to our significantly higher average cash
and short-term investment balances in 2000.

Interest expense increased to $13.2 million in 2000, compared with
$11.4 million in 1999. This increase in interest expense was due primarily to
borrowings under the $18.4 million and $12.0 million convertible debt facilities
available to us from Elan to fund research and development activities for
Orasense and HepaSense, respectively. During 2000, we borrowed $6.7 million from
Elan related to Orasense and $1.8 million from Elan related to HepaSense. The
terms of the Elan debt provide that the payment of principal and interest is
deferred until maturity in 2005 and 2006 for Orasense and HepaSense,
respectively. In 2000, $9.7 million of the $13.2 million in interest expense,
which was accrued under various long-term debt agreements, will not require
current cash payment.

Our net operating loss of $30.6 million in 2000 was 29% lower than our
net operating loss of $43.1 million in 1999 for the reasons stated earlier.
During 2001 we expect to be conducting two pivotal Phase III clinical trial
programs: the ongoing trial of ISIS 3521 in patients with non-small cell lung
cancer and the planned trial of ISIS 2302 in patients with Crohn's disease.
These programs, in addition to the continued aggressive development of our large
pipeline, will result in increased expenses and lead to an increase in our net
loss from operations in 2001. Operating losses may fluctuate from quarter to
quarter because of differences in the timing of revenue and expense recognition.
Our 2000 loss applicable to common stock was $54.7 million, compared to $59.6
million in 1999. The 2000 loss applicable to common stock included $15.9 million
for our equity in the losses of Orasense and HepaSense and $0.3 million for our
equity in the loss of Pantheco. The 1999 loss applicable to common stock
included $7.2 million for our equity in the loss of Orasense.

At December 31, 2000, our net operating loss carryforward for federal
income tax purposes was approximately $295.5 million. The net operating loss and
research credit carryforwards make up the majority of our deferred tax assets.
We will only be able to use the net operating loss and research credits, and
realize the benefit of these deferred tax assets, if we become profitable. We
have fully reserved all of our deferred tax assets, as their realization is
uncertain. Our research credit carryforward for federal income tax purposes was
approximately $13.2 million. Our federal net operating loss and research credit
carryforwards will begin expiring in 2004 unless previously utilized. Our net
operating loss and tax credit carryforwards will be subject to an annual
limitation regarding utilization against taxable income in future periods, due
to "change of ownership" provisions of the Tax Reform Act of 1986. We believe
that such limitation will not have a material adverse impact on the benefits
that may arise from our net operating loss and tax credit carryforwards.
However, there may or may not be additional limitations arising from any future
changes in ownership that may have a material adverse impact on us.

We believe that inflation and changing prices have not had a material
effect on our operations to date.

YEARS ENDED DECEMBER 31, 1999 AND DECEMBER 31, 1998

Our total revenue was $33.9 million for the year ended December 31,
1999, compared with $39.2 million in 1998. The decrease was principally due to
$5.0 million of revenue recognized in 1998 from licensing certain patents.
Revenue earned in 1999 from licensing patents was not significant. During 1999,
we recognized $4.4 million in contract revenue for research and development
activities performed for Orasense. We delivered our first commercial shipment of
Vitravene to our partner Novartis Ophthalmics in 1998, earning



26
product revenue of $0.6 million. No commercial shipments of Vitravene were made
in 1999, and no product revenue was earned.

Research and development expenses were $66.4 million in 1999, compared
to $62.2 million in 1998. The increase in research and development expenses
occurred because compounds in preclinical and clinical development continued to
advance into later and more expensive stages of development during 1999.
Operating expenses in 1998 included a $5.2 million write-off of acquired
patents. No similar expenses were incurred in 1999.

General and administrative expenses were $10.6 million for 1999,
compared with $9.5 million in 1998. This increase was primarily due to expanded
business development and investor relations activities in support of our
increasing research and development efforts.

Interest income declined to $2.5 million in 1999 from $4.2 million in
1998. This decrease was primarily due to lower levels of cash and short-term
investments during 1999.

Interest expense increased to $11.4 million in 1999, compared with $9.4
million in 1998. This increase in interest expense was due primarily to
borrowing a total of $40 million in 1997 and 1998 under the terms of ten-year
private debt financings. Under the terms of the private debt financing
arrangements, payment of both principal and interest is deferred for the first
five years. During the third and fourth quarters of 1999, the company also
borrowed $2.3 million from Elan related to the Orasense joint venture. The terms
of the Elan debt also provide that the payment of principal and interest is
deferred until maturity in 2005. Therefore, of the $11.4 million interest
expense in 1999, $8.1 million was accrued under long-term debt agreements and
will not require current cash payment.

Our net loss applicable to common stock for 1999 was $59.6 million, or
$2.08 per share, compared to $43.0 million, or $1.60 per share, for 1998. The
1999 loss included $7.2 million for equity in the loss of Orasense. Our loss
from operations was $43.1 million in 1999, compared to $37.8 million in 1998.

LIQUIDITY AND CAPITAL RESOURCES

We have financed our operations with revenue from contract research and
development, revenue from the sale or licensing of our intellectual property,
the sale of our equity securities and the issuance of long-term debt. From our
inception through December 31, 2000, we have earned approximately $217 million
in revenue from contract research and development and the sale and licensing of
our intellectual property. Since we were founded, we have raised net proceeds of
approximately $368 million from the sale of equity securities. We have borrowed
approximately $82.3 million under long-term debt arrangements to finance a
portion of our operations.

As of December 31, 2000, we had cash, cash equivalents and short-term
investments of $127.3 million and working capital of $118.6 million. In
comparison, we had cash, cash equivalents and short-term investments of $52.8
million and working capital of $44.2 million as of December 31, 1999. This
increase in cash and short term investments resulted primarily from the sale of
common and preferred stock to institutional investors, the exercise of stock
options by our employees and borrowings under our long term debt arrangements.
During 2000, we used $23.2 million in cash for operating requirements. Other
significant cash uses included $20.6 million related to our investment in our
affiliates, $3.9 million in principal payments on debt and capital lease
obligations, $3.2 million for patent costs and $1.6 million for purchases of
property and equipment.

Under the terms of our agreements with Elan, Elan will provide us with
up to $18.4 million and $12.0 million in convertible debt to support our
research and development activities related to Orasense and HepaSense,
respectively. Restrictions on the availability of the debt facility are based on
the anticipated collaboration costs and the balance of the funds available under
each facility. As of December 31, 2000, the outstanding balance under the Elan
line of credit facilities was $9.7 million and $1.9 million for Orasense and
HepaSense, respectively. See Note 3 to the Financial Statements, "Long-term
Obligations and Commitments."

In 1997 and 1998, we borrowed a total of $40 million in private
transactions. The loans must be repaid on November 1, 2007, and bear interest at
14% per annum. No payments of either principal or interest are



27
required during the first 5 years of the loans. After the first 5 years,
interest must be paid quarterly until the end of the loans. No principal
payments are required until November 1, 2007. In conjunction with this
transaction, we issued warrants to purchase 800,000 shares of common stock at a
price of $25 per share. The warrants issued in connection with these financings
expire on November 1, 2004. The warrants have been valued at a combined total of
$5.4 million. This amount has been credited to stockholders' equity. Because
interest is deferred during the first 5 years, the combined principal balance of
both borrowings will accrue to a total of $78 million on November 1, 2002. The
debt under these arrangements is carried on the balance sheet net of the
unamortized amount allocated to the warrants and including accrued interest. The
combined carrying amount of these notes at December 31, 2000 was $58.0 million.
See Note 3 to the Financial Statements, "Long-term Obligations and Commitments".

As of December 31, 2000, our long-term obligations, including the
current portions, totaled $106.9 million, compared to $91.1 million at December
31, 1999. This increase was due to the accrual of interest on the private debt
financing together with the additional debt acquired during the year as
described above. Additional capital lease financing to fund equipment
acquisitions also contributed to the increase. We expect that capital lease
obligations will increase over time to fund capital equipment acquisitions
required for our business. We will continue to use lease lines as long as the
terms continue to remain commercially attractive. We believe that our existing
cash, cash equivalents and short-term investments, combined with interest income
and committed contract revenue will be sufficient to meet our anticipated
requirements for at least three years.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

We are exposed to changes in interest rates primarily from our
long-term debt arrangements and, secondarily, our investments in certain
short-term investments. We invest our excess cash in highly liquid short-term
investments that are typically held for the duration of the term of the
respective instrument. We do not utilize derivative financial instruments,
derivative commodity instruments or other market risk sensitive instruments,
positions or transactions to manage exposure to interest rate changes.
Accordingly, we believe that, while the securities we hold are subject to
changes in the financial standing of the issuer of such securities, we are not
subject to any material risks arising from changes in interest rates, foreign
currency exchange rates, commodity prices, equity prices or other market changes
that affect market risk sensitive instruments. A hypothetical 100 basis point
adverse move in interest rates along the entire interest rate yield curve would
not materially affect the fair value of our interest sensitive financial
instruments. Declines in interest rates over time will, however, reduce our
interest income while increases in interest rates over time will increase our
interest expense.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Our financial statements and supplementary data required by this item
are filed as exhibits hereto, are listed under Item 14(a)(1) and (2), and are
incorporated herein by reference.

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
FINANCIAL DISCLOSURE

Not applicable.

PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS

The information required by this item (with respect to Directors) is
incorporated by reference from the information under the caption "Election of
Directors" contained in our definitive Proxy Statement (the "Proxy Statement")
which will be filed on or about February 28, 2001 with the Securities and
Exchange Commission in connection with the solicitation of proxies for our 2000
Annual Meeting of stockholders to be held on April 6, 2001.



28
The required information concerning our Executive Officers is contained
in Item 1, Part I of this Report.

ITEM 11. EXECUTIVE COMPENSATION

The information required by this item is incorporated by reference to
the information under the caption "Executive Compensation" contained in the
Proxy Statement.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The information required by this item is incorporated by reference to
the information under the captions "Security Ownership of Certain Beneficial
Owners and Management" contained in the Proxy Statement.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

The information required by this item is incorporated by reference to
the information under the caption "Compensation Committee Interlocks and Insider
Participation" and "Certain Transactions" contained in the Proxy Statement.

PART IV

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

(a)(1) INDEX TO FINANCIAL STATEMENTS

The financial statements required by this item are submitted in a
separate section beginning on page F-1 of this Report.

(a)(2) INDEX TO FINANCIAL STATEMENT SCHEDULES

These schedules are omitted because they are not required, or are not
applicable, or the required information is shown in the financial statements or
notes thereto.

(a)(3) INDEX TO EXHIBITS

See Index to Exhibits on pages 32 through 33.

(b) REPORTS ON FORM 8-K

On December 12, 2000, the registrant filed a report on Form 8-K
relating to the adoption of a stockholder rights plan.

(c) EXHIBITS

The exhibits required by this Item are listed under Item 14(a)(3).

(d) FINANCIAL STATEMENT SCHEDULES

The financial statement schedules required by this Item are listed
under Item 14(a)(2).


29
SIGNATURES

Pursuant to the requirements of Section 14 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report on Form 10-K to
be signed on its behalf by the undersigned, thereunto duly authorized on the
26th day of February, 2001.

ISIS PHARMACEUTICALS, INC.

By: /s/ STANLEY T. CROOKE, M.D., Ph.D.
-----------------------------------
Stanley T. Crooke, M.D., Ph.D.
Chairman of the Board, President and
Chief Executive Officer
(Principal executive officer)


POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Stanley T. Crooke and B. Lynne Parshall,
or any of them, his or her attorney-in-fact, each with the power of
substitution, for him or her in any and all capacities, to sign any amendments
to this Report, and to file the same, with exhibits thereto and other documents
in connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his or her
substitute or substitutes, may do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934,
this report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.

<TABLE>
<CAPTION>
SIGNATURES TITLE DATE
---------- ----- ----
<S> <C> <C>

/s/ STANLEY T. CROOKE, M.D., Ph.D.
- ------------------------------------
Stanley T. Crooke, M.D., Ph.D. Chairman of the Board,
Chief Executive Officer and
Director (Principal
executive officer) February 26, 2001
/s/ B. LYNNE PARSHALL
- ------------------------------------
B. Lynne Parshall Executive Vice President, Chief
Financial Officer and Director
(Principal financial and
accounting officer) February 26, 2001



/s/ CHRISTOPHER F. O. GABRIELI
- ------------------------------------
Christopher F. O. Gabrieli Director February 26, 2001



/s/ WILLIAM R. MILLER
- ------------------------------------
William R. Miller Director February 26, 2001

</TABLE>


30
<TABLE>
<CAPTION>
SIGNATURES TITLE DATE
---------- ----- ----
<S> <C> <C>
/s/ MARK B. SKALETSKY
- ------------------------------------
Mark B. Skaletsky Director February 26, 2001



/s/ JOSEPH H. WENDER
- ------------------------------------
Joseph H. Wender Director February 26, 2001

</TABLE>







31
INDEX TO EXHIBITS

<TABLE>
<CAPTION>

EXHIBIT
NUMBER DESCRIPTION OF DOCUMENT
- -------------- ------------------------
<S> <C>
1.1 - Form of Common Stock Purchase Agreement between the Registrant and Ridgeway Investment Limited. (16)
3.1 - Amended and Restated Certificate of Incorporation filed June 19, 1991. (1)
3.2 - Bylaws. (1)
3.3 - Certificate of Designation of the Series A Convertible Preferred Stock. (11)
3.4 - Certificate of Designation of the Series B Convertible Preferred Stock. (14)
3.5 - Certificate of Designation of the Series C Junior Participating Preferred Stock. (17)
4.1 - Reference is made to Exhibits 3.1 through 3.5.
4.2 - Specimen Stock Certificate. (1)
4.3 - Specimen Series A Preferred Stock Certificate. (18)
4.4 - Specimen Series B Preferred Stock Certificate. (18)
4.5 - Form of Right Certificate. (17)
10.1 - Form of Indemnification Agreement entered into between the Registrant and its Directors and Officers with
related schedule. (1)
10.2 * - Registrant's 1989 Stock Option Plan, as amended. (6)
10.3 * - Registrant's 1992 Non-Employee Directors Stock Option Plan, as amended. (4)
10.4 * - Form of Performance-Based Supplemental Stock Option Agreement dated January 6, 2000 under the 1989
Stock Option Plan entered into between the Registrant and certain of its officers together with related
schedule.
10.5 * - Registrant's Employee Stock Purchase Plan. (10)
10.6 * - Form of Employee Assignment of Patent Rights. (1)
10.7 * - Registrant's 2000 Broad-Based Equity Incentive Stock Option Plan. (10)
10.8 * - Severance Agreement dated January 11, 2000 entered into between the Registrant and its executive officers,
together with related schedule. (10)
10.9 - Stock Purchase Agreement between the Registrant and Boehringer Ingelheim International GmbH, dated as of
July 18, 1995 (with certain confidential information deleted). (2)
10.10 - Collaborative Agreement between the Registrant and Boehringer Ingelheim International GmbH, dated as of
July 18, 1995 (with certain confidential information deleted). (3)
10.11 - Agreement between the Registrant and CIBA Vision Corporation (now Novartis Ophthalmics) dated July 10, 1997
(with certain confidential information deleted). (5)
10.12 - Amendment No. 2 to the Agreement between the Registrant and CIBA Vision Corporation, dated September 14,
1998 (with certain confidential information deleted). (8)
10.13 - Imperial Bank Note Secured by Deed of Trust dated March 24, 1997 in the amount of $6,000,000, together with
the related Deed of Trust and Assignment of Rents dated March 24, 1997. (5)
10.14 - Imperial Bank Note Secured by Deed of Trust dated March 24, 1997 in the amount of $3,706,620, together with
the related Deed of Trust and Assignment of Rents dated March 24, 1997. (5)
10.15 - Purchase Agreement between the Registrant and Reliance Insurance Company for 14% Senior Subordinated Discount
Notes due November 1, 2007 and Warrants for Common Stock dated October 24, 1997 (with certain confidential
information deleted). (6)
10.16 - First Supplement to Purchase Agreement between the Registrant and Reliance Insurance Company for 14% Senior
Subordinated Discount Notes due November 1, 2007 and Warrants for Common Stock dated May 1, 1998 (with certain
confidential information deleted). (7)
10.17 - Asset Purchase Agreement between the Registrant and Gen-Probe Incorporated dated December 19, 1997 (with
certain confidential information deleted). (6)
10.18 - Research Collaboration and License Agreement between Merck & Co., Inc. and the Registrant dated June 1,
1998 (with certain confidential information deleted). (7)
10.19 - Patent Rights Purchase Agreement between the Registrant and Gilead Sciences, Inc., dated December 18, 1998
(with certain confidential information deleted). (9)
10.20 - Subscription, Joint Development and Operating Agreement, dated April 20, 1999 by and among the Registrant,
Elan Corporation, plc, Elan International Services, Ltd. And Orasense, Ltd. (with certain confidential
information deleted); together with the related Securities Purchase Agreement,


</TABLE>

32
<TABLE>
<CAPTION>

EXHIBIT
NUMBER DESCRIPTION OF DOCUMENT
- -------------- ------------------------
<S> <C>
Convertible Promissory Note, Warrant to Purchase Shares of Common Stock, Registration Rights Agreements
and License Agreements. (12)
10.21 - Agreement dated August 31, 1999 between Boehringer Ingelheim International GmbH and the Registrant;
together with related Amendment to the Stock Purchase Agreement. (13)
10.22 - Subscription, Joint Development and Operating Agreement, dated January 14, 2000 by and among the
Registrant, Elan Corporation, plc, Elan International Services, Ltd. and HepaSense, Ltd. (with certain
confidential information deleted); together with the related Securities Purchase Agreement, Convertible
Promissory Note, Warrant to Purchase Shares of Common Stock, Registration Rights Agreements and License
Agreements. (14)
10.23 - Agreement between the Registrant and Agouron Pharmaceuticals, dated June 9, 2000 (with certain confidential
information deleted). (15)
10.24 - Rights Agreement dated as of December 8, 2000 between the Registrant and American Stock Transfer & Trust
Company. (17)
23.1 - Consent of Ernst & Young LLP, Independent Auditors.
24.1 - Power of Attorney. Reference is made to page 30.
99.1 - Form of Confidentiality Agreement. (11)

</TABLE>
- ------------------

(1) Filed as an exhibit to the Registrant's Registration Statement on Form S-1
(No. 33-39640) or amendments thereto and incorporated herein by reference.
(2) Filed as an exhibit to the Registrant's Report on Form 8-K dated July 18,
1995 and incorporated herein by reference.
(3) Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended September 30, 1995 and incorporated herein by reference.
(4) Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended September 30, 1996 and incorporated herein by reference.
(5) Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended June 30, 1997 and incorporated herein by reference.
(6) Filed as an exhibit to the Registrant's Annual Report on Form 10-K for the
year ended December 31, 1997 and incorporated herein by reference.
(7) Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended June 30, 1998 and incorporated herein by reference.
(8) Filed as an exhibit to the Registrant's Quarterly Report on Form 10-Q for
the quarter ended September 30, 1998 and incorporated herein by reference.
(9) Filed as an exhibit to the Registrant's Annual Report on Form 10-K for the
year ended December 31, 1998 and incorporated herein by reference.
(10) Filed as an exhibit to the Registrant's Annual Report on Form 10-K for the
year ended December 31, 1999 and incorporated herein by reference.
(11) Filed as an exhibit to the Registrant's Registration Statement on Form S-3
(No. 333-71911) or amendments thereto and incorporated herein by reference.
(12) Filed as an exhibit to the Registrant's Report on Form 8-K dated April 20,
1999 and incorporated herein by reference.
(13) Filed as an exhibit to the Registrant's Report on Form 8-K dated August 31,
1999 and incorporated herein by reference.
(14) Filed as an exhibit to the Registrant's Report on Form 8-K dated
January 28, 2000 and incorporated herein by reference.
(15) Filed as an exhibit to the Registrant's Report on Form 10-Q for the quarter
ended June 30, 2000 and incorporated herein by reference.
(16) Filed as an exhibit to the Registrant's Registration Statement on Form S-3
(No. 333-90811) or amendment thereto and incorporated by reference.
(17) Filed as an exhibit to Registrant's Report on Form 8-K dated December 8,
2000 and incorporated herein by reference.
(18) Filed as an exhibit to the Registrant's Report on Form 10-Q/A for the
quarter ended June 30, 2000 and incorporated herein by reference.


* Indicates management compensatory plans and arrangements as required to be
filed as exhibits to this Report pursuant to Item 14(c).



33
ISIS PHARMACEUTICALS, INC.
INDEX TO FINANCIAL STATEMENTS

<TABLE>
<CAPTION>
PAGE
--------

<S> <C>
Report of Ernst & Young LLP, Independent Auditors F-2

Balance Sheets at December 31, 2000 and 1999 F-3

Statements of Operations for the years ended December 31, 2000, 1999 and 1998 F-4

Statements of Stockholders' Equity (Deficit) for the years ended December 31, 2000, 1999 and 1998 F-5

Statements of Cash Flows for the years ended December 31, 2000, 1999 and 1998 F-6

Notes to Financial Statements F-7


</TABLE>


F-1
REPORT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

The Board of Directors
Isis Pharmaceuticals, Inc.

We have audited the accompanying balance sheets of Isis
Pharmaceuticals, Inc. as of December 31, 2000 and 1999, and the related
statements of operations, stockholders' equity (deficit), and cash flows for
each of the three years in the period ended December 31, 2000. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.

We conducted our audits in accordance with auditing standards generally
accepted in the United States. Those standards require that we plan and perform
the audit to obtain reasonable assurance about whether the financial statements
are free of material misstatement. An audit includes examining, on a test basis,
evidence supporting the amounts and disclosures in the financial statements. An
audit also includes assessing the accounting principles used and significant
estimates made by management, as well as evaluating the overall financial
statement presentation. We believe that our audits provide a reasonable basis
for our opinion.

In our opinion, the financial statements referred to above present
fairly, in all material respects, the financial position of Isis
Pharmaceuticals, Inc. at December 31, 2000 and 1999, and the results of its
operations and its cash flows for each of the three years in the period ended
December 31, 2000, in conformity with accounting principles generally accepted
in the United States.





/s/ ERNST & YOUNG LLP



San Diego, California
February 2, 2001



F-2
ISIS PHARMACEUTICALS, INC.
BALANCE SHEETS
(IN THOUSANDS, EXCEPT SHARE DATA)

<TABLE>
<CAPTION>
ASSETS

DECEMBER 31,
-----------------------------------
2000 1999
---------------- --------------
<S> <C> <C>
Current assets:
Cash and cash equivalents $ 39,615 $ 35,296
Short-term investments 87,647 17,543
Contracts receivable 3,346 5,429
Prepaids and other current assets 2,596 929
---------------- --------------
Total current assets 133,204 59,197

Property, plant and equipment, net 22,625 23,945
Patent costs, net 13,815 11,250
Investments in affiliates 12,491 6,991
Deposits and other assets 1,121 1,724
---------------- --------------
Total assets $ 183,256 $ 103,107
================ ==============

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
Accounts payable $ 2,231 $ 3,148
Accrued compensation 3,598 1,215
Accrued liabilities 1,429 2,563
Deferred contract revenues 2,771 4,166
Current portion of long-term obligations 4,607 3,892
---------------- ---------------
Total current liabilities 14,636 14,984

Long-term obligations, less current portion 102,254 87,254

Commitments

Stockholders' equity:
Series A Convertible Exchangeable 5% Preferred stock, $.001 par value,
120,150 shares authorized, issued and outstanding
at December 31, 2000 and 1999 12,015 12,015
Accretion of Series A Preferred stock dividends 1,050 420
Series B Convertible Exchangeable 5% Preferred stock, $.001 par value,
16,620 shares authorized, 12,015 shares issued and outstanding at
December 31, 2000 and no shares issued and outstanding at
December 31, 1999 12,015 -
Accretion of Series B Preferred stock dividends 584 -
Common stock, $.001 par value; 50,000,000 shares authorized, 40,086,000
shares and 31,613,000 shares issued and outstanding at December 31,
2000 and 1999, respectively 40 32
Additional paid-in capital 352,854 245,192
Deferred compensation (858) -
Accumulated other comprehensive income (loss) 126 (29)
Accumulated deficit (311,460) (256,761)
---------------- ---------------
Total stockholders' equity 66,366 869
---------------- ---------------
$ 183,256 $ 103,107
================ ===============

</TABLE>


See accompanying notes.


F-3
ISIS PHARMACEUTICALS, INC.
STATEMENTS OF OPERATIONS
(IN THOUSANDS, EXCEPT FOR PER SHARE AMOUNTS)

<TABLE>
<CAPTION>
YEARS ENDED DECEMBER 31,
-----------------------------------------------------------
2000 1999 1998
------------------ ---------------- ---------------
<S> <C> <C> <C>
Revenues:
Research and development revenues
under collaborative agreements $ 16,912 $ 29,357 $ 34,130
Research and development revenues
from affiliates 7,967 4,402 -
Licensing and royalty revenues 12,376 166 5,041
------------------ ---------------- ---------------
Total revenue 37,255 33,925 39,171
------------------ ---------------- ---------------
Expenses:
Research and development (not including
compensation related to stock options of $435 for
the year ended December 31, 2000) 57,014 66,413 62,200
General and administrative (not including
compensation related to stock options of $152 for
the year ended December 31, 2000) 8,644 10,571 9,511
Write-off of acquired patents - - 5,238
Compensation related to stock options 587 - -
Restructuring activities 1,635 - -
------------------ ---------------- ---------------
Total operating expenses 67,880 76,984 76,949
------------------ ---------------- ---------------

Loss from operations (30,625) (43,059) (37,778)

Equity in loss of affiliates (16,224) (7,242) -
Interest income 6,524 2,500 4,150
Interest expense (13,160) (11,424) (9,355)
------------------ ---------------- ---------------

Net loss (53,485) (59,225) (42,983)

Accretion of dividends on preferred stock (1,214) (420) -

------------------ ---------------- ---------------
Net loss applicable to common stock $ (54,699) $ (59,645) $ (42,983)
================== ================ ===============

Basic and diluted net loss per share $ (1.48) $ (2.08) $ (1.60)
================== ================ ===============

Shares used in computing basic and
diluted net loss per share 37,023 28,703 26,873
================== ================ ===============

</TABLE>

See accompanying notes.



F-4
ISIS PHARMACEUTICALS, INC.
STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT)
YEARS ENDED DECEMBER 31, 2000, 1999 AND 1998
(IN THOUSANDS)

<TABLE>
<CAPTION>



PREFERRED STOCK COMMON STOCK
-------------------------------- ---------------------- ADDITIONAL
DIVIDEND PAID IN DEFERRED
DESCRIPTION SHARES AMOUNT ACCRETION SHARES AMOUNT CAPITAL COMPENSATION
- ----------------------- -------- --------- ----------- -------- -------- ------------ ------------
<S> <C> <C> <C> <C> <C> <C> <C>
Balance at December 31, 1997 -- $ -- $ -- 26,655 $ 27 $ 188,793 $ --

Comprehensive Loss
Net loss -- -- -- -- -- -- --
Change in unrealized gains
and (losses) -- -- -- -- -- -- --
Comprehensive loss -- -- -- -- -- -- --
Options exercised and
employee stock
purchase plan -- -- -- 398 -- 2,298 --
Issuances of warrants
to purchase common stock -- -- -- -- -- 1,646 --
--------- --------- ----------- ------- -------- ---------- -------
Balance at December 31, 1998 -- -- -- 27,053 27 192,737 --
--------- --------- ----------- ------- -------- ---------- -------

Comprehensive Loss
Net loss -- -- -- -- -- -- --
Change in unrealized gains
and (losses) -- -- -- -- -- -- --
Comprehensive loss -- -- -- -- -- -- --
Issuance of preferred stock,
Series A 120 12,015 -- -- -- -- --
Dividends accrued on
preferred stock -- -- 420 -- -- -- --
Issuances of common
stock, net of repurchases -- -- -- 3,974 4 49,051 --
and offering costs
Warrants exercised -- -- -- 157 -- 17 --
Options exercised and
employee stock
purchase plan -- -- -- 429 1 3,250 --
Compensation relating
to the granting of options -- -- -- -- -- 137 --
--------- --------- ----------- ------- -------- ---------- -------
Balance at December 31, 1999 120 12,015 420 31,613 32 245,192 --
--------- --------- ----------- ------- -------- ---------- -------
Comprehensive Loss
Net loss -- -- -- -- -- -- --
Change in unrealized gains
and (losses) -- -- -- -- -- -- --
Comprehensive loss -- -- -- -- -- -- --
Issuance of preferred stock,
Series B 12 12,015 -- -- -- -- --
Dividends accrued on
preferred stock -- -- 1,214 -- -- -- --
Deferred compensation -- -- -- -- -- 1,445 (1,445)
Issuances of common stock,
net of offering costs -- -- -- 6,600 6 91,483 --
Options exercised and
employee stock
purchase plan -- -- -- 1,873 2 14,734 --
Compensation relating
to the granting of options -- -- -- -- -- -- 587
--------- --------- ----------- ------- -------- ---------- -------
Balance at December 31, 2000 132 $24,030 $ 1,634 40,086 $ 40 $352,854 $ (858)
========= ========= =========== ======= ======== ========== ========
</TABLE>

<TABLE>
<CAPTION>

ACCUMULATED
OTHER TOTAL
COMPREHENSIVE ACCUMULATED STOCKHOLDERS
DESCRIPTION INCOME/(LOSS) DEFICIT EQUITY (DEFICIT)
- ----------------------- ------------- ----------- ----------------
<S> <C> <C> <C>
Balance at December 31, 1997 $ 165 $(154,133) $ 34,852

Comprehensive Loss
Net loss -- (42,983) (42,983)
Change in unrealized gains
and (losses) 1 -- 1
Comprehensive loss -- -- (42,982)
Options exercised and
employee stock
purchase plan -- -- 2,298
Issuances of warrants
to purchase common stock -- -- 1,646
---------- ---------- ---------
Balance at December 31, 1998 166 (197,116) (4,186)
---------- ---------- ---------

Comprehensive Loss
Net loss -- (59,645) (59,645)
Change in unrealized gains
and (losses) (195) -- (195)
---------
Comprehensive loss -- -- (59,840)
---------
Issuance of preferred stock,
Series A -- -- 12,015
Dividends accrued on
preferred stock -- -- 420
Issuances of common
stock, net of repurchases -- -- 49,055
and offering costs
Warrants exercised -- -- 17
Options exercised and
employee stock
purchase plan -- -- 3,251
Compensation relating
to the granting of options -- -- 137
---------- ---------- ---------
Balance at December 31, 1999 (29) (256,761) 869
---------- ---------- ---------
Comprehensive Loss
Net loss -- (54,699) (54,699)
Change in unrealized gains
and (losses) 155 -- 155
---------
Comprehensive loss -- -- (54,544)
---------
Issuance of preferred stock,
Series B -- -- 12,015
Dividends accrued on
preferred stock -- -- 1,214
Deferred compensation -- --
Issuances of common stock,
net of offering costs -- -- 91,489
Options exercised and
employee stock
purchase plan -- -- 14,736
Compensation relating
to the granting of options -- -- 587
---------- ---------- ---------
Balance at December 31, 2000 $ 126 $(311,460) $ 66,366
========== ========== =========
</TABLE>


See accompanying notes.




F-5
ISIS PHARMACEUTICALS, INC.
STATEMENTS OF CASH FLOWS
(IN THOUSANDS)

<TABLE>
<CAPTION>
YEARS ENDED DECEMBER 31,
--------------------------------------
2000 1999 1998
---------- ---------- ----------
<S> <C> <C> <C>
Operating activities:
Net loss $ (53,485) $ (59,225) $ (42,983)
Adjustments to reconcile net loss to net cash used in
operating activities:
Depreciation and amortization 5,535 5,196 4,258
Compensation related to stock options 587 137 --
Deferred interest on long term debt 9,685 8,077 6,112
Equity in losses of affiliates 16,224 7,242 --
Equity in affiliate received in exchange for patent licensing (1,125) -- --
Write-off of acquired patents -- -- 5,238
Write-off of inventory 301 -- --
Changes in operating assets and liabilities:
Contracts receivable 2,083 (1,963) (3,177)
Prepaids and other assets (1,604) 220 1,172
Accounts payable (917) 171 134
Accrued compensation 2,383 (1,873) 846
Accrued liabilities (1,458) (60) (1,633)
Deferred contract revenues (1,395) (6,010) (4,717)
--------- --------- ---------
Net cash used in operating activities (23,186) (48,088) (34,750)
--------- --------- ---------
Investing activities:
Short-term investments (69,949) 13,492 17,455
Purchases of property, plant and equipment (1,649) (4,791) (4,434)
Patent costs (3,182) (2,642) (3,882)
Investments in affiliates (20,599) (14,233) --
--------- --------- ---------
Net cash (used in) provided by investing activities (95,379) (8,174) 9,139
--------- --------- ---------
Financing activities:
Net proceeds from issuance of equity 118,240 64,338 3,944
Proceeds from long-term borrowing 8,583 3,233 13,354
Principal payments on debt and capital lease obligations (3,939) (3,631) (2,171)
--------- --------- ---------
Net cash provided by financing activities 122,884 63,940 15,127
--------- --------- ---------

Net increase (decrease) in cash and cash equivalents 4,319 7,678 (10,484)
Cash and cash equivalents at beginning of year 35,296 27,618 38,102
--------- --------- ---------
Cash and cash equivalents at end of year $ 39,615 $ 35,296 $ 27,618
========= ========= =========

Supplemental disclosures of cash flow information:
Interest paid $ 3,454 $ 2,402 $ 3,191
Supplemental disclosures of non-cash investing and
financing activities:
Additions to debt and capital lease obligations for
acquisitions of property, plant and equipment $ 1,710 $ 2,071 $ 2,068
Additions to debt for patent acquisitions $ -- $ -- $ 3,238
Additions to prepaids and other current assets from sale of
equipment $ 27 $ -- $ --


</TABLE>

See accompanying notes.



F-6
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS
DECEMBER 31, 2000

1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES

ORGANIZATION AND BUSINESS ACTIVITY

Isis Pharmaceuticals was incorporated in California on January 10,
1989. In conjunction with its initial public offering, Isis Pharmaceuticals was
reorganized as a Delaware corporation, as Isis Pharmaceuticals, Inc. (Isis or
the Company), in April 1991. Isis was organized principally to develop human
therapeutic drugs using antisense and combinatorial technology.

BASIC NET LOSS PER SHARE

Isis follows provisions of Statement of Financial Accounting Standards
No. 128, "Earnings per Share" ("SFAS 128"). Basic loss per share is computed by
dividing the net loss by the weighted average number of common shares
outstanding during the period ("Basic EPS method"). Diluted earnings (loss) per
common share is computed using the weighted-average number of common and
dilutive common equivalent shares outstanding during the period ("Diluted EPS
method"). Diluted common equivalent shares consist of shares issuable upon
exercise of stock options and warrants and conversion of preferred stock. As
Isis incurred a loss in the years ended December 31, 2000, 1999 and 1998,
options and warrants to purchase common stock were not included in the
computation of diluted net loss per share because the effect would be
antidilutive.

CONTRACT REVENUES AND EXPENSES

Contract revenues consist of non-refundable research and development
funding and are recorded as earned based on the performance requirements of the
collaborative research and development contracts. Contract fees for which no
further performance obligations exist are recognized when the payments are
received or when the collection is assured. Payments received in excess of
amounts earned are recorded as deferred contract revenues. Research and
development costs are expensed as incurred. For the years ended December 31,
2000, 1999 and 1998, costs and expenses of approximately $28,400,000,
$26,000,000 and $35,000,000, respectively, were related to collaborative
research and development arrangements.

REVENUE RECOGNITION

Isis recognizes revenue from product sales at the time of shipment. An
estimate is made of the amount of the product that may be returned and current
period sales are reduced accordingly. License fees consist of non-refundable
fees from the sale of license rights to our proprietary technologies. Revenue
from technology access fees, license fees and similar up-front payments will be
deferred and recognized over the exclusivity period or term of the license or
ongoing research period, as applicable, in accordance with Staff Accounting
Bulletin No. 101.

CONCENTRATION OF CREDIT RISK

Financial instruments that potentially subject the Company to
concentrations of credit risk consist primarily of cash equivalents, short-term
investments and receivables. The Company places its cash equivalents and
short-term investments with high credit-quality financial institutions. The
Company invests its excess cash primarily in auction and money market
instruments, and municipal and floating rate bonds. The Company has established
guidelines relative to credit ratings, diversification and maturities that seek
to maintain safety and liquidity. To date, the Company has not experienced
significant losses on any of these investments.

CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Isis considers all liquid investments with maturities of ninety days or
less when purchased to be cash equivalents. The Company's short-term investments
have initial maturities of greater than ninety days. The Company's securities
are classified as "available-for-sale" in accordance with Statement of Financial
Accounting Standards No. 115, "Accounting for Certain Investment in Debt and
Equity Securities". These investments are carried at fair market value with any
unrealized gains and losses recorded as a separate component of stockholders'
equity. Fair value is based upon market prices quoted on the last day of the
fiscal year. The cost of debt securities sold is based on the specific
identification method. Gross realized gains and losses are included in interest
income and have not been material. See Note 2 - Investments.




F-7
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment is stated at cost and consists of the
following (in thousands):

<TABLE>
<CAPTION>

DECEMBER 31,
--------------------------------
2000 1999
------------ ------------
<S> <C> <C>
Land $ 1,163 $ 1,163
Buildings and improvements 18,495 16,911
Equipment 32,750 31,075
Furniture and fixtures 1,521 1,510
----------- -----------
53,929 50,659
Less accumulated depreciation (31,304) (26,714)
----------- -----------
$ 22,625 $ 23,945
=========== ===========

</TABLE>


Depreciation of property, plant and equipment is provided on the
straight-line method over estimated useful lives as follows:

<TABLE>

<S> <C>
Building 31.5 years
Improvements 15 years
Equipment 2.5-5 years
Furniture and fixtures 5 years

</TABLE>


PATENT COSTS

Isis capitalizes certain costs related to patent applications,
principally consisting of legal and filing fees. These costs are regularly
reviewed to determine that they include costs for patent applications Isis is
pursuing. Costs related to applications that are not being actively pursued are
evaluated under Accounting Principles Board Statement 17, "Accounting for
Intangible Assets" and are adjusted to an appropriate amortization period or
immediately written-off if appropriate. Accumulated patent costs are amortized
over their estimated economic lives of approximately 10 years, beginning with
the date the patents are issued. The weighted average remaining life of issued
patents was 7.6 years at December 31, 2000 and December 31, 1999. Accumulated
amortization related to patents was $1,615,000 and $999,000 at December 31, 2000
and 1999, respectively.

INVESTMENT IN AFFILIATES

Isis accounts for investments in joint ventures and other investments
in 50% or less owned companies over which it has the ability to exercise
significant influence using the equity method of accounting. At December 31,
2000, the Company had the following investments accounted for using the equity
method:

ORASENSE AND HEPASENSE

In April 1999, Isis and Elan Corporation, plc (Elan) formed Orasense,
Ltd., a Bermuda limited company. In January 2000, Isis and Elan Corporation, plc
formed HepaSense, Ltd., a Bermuda limited company. Each joint venture is owned
80.1% by Isis and 19.9% by Elan. While Isis owns 80.1% of the outstanding common
stock of Orasense and HepaSense, Elan and its subsidiaries have retained
significant minority investor rights that are considered "participating rights"
as defined in EITF 96-16. Therefore, Isis accounts for its investment in each
joint venture under the equity method of accounting.

PANTHECO

During 2000, Isis entered into an agreement with Pantheco A/S
("Pantheco"), a Danish biotechnology company, in which Isis obtained a 22%
equity position in Pantheco. The carrying value at December 31, 2000 was
$840,000. Isis accounts for its investment in Pantheco under the equity method
of accounting.

FAIR VALUE OF FINANCIAL INSTRUMENTS

The Company has determined the estimated fair value of its financial
instruments. The amounts reported for cash, accounts receivable, short-term
borrowings, accounts payable, notes payable and accrued expenses approximate the
fair value because of their short maturities. Investment securities are reported
at


F-8
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


their estimated fair value based on quoted market prices of comparable
instruments. The estimated fair value of fixed rate long-term debt is primarily
based on the borrowing rates currently available to the Company for bank loans
with similar terms and maturities. This fair value approximated the carrying
amount of long-term debt at December 31, 2000.

LONG-LIVED ASSETS

Isis follows Statement of Financial Accounting Standards (SFAS) No.
121, "Accounting for the Impairment of Long-Lived Assets and for Long-Lived
Assets to be Disposed of" and evaluates long-lived assets for impairment
whenever events or changes in circumstances indicate that the carrying value of
such assets or intangibles may not be recoverable. Recoverability of assets to
be held and used is measured by comparison of the carrying amount of the asset
to future undiscounted net cash flows expected to be generated by the asset. If
such assets are considered to be impaired, the impairment to be recognized is
measured by the amount by which the carrying amount of the asset exceeds the
fair value of the assets. Assets to be disposed of are reported at the lower of
the carrying amount or fair value less costs to sell.

USE OF ESTIMATES

The preparation of financial statements in conformity with accounting
principles generally accepted in the United States requires management to make
estimates and assumptions that affect the amounts reported in the financial
statements and accompanying notes. Actual results could differ from those
estimates.

COMPREHENSIVE INCOME (LOSS)

Statement of Financial Accounting Standards (SFAS) 130, "Reporting
Comprehensive Income" requires Isis to display comprehensive income (loss) and
its components as part of Isis' full set of financial statements. The
measurement and presentation of net income (loss) did not change. Comprehensive
income (loss) is comprised of net income (loss) and certain changes in equity
that are excluded from net income (loss). Specifically, SFAS 130 requires
unrealized holding gains and losses on Isis' available-for-sale securities,
which were reported separately in stockholders' equity, to be included in
accumulated other comprehensive income (loss). Comprehensive income (loss) for
the years ended December 31, 2000, 1999 and 1998 have been reflected in the
Consolidated Statement of Stockholders' Equity (Deficit).

RECLASSIFICATION

Certain prior period amounts have been reclassified to conform to
current presentation.

IMPACT OF RECENTLY ISSUED ACCOUNTING STANDARDS

In March 2000, the Financial Accounting Standards Board issued FASB
Interpretation ("FIN") No. 44, "Accounting for Certain Transactions Involving
Stock Compensation--an Interpretation of APB Opinion No. 25." FIN 44 primarily
clarifies (a) the definition of an employee for purposes of applying APB Opinion
No. 25, (b) the criteria for determining whether a plan qualifies as a
non-compensatory plan, (c) the accounting consequence of various modifications
to the terms of previously fixed stock options or awards, and (d) the accounting
for an exchange of stock compensation awards in a business combination. FIN 44
was effective July 1, 2000, but certain conclusions in FIN 44 cover specific
events that occurred after either December 15, 1998 or January 12, 2000. In
January 2000 Isis offered non-officer employees an opportunity to exchange
certain of their existing stock options. These options are required to be
accounted for as variable stock options in accordance with FIN 44. Variable
stock options can result in significant increases and decreases in compensation
expense subject to the variability of Isis' stock price.

In December 1999, the Securities and Exchange Commission (SEC) issued
Staff Accounting Bulletin (SAB) No. 101, "Revenue Recognition in Financial
Statements," which provides guidance on the recognition, presentation and
disclosure of revenue in financial statements filed with the SEC. As amended,
SAB 101, outlines the basic criteria that must be met in order to recognize
revenue and provides guidance for disclosures related to revenue recognition
policies, including revenue earned from collaborations between companies. The
SEC deferred the implementation date of SAB 101 until the quarter ended December
31, 2000, with retroactive application to the beginning of the Company's
calendar year. The Company believes that revenue recorded through December 31,
2000 complies with SAB 101.


F-9
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


2. INVESTMENTS

Isis invests its excess cash in U.S. Government securities and debt
instruments of financial institutions and corporations with strong credit
ratings. Isis has established guidelines relative to diversification and
maturities that maintain safety and liquidity. These guidelines are periodically
reviewed and modified to take advantage of trends in yields and interest rates.
Isis has not experienced any material losses on its short-term investments. As
of December 31, 2000, 73% of the debt securities held by Isis had a contractual
maturity of one year or less, and the remaining 27% of the portfolio was due
within 2 years.

The following is a summary of Isis' short-term investments, accounted
for as available-for-sale securities:

<TABLE>
<CAPTION>

AVAILABLE-FOR-SALE SECURITIES
(in thousands)
---------------------------------------------------------------
GROSS
UNREALIZED ESTIMATED
COST GAINS (LOSSES) FAIR VALUE
------------------ ------------------ -------------------
<S> <C> <C> <C>
DECEMBER 31, 2000
U.S. Treasury securities and obligations of
U.S. Government agencies $ 26,161 $ (14) $ 26,147
U.S. corporate debt securities 61,360 140 61,500
------------------ ------------------ -------------------
Total debt securities $ 87,521 $ 126 $ 87,647
================== ================== ===================

DECEMBER 31, 1999
U.S. Treasury securities and obligations of
U.S. Government agencies $ 7,311 $ (29) $ 7,282
U.S. corporate debt securities 10,261 0 10,261
------------------ ------------------ -------------------
Total debt securities $ 17,572 $ (29) $ 17,543
================== ================== ===================

</TABLE>


3. LONG-TERM OBLIGATIONS AND COMMITMENTS

In 1996 and 1997, Isis borrowed a total of $22,576,000 under a
$40,000,000 line of credit made available under the terms of its collaborative
agreement with Boehringer Ingelheim International GmbH. The borrowed funds were
used to fund research and development costs associated with the collaboration.
Borrowings under the line of credit bear interest at the seven year U.S.
interbanking rate plus 2.0%, determined at the time each advance was made, and
have ranged from 8.36% to 8.46%. Interest payments are due twice each year with
principal repayment due seven years after the advance date. The principal may be
repaid in cash or stock, at Isis' option. If Isis elects to repay the loan in
shares of Isis common stock, repayment will be made at a share price equal to
90% of the average market value over the 20 trading days preceding the maturity
date. The balance under this line of credit as of December 31, 2000 and 1999 was
$22,576,000, which approximated fair value.

In 1997, Isis obtained two term loans from a bank to refinance existing
notes secured by real property and to fund facilities expansion. Both notes are
secured by Isis' real property and bear interest at the prime interest rate
(9.5% and 8.5% at December 31, 2000 and 1999, respectively) plus 0.5%. The first
note in the amount of $3,707,000 requires monthly principal repayments of
$12,433 plus interest with the remaining principal balance due in April 2002.
The balance of this first note at December 31, 2000 and 1999 was $3,140,000 and
$3,290,000, respectively. The second note in the amount of $6,000,000 requires
monthly principal repayments of $50,000 plus related interest with the remaining
principal balance due in July 2002. The balance at December 31, 2000 and 1999
was $3,900,000 and $4,500,000, respectively. As of December 31, 2000 and 1999,
the carrying value of these variable rate long-term notes approximated fair
value.

Between 1997 and 1998, Isis obtained a total of $40,060,000 in private
debt financing. The terms of the financing provide for a ten year maturity on
the debt, interest of 14% per annum and deferred interest

F-10
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


payments for the first five years of the loan. After the first five years,
interest must be paid quarterly until the end of the loan, which is November 1,
2007. No principal repayments are required until the end of the loan. Because
interest is deferred during the first five years, the principal balance will be
$78 million on November 1, 2002. In conjunction with the debt financing, Isis
issued warrants to purchase a total of 800,000 common stock shares to the
lender, exercisable at $25 per share. The fair value of the warrants was
estimated using the Black-Scholes option pricing model, with the following
assumptions: expected life of 4.5 years, expected dividend yield of zero
percent, expected volatility of 60 percent and a risk free interest rate of
5.9%. A total fair value of $5,426,000 was calculated for the warrants and was
credited to equity. The allocation of value to the warrants creates an effective
debt discount which is amortized using the effective interest method. The
effective interest rate of this debt is approximately 16%, including the effect
of the discount amortization. The debt of $57,995,000 and $49,086,000 at
December 31, 2000 and 1999, respectively, is carried on the balance sheet net of
accrued interest and the unamortized amount allocated to the warrants. The fair
value of this debt at December 31, 2000 and 1999 approximated $60,479,000 and
$52,000,000, respectively. The fair value of the long-term debt is estimated
using discounted cash flow analyses, based on current borrowing rates for
similar types of borrowing arrangements.

In December 1998, Isis purchased from Gilead Sciences, Inc. (Gilead),
the holdings of Gilead's antisense patent estate. This acquisition included
patents and patent applications covering a broad proprietary suite of antisense
chemistry and antisense drug delivery systems. The purchase price was $6,000,000
payable in four installments over three years. Isis has recorded the net present
value of the future payments, using a discount rate of 10%. The balance of this
obligation at December 31, 2000 and 1999 was $1,823,000 and $2,568,000,
respectively, which approximated fair value.

In April 1999, Elan International Services (EIS) made available to Isis
an $18.4 million line of credit under a convertible debt arrangement made in
conjunction with the Orasense joint venture. The terms of the convertible debt
provide interest at 12% per annum, compounded semi-annually, maturing April 19,
2005. No principal or interest payments are required until the end of the loan.
The loan may be prepaid by the Isis at any time, at its option, in whole or in
part, in cash or in common stock (at a price equal to the average market value
of the common stock for the 60 trading days ending two business days prior to
the date of prepayment). At any time prior to maturity, EIS may convert all or
any portion of the loan outstanding, on a per tranche basis, into the number of
shares of common stock obtained by dividing the amount to be converted by 150%
of the average market value of the common stock for the 60 trading days ending
two business days prior to the date of disbursement of such tranche. This debt
facility is subordinate to the $40,000,000 private debt financing which matures
November 2007. During 2000 and 1999, Isis borrowed $6,749,000 and $2,213,000,
respectively, under this convertible debt agreement to provide development
funding to Orasense. Based on the principal and accrued interest outstanding at
December 31, 2000, the loan balance due at maturity will be $16,200,000,
provided that no prepayments or conversions occur prior to maturity. The balance
under this borrowing facility as of December 31, 2000 and 1999 was $9,724,000
and $2,284,000, respectively, which approximated fair value.

In September 1999, Isis borrowed $1,019,000 from Abbott Laboratories,
Inc. to be used by Isis as its contribution toward costs associated with
Abbott's design and construction of a facility for commercial scale
manufacturing of oligonucleotides. The terms of the financing provide for a two
year maturity of the debt, with an annual interest rate of 2% over the Citibank
prime rate calculated annually at the date of borrowing. The interest rate on
this debt was 11.5% and 10.25% at December 31, 2000 and 1999, respectively.
Interest is payable annually. The principal, which is due at maturity, can be
paid in cash, common stock (based on 100% of the average closing price for the
20 trading days preceding loan maturity), or through increasing the price Isis
would pay for the oligonucleotides produced by Abbott until the loan is repaid.
The balance under this borrowing facility as of December 31, 2000 and 1999 was
$1,019,000, which approximated fair value.

In January 2000, EIS made available to Isis a $12,000,000 line of
credit under a convertible debt arrangement made in conjunction with the
HepaSense joint venture. The terms of the convertible debt provide interest at
12% per annum, compounded semi-annually, maturing January 14, 2006. No principal
or interest payments are required until the end of the loan. The loan may be
prepaid by Isis at any time, at its option, in whole or in part, in cash or in
common stock (at a price equal to 95% of the average market value of




F-11
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


the common stock for the 60 trading days ending two business days prior to the
date of repayment); provided that no more than 50% of any prepayment amount
shall be payable by the Company in the Company's common stock. At any time prior
to maturity, EIS may convert all or any portion of the loan outstanding, on a
per tranche basis, into the number of shares of common stock obtained by
dividing the amount to be converted by 140% of the average market value of the
common stock for the 60 trading days ending two business days prior to the date
of disbursement of such tranche. This debt facility is subordinate to the
$40,000,000 private debt financing which matures November 2007. During 2000,
Isis borrowed $1,834,000 under this convertible debt agreement to provide
development funding to HepaSense. Based on the principal and accrued interest
outstanding at December 31, 2000, the loan balance due at maturity will be
$3,400,000, providing that no prepayments or conversions occur prior to
maturity. The balance under this borrowing facility as of December 31, 2000 was
$1,856,000, which approximated fair value.

Annual debt maturities at December 31, 2000 are as follows (in
thousands):

<TABLE>

<S> <C>
2001 $ 2,252
2002 7,310
2003 16,200
2004 6,376
2005 9,726
Thereafter 59,829
------------
Total $ 101,693
============
</TABLE>

Isis leases equipment and certain office and lab space under
non-cancelable operating and capital leases with terms through February 2007.
Two of the building leases have two extension options for five years each.
Annual future minimum payments under capital and operating leases as of December
31, 2000 are as follows (in thousands):


<TABLE>
<CAPTION>

OPERATING CAPITAL
LEASES LEASES
------------------ -----------------
<S> <C> <C>
2001 $ 2,143 $ 2,732
2002 1,967 1,801
2003 1,947 1,152
2004 1,722 104
2005 1,493 -
Thereafter 4,633 -
------------------ -----------------
Total minimum payments $ 13,905 $ 5,789
==================
Less amount representing interest (621)
-----------------
Present value of future minimum payments 5,168
Less current portion (2,355)
-----------------
Long term portion $ 2,813
=================
</TABLE>

Rent expense for the years ended December 31, 2000, 1999 and 1998 was
$2,115,000, $1,736,000, and $1,760,000, respectively. Cost of equipment under
capital leases at December 31, 2000 and 1999 was $9,754,000 and $8,394,000,
respectively. Accumulated depreciation of equipment under capital leases at
December 31, 2000 and 1999 was approximately $5,425,000 and $4,633,000,
respectively.

4. STOCKHOLDERS' EQUITY

PREFERRED STOCK

The Company is authorized to issue up to 15,000,000 shares of "blank
check" Preferred Stock. Preferred Stock consists of Series A and Series B
Convertible Exchangeable 5% Preferred Stock and Series C Junior Participating
Preferred Stock.


F-12
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


SERIES A CONVERTIBLE EXCHANGEABLE 5% PREFERRED STOCK

At December 31, 2000, Isis has 120,150 shares authorized, issued and
outstanding of Series A Convertible Exchangeable 5% Preferred Stock. The shares
have a term of six years and are convertible into Isis' common stock on or after
March 31, 2002 at 125% of the average closing price of Isis common stock for the
60 trading days ending two business days prior to March 31, 2002, or
automatically in the event of a significant transaction, at 120% of the average
closing price of Isis common stock for the 60 trading days ending two business
days prior to the transaction if the significant transaction occurs prior to
March 31, 2002, or 125% if the significant transaction occurs thereafter. The
Preferred Stock is exchangeable at the option of Elan at any time through and
including June 30, 2002 for an incremental 30.1% of the issued and outstanding
shares owned by Isis of Orasense. It also bears a mandatory pay-in-kind dividend
of 5.0% per year based on the original issue price per share, compounded
semi-annually payable only upon conversion into Isis' common stock or cash.

SERIES B CONVERTIBLE EXCHANGEABLE 5% PREFERRED STOCK

At December 31, 2000, Isis has 16,620 shares authorized, of which
12,015 shares are issued and outstanding of Series B Convertible Exchangeable 5%
Preferred Stock. The shares have a term of six years and are convertible into
Isis' common stock on or after June 30, 2002 at 125% of the average closing
price of Isis common stock for the 60 trading days ending two business days
prior to June 30, 2002, or automatically in the event of a significant
transaction, at 120% of the average closing price of Isis common stock for the
60 trading days ending two business days prior to the transaction if the
significant event occurs prior to June 30, 2002, or 125% if the significant
transaction occurs on or after June 30, 2002. The Preferred Stock is also
exchangeable for the ownership Isis holds in HepaSense. It also bears a
mandatory pay-in-kind dividend of 5.0% per year based on the original issue
price per share, compounded semi-annually payable only upon conversion into
Isis' common stock or cash.

SERIES C JUNIOR PARTICIPATING PREFERRED STOCK

In December 2000, Isis adopted a Preferred Share Purchase Rights Plan
(the "Plan"). The Plan provides for a dividend distribution of one preferred
stock purchase right (a "Right") for each outstanding share of Isis common
stock, par value $0.001 per share (the "Common Shares"), held of record at the
close of business on January 10, 2001. The Rights are not currently exercisable.
Under certain conditions involving an acquisition or proposed acquisition by any
person or group of 20 percent or more of Isis' common stock, the Rights permit
the holders (other than the 20 percent holder) to purchase one one-hundredth of
a share of Series C Junior Preferred Stock, par value $0.001 per share (the
"Preferred Shares"), at a price of $85 per one one-hundredth of a Preferred
Share (the "Purchase Price"), subject to adjustment. Each one one-hundredth of a
share of Preferred Shares has designations and powers, preferences and rights,
and the qualifications, limitations and restrictions which make its value
approximately equal to the value of a Common Share. Under certain conditions,
the Rights may be redeemed by the Company's Board of Directors in whole, but not
in part, at a price of $0.001 per Right.

COMMON STOCK

During the year ended December 31, 2000, Isis sold 4,442,465 shares of
its common stock to institutional investors at negotiated prices ranging from
$9.85 per share to $27.25 per share. In addition, during the year ended December
31, 2000, the Company sold 2,158,030 shares of its common stock to Ridgeway
Investment Limited at prices ranging from $7.44 per share to $14.94 per share
under the terms of the Common Stock Purchase Agreement. The per share average
purchase prices reflect the average trading prices of the common stock over a
period of time less a discount percentage ranging from 4.5% to 5.875%.

STOCK OPTION PLANS

1989 STOCK OPTION PLAN AND OTHER EMPLOYEE OPTION GRANTS

In June 1989 and as amended, Isis adopted a stock option plan which
provides for the issuance of non-qualified stock options for the purchase of up
to 10,200,000 shares of common stock to its employees and certain other
individuals. The plan also includes provisions for the issuance of stock
pursuant to restricted stock purchases and bonuses. Typically, options expire 10
years from the date of grant. Options granted after


F-13
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


December 31, 1995 vest over a four year period, with 25% exercisable at the end
of one year from the date of the grant and the balance vesting ratably
thereafter. Options granted before January 1, 1996 generally vest over a five
year period. At December 31, 2000, a total of 5,710,000 options were
outstanding, options to purchase 3,414,000 shares were exercisable, and 849,000
shares were available for future grant. In fiscal year 1991 Isis granted 412,000
non-qualified stock options for common stock to certain individuals. At December
31, 2000, there were no options outstanding and 93,000 shares were available for
future grant.

1992 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

In July 1992, Isis adopted the 1992 Non-Employee Directors' Stock
Option Plan which provides for the issuance of non-qualified stock options for
the purchase of up to 300,000 shares of common stock to Isis's non-employee
directors. Options under this plan expire 10 years from the date of grant.
Options granted after December 31, 1995 become exercisable in four equal annual
installments beginning one year after the date of grant. Options granted before
January 1, 1996 vest over a five year period. At December 31, 2000, a total of
198,000 options were outstanding, 148,000 shares issued under this plan were
exercisable and 61,000 shares were available for future grant.

2000 BROAD-BASED EQUITY INCENTIVE STOCK OPTION PLAN

In January 2000, Isis adopted the 2000 Broad-Based Equity Incentive
Stock Option Plan which provides for the issuance of non-qualified stock options
for the purchase of up to 3,990,000 shares of common stock to its employees,
directors, and consultants. Typically options expire 10 years from the date of
grant. Options granted under this plan generally vest over a four year period,
with 25% exercisable at the end of one year from the date of the grant and the
balance vesting ratably thereafter. Under the 2000 plan, a total of 1,763,000
options were outstanding, 9,000 shares were exercisable, and 2,225,000 shares
were available for future grant at December 31, 2000.

The following table summarizes stock option activity for the years
ended December 31, 1998 through December 31, 2000 (in thousands, except per
share data):

<TABLE>
<CAPTION>
WEIGHTED AVG
NUMBER OF PRICE PER
SHARES PRICE PER SHARE SHARE
------------- ----------------------- --------------
<S> <C> <C> <C>
Outstanding at December 31, 1997 6,442 $.14 to $20.00 $ 9.80
Granted 1,168 $7.06 to $15.44
Exercised (320) $.14 to $14.50
Terminated (304) $3.75 to $20.00
-------------
Outstanding at December 31, 1998 6,986 $.14 to $19.88 $10.27
Granted 1,539 $4.00 to $18.00
Exercised (333) $.14 to $14.50
Terminated (490) $3.88 to $19.75
-------------
Outstanding at December 31, 1999 7,702 $.43 to $19.88 $10.68
Granted 4,069 $6.25 to $17.69
Exercised (1,800) $.42 to $19.38
Terminated (2,300) $5.75 to $19.88
-------------
Outstanding at December 31, 2000 7,671 $3.57 to $18.63 $ 9.21
=============

</TABLE>





F-14
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


The following table summarizes information concerning currently
outstanding and exercisable options (in thousands, except contractual life and
exercise price data):

<TABLE>
<CAPTION>

OPTIONS OUTSTANDING OPTIONS EXERCISABLE
------------------------------------------------------------- --------------------------------------
WEIGHTED
NUMBER AVERAGE WEIGHTED NUMBER WEIGHTED
RANGE OF OUTSTANDING REMAINING AVERAGE EXERCISABLE AVERAGE
EXERCISE PRICE AS OF 12/31/00 CONTRACTUAL LIFE EXERCISE PRICE AS OF 12/31/00 EXERCISE PRICE
- ------------------- ------------------- -------------------- ------------------ ------------------ -----------------
<S> <C> <C> <C> <C> <C>
$ 3.57 - $ 5.38 405 3.85 $ 4.16 404 $ 4.15
$ 5.50 - $ 6.88 3,473 6.64 $ 6.68 990 $ 6.40
$ 7.00 - $ 9.94 660 4.52 $ 8.92 479 $ 8.76
$10.00 - $10.94 559 8.43 $10.31 170 $10.34
$11.00 - $11.94 243 8.39 $11.50 78 $11.48
$12.00 - $12.94 1,474 7.42 $12.58 773 $12.54
$13.00 - $13.94 385 5.75 $13.21 330 $13.18
$14.00 - $17.88 292 6.50 $15.32 174 $15.58
$18.00 - $18.63 180 6.01 $18.07 173 $18.07
------------------- ------------------
$ 3.57 - $18.63 7,671 6.58 $ 9.21 3,571 $ 9.73
=================== ==================
</TABLE>

EMPLOYEE STOCK PURCHASE PLAN

In 1991, the Board of Directors adopted and the stockholders
subsequently approved, the Employee Stock Purchase Plan and reserved 500,000
shares of common stock for issuance thereunder. The plan permits full-time
employees to purchase common stock through payroll deductions (which cannot
exceed 10% of each employee's compensation) at the lower of 85% of fair market
value at the beginning of the offer or the end of each six-month purchase
period. During 2000, 73,000 shares were issued under this plan to employees at
prices ranging from $5.32 to $10.57 per share. At December 31, 2000, 341,000
shares were available for purchase under this plan.

STOCK-BASED EMPLOYEE COMPENSATION

Isis has adopted the disclosure-only provision of Statement of
Financial Accounting Standards No. 123, "Accounting for Stock-Based
Compensation." Accordingly, no compensation expense has been recognized for the
stock option plans. Had compensation expense been determined consistent with
Statement No. 123, Isis' net loss and basic net loss per share would have been
changed to the following pro forma amounts (in thousands, except per share
amounts):

<TABLE>
<CAPTION>
2000 1999 1998
-------------- -------------- ---------------
<S> <C> <C> <C>
Net loss - as reported $ (54,699) $ (59,645) $ (42,983)
Net loss - pro forma $ (63,110) $ (69,446) $ (49,761)

Basic net loss per share - as reported $ (1.48) $ (2.08) $ (1.60)
Basic net loss per share - pro forma $ (1.71) $ (2.42) $ (1.85)

</TABLE>


The fair value of each option grant is estimated on the date of grant
using the Black-Scholes option pricing model with the following weighted-average
assumptions for 2000: a risk-free interest rate of 6%; a dividend yield of 0%; a
volatility factor of 80.0 % and an option life of 4.2 years; for 1999: a
risk-free interest rate of 5.7%; a dividend yield of 0%; a volatility factor of
60.0 % and an option life of 3.7 years; and for 1998: a risk-free interest rate
of 4.6%; a dividend yield of 0%; a volatility factor of 60.0 % and an option
life of 4.1 years. The weighted average fair value of options granted was $7.81
for 2000, $6.41 for 1999, and 5.98 for 1998.



F-15
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000

WARRANTS

In 1997 and 1998, Isis issued 500,000 and 300,000 warrants,
respectively, in conjunction with a private debt financing agreement. As of
December 31, 2000, all of the warrants remain outstanding at an exercise price
of $25 per share. The warrants expire November 1, 2004. See Note 3.

In 1999, Isis issued 215,000 warrants to Elan International Services,
Ltd. as part of the joint venture collaboration between Isis and Elan to form
Orasense, Ltd. As of December 31, 2000, all of the warrants remain outstanding
at an exercise price of $24 per share. The warrants expire April 19, 2004.

In 2000, Isis issued 14,881 warrants to Elan International Services,
Ltd. as part of the joint venture collaboration between Isis and Elan to form
HepaSense, Ltd. As of December 31, 2000, all of the warrants remain outstanding
at an exercise price of $50.40 per share. The warrants expire May 1, 2008.

As of December 31, 2000, total common shares reserved for future
issuance was 8,402,000.

5. INCOME TAXES

Significant components of Isis' deferred tax assets as of December 31,
2000 and 1999 are shown below. Valuation allowances of $133,535,000 and
$113,814,000 have been recognized for 2000 and 1999, respectively, to offset the
net deferred tax assets as realization of such assets is uncertain.

<TABLE>
<CAPTION>
2000 1999
--------------------- --------------------
<S> <C> <C>
Deferred tax assets:
Capitalized research expense $ 10,856,000 $ 9,800,000
Net operating loss carryforwards 104,766,000 87,990,000
Research and development credits 17,351,000 13,910,000
Other, net 6,149,000 6,404,000
------------------ ----------------
Total deferred tax assets 139,122,000 118,104,000

Deferred tax liabilities:
Patent expense (5,587,000) (4,290,000)
------------------ ----------------
Total deferred tax liabilities (5,587,000) (4,290,000)

------------------ ----------------
Total net deferred tax assets 133,535,000 113,814,000
Valuation allowance for deferred tax assets (133,535,000) (113,814,000)
------------------ ----------------
Net deferred tax assets $ - $ -
================== ================

</TABLE>

At December 31, 2000, approximately $16,273,000 of the valuation
allowance for deferred tax assets relates to stock option deductions which, when
recognized, will be allocated directly to additional paid-in capital.

At December 31, 2000, Isis had federal and California tax net operating
loss carryforwards of approximately $295,543,000 and $29,645,000, respectively.
Isis also had federal and California research credit carryforwards of
approximately $13,226,000 and $6,346,000, respectively. The difference between
the tax loss carryforwards for federal and California purposes was attributable
to the capitalization of research and development expenses for California tax
purposes and a required 50% limitation in the utilization of California loss
carryforwards. The federal tax loss carryforward and the research credit
carryforwards will begin expiring in 2004 unless previously utilized.
Approximately $354,000 of the California tax loss carryforward expired during
2000 and the related deferred tax asset and tax loss carryforward amounts have
been reduced accordingly. The remaining California tax loss carryforward will
continue expiring in 2001, unless utilized.

Annual use of Isis' net operating loss and credit carryforwards will be
limited under the Internal Revenue Code as a result of cumulative changes in
ownership of more than 50% during the periods ended December 31, 1989 and 1991.
However, Isis believes that such limitations will not have a material impact
upon the utilization of the carryforwards.


F-16
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


6. RESEARCH AND DEVELOPMENT COLLABORATIVE ARRANGEMENTS AND LICENSING AGREEMENTS

In 1990, Isis entered into a collaborative agreement with Novartis to
discover and investigate oligonucleotide compounds active against specific
targets. In 1996, Isis and Novartis signed a definitive agreement broadening
each company's antisense research and development collaboration to include the
development of ISIS 3521 and ISIS 5132, anticancer compounds that were
discovered through the research collaboration. The broadened collaboration also
included research to discover additional therapeutic compounds. Under the terms
of the expanded collaboration, Novartis funded the development of both ISIS 3521
and ISIS 5132. During 1999, Novartis concluded its participation in the
development of ISIS 3521 and ISIS 5132, and as a result no further revenue was
recognized in 2000. Included in the statement of operations for the years ended
December 31, 1999 and 1998 are contract revenues arising from this collaboration
totaling $7,527,000 and $15,641,000, respectively.

In July 1995, Isis and Boehringer Ingelheim International GmbH signed
definitive agreements and formed a major collaboration in cell adhesion drug
design, discovery, development and commercialization. Boehringer Ingelheim
purchased 2,000,000 shares of Isis's common stock for $28,500,000 in cash plus
certain license rights. Boehringer Ingelheim and Isis provided equal funding for
the combined research and development program, which came to a conclusion in
December 1999. As a result, there was no related revenue included in the
statement of operations for 2000. For the years ended December 31, 1999 and
1998, Isis recognized contract revenues of $6,974,000 and $6,544,000,
respectively, from this collaboration.

In July 1997, Isis and Novartis Ophthalmics, formerly CIBA Vision
Corporation, entered into an agreement granting Novartis Ophthalmics exclusive
worldwide distribution rights for Vitravene-TM- (fomivirsen). Under the terms of
the agreement, Isis will manufacture and sell Vitravene to Novartis Ophthalmics
at a price that will allow Isis and Novartis Ophthalmics to share the commercial
value of the product. Under the terms of the agreement, Novartis Ophthalmics is
responsible for marketing and selling Vitravene worldwide and also for
regulatory approvals outside of the United States and Europe. Additionally,
Novartis Ophthalmics received the option to acquire the exclusive license to
market and distribute a second generation antisense compound to treat CMV
retinitis. At the inception of the agreement, Novartis Ophthalmics paid Isis a
$5 million non-refundable pre-commercial fee to partially reimburse Isis for the
costs incurred in discovering and developing Vitravene. That payment was
recognized as revenue in 1997. In August 1998, the FDA approved Vitravene for
marketing, and in the fourth quarter of the year Novartis Ophthalmics began
selling Vitravene commercially. Since August 1998, Isis has recognized $674,000
in revenue related to shipments of Vitravene, which is included in the statement
of operations under research and development revenues under collaborative
agreements. Under the Novartis Ophthalmics agreement, Isis received a $2,500,000
milestone payment in each of 2000 and 1999, and earned contract revenue of
$7,500,000 in 1998.

In June 1998, Isis entered into a research collaboration with Merck &
Co. to discover small molecule drug candidates to treat patients infected with
Hepatitis C virus (HCV). Isis and Merck will design, synthesize, and evaluate
novel compounds that Merck will screen in its proprietary assays for identifying
HCV replication inhibitors. Merck will commercialize drugs arising from the
collaboration, and Isis retains the right to use technology developed in the
collaboration in its antisense program. The three-year collaboration provides
Isis with annual research support plus technology access fees, and milestone
payments and royalties upon commercialization. The statement of operations for
the years ended December 31, 2000, 1999 and 1998, reflects contract revenues of
$3,000,000, $3,500,000 and $3,875,000, respectively, from Merck under the terms
of this agreement.

In December 1998, Isis purchased from Gilead the holdings of Gilead's
antisense patent estate. This acquisition included patents and patent
applications covering a broad proprietary suite of antisense chemistry and
antisense drug delivery systems. The purchase price was $6,000,000 payable in
four installments over three years. Isis made the initial $2,000,000 payment in
December 1998, the second payment of $1,000,000 in December 1999 and the third
payment of $1,000,000 in December 2000. Isis has recorded the net present value
of the future payments as a long-term obligation on the balance sheet. The
balance of this obligation


F-17
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


as of December 31, 2000 and 1999 was $1,823,000 and $2,568,000, respectively.
Isis acquired the Gilead patents to enhance its dominant proprietary position in
antisense technology. Isis also believes that the acquisition of the Gilead
patents may reduce the risk of possible future patent infringement claims.
Effort will be required by Isis' scientists to determine if the acquired patents
can be used to develop potentially viable products.

In December 1998, Isis entered into a collaborative research agreement
with AstraZeneca Pharmaceuticals to discover, develop and commercialize novel
antisense-based cancer drugs. Under the terms of this collaboration, Isis will
create and, with AstraZeneca, screen antisense-based candidates for certain
cancer targets. The agreement specifies that Isis will receive a technology
access fee and annual research funding during the first two years of the
collaboration. The initial term of the research collaboration is three years
with a clause that allowed AstraZeneca to terminate at the end of the second
year. In December 2000, AstraZeneca terminated the agreement. The statement of
operations for the years ended December 31, 2000 and 1999 each reflect contract
revenues of $3,420,000 from AstraZeneca under the terms of this agreement.

Also in December 1998, Isis entered into a two-year research
collaboration with Abbott Laboratories, Inc. to prioritize drug development
targets using Isis' Antisense Target Validation Technology. The collaboration
will enable Abbott to validate numerous gene targets, identify the function of
these genes and prioritize the targets. Isis received from Abbott an up-front
fee, and will receive quarterly research fees, milestone payments and royalties
on net sales of any Abbott non-antisense product arising from the collaboration.
Isis will receive rights to Abbott genes to develop antisense drugs. The
statement of operations for the years ended December 31, 2000 and 1999 reflects
contract revenues of $1,000,000 and $1,250,000, respectively, from Abbott under
the terms of this agreement.

In April 1999, Isis and Elan formed a joint venture to develop
technology for the formulation of oral oligonucleotide drugs. The joint venture,
Orasense, Ltd., is a Bermuda limited company which is currently owned 80.1% by
Isis and 19.9% by Elan. Isis and Elan each contributed rights to certain oral
drug delivery technology to the joint venture. In addition, Isis contributed
rights to a proprietary oligonucleotide, which will be the first candidate for
oral formulation by Orasense. Isis and Elan will provide development and
manufacturing services to Orasense and will be entitled to royalties on
milestone payments and royalties received by Orasense for development of orally
formulated oligonucleotide drugs. If Isis enters into an agreement with Orasense
for oral formulation of any Isis oligonucleotide drug, Isis will pay Orasense
royalties and a portion of certain third party milestone payments with respect
to the drug. In conjunction with this transaction, Isis sold 910,844 shares of
Isis' common stock to Elan International Services (EIS) for $15,000,000, and
issued a warrant to purchase up to 215,000 shares of Isis' common stock at $24
per share. The term of the warrant is five years. Isis also sold 120,150 shares
of Isis' Series A Convertible Preferred Stock to EIS for $12,015,000 (See Note
4). For the years ended December 31, 2000 and 1999, Isis recorded $5,217,000 and
$4,402,000, respectively, in revenue from Orasense. For the years ended December
31, 2000 and 1999, Isis recorded $9,702,000, and $7,242,000, respectively, as
equity in the net loss of Orasense. Additionally, at December 31, 2000 and 1999,
the balance sheet included $968,000 and $1,961,000, respectively, of contracts
receivable relating to Orasense.

In September 1999, Isis entered into a three year target validation
collaboration with Aventis (formerly Rhone-Poulenc Rorer). The collaboration
uses Isis' target validation technology to assess genes identified within
Aventis' genomics programs. This collaboration enables Aventis to determine the
function and therapeutic value of numerous novel gene targets and to use this
information about gene function to develop pharmaceutical products. It also
provides Isis with valuable information on these targets to assist in the
development of novel antisense drugs. Under the terms of the agreement, Aventis
will pay Isis research fees and milestone payments based on the success of the
program. For the years ended December 31, 2000 and 1999, Isis recorded revenue
of $1,062,000 and $200,000, respectively, in total contact revenues from
Aventis.

In January 2000, Isis and Elan formed a new joint venture to develop
an antisense drug to treat patients chronically infected with the Hepatitis C
virus (HCV). This new joint venture, HepaSense Ltd., is a Bermuda limited
company which is currently owned 80.1% by Isis and 19.9% by Elan. HepaSense
plans to develop and commercialize this novel therapeutic for HCV, while
investigating delivery of the therapeutic with Elan's proprietary
MEDIPAD-Registered Trademark- Drug Delivery System, a disposable subcutaneous
infusion device. Isis and Elan have each licensed technology to HepaSense.
Isis and Elan will provide development and manufacturing services to

F-18
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


HepaSense and will be entitled to royalties on any milestone payments and
royalties received by HepaSense for development of HCV drugs. In conjunction
with this transaction, Isis sold 297,619 shares of Isis' common stock to EIS for
$7,500,000, and issued a warrant to purchase up to 14,881 shares of Isis' common
stock at $50.40 per share. The term of the warrant is five years. Isis also sold
12,015 shares of Isis' Series B Convertible Preferred Stock to EIS for
$12,015,000 (See Note 4). For the year ended December 31, 2000, Isis recorded
$2,751,000 in revenue from HepaSense, and recorded $6,237,000 as equity in the
net loss of HepaSense. Additionally, at December 31, 2000, the balance sheet
included $481,000 of contracts receivable relating to HepaSense.

In June 2000, Ibis Therapeutics, a division of Isis and Agouron
Pharmaceuticals, Inc., a Pfizer Company (Pfizer), entered into a collaboration
for the discovery and development of small molecule drugs against certain RNA
targets in an undisclosed therapeutic area. Using Ibis' proprietary technology
and Pfizer's expertise in small molecule drug discovery, the collaboration
focuses on discovering drugs that bind to RNA. Pfizer will fund collaborative
research, pay an up-front technology access fee and make milestone payments
totaling up to $37 million for the first product. In addition, Pfizer will
develop and commercialize drugs discovered by the collaboration and will pay
Isis royalties on the sales of drugs. For the year ended December 31, 2000, Isis
recorded $2,393,000 in total contract revenues from Pfizer.

In August 2000, GeneTrove-TM-, a division of Isis, initiated an
antisense target validation collaboration with the R.W. Johnson Pharmaceutical
Research Institute, a member of the Johnson & Johnson family of companies, to
assess and prioritize genes as drug discovery targets. GeneTrove will use its
proprietary antisense technology to assist Johnson & Johnson to study the
function and therapeutic relevance of novel gene targets. Johnson & Johnson will
make milestone payments for the successful validation of such novel gene
targets. For the year ended December 31, 2000, Isis recorded $255,000 in total
contract revenues from Johnson & Johnson.

In September 2000, Isis sold its patents concerning the use of
phosphorothioate oligonucleotides for activating the immune system to Coley
Pharmaceutical Group (Coley). The patents were originally licensed to Coley in
1998 for a limited scope of use, at which time Coley paid Isis $5 million in
cash and issued preferred stock to Isis. In exchange for all nonantisense rights
to this group of immunomodulation patents and in lieu of any and all future
payments that could potentially be owed under the original agreement, Coley paid
Isis an additional $10.7 million in 2000. For the year ended December 31, 2000,
Isis recognized $10.7 million in licensing revenue from the transaction.

In September 2000, Isis entered into an agreement to license its novel
antisense chemistry, Peptide Nucleic Acid (PNA), to Pantheco A/S (Pantheco), a
Danish biotechnology company, on a nonexclusive basis to treat diabetes and
cardiovascular diseases. Pantheco completed a financing to raise funds to
support its current business and to fund this expansion of therapeutic focus in
October 2000. Isis received 40,000 shares of Pantheco common stock valued at
$1.1 million based on Pantheco's recent financing as consideration for the
license agreement. In addition, Pantheco will pay Isis royalties and milestones
on products developed using the PNA. This is the second license of PNA
technology from Isis to Pantheco. As part of the first licensing transaction
completed in November 1998, Isis received an equity position in Pantheco for
which no carrying value was given as realization of the value of the equity
interest in Pantheco was uncertain. As a result of the current transaction,
Isis' ownership of Pantheco is approximately 22%. For the year ended December
31, 2000, Isis recorded $285,000 as equity in the net loss of Pantheco.

7. RESTRUCTURING

In December 1999, the unexpected failure of the Company's Phase III
clinical trial of ISIS 2302 in Crohn's disease prompted a restructuring of the
Company. In January 2000, the Company announced a restructuring plan to reduce
expenses and focus resources on the development of antisense drugs with
significant commercial potential. The estimated cost of restructuring activities
was recorded in the first quarter of 2000, and totaled $1.6 million. Actual
restructuring costs were primarily related to the Company's elimination of
approximately 140 positions during the first four months of 2000. These
positions were from all


F-19
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


departments of the Company. For the year ended December 31, 2000, the Company
incurred total restructuring costs of $1.6 million.

8. EMPLOYEE POSTEMPLOYMENT BENEFITS

Isis has an employee 401(k) salary deferral plan, covering all domestic
employees. Employees may make contributions by withholding a percentage of their
salary up to the IRS annual limit ($10,500 for 2000). The Company has not made
any matching contributions into the plan as of December 31, 2000.

9. AFFILIATE SUPPLEMENTARY DISCLOSURE

ORASENSE

Due to the significant minority investor rights retained by Elan and
its subsidiaries, Isis accounts for its investment in Orasense under the equity
method of accounting. The following table presents summary financial information
(in thousands, except per share amounts) for Orasense, Ltd. as of and for the
year ended December 31:

<TABLE>
<CAPTION>
2000 1999
---------------- ----------------
<S> <C> <C>
BALANCE SHEET:

Assets
Cash and cash equivalents $ 10 $ 6
In-license costs, net 6,250 11,250
-------------- --------------
Total assets $ 6,260 $ 11,256
============== ==============

Liabilities and Stockholders' Equity
Amounts due to affiliates $ 1,216 $ 2,534
Other current liabilities 8 -
Common stock, $1.00 par value; 12,000
Authorized, issued and outstanding
at December 31, 2000 and 1999 12 12
Additional paid-in capital 26,177 17,751
Accumulated deficit (21,153) (9,041)
-------------- --------------
Total liabilities and stockholders' equity $ 6,260 $ 11,256
============== ==============

RESULTS OF OPERATIONS:
Revenues $ - $ -

Research and development expenses 7,112 5,290
Amortization of acquired license 5,000 3,751
-------------- --------------
Total operating expenses 12,112 9,041
-------------- --------------
Net loss $ (12,112) $ (9,041)
============== ==============

</TABLE>



F-20
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000


HEPASENSE

Due to the significant minority investor rights retained by Elan and
its subsidiaries, Isis accounts for its investment in HepaSense under the equity
method of accounting. The following table presents summary financial information
(in thousands, except per share amounts) for HepaSense, Ltd. as of and for the
year ended December 31, 2000.

<TABLE>
<CAPTION>
2000
------------------
<S> <C>
BALANCE SHEET:

Assets
Cash and cash equivalents $ 1
In-license costs, net 10,000
---------------
Total assets $ 10,001
===============

Liabilities and Stockholders' Equity
Amounts due to affiliates $ 488
Other current liabilities 9
Common stock, $1.00 par value; 6,001 shares
authorized, issued and outstanding
at December 31, 2000 6
Series A Preferred stock, $1,250 par value; 6,000 shares
authorized, issued and outstanding
at December 31, 2000 7,500
Additional paid-in capital 9,784
Accumulated deficit (7,786)
---------------
Total liabilities and stockholders' equity $ 10,001
===============

RESULTS OF OPERATIONS:
Revenues $ -

Research and development expenses 2,786
Amortization of acquired license 5,000
---------------
Total operating expenses 7,786
---------------
Net loss $ (7,786)
===============
</TABLE>

10. QUARTERLY FINANCIAL DATA (UNAUDITED)

The following financial information reflects all normal recurring
adjustments which are, in the opinion of management, necessary for a fair
statement of the results of the interim periods. Summarized quarterly data for
fiscal 2000 and 1999 are as follows (in thousands, except per share data).


<TABLE>
<CAPTION>

MAR. 31 JUN. 30 SEP. 30 DEC. 31
--------------- -------------- -------------- --------------
<S> <C> <C> <C> <C>
2000 QUARTER ENDED
Revenues $ 4,054 $ 6,985 $ 18,280 $ 7,936
Operating expenses 16,671 15,160 18,661 17,388
Loss from operations (12,617) (8,175) (381) (9,452)
Net loss (18,327) (14,302) (5,409) (15,447)
Accretion of dividends on preferred stock (281) (306) (311) (316)
Net loss applicable to common stock $ (18,608) $ (14,608) $ (5,720) $ (15,763)
Basic and diluted net loss per share (1) $ (0.56) $ (0.40) $ (0.15) $ (0.40)
</TABLE>



F-21
ISIS PHARMACEUTICALS, INC.
NOTES TO FINANCIAL STATEMENTS - (CONTINUED)
DECEMBER 31, 2000

<TABLE>
<CAPTION>

MAR. 31 JUN. 30 SEP. 30 DEC. 31
--------------- -------------- -------------- --------------
<S> <C> <C> <C> <C>
1999 QUARTER ENDED
Revenues $ 6,576 $ 7,208 $ 10,638 $ 9,503
Operating expenses 17,131 19,205 18,679 21,969
Loss from operations (10,555) (11,997) (8,041) (12,466)
Net loss (12,604) (16,523) (12,430) (17,668)
Accretion of dividends on preferred stock - (117) (150) (153)
Net loss applicable to common stock $ (12,604) $ (16,640) $ (12,580) $ (17,821)
Basic diluted net loss per share (1) $ (0.46) $ (0.59) $ (0.44) $ (0.58)

</TABLE>


(1) Net loss per share is computed independently for each of the quarters
presented. Therefore, the sum or the quarterly net loss per share will not
necessarily equal the total for the year.


F-22