UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

FORM 10-K

FOR ANNUAL AND TRANSITION REPORTS
PURSUANT TO SECTIONS 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934

OR

Commission file number:0-24274

LA JOLLA PHARMACEUTICAL COMPANY

DOCUMENTS INCORPORATED BY REFERENCE

     Part II, Item 5 and Part III of this report incorporate information by reference from the registrant’s proxy statement for its annual meeting of stockholders to be held on May 21, 2004,19, 2005, which proxy statement will be filed with the Securities and Exchange Commission no later than 120 days after the close of the fiscal year ended December 31, 2003.2004.

FORWARD-LOOKING STATEMENTS

     This report contains forward-looking statements including without limitation those dealing with La Jolla Pharmaceutical Company’s drug development plans and clinical trials.     The forward-looking statements in this report involve significant risks and uncertainties, and a number of factors, both foreseen and unforeseen, could cause actual results to differ materially from our current expectations. Forward-looking statements include those that express a plan, belief, expectation, estimation, anticipation, intent, contingency, future development or similar expression. Although our New Drug Application (“NDA”) for Riquent^® has been accepted by the United States Food and Drug Administration (the “FDA”) for review, there is no guarantee that the FDA will approve Riquent in a timely manner, or at all. OurThe analyses of clinical results of Riquent,Riquent® (abetimus sodium), previously known as LJP 394, our drug candidate for the treatment of systemic lupus erythematosus (“SLE” or “lupus”), and LJP 1082, our drug candidate for renal disease, including the treatmentresults of antibody-mediated thrombosis (“thrombosis”),any trials that are ongoing andor that we may initiate in the future, could result in a finding that thesethis drug candidates arecandidate is not effective in large patient populations, dodoes not provide a meaningful clinical benefit, or may reveal a potential safety issue requiring us to develop new candidates. The analysis of the data from our Phase 3 trial of Riquent showed that the trial did not reach statistical significance with respect to its primary endpoint, time to renal flare, or with respect to theits secondary endpoint, time to treatment with high-dose corticosteroids or cyclophosamide. Although our NDA for Riquent has been accepted for review by the FDA, thecyclophosphamide. The results from our clinical trials of Riquent, including the results of any trials that are ongoing or that we may initiate in the future, may not ultimately be sufficient to obtain regulatory clearance to market Riquent either in the United States or Europe, and we may be required to conduct additional clinical studies to demonstrate the safety and efficacy of Riquent in order to obtain marketing approval. There iscan be no guarantee,assurance, however, that we will have the necessary resources to complete any additional trial, that we will elect to conduct an additional trial or that any additional trial will sufficiently demonstrate the safety and efficacy of Riquent. Many of the analyses of data from our clinical trials of Riquent were conducted on a retrospective basis and the p values reported are nominal, without adjustment for multiple comparisons. Our blood test to measure thepatient’s binding affinity for Riquent is experimental, has not been validated by independent laboratories and will likely be reviewed as part of the Riquent approval process. Our other potential drug candidates are at earlier stages of development and involve comparable risks. Analysis of data from our ongoing, or any future, clinical trials could have negative or inconclusive results. Any positive results observed to date may not be indicative of future results. In any event, regulatory authorities may require additional clinical trials in addition to our current clinical trial, or may not approve our drugs. Our ability to develop and sell our products in the future may be adversely affected by the intellectual property rights of third parties. Additional risk factors include the uncertainty and timing of: our clear need for additional financing; obtaining required regulatory approvals, including delays associated with any approvals that we may obtain; the clear need for additional financing; our ability to pass all necessary FDA pre-approval inspections of our manufacturing facilities and processes;or other regulatory authorities inspections; the increase in capacity of our manufacturing capabilities for possible commercialization; successfully marketing and selling our products; our lack of manufacturing, marketing and sales experience; our ability to make use of the orphan drug designation for Riquent; generating future revenue from product sales or other sources such as collaborative relationships; future profitability; and our dependence on patents and other proprietary rights. Readers are cautioned to not place undue reliance upon forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to update forward-looking statements to reflect events or circumstances occurring after the date hereof. Interested parties are urged to review the risks described below under the heading “Risk Factors”

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and elsewhere in this report and in our other reports and registration statements filed with the Securities and Exchange Commission from time to time.

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PART I

In this report, all references to “we,” “our,” and “us” refer to La Jolla Pharmaceutical Company, a Delaware corporation.

Item 1. Business

Overview

     La Jolla Pharmaceutical Company was incorporated in Delaware in 1989. In October 2004 the Company established a subsidiary, La Jolla Limited, which was organized in England in connection with the potential development efforts for Riquent in Europe. We are a biopharmaceutical company focused on the research and development of highly specific therapeutic products for the treatment of certain life-threatening antibody-mediated diseases. These diseases, including autoimmune conditions such as lupus, and antibody-mediated thrombosis, are caused by abnormal B cell production of antibodies that attack healthy tissues. Current treatments for these autoimmune disorders often address only symptoms of the disease, or nonspecifically suppress the normal operation of the immune system, which can result in severe, negative side effects and hospitalization. We believe that our drug candidates, called Toleragens^®Toleragens®, have the potential to treat the underlying cause of many antibody-mediated diseases without these severe, negative side effects.

Recent Developments in 2004 to Date

     We submittedOn February 16, 2004, we announced that our NDANew Drug Application (“NDA”) for Riquent withÒ (abetimus sodium), our clinical drug candidate for the FDA on December 14, 2003. In February 2004, our NDA for Riquent wastreatment of lupus renal disease, had been accepted for review by the FDA. The acceptance of theUnited States Food and Drug Administration (the “FDA”). Our NDA bysubmission was prepared on our understanding that the FDA indicates thatcould potentially approve Riquent on the NDA is sufficiently complete to permit a substantive reviewbasis of our clinical trial results or under the application. We anticipate that further discussions with the FDA will be needed to determine whether any additional supportive information or studies will be required to support theaccelerated approval of the NDA.regulation known as Subpart H. Under the FDA’s Subpart H, regulation, drugs in development for serious, life-threatening diseases with an unmet medical need can be approved on an accelerated basis if the FDA determines that the effect of the drug on a surrogate endpoint is reasonably likely to predict clinical benefit and it is likely that a post-marketing clinical trial can be successfully completed following drug approval which confirms thatthe clinical benefit. TheAs previously announced, in our Phase 3 and Phase 2/3 trials, patients treated with Riquent had significantly reduced levels of antibodies to double-stranded DNA (“dsDNA”) compared with patients treated with placebo.

     On August 2, 2004, we announced that we had reached a written agreement with the Cardio-Renal Division of the FDA will determine whetherunder a special protocol assessment concerning a trial that is designed to approvemeet the requirements of a post-marketing clinical benefit trial which would have to be conducted if Riquent either on the basis of our clinical trial results orwere to be approved under Subpart H and that we had initiated the conditionstrial. The special protocol assessment process is a formal procedure that results in a written agreement between a company and the FDA that documents the design and planned analysis of any approval, after it has revieweda study used in support of a regulatory submission. Agreements reached under the special protocol assessment process are generally binding except in circumstances where public health concerns are raised or when there are significant changes in medical science or practice.

     Based on the data that we submitted in our NDA.NDA, we expected that the FDA would notify us in mid-October of its decision regarding the approvability of Riquent. On October 14, 2004, we announced that we had received a letter from the FDA indicating that Riquent is approvable, but that an additional, randomized, double-blind study demonstrating the clinical benefit of Riquent would need to be completed prior to approval. The FDA letter indicated that the

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successful completion of the clinical trial that we initiated in August 2004 would appear to satisfy this requirement.

     On November 23, 2004, we provided an update on our clinical and regulatory activities concerning Riquent. We announced that the clinical trial that we initiated in August 2004 was evaluating doses of 100 mg and 300 mg of Riquent over a 12-month period in lupus patients with a history of renal disease. We are currently recruiting patients in discussion37 of approximately 60 planned clinical trial sites in the United States. We also announced that we were conducting an additional study to evaluate higher doses of Riquent for use in the multi-dose study. To date, this additional study, conducted in healthy volunteers, has evaluated single doses of 600 mg in one group and 1200 mg in another group treated with Riquent or placebo. Both dose levels of Riquent appeared to be well tolerated and we may test additional dose levels in connection with this trial. Based on previous studies of Riquent, we believe that some lupus patients may benefit from higher doses of Riquent. Once the dosing study is completed, we plan to review the data from the study with the FDA aboutand may choose to study additional doses of Riquent in the design and timing of a post-marketing clinical trial that would be required if Riquent is approved under Subpart H. We arewe initiated in August 2004.

     Our November 2004 announcement also currently meetingnoted that we had met with the European Agency for the Evaluation of Medicinal Products (the “EMEA”) which had designated two countries to lead the review of our European regulatory authoritiesfiling and that, due to discuss potential next stepsthe efforts involved in our ongoing discussions with the FDA, we anticipated a delay in filing our Marketing Authorization Application (“MAA”) for Riquent in Europe. ThereWe also announced that, while our discussions with the FDA were ongoing, we had taken steps to control certain costs associated with our research, development and other activities. Finally, we announced that, since receiving the approvable letter from the FDA in October 2004, we and the FDA had met twice to discuss the approvable letter and data concerning Riquent and that we had two additional meetings scheduled.

     Since our November 2004 announcement, we completed three additional meetings with the FDA regarding the approvable letter and whether the FDA would consider approving Riquent under Subpart H. During our discussions with the FDA, we have provided the FDA with additional evidence in support of the potential efficacy of Riquent and with information that we believe supports a determination that antibodies to dsDNA are an appropriate surrogate endpoint for lupus renal disease and that the magnitude of the effect of Riquent on antibodies to dsDNA is reasonably likely to predict clinical benefit, which is a requirement for any potential approval under Subpart H. Many of the analyses of data from our clinical trials of Riquent were conducted on a retrospective basis and the p values reported are nominal, without adjustment for multiple comparisons. While we are in discussions with the FDA regarding the possibility of approval under Subpart H, we are continuing the clinical benefit study that we initiated in August 2004 in order to satisfy the additional trial requirement set forth in the FDA’s October 2004 approvable letter. In the event that the FDA approves Riquent under Subpart H, we expect that we would continue the ongoing trial as a post-marketing benefit trial, which would need to be completed after approval.

     We currently expect to continue our discussions with the FDA regarding possible Subpart H approval, although there can be no guarantee that any future meetings with the FDA and other regulatory agencies can be held in a timely manner, or at all, or that our meetings with them will result in our being able to continue to develop Riquent. If for any reason our development efforts as to Riquent are terminated, it would have a material adverse effect on our business and future prospects.

     The evidence in the NDA supporting the safety and effectiveness of Riquent was derived from 12 clinical trials involving approximately 900 patients and subjects conducted over a period of approximately 10 years. Our submission was primarily based on data from our Phase 3 trial of Riquent that enrolled 298 patients with high-affinity antibodies to Riquent who were treated for up to 22 months and our Phase 2/3 trial that enrolled 189 patients with high-affinity antibodies to Riquent who were treated for up to 18 months.

     It is possible that the FDA and European regulatory agencies may requirewill eliminate or change the current FDA requirement that we conduct an additional clinical trialstrial for Riquent prior to any further consideration of Riquent, such aspossible approval.

     On February 2, 2005, we announced that we had completed a post-marketing clinical trial under Subpart H or an additionalpublic offering of 12,250,000 shares of our common stock. The net proceeds to us, after expenses, were approximately $15.8 million.

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Phase 3 clinical trial, in order to obtain marketing approval of Riquent. The size, complexity and timing of any additional trial would require significant discussions with the agencies. If any additional trial is required prior to approval, the marketing approval of Riquent, if any, will be significantly delayed, even if the additional trial ultimately demonstrates the safety and efficacy of Riquent. In any event, we will require additional funding.

     Further discussion of the results of our Phase 3 trial of Riquent is contained in this report under the heading “Riquent Clinical Trial History” beginning at page 6.

Antibody-Mediated Diseases

     The immune system is the major biological defense mechanism responsible for recognizing and fighting disease. The immune system identifies antigens, such as bacteria, viruses and other disease-causing substances, and seeks to rid the body of these antigens. There are two fundamental types of immune responses: cell-mediated and antibody-mediated. These immune responses are controlled by the activities of white blood cells called T cells and B cells. T cells provide cell-mediated immunity and regulate B cells. B cells provide antibody-mediated immunity by producing antibodies that recognize and help to eliminate antigens.

     Each B cell produces antibodies against a specific structure on the antigen’s surface called an epitope. The B cell is triggered to produce antibodies when the specific epitope is recognized by and binds to the antibody receptors on the surface of the B cell, and only when the B cell receives an appropriate signal from a T cell. When an epitope binds to the B cell with no corresponding T cell signal, the B cell may become “tolerized”“tolerized,” and cease to produce antibodies.

     A properly functioning immune system distinguishes between foreign, or “non-self,” antigens and the body’s own healthy tissues. In a malfunctioning immune system, healthy tissue may trigger an immune response that causes B cells to produce disease-causing antibodies, resulting in antibody-mediated autoimmune disease. For example, B cells can produce disease-causing antibodies that are associated with the impairment of kidney function and can result in the need for dialysis in people with lupus and with the development of blood clots that can result in stroke, heart attack, deep vein thrombosis and recurrent fetal loss in people with antibody-mediated thrombosis, also known as Antiphospholipid Syndrome. Other antibody-mediated disorders include the wasting of muscles in myasthenia gravis, organ rejection in xenotransplantation and Rh hemolytic disease in newborns.

     Many currently available therapies for antibody-mediated diseases have significant shortcomings, including the potential for causing severe side effects and a lack of specificity. Mild forms of antibody-mediated diseases are generally treated with drugs that address only the disease symptoms and fail to suppress disease progression because such drugs do not affect the causative factors of the disease itself. Exacerbations of antibody-mediated diseases like lupus are generally treated with high levels of corticosteroids andand/or immunosuppressive therapy (primarily anti-cancer or chemotherapy drugs and drugs designed to reduce the risk of organ transplant rejection), which can broadly suppress the normal function of the entire immune system. These therapies can leave patients susceptible to potentially life-threatening infections that may require hospitalization. Repeated dosing withadministration of high doses of corticosteroids may cause other serious conditions, including diabetes, hypertension, cataracts, osteonecrosis and psychosis, and an increased risk of severe infections that may limit the use of this therapy. The use of chemotherapy may lead to acutea wide range of problems includingthat can include weight loss, nausea, an increased risk of severe infections, and long-term adverse effects, including sterility and an increased risk of malignancies.

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Tolerance Technology®

     Our Tolerance Technology program focuses on the discovery and development of proprietary therapeutics, called Toleragens, which are intended to target and suppress the production of specific disease-causing antibodies without affecting the protective functions of the immune system. We believe that Toleragens have the potential to treat the underlying causes of antibody-mediated diseases, and that our Tolerance Technology mayhas the potential to be applied broadly wherever specific antibodies are involved in causing diseases.

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     Since the 1970s, hundreds of papers have been published by the scientific community describing laboratory studies and a Nobel Prize was awarded for research in tolerance. The underlying science supporting our Tolerance Technology is based on these discoveries as well as on our own research.

     Toleragens are composed of disease-specific epitopes and a carrier platform, which are proprietary chemical structures that we have developed and synthesized. To mimic the unique epitopes on an antigen’s surface, we identify and synthesize epitopes specific to particular antibody-mediated diseases and attach or conjugate these epitopes to the carrier platform, which serves as a vehicle for presenting the epitopes to the antibody receptors on the targeted B cell. When the epitope binds to the antibody receptors on the B cell in the absence of a T cell signal, the B cell may become tolerized and cease to produce disease-causing antibodies.

     We design our Toleragens to bind selectively todisease-causingB cells without affecting the function ofdisease-fightingB cells. This process involves: collecting and purifying the disease-causing antibodies from patients with the targeted disease; generating and selecting an epitope that strongly binds to the purified antibodies; modifying the epitope’s structure to maximize its binding properties while eliminating, if necessary, structures that can activate a patient’s T cells (this process is called “optimization”); and linking the optimized epitope to the carrier platform. We believe this process enables us to create Toleragens that will preferentially tolerize and shut down B cells that generate antibodies with the highest binding affinity, and which are believed to be the most harmful.

Business Strategy

     Our objective is to become the leading developer of highly specific therapeutics for the treatment of life-threatening antibody-mediated diseases such as lupus and antibody-mediated thrombosis, organ rejection in xenotransplantation, myasthenia gravis and Rh hemolytic disease in newborns.acute and chronic inflammatory disorders. Our strategy includes the following key elements:

SupportComplete any clinical studies to satisfy regulatory requirements.Based on the FDA’s reviewapprovable letter we received in October 2004, we are required to complete an additional, randomized, double-blind study that demonstrates the clinical benefit of Riquent prior to any potential approval. The letter indicated that the successful completion of the NDA and submit the Marketing Authorisation Application for Riquentclinical trial we initiated in August 2004 would appear to European regulatory agencies for review.satisfy this requirement. Our primary near-term goal is to supportcomplete this study in order to satisfy the review byrequirement set forth in the FDA’s letter. In the event that the FDA approves Riquent under Subpart H, we expect that we would continue the ongoing trial as a post-marketing benefit trial, which we would need to complete after approval.

Continue discussions with the FDA regarding the possibility of our NDA filingobtaining accelerated approval for Riquent under Subpart H.We have had several meetings with the FDA since we received the approvable letter regarding Riquent. We have also provided the FDA with additional evidence in support of the potential efficacy of Riquent and with information that we believe supports a determination that antibodies to submitdsDNA are an appropriate surrogate endpoint for lupus renal disease and that the study resultsmagnitude of the effect of Riquent on antibodies to regulatory agencies in Europe for their review. Thereafter, wedsDNA is reasonably likely to predict clinical benefit. We expect to meetcontinue our discussions with these regulatory agencies, tothe FDA regarding Subpart H approval and provide the FDA with any additional results or analyses of Riquent data if requested and, with input from the agencies, to determine a future development strategy, if needed, for Riquent. No assurancerequested. However, there can be givenno guarantee that any future meetings with the FDA can be held in a timely manner, or at all, or that our meetings with the FDA will eliminate or change the current FDA requirement that we can reach agreements with any regulatory agencies regarding the future development or commercialization of Riquent.

Complete any additional analyses or clinical studies requested by the regulatory agencies.The FDA and European regulatory agencies may require us to complete a post-marketing clinical trial under Subpart H or to complete a second Phase 3 clinical trial in order to obtain marketing approval of Riquent. The size, complexity and timing of any requiredconduct an additional trial will not be known until after we meet with the agenciesfor Riquent prior to discuss the clinical trial resultsany further consideration of Riquent.possible approval.

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If one or moreSeek additional trials are required priorfunding, including through collaborative arrangements and through public and private financings, to approval, the marketing approval of Riquent, if any, will be significantly delayed even if the additional trial(s) ultimately demonstrates that Riquent is safedevelop and effective.

Obtain FDA and European regulatory approvalcommercialize product candidates.In order to continue our development of Riquent and other product candidates, including our ongoing clinical trial, we will need significant additional funding. Our choice of financing alternatives may vary depending on a number of factors, including the outcome of our discussions with the FDA regarding the possibility of Subpart H approval for Riquent, the interest of other entities in strategic transactions with us, the market price of our securities and conditions in the financial markets. There can be no guarantee that additional financing will be available on favorable terms, if at all, whether through collaborative arrangements, the issuance of securities, or otherwise.

Develop additional therapeutics for other life-threatening antibody-mediated diseases and inflammatory disorders.Substantially all of our resources are currently devoted to the development of Riquent. Nevertheless, we are conducting other, limited research and development activities, that are currently focused on chronic, life-threatening diseases and conditions caused by antibodies or inflammation for which current therapies have significant limitations. We intend to use our Tolerance Technology and scientific research to design therapeutics that specifically target other autoimmune diseases, without adversely affecting normal immune system function, as well as acute and chronic inflammatory disorders.

Possibly initiate commercialization activities.activities. If Riquent is ultimately approved in the United States, as to which we can provide no assurance, we currently anticipate marketing Riquent ourselves using a specialty pharmaceutical sales force that canwhich would target the rheumatology and nephrology specialists who treat the majority of lupus patients with renal disease. If Riquent is approved in Europe, as to which we can provide no assurance, we currently expect to either market Riquent ourselves or seek a marketing collaboration with a European partner. We believe that the majority of European patients are treated at a limited number of major hospitals, and, as is the case in the United States, that a specialty pharmaceutical sales force could successfully market Riquent to the physicians at a majority of these sites.

Apply Tolerance Technology to other life-threatening antibody-mediated diseases. Our other research and development activities, while limited, are currently focused on chronic, life-threatening diseases and conditions caused by antibodies, such as antibody-mediated thrombosis, for which current therapies have significant limitations. We intend to use our Tolerance Technology to design therapeutics that specifically target other antibody-mediated diseases without adversely affecting normal immune system function. Potential development targets include antibody-mediated thrombosis, organ rejection in xenotransplantation, myasthenia gravis and Rh hemolytic disease in newborns.

Enter into collaborative relationships to develop and commercialize product candidates. We may seek collaborative relationships with other pharmaceutical companies to provide support for some of our early stage research programs and for the clinical development and commercialization of our drug candidates.

Expand intellectual property position.position. As of December 31, 2003,2004, we owned 101100 issued patents and 8485 pending patent applications covering various technologies and drug candidates, including Riquent and LJP 1082. We hopeRiquent. Our goal is to expand our intellectual property position with future discoveries and additional patent filings.

Products Under Development

     We have focused our product development efforts on our programs for lupus, antibody-mediated thrombosis and other antibody-mediated diseases.diseases, and anti-inflammatory approaches. In each of the years ended December 31, 2004, 2003 2002 and 2001,2002, we incurred expenses of approximately $33.2 million, $32.4 million $37.7 million and $23.2$37.7 million, respectively, for product research and development on these programs.

The Lupus Program

     Lupus is a life-threatening, antibody-mediated disease in which disease-causingdisease causing antibodies damage various tissues. According to recent statistics compiled by the Lupus Foundation of America, epidemiological studies and other sources, the number of lupus patients in the United States is estimated to be between 250,000500,000 and 1,000,000, and approximately 16,000 new cases are diagnosed each year. Approximately nine out of 10 lupus patients are women, who usually develop the disease during their childbearing years. Lupus is characterized by a multitude of symptoms that can include chronic kidney inflammation, which can lead to kidney failure, serious episodes of cardiac and central-nervous-system inflammation, as well as extreme fatigue,

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arthritis and rashes. Approximately 80% of all lupus patients progress to serious symptoms. Approximately 50% of lupus patients will develop kidney disease.

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     Antibodies to double stranded DNA (“dsDNA”) can be detected in approximately 90% of lupus patients who are not receiving immunosuppressive therapy. Antibodies to dsDNA are widely believed to cause kidney disease (nephritis), often resulting in morbidity and mortality in lupus patients. Episodes of potentially life-threatening kidney inflammation — called “renal flares” — often require intensive-care,intensive care, treatment with high-dose corticosteroids and immunosuppressive agents, and hospitalization. Lupus nephritis can lead to deterioration of kidney function and to end-stage kidney disease, requiring long-term renal dialysis or kidney transplantation to sustain a patient’s life.

     Current treatments for lupus patients that have a renal flare often involve repeated administration of corticosteroids, often at high levels, that, when used long-term, can lead to serious side effects. Many patients with renal flares are also treated with immunosuppressive therapy, including anti-cancer drugs, that can have a general suppressive effect on the immune system and may be carcinogenic. Treatment with immunosuppressive therapies can leave patients vulnerable to serious infection, which is a significant cause of sickness and death.

     We have designed Riquent to suppress the production of antibodies to dsDNA in lupus patients without suppressing the normal function of the immune system. The design of Riquent is based on scientific evidence of the role of antibodies to dsDNA in lupus. Published studies of lupus patients indicate that a rise in the level of antibodies to dsDNA may be predictive of renal flares in lupus patients with renal involvement, and that suppressingreducing antibodies to dsDNA by treating with corticosteroids can prevent relapse. In a mouse model of lupus nephritis that generates elevated levels of antibodies to dsDNA, administration of Riquent reduced the production of antibodies to dsDNA, reduced the number of antibody-forming cells, reduced kidney disease and extended the life of the animals. We believe that our own and other studies provide evidence that reducing levels of antibodies to dsDNA may provide an effective therapy for lupus nephritis.

     Some studies of lupus patients indicate that antibodies to dsDNA with the highest binding affinity are associated with the most damage to the kidneys. We believe that Riquent preferentially targets these antibodies.

Riquent Clinical Trial History

Phase 1 trial

     Based on our pre-clinical findings, we filed an Investigational New Drug application for Riquent with the FDA in August 1994. In a double-blind, placebo-controlled Phase 1 clinical trial conducted in December 1994, healthy volunteers received Riquent and displayed no drug-related adverse effects. Upon completion of our Phase 1 trial, we began four Phase 2 clinical trials.

Phase 2 trials

     Our Phase 2 clinical trials included a single-dose trial, a repeat dose-escalating trial and two dose-ranging trials.

     In 1994, the single-dose clinical trial was initiated to evaluate the safety of a single, 100 mg intravenous dose of Riquent in four female lupus patients. We monitored antibody levels, blood chemistry, vital signs and complement (inflammation-promoting proteins) levels for 28 days after dosing. Riquent was well tolerated by all four patients, with no drug-related adverse

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clinical symptoms and no clinically significant complement level changes. In addition, no clinically significant immune complex formation (inflammation-promoting accumulation of antibodies and antigens) was observed, indicating the absence of anthere was no significant adverse immune response to Riquent. A transient reduction in antibodies to dsDNA levels was also observed. These results

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were presented at the Annual Scientific Meeting of the American College of Rheumatology in October 1995.

     In 1995, the repeat dose-escalating clinical trial was initiated in which two female lupus patients each received doses of 10, 10, 50, 50, 100 and 100 mg of Riquent at two-week intervals. After the 10-week dosing regimen was completed, the patients were monitored for six weeks. Riquent was well tolerated by both patients with no drug-related adverse clinical symptoms, no clinically significant complement changes and no significant immune complex formation. Six weeks after the last dose, the antibodies to dsDNA levels in both patients remained suppressed below baseline levels.

     Also in 1995, we conducted our first double-blind, placebo-controlled dose-ranging trial, in which 58 lupus patients (53 females and five males) with mild lupus symptoms were treated for a four-month period with Riquent or placebo, and then were monitored for two months. Patients were enrolled who were clinically stable and had antibodies to dsDNA levels exceeding those generally found in healthy individuals. The patients were organized into nine treatment groups at three dose levels (1 mg, 10 mg and 50 mg) and three frequencies (once per week, once every two weeks and once every four weeks). Patients were randomized to one of the nine treatment groups so that at each dose and frequency four to seven patients received Riquent and one patient received placebo.

     Patients in the weekly treatment groups showed a dose-response correlation between increasing doses of Riquent and reductions of levels of antibodies to dsDNA. In patients treated weekly with 10 mg or 50 mg doses of Riquent, antibodies to dsDNA were reduced by statistically significant levels and remained suppressed in certain patients for up to two months after the last dose. In this trial, patients treated weekly with 50 mg of Riquent exhibited a trend toward normalization of C3 complement levels in parallel to the reduction in antibodies to dsDNA.

C3 is an important inflammation-related complement protein. Throughout this first dose-ranging trial, the drug was well tolerated with no clinically significant dose-related adverse reactions observed. Three patients experienced lupus renal flares, and three other patients were hospitalized as a result of transient adverse events that the treating clinicians believed were unrelated to the underlying disease or to Riquent. Two of the patients with renal flares withdrew from the study, as did four patients who experienced exacerbations of lupus and one patient who experienced a herpes rash. However, no relationship was observed between the development of an adverse event and the dose or the frequency of administration of Riquent.

     In 1999, we completed a second double-blind, placebo-controlled dose-ranging trial, in which 74 lupus patients received weekly injections of 10, 50 or 100 mg of Riquent or placebo for a 12-week period. In patients treated weekly with placebo, 10 mg or 50 mg of Riquent, antibodies to dsDNA increased by 100%, 53% and 10%, respectively, while in patients treated weekly with 100 mg of Riquent, antibodies to dsDNA decreased by 43%, a statistically significant difference from placebo. Seven Riquent-treated patients had serious adverse events, but none were considered related to Riquent treatment.

Phase 2/3 trial

     In December 1996, we initiated a double-blind, placebo-controlled, multi-center Phase 2/3 clinical trial of Riquent in which lupus patients with a history of lupus nephritis received Riquent or placebo and were in the trial for up to 18 months. The purpose of the Phase 2/3 trial was to evaluate the safety of the drug and its potential to delay the time to or reduce the incidence of renal flares, to delay orreduce antibodies to dsDNA, to reduce the need for immunosuppressivecyclophosphamide or corticosteroids, and/or chemotherapy drugs and to improve patients’ health-related quality of life (“(��HRQOL”). More than 200 patients at more than 50 sites in North America and Europe enrolled in the trial which

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was we conducted bywith Abbott Laboratories (“Abbott”) and us as part of our joint development agreement.

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     In May 1999, an interim analysis of the Phase 2/3 trial indicated that the trial was unlikely to reach statistical significance for the primary endpoint, time to renal flare, and the trial was stoppedstopped. Although patients in order to evaluate the data. Although both the drug- and placebo-treated groups exhibited serious adverse events, there were no statistically significant differences in the number of events in the two groups. In September 1999, theour joint development agreement for Riquent betweenwith Abbott and usLaboratories was terminated.

     In November 1999, we announced encouraging initial results from the analysisretrospective analyses of the data from the Phase 2/3 clinical trial which showed that a certain group of patients treated with Riquent had fewer renal flares and longer time to treatment with high dose corticosteroids and/or cyclophosphamide (“HDCC”). These results were based on an analysis of the trial using a new blood test that we developed and that appears to predict which patients will respond to treatment with Riquent. Developed in 1998, the blood test measures the strength of the binding between Riquent and a patient’s antibodies. Prior to using the blood test in the Phase 2/3 trial, we used it retrospectively to evaluate patient samples from the 1995 Phase 2 dose-ranging trial and found that the blood test predicted which patients would respond to drug treatment as measured by changes in antibody affinity to Riquent following drug treatment.

     In May 2000, we completed our analysis of the Phase 2/3 clinical trial data after testing more than 99% of the North American patient samples from the trial. The blood test showed that 89% of the patients in the trial had high-affinity antibodies to Riquent (the “high-affinity patients”). The high-affinity patients treated with Riquent experienced significantly longer time to renal flare (p=0.007), the primary endpoint of the trial, fewer renal flares (p=0.008), longer time to treatments with HDCC (p=0.002)0.0003) and fewer exposures to HDCC (p=(p<0.001) when compared to the placebo-treated group.

     Also in the Phase 2/3 trial, mean levels of circulating antibodies to dsDNA in patients treated with Riquent were reduced by a statistically significant amount relative to placebo during drug treatment (p=(p<0.0001). Levels of an important inflammation-related complement protein, C3 improved when antibodies were reduced. In lupus patients, it is generally observed that complement C3 levels decrease during active renal disease and increase with clinical improvement. The concurrent reduction of antibodies to dsDNA and increase in C3 complement levels is biologically consistent. As discussed above, this effect had been observed in the 1995 Phase 2 dose-ranging study of Riquent in 58 lupus patients.

     The Phase 2/3 trial design included periods during which patients received no drug for approximately two months (the “off” periods) and weekly doses of 50 mg over three months (the “on” periods). When patients were on drug,Riquent, mean levels of antibodies to dsDNA decreased. When patients were off drug,Riquent, mean levels of antibodies to dsDNA increased. During the first four months of the trial, when patients were treated with 100 mg per week, there were nine renal flares in the placebo-treated group and four in the drug-treatedRiquent-treated group — approximately a 2:1 ratio in favor of drug treatment. Furthermore, in high-affinity patients, during the first four months of the trial, there were eight renal flares in the placebo-treated group and only one renal flare in the drug-treatedRiquent-treated group (p=0.035) — an 8:1 ratio in favor of drugRiquent treatment.

     The results of the Phase 2/3 clinical trial were published inArthritis & Rheumatism,Vol. 48, No. 2, February 2003, pp. 442-454 by Alarcon-Segovia, D., et al.

     In patients with impaired renal function at baseline (defined as serum creatinine> 1.5 mg/dL), there were more renal flares in the patients treated with placebo than in the patients treated with Riquent (p=0.046)0.095). In a group of high-affinity patients with impaired renal function,

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there were six renal flares in 1011 patients treated with placebo and no renal flares in 11 patients treated with drug (p=0.004)0.012).

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     In January 2001, we announced that approximately 90% of patients in each of three previous clinical trials from whom blood serum specimens were available had high-affinity antibodies to Riquent prior to drug treatment. The ratios for the trials were: 89% of the 213 patients in the Phase 2/3 trial, 94% of the 31 patients in the Phase 2 trial completed in 1996, and 90% of the 60 patients in the Phase 2 trial completed in 1999. Patients in the Phase 2/3 trial had moderate to severe disease and a history of renal flares. Patients in the two dose-ranging Phase 2 trials had mild to moderate disease. Placebo- and drug-treated groups had similar percentages of patients with high-affinity antibodies at baseline in each clinical trial. These data suggest that the percentage of high-affinity patients in a larger population of lupus patients may be 90%, but a larger population of patients would need to be evaluated to confirm this result.

     The Phase 2/3 trial also showed that 83% of patients in the trial who had a renal flare also had a treatment with HDCC and that 48% were hospitalized during the trial. In patients who entered the trial with impaired renal function and who experienced renal flare, serum creatinine levels worsened significantly and increased from an average of 1.9 mg/dL at baseline to 5.0 mg/dL at final visit.

     Additional data from the Phase 2/3 trial indicated that treatment with Riquent appeared to be as effective as current immunosuppressive therapytreatment with HDCC in reducing antibodies to dsDNA. Patients on placebo who were treated with HDCC were compared to patients who received Riquent. Following treatment with HDCC, levels of antibodies to dsDNA in 38 patients receiving placebo were reduced within four weeks by a mean of 25%. In 100 patients treated weekly with 100 mg of Riquent, but not HDCC, antibodies to dsDNA were reduced within four weeks by an average of 36%. In patients requiring HDCC, mean levels of antibodies to dsDNA decreased 37% in 22 patients receiving Riquent treatment compared with 25% in 38 patients receiving placebo. In patients receiving HDCC, the median dose of corticosteroids was 50 mg per day.

     Additional data from the Phase 2/3 trial indicated that treatment with Riquent had a positive impact on HRQOL in patients with lupus renal disease following 16 weeks of treatment with Riquent and following renal flares, when compared to placebo. HRQOL is a measure of a patient’s sense of mental and physical well-being, or how the patient feels, and was measured by using a standard scoring instrument called the Medical Outcomes Study 36-Item Short Form, or SF-36^®â, that categorizes results in eight domains: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health, as well as mental and physical composite summary scores. Riquent-treated patients had better scores in certain domains when compared to baseline than did placebo-treated patients.

     Results from the Phase 2/3 lupus study suggested three ways to improve the clinical trial design of a Phase 3 trial: (i) eliminate “off” periods during which patients are not treated with either drug or placebo; (ii) increase the dosing to 100 mg per week throughout the study; and (iii) evaluate the efficacy of the drug in high-affinity patients.

Phase 3 trial

     Based on the observations from our Phase 2/3 trial and following discussions with the FDA, we initiated a Phase 3 clinical trial in September 2000 to further evaluate the safety and efficacy of Riquent in the treatment of lupus renal disease. The double-blind, placebo-controlled study was conducted at more than 7091 sites in North America and Europe and was designed to evaluate the potential of Riquent to delay and reduce the number of renal flares and to delay and reduce the need for treatment with HDCC and/or chemotherapyother immunosuppressive drugs in high-affinity patients.

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Patients in the trial were treated weekly with either 100 mg of Riquent or placebo for a period of up to 22 months. The trial design eliminated the two-month “off” periods from the Phase 2/3 trial during which patients were not treated with either drug or placebo.

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     The prospectively defined analysis groups in the Phase 3 trial were the high-affinity patients (the intent-to-treat population)“intent-to-treat population”) and high-affinity patients with impaired renal function. Patients with impaired renal function were defined as those who had a serum creatinine level of > ³1.5 mg/dL at baseline. In general, patients with impaired renal function are considered to be at greater risk of progressing to renal flare, kidney failure and dialysis.

     The primary endpoint in the Phase 3 trial was time to renal flare. A renal flare was defined as a significant, reproducible increase in serum creatinine, urine protein or blood in the urine. The secondary endpoint was time to treatment with HDCC. Treatment with HDCC was defined as any dose of cyclophosphamide or an increase in prednisone of 15 mg/day or higher resulting in a final dose greater than 20 mg/day for greater than two days or any dose greater than 200 mg/day.

     Other prospectively defined outcomesendpoints included time to Major SLE flare, treatment associated maintenance and/or improvementchanges in HRQOL, decreases in antibodies to dsDNA and associated increases in complement C3 levels. A Major SLE flare was defined as the occurrence of any one of the following due to manifestations of active SLE: treatment with HDCC or initiation or increase in treatment with otherthe following immunosuppressive agents, includingagents: azathioprine, mycophenolate mofetil, methotrexate, cyclosporin and leflunomide; hospitalization; or death. This definition of Major SLE flare was designed to capture serious events where patients were treated forassess the effect of Riquent on a broader spectrum of SLE manifestations of active SLE as well as renal disease or where treatment, hospitalization or death could have preceded the occurrence of a documentedthan just renal flare.

     Complement protein changes were evaluated by determining the mean change from baseline in the complement protein C3, thatwhich measure indicates overall complement consumption due to active inflammation. Antibody changes were evaluated by determining the mean percent change of antibodies to dsDNA from baseline. Patients’ assessments of disease activity and HRQOL were measured on a regular basis, including at the time of, and seven days following, a documented renal flare.

     In February 2003, we announced our preliminary findings from the Phase 3 trial. The study results indicated that Riquent appeared to be well tolerated with no apparent differences in the overall incidence of serious adverse events or adverse events between Riquent-treated and placebo-treated patients. The trial data indicated that treatment with Riquent did not increase length of time to renal flare, the primary endpoint, or time to treatment with HDCC, the secondary endpoint, in a statistically significant manner when compared with placebo through the end of the study. There were 298 patients in the intent-to-treat population of high-affinity patients, 145 on Riquent and 153 on placebo. Patients were treated for up to 92 weeks with a median of 46 weeks.

     In the intent-to-treat population, there were fewer renal flares, fewer treatments with HDCC and fewer Major SLE flares in Riquent-treated patients compared with placebo-treated patients. The estimated median time to renal flare was 123 months in the Riquent-treated group and 89 months in the placebo-treated group. There were 41 renal flares, 17 (12%) in Riquent-treated patients and 24 (16%) in placebo-treated patients. There were 6869 treatments with HDCC, 32 (22%33 (23%) in the Riquent-treated group and 36 (24%) in the placebo-treated group. There were 82 Major SLE flares in the trial, 35 (24%) in patients on Riquent and 47 (31%) in patients on placebo. None of these differences were statistically significant.

     There was a statistically significant reduction in antibodies to dsDNA in the Riquent-treated group compared with the placebo-treated group (p<0.001)0.0001). Antibodies to dsDNA are believed to result in renal flares and other clinical manifestations of lupus. Riquent was designed

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to reduce antibodies to dsDNA and this effect has been demonstrated in all clinical studies of Riquent to date.

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     In the Phase 3 trial, reductions in antibodies to dsDNA strongly correlated with increases in complement C3levels (p<0.001). Inverse correlations between antibody levels and complement C3 were observed in the previous Phase 2/3 trial (p=0.0001)(p<0.001). Complement C3 levels below normal at baseline (hypocomplementemia) correlated with an increased risk of renal flare (p<0.001)(p=0.0001) in the Phase 3 trial although a statistically significant correlation was not demonstrated in the Phase 2/3 trial. Together, these data support the pathogenic nature of these antibodies to dsDNA in lupus patients.

     A review of the Phase 3 trial results for time to renal flare and for the increases in antibody levels showed that the Riquent and placebo groups were separating in favor of Riquent until weeks 46 to 48.week 48 of the trial. In the first 4648 weeks, 22 of 24 (90%) renal flares occurred in the study in the placebo patients compared with 1011 of 17 (59%(65%) in the Riquent-treated patients. At weeks 44, 46, and 48, the incidence of renal flares in the placebo-treated group compared with the Riquent-treated group (placebo-treated: Riquent-treated) was: 20:10 (p=0.085), 22:10 (p = 0.041) and 22:11 (p = 0.067), respectively, in favor of Riquent. At weeks 44, 46 and 48, the incidence of renal and/or Major SLE flares was 43:27 (p=0.057), 46:28 (p=0.033) and 46:29 (p=0.061), respectively, in favor of Riquent.

     In a prospectively defined subpopulation with impaired renal function at baseline, defined as a serum creatinine level of³> 1.5 mg/dl at baseline, there were 43 patients, 20 on Riquent and 23 on placebo. Riquent-treated patients had fewer renal flares, treatments with HDCC and Major SLE flares compared with patients on placebo, but the numbersample size of patientsthis subgroup was small and the differences were not statistically significant. There were eight renal flares, two (10%) in patients on Riquent and six (26%) in patients on placebo. There were nine10 treatments with HDCC, three (15%four (20%) in patients on Riquent and six (26%) in patients on placebo. There were 11 Major SLE flares, four (20%) in patients on Riquent and seven (30%) in patients on placebo. There were 14 renal flares and/or Major SLE flares, five (25%) in patients on Riquent and nine (39%) in patients on placebo. Similar results in the same group were observed for renal flares in the Phase 2/3 trial: no renal flares (0%) were observed in the 11 Riquent-treated high-affinity patients compared with six of 11 (55%) of the placebo – placebo–treated high-affinity patients. We believe that a delay in time to, or a decrease in, the incidence of renal flares and/or Major SLE flares in this high-risk population would be considered by expertsclinicians in the lupus field to be medically meaningful.

     The results from the Phase 3 trial appear to support the use of our high-affinity assay to identify patients who may respond well to Riquent.

Additional findings from the Phase 3 and Phase 2/3 trials

     On March 31, 2003, we announced additional retrospective analyses of data from our Phase 3 and Phase 2/3 trials of Riquent. The data showed a statistically significant correlation between reductions in antibodies to dsDNA and a reduced risk of renal flare in lupus patients (Phase 3: p < 0.0001; Phase 2/3: p = 0.0004). These results were presented at the Biomarkers for the Assessment of Systemic Lupus Erythematosus Conference in March 2003.

     In the Phase 3 trial, renal flares occurred approximately one fifth as often in patients with sustained reductions in antibodies to dsDNA compared with patients with unchanged or increasing antibodies. In both the Phase 3 and Phase 2/3 trials, patients with sustained reductions were defined as those who had at least a 10% reduction in antibodies to dsDNA from baseline for at least two-thirds of all measurements of antibodies to dsDNA during the trial, unless they were treated with high-dose corticosteroids and/or cyclophosphamide. Because HDCC suppresses antibodies to dsDNA, antibody values subsequent to HDCC treatment were adjusted to have a

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value equivalent to baseline. Patients meeting the criteria for sustained reductions in antibodies to dsDNA are also referred to below as “responders.” The analyses on sustained reductions were conducted after the trial was unblinded.

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     In the Phase 3 trial, renal flares occurred in only 4% of patients (five of 121) with sustained reductions whereas renal flares occurred in 20% of patients (36 of 177) who did not experience sustained reductions (p<0.0001). Twice as many Riquent-treated patients had sustained reductions (80 of 145, or 55%) compared with placebo-treated patients (41 of 153, or 27%).

     In the Phase 2/3 trial, renal flares occurred in only 3% of patients (two of 67) with sustained reductions whereas renal flares occurred in 21% of patients (26 of 122) who did not experience sustained reductions (p=0.0004). Four times as many Riquent-treated patients had sustained reductions (54 of 92, or 59%) compared with placebo-treated patients (13 of 97, or 13%).

     The results from both studies also confirm the correlation between increasing levels of antibodies to dsDNA and the occurrence of renal flares in lupus patients (Phase 3: p < 0.0001; Phase 2/3: p < 0.0007).

     The number of Major SLE flares was also significantly reduced in patients with sustained reductions in antibodies to dsDNA in the Phase 3 and Phase 2/3 trials. Patients with sustained reductions in antibodies to dsDNA had a 70%68% reduction in the risk of Major SLE flare in the Phase 3 trial and a 75%73% reduction in risk in the Phase 2/3 trial when compared with patients who did not have sustained reductions (p < 0.0001 for each trial).

     The majority of Major SLE flares were observed in patients who did not have a sustained reduction in antibodies to dsDNA. This group included 68 of 82 (83%) total Major SLE flares in the Phase 3 trial and 55 of 63 (87%) total Major SLE flares in the Phase 2/3 trial.

     On November 17, 2003, we presented additional analyses at the American Society of Nephrology Annual Meeting of data using Cox’s Proportional Hazards Regression Model that predicts that a 50% reduction in antibodies to dsDNA from baseline is associated with a 52% lower risk of renal flare in the Phase 2/3 trial (p = 0.0007) and a 53% lower risk in the Phase 3 trial (p<0.0001). These findings are consistent with previously released data showing that patients with sustained reductions in antibodies to dsDNA had fewer renal flares.

     On March 11, 2004, we announced additional analyses of data from our Phase 3 and Phase 2/3 trials of Riquent. The data showed that after one year of treatment, the number of lupus patients with a reduction in proteinuria of at least 50% from baseline was greater in the Riquent-treated group than in the placebo-treated group. Proteinuria, or protein in the urine, results from ongoing kidney inflammation. The reduction of proteinuria is one of the goals for the treatment of lupus patients with renal disease. Monitoring the level of a patient’s proteinuria is a routine and important way to help determine the severity and progression of renal disease. These results were presented at the SG Cowen 24th Annual Healthcare Conference on March 11, 2004.

     In patients who had 24-hour urine protein measured at both baseline and at week 52 during the Phase 3 trial, 41% (26 of 63) of patients in the Riquent-treated group with high-affinity antibodies to Riquent achieved a 50% or greater reduction from baseline in the amount of protein in their urine at week 52, compared with 28% (23 of 81) of patients in the placebo-treated group with high-affinity antibodies (nominal p(p = 0.047). In patients who had 24-hour urine protein measured at both baseline and at approximately week 52 during the Phase 2/3 trial, 44% (23 of 52) of patients in the Riquent-treated group with high-affinity antibodies had a 50% or greater reduction from baseline in the amount of protein in their urine at approximately week 52, compared with 18% (11 of 61) of patients in the placebo-treated group with high-affinity antibodies

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(nominal p (p = 0.002). The measurement of 24-hour urine protein was specified in each protocol at defined time points, but the analysis of the reduction in proteinuria was conducted on a retrospective basis.

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Health-related quality of life

     Results from the Phase 3 and Phase 2/3 trials were consistent among patients who were “responders.” As discussed above, patients were considered to be “responders” if they had sustained reductions in antibodies to dsDNA.dsDNA, so called “responders.” Responders reported improved or maintained HRQOL compared with patients without sustained reductions in antibodies to dsDNA, regardless of treatment group. Similar analyses within each treatment group demonstrated that responders reported improved or maintained HRQOL compared with non-responders. This evidence supports the conclusion that decreases in levels in antibodies to dsDNA result in improvements in, or maintenance of, patient-reported HRQOL, as assessed by SF-36, whether sustained reductions in antibodies to dsDNA are due to spontaneous improvement or to treatment with Riquent. In the Phase 2/3 trial, responders at visit 18 (week 16) showed improvement in all domains relative to non-responders. In the Phase 3 trial, responders at visitvisits 27 (week 24) and 51 (week 48) showed improvement in all domains relative to non-responders and in six of eight domains at their last visit.

     In the Phase 2/3 trial, approximately four times as many patients in the Riquent-treated group were responders than in the placebo group. In the Phase 3 trial, approximately twice as many patients in the Riquent-treated group were responders than in the placebo group.

     Although the sample size was small, a potentially important finding in the Riquent-treated group was that, following a renal flare, compared to pre-flare assessments, patients reported improvement or less deterioration in all domain scores compared with no change or deterioration in the placebo-treated group. These findings were also seen when seven patients receiving HDCC prior to a flare were excluded, suggesting that deterioration in reported HRQOL due to administration of HDCC did not account for the differences between the treatment groups. In an analysis of SF-36 scores pre- and post-renal flare in the Phase 3 trial (41 patients), Riquent-treated patients reported less deterioration than placebo-treated patients in six of eight domains. When eight patients receiving HDCC prior to renal flare were excluded, Riquent-treated patients reported less deterioration than placebo-treated patients in five of eight domains, suggesting that deterioration in reported HRQOL due to administration of HDCC did not account for the differences between treatment groups.

     The differences in HRQOL between the Riquent-treated and placebo-treated groups were not significantly different during the Phase 3 trial, and mirror the renal flare results reported for the Phase 3 trial. The lack of significance may have been due to changes in medical practice during the trial and a loss of susceptible patients as discussed in detail in our February 18, 2003 press release.

Comments on trial data

     Several observations may help to explain the results from the recentour Phase 3 trial. These are only observations are preliminary and they will all require review by appropriate regulatory agencies and medical experts.their potential impact on the trial results have not been confirmed.

     There appear to have been changesChanges in medical practice since the completion of the Phase 2/3 trial as evidenced by a difference in prescribing regimens for immunosuppressive drugs.drugs may impact the ability of our study to assess treatment efficacy. In particular, it appears there were differences in baseline treatments in the patient population in the Phase 3 trial compared with the Phase 2/3 trial. A higher percentage of patients were receiving immunosuppressive treatments at study entry: 73 of 145 (50%) in the Riquent-treated group versus 63 of 153 (41%) in the placebo-treated group in the Phase 3 trial compared to 35 of 114

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(31%) in the Riquent-treated group versus 40 of 116 (34%) in the placebo-treated group in the Phase 2/3 trial. The sample size selected for the Phase 3 trial was based on the Phase 2/3 trial.

     In addition, the definition of HDCC may not have captured all of the potential events in the Phase 3 trial because the definition did not include some of the newer immunosuppressive drugs that are increasingly used instead of cyclophosphamide. Although these newer drugs have a better side effect profile than cyclophosphamide, they are still broadly immunosuppressive.

     Reviewing a graph of the Phase 3 trial results showed that the curves of Riquent and placebo lines for time to renal flare and for the changes in antibody levels were separating until weeks 46 toweek 48.

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After weeks 46 toweek 48, the placebo flare rate decreased significantly. In the placebo-treated group, those who remained in the study after weeks 44 toweek 48 showed acontinuing reduction in antibodies to dsDNA compared with levels observed inat the prior weeks.baseline.

     We believeIt is possible that the high-affinity antibody blood test we developed identifies lupus patients who are most likely to respond to Riquent treatment. The FDA and other regulatory agencies may require screeninghigh percentage of patients for high-affinity antibodies with this test priorcoming into the study on concomitant immunosuppressive drugs reduced the ability of the study to treatment with Riquent. We have filed a patent application for this blood test.discriminate the clinical effect of drug from placebo.

Orphan drug designation for Riquent

     In September 2000, the FDA granted us orphan drug designation for Riquent for the treatment of lupus kidney disease.nephritis. The Orphan Drug Act provides for seven years of marketing exclusivity in the United States andpotentially enables us to obtain research funding, tax credits for certain research expenses and a waiver of the application user fees. In addition, the Orphan Drug Act allows for seven years of exclusive marketing rights to a specific drug for a specific orphan indication. Exclusivity is conferred upon receipt of marketing approval from the FDA. The marketing exclusivity prevents FDA approval during the seven year period of the “same” drug from another company for the same orphan indication. Two drugs with substantially similar characteristics are considered to be the same, and exclusivity granted to one drug will block approval of the subsequent drug for the same indication. However, one may overcome the exclusivity designation by demonstrating that, despite the similarity of the drugs, a subsequent drug is clinically superior in terms of increased effectiveness and adequate safety, increased safety and adequate effectiveness or represents a major contribution to patient care, and therefore is not barred by the exclusivity. In the course of the FDA’s initial review of our NDA, the FDA has indicated that the indication for Riquent proposed in our NDA may be broader than the indication identified in our orphan drug designation. Accordingly, the FDA has indicated that we will bewere required to pay the filing fee for the NDA for Riquent at this time, even though the FDA’s final approved indication, if any, may be within the original orphan drug designation. We intend to seek, and believe thatRiquent. However, we qualify for,subsequently received a refund of the full filing fee under the FDA’s small business regulations. Whether we will be able to take advantage of the benefits afforded by the orphan drug designation will ultimately be determined by the FDA only after further review of our NDA. If the FDA approves Riquent for a broader indication, we believe that we will be able to market Riquent to a larger number of patients, although, in such case, we would not be able to take advantage of the orphan drug designation for market exclusivity, research funding and certain tax credits.

     In November 2001, the European Commission granted us orphan medicinal product designation in the European Union for Riquent on the recommendationfor treatment of the Committee on Orphan Medical Products.lupus nephritis. Orphan designation in Europe provides for 10 years of marketing exclusivity in the European Union and enables us to receive significant fee reductions for scientific advice from the Committee for Orphan Medicinal Products, marketing authorization and inspections.

Continuing risks

     The continued development of Riquent involves a number of risks and uncertainties. There can be no assurance that any previous clinical results can be replicated in further clinical testing or that Riquent will be effective in inducing and sustaining antibody suppression; will prove to be clinically safe or effective; will receive required regulatory approvals; or will not require further FDA or other regulatory mandated clinical testing. In addition, there can be no assurances that regulatory authorities will accept as evidence of efficacy the retrospective analyses that are contained within the NDA and that are a key part of the arguments for FDA approval. If the continued development of Riquent is significantly delayed or if additional trials produce negative or inconclusive results, our business and financial condition will be adversely

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affected and it may be difficult or impossible for us to survive. Our blood test to measure the binding affinity for Riquent is experimental, has not been validated by independent laboratories and willis likely be reviewedto require regulatory review as part of the Riquent approval process.

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Antibody-Mediated Thrombosis, Including Stroke, Heart Attack, Deep Vein Thrombosis and Recurrent Fetal Loss

     As further described below, we have been developing a drug for the treatment of antibody-mediated thrombosis. However, substantially all of our resources are currently devoted to the development of Riquent. Whether we will again devote substantial resources to this program depends on a number of factors, including the progress of our Riquent development program and the availability of capital.

     Researchers believe that antibodies called “antiphospholipid” antibodies promote arterial and venous blood clots, which can cause a variety of recurring and potentially life-threatening medical problems. For example, blood clots that lodge in the brain may cause stroke and those that lodge in the legs may cause deep vein thrombosis. There are multiple conditions associated with these antibodies that we collectively refer to as antibody-mediated thrombosis: antibody-mediated stroke, heart attack, deep vein thrombosis, recurrent fetal loss and complications following cardiovascular surgery. We believe that our program to develop a Toleragen to treat antibody-mediated thrombosis could be helpful in preventing these problems. WeBased on data from the medical literature, we estimate that there are up to 2,000,000 patients in the United States and Europe with antibody-mediated thrombosis.

     Stroke is a leading cause of death in the United States. In 2002,2003, there were approximately 4,000,0004,600,000 stroke patients in the United States and approximately 750,000 new episodes are expected to occur each year. In 2002,2003, approximately 160,000175,000 people died from stroke in the United States. This debilitating condition results from acute neurological injury caused by the blockage or rupture of blood vessels in the brain. Many of the blockages are caused by thromboses, or blood clots, which many clinicians believe may be caused by a number of factors, including antiphospholipid antibodies. We believe that these antibodies contributedmay contribute to approximately 10% of strokes in the United States. Antibody-mediated stroke is thought to occur in younger individuals and with greater frequency than non-antibody-mediated stroke. The cost of treatment to provide hospitalization and home nursing care for a survivor of a serious stroke is approximately $30,000$40,000 per year for life.

     Antibody-mediated thrombosis is also associated with recurrent fetal loss, a syndrome of repeated miscarriage. Published clinical reports estimate that many women with elevated antiphospholipid antibody levels experience multiple miscarriages, delayed fetal development or premature childbirth. Recent academic research suggests that elevated levels of these antibodies are also found in approximately 10% to 30% of patients with other clotting disorders, including myocardial infarction (heart attack), deep vein thrombosis and cardiac valve lesion, as well as in approximately 30% of lupus patients. In myocardial infarction, recent research suggests the relative risk of a thrombotic event or death is approximately twice as high in people with high antiphospholipid antibodies, and this risk is independent of other risk factors. In deep vein thrombosis, research indicates antiphospholipid antibody-positive patients have recurring deep vein thromboses about twice as often as antiphospholipid antibody-negative patients.

     Current treatments for antibody-mediated thrombosis involve the use of chronic, potentially life-long anticoagulant therapy with drugs such as heparin or warfarin to prevent the formation of blood clots. Patients must be carefully monitored to minimize serious bleeding episodes that can occur because of the therapy. If patients are removed from anticoagulant therapy, they are at an increased risk of stroke or another thrombotic episode. Warfarin is not recommended in the treatment of recurrent fetal loss because it is toxic to the developing fetus.

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     We believe that a Toleragen to treat antibody-mediated thrombosis would be a major step forward in specifically targeting the cause of this clotting disorder, thereby minimizing or avoiding the side effects of current therapies.

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     Our research supports the finding that specific antibodies in antibody-mediated thrombosis enhance blood-clot formation by interfering with the natural breakdown of a blood component — Factor Va — that accelerates clotting. The true target of these clot-promoting antibodies is not cardiolipin, but a region on a blood protein called beta 2-glycoprotein I (“beta 2 GPI”). To date, our scientists have shown that approximately 90% of patients studied with antibody-mediated thrombosis have antibodies that bind to this region. The identification of a disease target for antibody-mediated thrombosis has allowed us to begin building new drug candidates that bind to these antibodies with high-affinity and are designed to tolerize, or shut down, the B cells that produce them.

     We have synthesized a family of candidate antibody-mediated thrombosis Toleragens for testing. We have also developed a mouse model of the disease in which animals produce antibodies to beta 2 GPI. In this animal model, several candidate molecules have been shown to reduce the production of antibodies to beta 2 GPI, a key step in the development of a drug to treat this disorder.

LJP 1082 Clinical Trial History

     In July 2000, we selected LJP 1082 as our clinical drug candidate for the treatment of antibody-mediated thrombosis. Based on positive pre-clinical results in mice, rats and primates, we chose this candidate for toxicology studies required for the filing of an Investigational New Drug application. In September 2000, at the 9^th International Symposium on Antiphospholipid Antibodies in Tours, France, we presented results that showed LJP 1082 reduced disease-causing antibodies and the B cells involved in antibody-mediated thrombosis in an animal model of the disease.

     In September 2001, we announced that we had filed an Investigational New Drug application with the FDA to begin a Phase 1/2 clinical trial of LJP 1082. In November 2001, we announced the initiation of the Phase 1/2 clinical trial. The objective of the study was to evaluate the safety of LJP 1082 and its ability to reduce disease-causing antibody levels in patients with antibody-mediated thrombosis. The Phase 1/2 trial was a randomized, placebo-controlled dose escalating study designed to evaluate the safety and activity of a single dose of LJP 1082 in a small group of patients. In the Phase 1/2 trial, five different groups, each consisting of four or five patients, were treated with a single intravenous dose of LJP 1082 of 1, 3, 10, 50 or 200 mg and then monitored for 30 days. One patient in each group received placebo. In order to participate in the trial, patients were required to have elevated levels of antibodies to beta 2 GPI, the target of the antibodies involved in antibody-mediated thrombosis.

     In October 2002, we announced preliminary results from the Phase 1/2 clinical trial. Based on an initial assessment of the trial data, the drug appeared to be well tolerated at the five dose levels used in the study. LJP 1082 had an elimination half-life of at least 12 hours following intravenous administration. Following treatment with a single 50 mg or 200 mg dose, antibodies to LJP 1082 appeared to be reduced in some patients. In total, 20 patients with a history of antibody-mediated thrombosis participated in the trial period.

     Standard safety assessments, including physical exams, lab values and vital signs, and immunology specific measurements were taken during the 30 days following a single dose of LJP 1082. All adverse events observed were categorized as mild to moderate and were deemed to have no or an unlikely relationship to LJP 1082. The adverse event profiles appeared similar

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between drug-treated and placebo-treated groups. There were no serious adverse events reported. We observed no significant increase in circulating immune complexes, changes in complement protein C3 or activation of patient T cells following drug treatment.

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     This study is the first of several that may be required to establish appropriate dose regimens and the observed reductions may not be large enough to affect patient health or reduce antibodies to beta 2 GPI in a majority of patients. Additional analyses are ongoing. Potential drug interference in some of the antibody assays is also being evaluated. This study was not designed to evaluate the ability of LJP 1082 to tolerize B cells that produce antibodies to beta 2 GPI and additional studies will be needed for this purpose.

SSAO Inflammation Program

     On December 2, 2003, we announced the discovery of novel, orally-active small molecules for the treatment of autoimmune diseases and acute and chronic inflammatory disorders. Our scientists have generated highly selective inhibitors of semicarbazide-sensitive amine oxidase (“SSAO”), an enzyme that has been implicated in inflammatory responses in many tissues and organs. SSAO, also know as vascular adhesion protein-1 or VAP-1, was recently discovered to be a dual-function molecule with enzymatic and adhesion activities. SSAO contributes to the adhesion of white blood cells to endothelial cells and is amplified in inflamed blood vessels. The enzyme also contributes to the production of molecules that exacerbate inflammation. Increases in the levels of plasma or membrane-associated SSAO have been reported for many inflammation-associated diseases including rheumatoid arthritis, inflammatory bowel disease, diabetes, atherosclerosis and chronic heart failure.

     Preclinical studies in animal models of multiple sclerosis, rheumatoid arthritis, stroke, systemic inflammation and acute inflammation have shown that treatment with the inhibitors both maintained function and reduced disease activity compared with placebo treatment. The impact of these lead compounds on animal models of multiple sclerosis and rheumatoid arthritis was similar to that of methotrexate, a widely used anti-inflammatory agent. WeAlthough we are currently devoting substantially all of our resources to the development of Riquent, we expect to continue to explore the potential to use inhibitors of SSAO to provide a novel approach to treating a number of debilitating diseases. These results were presented at the 2^nd International Inflammatory & Immune Diseases World Summit on March 8-10, 2004 in Baltimore, Maryland.

Other Antibody-Mediated Diseases

     We believe our Tolerance Technology may be applicable to additional diseases and conditions caused by the production of disease-causing antibodies, including xenotransplantation, myasthenia gravis and Rh hemolytic disease in newborns.

     Xenotransplantation, the use of animals as a source of donor organs for human transplantation, has become an area of significant interest due to the worldwide shortage of human organs available for transplantation. According to the American Society of Transplant Physicians, approximately 100,000 patients in the United States are currently on waiting lists for organ transplants. More than 5,000 patients die annually, many of whom are too sick to qualify for waiting lists.

     Hyper acute rejection, or the immediate destruction of the transplanted animal organ by the recipient’s antibodies, is a major barrier to xenotransplantation. Human antibodies recognize and bind to an epitope called alpha galactose found on the tissues of transplanted animal organs. This binding causes massive blood clots that block the blood supply to the transplanted organ, destroying it within minutes.

     Myasthenia gravis is a form of muscular paralysis in which neuromuscular receptors are attacked by antibodies, which can lead to a wasting of muscles, progressive loss of strength and life-threatening respiratory arrest. This disease currently affects an estimated 20,00025,000 people in the United States.

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     Rh hemolytic disease in newborns is a life-threatening fetal condition characterized by the hemolysis, or destruction, of fetal red blood cells. This condition occurs in Rh-incompatible pregnancies in which maternal antibodies to Rh cross the placenta, bind to fetal red blood cells and cause their destruction. Each year approximately 500,000 women in the United States have Rh-incompatible pregnancies. We believe that a Toleragen that binds to the appropriate maternal B cells will suppress Rh antibody production, and that once the level of antibodies to Rh(+) red blood cells is reduced, the risk of life-threatening hemolysis will be reduced.

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Collaborative Arrangements

     As part of our business strategy,In circumstances where we attempt to pursue collaborations with pharmaceutical companies in an effort to access their research, drug development, manufacturing, marketing and financial resources. In December 1996, we entered intobelieve that a collaborative relationship with Abbott for the worldwide development and commercialization of Riquent. This agreement was terminated in September 1999 following the initial analysis of the Phase 2/3 lupus trial, and all rightsis necessary or strategically beneficial to Riquent were returned to us.

     Weus, we intend to pursue collaborative arrangements with other pharmaceutical companies to assist in our research programs and the clinical development and commercialization of our drug candidates.candidates and to access their research, drug development, manufacturing, marketing and financial resources. There can be no assurance that we will be able to negotiate arrangements with any collaborative partner on acceptable terms, ifor at all. OnceIf a collaborative relationship is established, there can be no assurance that the collaborative partner will continue to fund any particular program or that it will not pursue alternative technologies or develop alternative drug candidates, either individually or in collaboration with others, including our competitors, as a means for developing treatments for the diseases we have targeted. Furthermore, competing products, either developed by a collaborative partner or to which a collaborative partner has rights, may result in the withdrawal of support by the collaborative partner with respect to all or a portion of our technology.

     Failure to establish or maintain collaborative arrangements will require us to fund our own research and development activities, resulting in significant expenditure of our own capital, and will require us to develop our own marketing capabilities for any drug candidate that may receive regulatory approval. The failure of any collaborative partner to continue funding any particular program of ours, or to commercialize successfully any product, could delay or halt the development or commercialization of any products involved in such program. As a result, the failure to establish or maintain collaborative arrangements could hurt our business, financial condition and results of operations.

Manufacturing

     We currently operate a production facility that we believe provides sufficient capacity to exceed our anticipated requirements for research, clinical trial and any initial commercial launch of Riquent. If Riquent is approved, we expect to have the capacity to manufacture approximately 100 kg of Riquent per year, which, based on our current projections, we believe would be sufficient to treat approximately 20,000 patients per year.year at a weekly dose of 100mg. If Riquent is approved, and if future demand for Riquent exceeds our current capacity, we expect to increase our manufacturing capacity by improving our manufacturing processes, making capital investments in our current facilities and/or engaging third party contract manufacturers.

     We are required to comply with the FDA’s and other regulatory agencies’ current Good Manufacturing Practices (“GMPs”cGMPs”) when we manufacture our drug candidates for clinical trials. We will also be required to comply with the GMPscGMPs if Riquent, or our other drug candidates, are manufactured for commercial purposes. We have limited manufacturing experience and the FDA has never conducted a pre-approval inspection of our manufacturing facility. Wewe can

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provide no assurance that we will pass the FDA’s pre-approval inspection or that we will be able to successfully transition to commercial production if Riquent is approved.

     In order to meet the demand for any of our drugs that may be approved or to attempt to improve our manufacturing efficiency, we may enter into arrangements with third party contract manufacturers. If we choose to contract for manufacturing services, the FDA and comparable foreign regulators will have to approve the contract manufacturers prior to our use, and these contractors would be required to comply with strictly enforced manufacturing standards. We also enter into agreements with contractors to prepare our drug candidates for use by patients. If we encounter delays or difficulties in establishing or maintaining relationships with contractors to produce, package or distribute finished products, clinical trials, market introduction and subsequent sales of such products would be adversely affected. Our dependence on others for

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production, packaging or distribution of our products may adversely affect our profit margins and our ability to develop and deliver our products on a timely and competitive basis.

     There are currently a limited number of suppliers that produce the raw materials that are necessary to make our drug candidates, including Riquent. In order to manufacture Riquent LJP 1082 and our other drug candidates in sufficient quantities for our clinical trials and possible commercialization, our suppliers will be required to provide us with an adequate supply of chemicals and reagents. If we are unable to obtain sufficient quantities of chemicals or reagents, our ability to develop and deliver products on a timely and competitive basis will be negatively affected.

Marketing and Sales

     If we obtain FDA approval in the United States, we currently anticipate that we would market Riquent ourselves using a specialty pharmaceutical sales force of 40 to 50 sales representatives initially who canwould initially target the rheumatology and nephrology specialists who treat the majority of lupus patients with renal disease. We estimate that the majority of these patients are treated at approximately 1,000 clinical centers. If we obtain approval in Europe, we currently expect to market Riquent ourselves or seek a marketing collaboration with a European partner.partner or to market Riquent ourselves. We believe that the majority of European patients are treated at around 300 major hospitals and, as is the case in the United States, that a specialty pharmaceutical sales force could successfully market Riquent to the majority of these sites.

     In order to commercialize Riquent in Europe through a partner, we would need to enter into marketing arrangements with one or more pharmaceutical or biotechnology companies. These collaborative arrangements may be exclusive or nonexclusive and may provide for marketing rights for a geographic region or for specified countries.     We currently have no arrangements with others for the marketing of any of our drug candidates. There can be no assurance that we will be able to enter into any marketing agreements on favorable terms, if at all, or that any such agreements that we may enter into will result in payments to us. Under any co-promotion or other marketing and sales arrangements that we may enter into with other companies, any revenues that we may receive will be dependent on the efforts of others and there can be no assurance that such efforts will be successful.

     To the extent that we choose to attempt to develop our own marketing and sales capability (whether domestic or international), we will compete with other companies that currently have experienced and well-funded marketing and sales operations. Furthermore, there can be no assurance that we, or any collaborative partner, will be able to establish sales and distribution capabilities without undue delays or expenditures, or gain market acceptance for any of our drug candidates. The ultimate size of the markets for our products is uncertain and difficult to estimate. Moreover, we may not earn as much income as we hope due to possible changes in healthcare reimbursement policies by governments and other third party payors.

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Patents and Proprietary Technologies

     We file patent applications in the United States and in foreign countries for the protection of our proprietary technologies and drug candidates as we deem appropriate. We currently own 101100 issued patents and have 8485 pending patent applications (including three allowed patent applications) covering various technologies and drug candidates, including our Tolerance Technology, our lupus and antibody-mediated stroke drug candidates (Toleragens), andour Tolerance Technology, our carrier platform and linkage technologies for our Toleragens. Our issued patents include:

•

Lupus Toleragens — four issued United States patents, one issued Australian patent, one granted Portuguese patent, one granted Norwegian patent, one granted European patent (which has been unbundled as 13 European national patents), two granted Canadian patents, one granted Finnish patent and one

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		granted Irish patent concerning our lupus Toleragens (expiring in 2010, 2011, 2013, 2014, 2007,2011, 2013, 2011, 2011, 2011, 2011, 2011 and 2011, respectively);
	•		Tolerance Technology — two issued United States patents, one issued Australian patent, one granted European patent (which has been unbundled as 15 European national patents), one granted Japanese patent, two granted Canadian patents, one granted South Korean patent and one granted Irish patent concerning our Tolerance Technology (expiring in 2011, 2011, 2008,2012, 2012, 2012, 2012, 2012, 2012 and 2012, respectively);
	•		Carrier Platform and Linkage Technologies for our Toleragens — seven issued United States patents, fivesix issued Australian patents, one granted European patent (which has been unbundled as 15 European national patents), three issued Japanese patents, one granted Hong Kong patent, one granted Portuguese patent, one granted South Korean patent, and one granted Irish patent concerning carrier platform and linkage technologies for our Toleragens (expiring in 2012, 2014, 2015, 2015, 2015, 2016,,2019, 2014, 2014, 2012, 2012, 2012, 2017, 2019,2012, 2012, 2012, 2012, 2012, 2014,2014 and 2012, respectively); and
	•		Antibody-Mediated Thrombosis Drug Candidates two issued United States patents and onetwo issued Australian patent concerning our antibody-mediated stroke drug candidatespatents (expiring in 2016, 2015 2016, and 2016,2019, respectively).

     We have received Notices of Allowance from the U.S. Patent and Trademark Office for one patent application for our lupus Toleragen technology, one patent application for our carrier and platform linkage technology for our Toleragens, and one patent application for our antibody-mediated stroke drug candidate technology.

Competition

     The biotechnology and pharmaceutical industries are subject to rapid technological change. Competition from domestic and foreign biotechnology companies, large pharmaceutical companies and other institutions is intense and expected to increase. A number of companies are pursuing the development of pharmaceuticals in our targeted areas. These include companies that are conducting clinical trials and pre-clinical studies for the treatment of lupus, thrombosis and other antibody-mediated diseases.

     In addition, there are a number of academic institutions, both public and private, engaged in activities relating to the research and development of therapeutics for autoimmune, inflammatory and other diseases. Most of these companies and institutions have substantially greater facilities, resources, research and development capabilities, regulatory compliance expertise, and manufacturing and marketing capabilities than we do. In addition, other technologies may in the future be the basis of competitive products. There can be no assurance that our competitors will not develop or obtain regulatory approval for products more rapidly than

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we can, or develop and market technologies and products that are more effective than those being developed by uswe are developing or that would render our technology and proposed products obsolete or noncompetitive.

     We believe that our ability to compete successfully will depend on our ability to attract and retain experienced scientists, develop patented or proprietary technologies and products, obtain regulatory approvals, manufacture and market products either alone or through third parties, and secure additional capital resources to fund anticipated net losses for at least the next several years. We expect that competition among products approved for marketing will be based in large part on product safety, efficacy, reliability, availability, price and patent position.

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Government Regulation

United States

     Our research and development activities and the future manufacturing and marketing of any products we develop are subject to significant regulation by numerous government authorities in the United States and other countries. In the United States, the Federal Food, Drug and Cosmetic Act and/orand the Public Health Service Act govern the testing, manufacture, safety, efficacy, labeling, storage, record keeping, approval, advertising and promotion of our drug candidates and any products we may develop. In addition to FDA regulations, we are subject to other federal, state and local regulations, such as the Occupational Safety and Health Act and the Environmental Protection Act, as well as regulations governing the handling, use and disposal of radioactive and other hazardous materials used in our research activities. Product development and approval within this regulatory framework takes a number of years and involves the expenditure of substantial resources. In addition, this regulatory framework is subject to changes that may adversely affect approval, delay an application or require additional expenditures.

     The steps required before a pharmaceutical compound may be marketed in the United States include: pre-clinical laboratory and animal testing; submission to the FDA of an Investigational New Drug application, which must become effective before clinical trials may commence; conducting adequate and well-controlled clinical trials to establish the safety and efficacy of the drug; submission to the FDA of an NDA or Biologic License Application (“BLA”); and FDA approval of the NDA or BLA prior to any commercial sale or shipment of the drug. In addition to obtaining FDA approval for each product, each drug-manufacturingdrug manufacturing establishment must be registered with the FDA and be operated in conformity with current Good Manufacturing Practices (“cGMPs”).cGMPs. Drug product manufacturing facilities located in California also must be licensed by the State of California in compliance with separate regulatory requirements.

     Pre-clinical testing includes laboratory evaluation of product chemistry and animal studies to assess the safety and efficacy of the product and its formulation. The results of pre-clinical testing are submitted to the FDA as part of an Investigational New Drug application and, unless the FDA objects, the Investigational New Drug application becomes effective 30 days following its receipt by the FDA.

     Clinical trials involve administration of the drug to healthy volunteers and/orand to patients diagnosed with the condition for which the drug is being tested under the supervision of a qualified clinical investigator. Clinical trials are conducted in accordance with protocols that detail the objectives of the study, the parameters to be used to monitor safety, and the efficacy criteria to be evaluated. Each protocol is submitted to the FDA as part of the Investigational New Drug application. Each clinical trial is conducted under the auspices of an independent Institutional Review Board (“IRB”) or Ethics Committee (“EC”). The IRB or EC considers, among other matters, ethical factors and the safety of human subjects.

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     Clinical trials are typically conducted in three sequential phases, but the phases may overlap. In Phase 1, the phase in which the drug is initially introduced into healthy human subjects, the drug is tested for adverse effects, dosage tolerance, metabolism, distribution, excretion and clinical pharmacology. Phase 2 trials involve the testing of a limited patient population in order to characterize the actions of the drug in targeted indications, to determine drug tolerance and optimal dosage, and to identify possible adverse side effects and safety risks. When a compound appears to be effective and to have an acceptable safety profile in Phase 2 clinical trials, Phase 3 clinical trials are undertaken to further evaluate and confirm clinical efficacy and safety within an expanded patient population at multiple clinical trial sites. The FDA

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reviews the clinical plans and monitors the results of the trials and may discontinue the trials at any time if significant safety issues arise.

     The results of pre-clinical testing and clinical trials are submitted to the FDA in the form of an NDA or BLA for marketing approval. The testing and approval process is likely to require substantial time and effort and there can be no assurance that any approval will be granted on a timely basis, if at all, or that conditions of any approval, such as warnings, contraindications, or scope of indications will not materially impact the potential profitability of the drug product. The approval process is affected by a number of factors, including the severity of the disease, the availability of alternative treatments, and the risks and benefits of the product demonstrated in clinical trials.

     Additional pre-clinical testing or clinical trials may be requested during the FDA review period and may delay any marketing approval. After FDA approval for the initial indications, further clinical trials may be necessary to gain approval for the use of the product for additional indications. The FDA mandates that adverse effects be reported to the FDA and may also require post-marketing testing to monitor for adverse effects, which can involve significant expense. Adverse effects observed during the commercial use of a drug product or which arise in the course of post-marketing testing can result in the need for labeling revisions, including additional warnings and contraindications, and, if the findings significantly alter the risk/benefit assessment, the potential withdrawal of the drug from the market or the related NDA or BLA.market.

     Among the conditions for FDA approval is the requirement that the prospective manufacturer’s quality control and manufacturing procedures conform to the FDA’s cGMP requirements. Domestic manufacturing facilities are subject to biannual FDA inspections and foreign manufacturing facilities are subject to periodic inspections by the FDA or foreign regulatory authorities. If the FDA finds that a company is not operating in substantial compliance with cGMPs, the continued availability of the product can be interrupted until compliance is achieved and, if the deficiencies are not corrected within a reasonable time-frame,time frame, the drug or the related NDA or BLA could be withdrawn.withdrawn from the market. Failure to conform to requirements relating to licensing, manufacturing, and promoting drug products can result in informal or formal sanctions, including warning letters, injunctions, seizures, civil and criminal penalties, adverse publicity, and product withdrawal.

Foreign

     We are also subject to numerous and varying foreign regulatory requirements governing the design and conduct of clinical trials and marketing approval for pharmaceutical products to be marketed outside of the United States. The approval process varies among countries and regions and can involve additional testing, and the time required to obtain approval may differ from that required to obtain FDA approval. The foreignForeign regulatory approval process includesprocesses include all of the risks associated with obtaining FDA approval, and approval by the FDA does not ensure approval by the health authorities of any other country.

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Employees

     As of March 9, 2004,February 25, 2005, we employed 128151 full-time employees (including 1715 people who have a Ph.D. and two peopleone person who havehas an M.D.), 104109 of whom are involved full-time in research, development and manufacturing activities. All of our senior management has had prior experience with pharmaceutical, biotechnology or medical product companies. We believe that we have been successful in attracting skilled and experienced personnel, but competition for personnel is intense and there can be no assurance that we will be able to attract and retain the

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individuals needed. None of our employees are covered by collective bargaining agreements and management considers relations with our employees to be good.

Executive Officers of the Registrant

     Our executive officers and key employees and their ages are set forth below.

in 2002. He was appointed Assistant Secretary in 1999. Prior to joining the Company, from 1989 to 1998, Dr. Linnik served as Senior Pharmacologist, Scientist, Research Scientist and Project Leader for Hoechst Marion Roussel, formerly Marion Merrell Dow and Marion Laboratories, a publicly held pharmaceutical company. From 1996 to 1998, he also served as Adjunct Associate Professor of Neurosurgery at the University of Cincinnati School of Medicine. From 1986 to 1988, he served as Postdoctoral Fellow, then Instructor, in the Departments of Neurology and Neurosurgery at Massachusetts General Hospital and Harvard Medical School. Dr. Linnik holds a B.A. in Physiology from Southern Illinois University and a Ph.D. in Physiology and Pharmacology from Southern Illinois University School of Medicine.

     Bruce K. Bennett, Jr., Vice President of Manufacturing, joined the Companyus in January 2002. Prior to joining the Company,us, from 2000 to 2001, Mr. Bennett was Vice President of Operations at Provasis Therapeutics, Inc., a privately held medical device company. From 1997 to 2000, he served as Vice President of Operations, Regulatory Affairs/Quality Assurance and Commercial Development at VIA Medical Corporation, a privately held medical device company. From 1995 to 1996, he was Vice President of Manufacturing at Mulay Plastic, Inc., a privately held injection molding company. From 1992 to 1995, Mr. Bennett served as Vice President of Operations at Cygnus Therapeutic Systems, Inc., a publicly held company that develops drug-delivery systems for therapeutic drugs. From 1989 to 1992, he was Vice President of Manufacturing at Progress Lighting, a privately held manufacturer of decorative lighting fixtures. From 1987 to 1989, he was Vice President of Manufacturing at Sulzer Intermedics, Inc., a publicly held medical device company. From 1986 to 1987, Mr. Bennett served as Director of Manufacturing at Kendall Respiratory Care, Inc., a medical device division of Kendall — a subsidiary of Colgate-Palmolive Company. From 1979 to 1986, he was Operations Director at Kendall McGaw Laboratories, a medical device division of Kendall, and held several other positions. Mr. Bennett holds a B.S. in Industrial Technology from California State University, Long Beach and an M.B.A. from Pepperdine University.

Josefina T. Elchico,Vice President of Quality Systems, joined us in October 2004. Prior to joining us, from 2002 to 2004, Ms. Elchico was a consultant with Jeff Yuen and Associates, a privately held consulting firm, where she worked with biopharmaceutical companies in implementing quality systems worldwide, validating facilities, processes and systems, conducting audits, preparing for pre-approval inspections and supporting regulatory submissions. From 1991 to 2002, she was Vice President, Quality Assurance for the BioPharmaceutical Division at Chiron Corporation, a publicly held company with businesses in biopharmaceuticals, vaccines and blood testing. From 1984 to 1991, Ms. Elchico advanced to Director of Quality Assurance at Cetus Corporation (now part of Chiron Corporation). From 1974 to 1984, she held various management positions at the Lancer Division of Sherwood Medical, a subsidiary of American Home Products, a publicly held manufacturer and marketer of health care and food products (now part of Wyeth). Ms. Elchico received her B.S. in Medical Technology from the University of San Agustin, Philippines and completed an internship in medical technology at St. Peter’s General Hospital in New Brunswick, New Jersey. She is a licensed Medical Technologist and a member of the Parenteral Drug Association and the American Society for Clinical Pathologists.

     Kenneth R. Heilbrunn, M.D., Vice President of Clinical Development, joined the Companyus in June 2002. Prior to joining the Company,us, from 1998 to 2002, he progressedadvanced to Vice President of Clinical Research at Advanced Tissue Sciences, Inc., a publicly held tissue engineering company, where he was responsible for a multicenter Phase 3 clinical trial which led to the FDA approval of Dermagraft®, a bioengineered human tissue. From 1997 to 1998, Dr. Heilbrunn served as Vice President of Medical Affairs at Hepatix, Inc., a privately held company engaged in the development of a bioengineered liver (extracorporeal liver assist device). From 1994 to 1996, he served as Staff Vice President of Medical Affairs at C.R. Bard, Inc., a publicly held manufacturer of healthcare products. From 1989 to 1994, he served as Medical Affairs Director for

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Cardiovascular and Pulmonary Drugs at Ciba-Geigy Pharmaceuticals Division, a manufacturer of health-care products, where he participated in the launch of the nicotine patch, Habitrol®, and the antihypertensive drug, Lotensin®. From 1986 to 1989, Dr. Heilbrunn served as Staff Internist and, ultimately, Director of the Critical Care unit at the 31st Tactical Air Force Hospital in Homestead, Florida. Dr. Heilbrunn completed his residency in internal medicine at Baystate Medical Center in Springfield, Massachusetts after receiving his M.D. from New York Medical College and his B.A. from Brown University.

     Paul C. Jenn,,Ph.D., Vice President of Product Development, joined the Companyus in 1994 as Associate Director of Production and Process Development. Dr. Jenn was promoted to

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Director of Operations in 1999, Senior Director of Operations in 2000, Vice President of Operations in 2001, and Vice President of Product Development in 2002. Prior to joining the Company, from 1992 to 1994, Dr. Jenn was Director of Peptide Manufacturing at Telios Pharmaceuticals, Inc., a publicly held pharmaceutical company, and held several other positions. From 1988 to 1992, he served as Senior Research Associate at Mallinckrodt Specialty Chemicals Company, a publicly held specialty chemical company. From 1984 to 1988, Dr. Jenn served as a Research Scientist at International Minerals and Chemical Corporation, a publicly held chemical company. From 1982 to 1984, he performed his post-doctoral research at the Lawrence Berkeley Laboratory at the University of California, Berkeley. Dr. Jenn holds a B.S. in Chemistry from Fu-Jen Catholic University, Taipei, Taiwan and a Ph.D. in Chemistry from State University of New York at Buffalo.

     Theodora Reilly, Vice President of Human Resources, joined the Companyus in 1998 as Director of Human Resources and was promoted to Vice President of Human Resources in 2001. Prior to joining the Company,us, from 1997 to 1998, Ms. Reilly was Director of Human Resources at ThermoLase Corporation, a public subsidiary of Thermo Electron Corporation, which developed laser-based systems for laser-based skin resurfacing. From 1994 to 1997, Ms. Reilly served as Director of Human Resources at Solectek Corporation, a privately held high techtechnology manufacturer of wireless interconnectivity products. Prior to 1994, Ms. Reilly receivedwas a management consultant in human resources, executive coaching, employee relations, and strategic organizational development. Ms. Reilly holds a B.S. in Psychology from the Christian Bible College and Seminary, locatedIndependence, Missouri; a B.S. in Independence, Missouri.Business Management from the University of Phoenix, Phoenix, Arizona; and a certificate in Human Resource Management from the American Electronics Association, Santa Clara, California.

     Gail A. Sloan,,CPA, Vice President of Finance Controller and Secretary, joined the Companyus in 1996 as Assistant Controller, was promoted to Controller in 1997, to Senior Director of Finance in 2002 and to Vice President of Finance in 2004. She was appointed Secretary in 1999. Prior to joining the Company,us, from 1993 to 1996, Ms. Sloan served as Assistant Controller at Affymax Research Institute, a publicly held drug-discovery research company and a part of the Glaxo Wellcome Group. From 1985 to 1993, she progressed to the position of Audit Manager with Ernst & Young LLP. Ms. Sloan holds a B.S. in Business Administration from California Polytechnic State University, San Luis Obispo and is a Certified Public Accountant.

     William J. Welch, Vice President of Sales and Marketing, joined the Companyus in 1998 as Vice President of Business Development. After leaving the Companyus in 1999, he rejoined the Companyus in 2001 as Vice President of Marketing and was promoted to his current position in 2002. Prior to rejoining the Company,us, Mr. Welch was Vice President of Global Marketing at Dade Behring, a privately held global diagnostic company. From 1993 until 1998, Mr. Welch worked for Abbott Laboratories, a publicly held global healthcare company, as General Manager of Abbott Ambulatory Infusion Systems, Senior Marketing Manager of Abbott Renal Care and as Manager of Strategic Planning, Corporate Planning and Development. From 1991 to 1993, Mr. Welch was Director of Business Development for In-Process Technology, a privately held company that manufactured processing systems for the pharmaceutical industry. From 1989 to 1991, Mr. Welch was Senior Associate for D’Accord, Inc., a global investment banking company. Mr. Welch holds a B.S. in Chemical Engineering from the University of California, Berkeley and an M.B.A. from Harvard University.

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     Andrew Wiseman,,Ph.D., Senior Director of Business Development and Investor Relations, joined the Companyus in 1989 as Director of Business Development and was one of the Company’sour original founders. Dr. Wiseman has also served as head of investor relations since 1994. From 1983 to 1989, Dr. Wiseman held several positions with Quidel Corporation, a publicly held manufacturer of diagnostic tests, including Manager of Business Development, Project Manager in Diagnostic Research and Development and Senior Research Scientist. Dr. Wiseman was an Assistant Professor at the Medical Biology Institute and an Assistant Member at the Scripps Clinic and Research Foundation. He received a B.S. in Zoology and a Ph.D. in Genetics from Duke University.

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Available Information

     Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed with or furnished to the Securities and Exchange Commission pursuant to Section 13(a) or 15(d) of the Exchange Act of 1934, as amended, are available free of charge through our website at www.ljpc.com as soon as reasonably practicable after we electronically file or furnish the reports with or to the Securities and Exchange Commission.

RISK FACTORS

I. Risk Factors Relating To La Jolla Pharmaceutical And The Industry In Which We Operate

If the continued developmentIn order to complete our ongoing clinical trial of Riquent, is significantly delayed,we will need additional funding. If we are unable to successfully complete the trial, our business and financial condition will be adversely affected and it may be difficult or impossible for us to survive.

     The data from our Phase 2/3 and Phase 3We will need to successfully complete the clinical trialstrial of Riquent indicated that treatment with Riquent did not increase length of timewe commenced in August 2004. We expect that the trial will involve approximately 500 to renal flare in the intent-to-treat population, the primary endpoint for the trials, in a statistically600 patients, cost at least $60 million, and take several years to complete. In order to complete this trial, we will require significant manner when compared with placebo. As a result, our abilityadditional funding. There is no guarantee that we will be able to obtain regulatory clearance to market Riquent either inadditional funds from the United Statessale of additional securities, from a collaborative partner, or in Europe is uncertain, and we may be required to conduct additional clinical trials to demonstrate the safety and efficacy of Riquent. The uncertainty regarding the future development of Riquent may negatively affect our ability to raise necessary additional funding in the future.otherwise. If the continued development of Riquent is significantly delayed for any reason, and if we are unable to timely raise additional funding, we maywill not have the financial resources to complete the ongoing trial or to continue the research and development of Riquent, LJP 1082, our drug candidate for the treatment of antibody-mediated thrombosis, or any other potential drug candidates, and it may be difficult or impossible for us to survive.

In order to complete our ongoing clinical trial of Riquent, we will need to enroll a sufficient number of patients who meet the trial criteria. If we are unable to successfully complete the trial, our business and financial condition will be adversely affected and it may be difficult or impossible for us to survive.

     We expect that the ongoing clinical trial of Riquent will involve approximately 500 to 600 patients, which is significantly more than were involved in our Phase 3 trial. In order to complete this trial, we will need to locate and enroll a sufficient number of patients who meet the criteria for the trial. We may have difficulty enrolling patients because, among other matters, there are specific limitations on the medications that a patient may be taking upon entry into the trial. If we are unable to timely enroll a sufficient number of patients, we will not be able to complete successfully the ongoing trial. As a result, it may be difficult or impossible for us to survive.

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If we do not obtain Subpart H approval for Riquent and we do not raise additional funds in the near future, we will need to take significant cost reducing measures.

     If the FDA does not approve Riquent under Subpart H and we do not raise additional funds in the near future, either through the sale of additional securities or a collaborative agreement with a corporate partner, we will need to take significant additional cost-cutting measures to continue our operations into the first quarter of 2006. These measures may include, among other matters, ceasing the enrollment of additional patients in, or halting, the ongoing multi-dose trial of Riquent that we initiated in August 2004, further reducing the expenses associated with our other current drug development programs, or significantly reducing our workforce. If we do not receive a final Subpart H decision from the FDA in the near term, we may elect to initiate some or all of these cost reducing efforts as early as the second quarter of 2005.

Results from our clinical trials may not be sufficient to obtain approval to market Riquent or our other drug candidates in the United States or Europe on a timely basis, or at all.

     Our drug candidates are subject to extensive government regulations related to development, clinical trials, manufacturing and commercialization. In order to sell our products that are under development, we must first receive regulatory approval. To obtain regulatory approval, we must conduct clinical trials and toxicology studies that demonstrate that our drug candidates are safe and effective. The process of obtaining FDA and other regulatory approvals is costly, time consuming, uncertain and subject to unanticipated delays. The FDA and foreign regulatory authorities have substantial discretion in the approval process and may not agree that we have demonstrated that Riquent or LJP 1082 areis safe and effective after we complete our clinical trials.effective. If Riquent or LJP 1082 areis ultimately not found to be safe and effective, we would be unable to obtain regulatory approval to manufacture, market and sell these drugs. Currently,Riquent. Although we have orphan drug designation for Riquent. Inreceived an approvable letter from the courseFDA, the analysis of the FDA’s initial reviewdata from our Phase 3 trial of our NDA, the FDA has indicatedRiquent showed that the indication for Riquent proposed in our NDA may be broader than the indication identified in our orphan drug designation. Accordingly, the FDA has indicated that we will be requiredtrial did not reach statistical significance with respect to pay the filing fee for the NDA for Riquent at thisits primary endpoint, time even though the FDA’s final approved indication, if any, may be within the original orphan drug designation.to renal flare, or with respect to its secondary endpoint, time to treatment with high-dose corticosteroids or cyclophosphamide. We intend to seek, and believe that we qualify for, a refund of the full filing fee under the FDA’s small business regulations. Whether we will be able to take advantage of the benefits afforded by the orphan drug designation will ultimately be determined by the FDA only after further review of our NDA. Although our NDA for Riquent has been accepted for review by the FDA, we can provide no assurances that the FDA will approve Riquent.

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     We may be required to design and conduct additional studies to further demonstrate the safety and efficacy of our drug candidates, which may result in significant expense and delay. The FDA and foreign regulatory authorities may require new or additional clinical trials because of inconclusive results from earlier clinical trials, including the Phase 2/3 and Phase 3 trials of Riquent, a possible failure to conduct clinical trials in complete adherence to FDA good clinical practice standards and similar standards of foreign regulatory authorities, the identification of new clinical trial endpoints, or the need for additional data regarding the safety or efficacy of our drug candidates. It is possible that the FDA or foreign regulatory authorities may not ultimately approve Riquent LJP 1082 or, our other drug candidatesif approved, what the indication for commercial sale in any jurisdiction, even if future clinical results are positive.Riquent will be.

     Because Riquent is our only drug candidate for which we have completed a Phase 3 clinical trial, and because there is no guarantee that we would be able to develop an alternate drug candidate, our inability to obtain regulatory approval of Riquent would have a severe negative effect on our business, and we may not have the financial resources to continue research and development of Riquent LJP 1082 or any other potential drug candidates.

WeOur discussions with the FDA may be unsuccessfulnot result in us obtaining accelerated approval for Riquent under the Subpart H regulation.

     Although we may pursueand the FDA are currently discussing the possibility of obtaining accelerated FDA approval for Riquent under the Subpart H, regulation, there can be no assurance that reductions in levels of antibodies to dsDNA will be deemed by the FDA to be a surrogate endpoint that is reasonably likely to predict clinical benefit, that wethe demonstrated effect of Riquent on antibody levels, or any other results from our previous clinical trials, will be able to agree withsufficient for the FDA about the design and timing of a post-marketing clinical trial,to grant approval under Subpart H, or that we will be able to successfully complete any post-marketing clinical trial. The success of any futurethe clinical trial that we may be required to conductinitiated in August 2004, whether conducted as part of a Subpart H approval process or otherwise, will depend, in part, on our ability to locate and enroll patients meeting the criteria specified for such a trial.trial and the availability of a sufficient amount of funding. We may be required to commence patient enrollment or to complete patient enrollment milestones for a post-marketingin the ongoing clinical trial prior to obtaining any regulatory approval that we may receive.under Subpart H. The enrollment process may take a

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significant amount of time and may require significant funding. Any delay in meeting patient enrollment requirements may impact our ability to obtain timely regulatory approval for Riquent, if at all. A post-marketing efficacyThe current clinical trial may involveinvolves significantly more patients than were involved in the Phase 3 trial of Riquent and maywill require significant time to complete. Even if the FDA approves Riquent under Subpart H, we believe that it will take at least nine months from the date of approval for us to build our inventory and to expand our operations in order to bring Riquent to market. In addition, if we fail to successfully complete a post-marketing clinical trial, the FDA would have the authority to remove Riquent from the market. Because Riquent is our only drug candidate for which we have completed a Phase 3 clinical trial, and because there is no guarantee that we would be able to develop an alternate drug candidate, our inability to obtain or maintain regulatory approval of Riquent would have a severe negative effect on our business, and we may not have the financial resources to continue research and development of Riquent LJP 1082 or any other potential drug candidates.

Our blood test to measure the binding affinity for Riquent has not been validated by independent laboratories and is likely to require regulatory review as part of the Riquent approval process.

     In 1998, we developed a blood test that we believe can identify the lupus patients who are most likely to respond to Riquent. The blood test is designed to measure the strength of the binding between Riquent and a patient’s antibodies. This affinity assay was used to identify, prospectively in the Phase 3 trial and retrospectively in the Phase 2/3 trial, the patients included in the efficacy analyses. Independent laboratories have not validated the assay, and the results of the

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affinity assay observed in our clinical trials of Riquent may not be observed in the broader lupus patient population. In addition, regulatory agencies will likely require that the assay be reviewed as part of the approval process of Riquent. The testing laboratory that will conduct the assay if Riquent is approved may also require additional regulatory approval. If additional regulatory approval of the testing laboratory is required, or if regulatory agencies do not concur with the use of the assay to identify potential patients for treatment with Riquent, the approval and possible commercialization of Riquent may be delayed or prevented.

If we are to obtain regulatory approval of Riquent, we must pass FDA inspection of our manufacturing facilities and processes.

     In addition to demonstrating the safety and efficacy of Riquent in clinical trials, we must also pass FDA inspection of our manufacturing facilities in order to obtain FDA approval for the commercial use of Riquent. Before we can manufacture commercial product, we must validate our manufacturing facilities and processes to the satisfaction of the FDA. We have never operated a manufacturing facility that has passed an FDA pre-approval inspection. If we are unable to pass the necessary inspections, the FDA will not approve Riquent for commercial use.

We will need additional funds to support our operations.

     Our operations to date have consumed substantial capital resources, and we mayexpect to expend substantial amounts of capital resources for additional research, product development, pre-clinical testing and clinical trials of drug candidates. We may also devote substantial additional capital resources to establish commercial-scale manufacturing capabilities and to market and sell potential products. These expenses may be incurred prior to or after any regulatory approvals that we may receive. We will need to raise additional funds to finance our future operations. Our future capital requirements will depend on many factors, including:

	•	the scope and results of pre-clinical testing and clinical trials,
	•	our ability to obtain regulatory approval for Riquent,
	•		continued scientific progress in our research and development programs,
	•		the size and complexity of our research and development programs,
	•		the scope and results of pre-clinical testing and clinical trials,
	•		the time and costs involved in applying for regulatory approvals,
	•		the costs involved in preparing, filing, prosecuting, maintaining and enforcing patent claims,
	•		competing technological and market developments,
	•		our ability to establish and maintain collaborative research and development arrangements,
	•		our need to establish commercial manufacturing capabilities, and
	•		our ability to develop effective marketing and sales programs.

     We expect to incur substantial losses each year for at least the next several years as we continue our planned clinical trial, research, clinical development manufacturing and marketingmanufacturing activities. If we ultimately receive regulatory approval for Riquent, LJP 1082 or any of our other drug candidates, our manufacturing, marketing and sales activities are likely to substantially increase our expenses and

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our need for additional working capital. We anticipate that our existing cash and cash investments, including the net proceeds of $29.5$15.8 million that we received from the recent sale of 10.0 million12,250,000 shares of our common stock in February 2005, and interest earned thereon, will be

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sufficient to fund our operations as currently planned into the secondfirst quarter of 2005, assuming2006. This projection is based on the assumption that we do not obtain Subpart H approval, that we do not raise any additional funds, either through the sale of additional securities or a collaborative agreement with a corporate partner, that we do not engage in any significant clinical trial or commercialization activities, and further assuming that we do not enter into an agreementtake one or more significant cost-reducing measures, including ceasing the enrollment of additional patients in, or halting, the ongoing multi-dose trial of Riquent that we initiated in August 2004, further reducing the expenses associated with a collaborative partner our other current drug development programs and/or engage in any other fundraising activities.significantly reducing our workforce. However, the amounts expended by uswe expend may vary significantly, and it is possible that our cash requirements will exceed current projections and that we will therefore need additional financing sooner than currently expected. In the future, it is possible that we will not have adequate resources to support continuation of our business activities.

We may need to sell stock or assets, enter into collaborative agreements, reduce our operations, or merge with another entity to continue operations.

     WeOur business is highly cash-intensive. Therefore, regardless of whether we obtain Subpart H approval for Riquent, we will need to actively seek additional funding, including through public and private financings and collaborative arrangements. Our choice of financing alternatives may vary from time to time depending on various factors, including the market price of our securities, conditions in the financial markets and the interest of other entities in strategic transactions with us. There can be no guarantee that additional financing will be available on favorable terms, if at all, whether through issuance of securities, collaborative arrangements, or otherwise. If adequate funds are not available, we may be required to delay, scale back or eliminate one or more of our research and development programs, reduce the size of our workforce, sell or license our technologies, or obtain funds through other arrangements with collaborative partners or others that require us to relinquish rights to our technologies or potential products. We also may be required to merge with another entity to continue our operations. Any one of these outcomes could have a negative impact on our ability to develop products or achieve profitability if our products are brought to market. If, and to the extent, we obtain additional funding through sales of securities, your investment in us will be diluted, and dilution can be particularly substantial when the price of our common stock is low.

Our freedom to operate our business or profit fully from sales of our products may be limited if we enter into collaborative agreements.

     We may seek to collaborate with pharmaceutical companies to gain access to their research, drug development, manufacturing, marketing, sales and financial resources. However, we may not be able to negotiate arrangements with any collaborative partners on favorable terms, if at all. Any collaborative relationships that we enter into may include restrictions on our freedom to operate our business or may limit the sales of potential products. If a collaborative arrangement is established, the collaborative partner may discontinue funding any particular program or may, either alone or with others, pursue alternative technologies or develop alternative drug candidates for the diseases we are targeting. Competing products, developed by a collaborative partner or to which a collaborative partner has rights, may result in the collaborative partner withdrawing support as to all or a portion of our technology.

     Without collaborative arrangements, we must fund our own research, development, manufacturing, marketing and sales activities, which would accelerate the depletion of our cash and require us to develop our own manufacturing, marketing and sales capabilities. Therefore, if we are unable to establish and maintain collaborative arrangements and if other sources of cash are not available, we could experience a material adverse effect on our ability to develop products and, if developed and approved, to manufacture, market and sell them successfully.

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We may be required to design and conduct additional trials.

     We may be required to design and conduct additional studies to further demonstrate the safety and efficacy of our drug candidates, which may result in significant expense and delay. The FDA and foreign regulatory authorities may require new or additional clinical trials because of inconclusive results from current or earlier clinical trials, including the Phase 2/3 and Phase 3 trials of Riquent, a possible failure to conduct clinical trials in complete adherence to FDA good clinical practice standards and similar standards of foreign regulatory authorities, the identification of new clinical trial endpoints, or the need for additional data regarding the safety or efficacy of our drug candidates. It is possible that the FDA or foreign regulatory authorities may not ultimately approve Riquent or our other drug candidates for commercial sale in any jurisdiction, even if future clinical results are positive.

Current and future clinical trials may be delayed or halted.

     Current and future clinical trials of Riquent, trials of drugs related to Riquent, or clinical trials of other drug candidates may be delayed or halted. During the development of Riquent, our Phase 2/ 3 clinical trial, in collaboration with Abbott Laboratories, was terminated before planned patient enrollment was completed. Current and future trials may be delayed or halted for various reasons, including:

	•	the lack of available funding,
	•	patients do not enroll in the studies at the rate we expect,
	•	the products are not effective,
	•	patients experience severe side effects during treatment,
	•	the trials are not conducted in accordance with applicable clinical practices, or
	•	supplies of drug product are not sufficient to treat the patients in the studies.

     If any current or future trials are delayed or halted, we may incur significant additional expenses, which could have a severe negative effect on our business.

Our blood test to measure the binding affinity for Riquent has not been validated by independent laboratories and is likely to require regulatory review as part of the Riquent approval process.

     In 1998, we developed a blood test that we believe can identify the lupus patients who are most likely to respond to Riquent. The blood test is designed to measure the strength of the binding between Riquent and a patient’s antibodies. This affinity assay was used to identify, prospectively in the Phase 3 trial and retrospectively in the Phase 2/3 trial, the patients included in the efficacy analyses. Independent laboratories have not validated the assay, and the results of the affinity assay observed in our clinical trials of Riquent may not be observed in the broader lupus patient population. Although the FDA has reviewed the blood assay as part of the approval process of Riquent, the FDA’s review of the assay will not be complete until after Riquent is approved, if ever, and we and the FDA agree upon the label for Riquent. In addition, foreign regulatory agencies may require that the assay be reviewed as part of their approval process for Riquent. Even if Riquent and the assay are approved by the FDA or foreign regulatory agencies, we may have to conduct additional studies on the assay post-approval. The testing laboratory that will conduct the assay if Riquent is approved may also require additional regulatory approval. If

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the FDA or foreign regulatory agencies do not concur with the use of the assay to identify potential patients for treatment with Riquent, or if any of them requires additional studies on the assay or additional regulatory approval of the testing laboratory, the approval and possible commercialization of Riquent may be delayed or prevented, which would have a severe negative effect on our business.

If we are to obtain regulatory approval of Riquent, we must validate our manufacturing facilities and processes.

     Although a successful pre-approval inspection was conducted by the FDA in July 2004, we have never operated a commercial manufacturing facility and we have not yet validated our manufacturing facilities or processes. If we are unable to validate our manufacturing facilities and processes to the satisfaction of the FDA, the FDA will not approve Riquent for commercial use.

We are currently devoting nearly all of our resources to the development and approval of Riquent. Accordingly, our efforts with respect to other drug candidates have significantly diminished.

     For fiscal year 2005, we have currently budgeted a very limited amount of funds for our continued development of LJP 1082, our drug candidate for the treatment of antibody-mediated thrombosis. In addition, we have budgeted only a limited amount of funds for the development of small molecules for the treatment of autoimmune diseases and acute and chronic inflammatory disorders. As a result, significant progress with respect to drug candidates other than Riquent, if any, will be significantly delayed and our success and ability to survive depends on whether we obtain FDA approval to market Riquent.

We may not be able to take advantage of the orphan drug designation for Riquent.

     In September 2000, the FDA granted us orphan drug designation for Riquent for the treatment of lupus nephritis. The Orphan Drug Act potentially enables us to obtain research funding, tax credits for certain research expenses and a waiver of the application user fees. In addition, the Orphan Drug Act allows for seven years of exclusive marketing rights to a specific drug for a specific orphan indication. Exclusivity is conferred upon receipt of marketing approval from the FDA. The marketing exclusivity prevents FDA approval during the seven year period of the “same” drug from another company for the same orphan indication. Two drugs with substantially similar characteristics are considered to be the same, and exclusivity granted to one drug will block approval of the subsequent drug for the same indication. However, one may overcome the exclusivity designation by demonstrating that, despite the similarity of the drugs, a subsequent drug is clinically superior in terms of increased effectiveness and adequate safety, increased safety and adequate effectiveness or represents a major contribution to patient care, and therefore is not barred by the exclusivity. In the course of the FDA’s initial review of our NDA, the FDA indicated that the indication for Riquent proposed in our NDA may be broader than the indication identified in our orphan drug designation. Accordingly, we were required to pay the filing fee for the NDA for Riquent. However, we subsequently received a refund of the full filing fee under the FDA’s small business regulations. Whether we will be able to take advantage of the benefits afforded by the orphan drug designation will ultimately be determined by the FDA only after further review of our NDA.

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Our limited manufacturing capabilities and experience could result in shortages of products for clinical studies and future sale, and our revenues and profit margin could be negatively affected.

     SubstantialWe have never operated a commercial manufacturing facility and we will be required to manufacture Riquent pursuant to applicable FDA good manufacturing practices. Our inexperience could result in manufacturing delays or interruptions and higher manufacturing costs. This could negatively affect our ability to produce products for clinical studies and, therefore, to introduce products into the market on a timely and competitive basis. The subsequent sales of our products, if any, and our profit margins may also be negatively affected. In addition, substantial capital investment in the expansion and build-out of our manufacturing facilities will be required to enable us to manufacture Riquent, if approved, in significant commercial quantities. We have limited manufacturing experience, and we may be unable to successfully transition to commercial production. In addition, we have never operated a manufacturing facility that has passed an FDA pre-approval inspection, and we will be required to manufacture Riquent pursuant to applicable FDA good manufacturing practices. Our inexperience could result in manufacturing delays or interruptions and higher manufacturing costs. This could negatively affect our ability to introduce products into the market on a timely and competitive basis and the subsequent sales of our products and our profit margins may be negatively affected.

     We may enter into arrangements with contract manufacturing companies to expand our own production capacity in order to meet demand for our products or to attempt to improve manufacturing efficiency. If we choose to contract for manufacturing services, the FDA and comparable foreign regulators would have to approve the contract manufacturers prior to our use, and these contractors would be required to comply with strictly enforced manufacturing standards. We also enter into agreements with contractors to prepare our drug candidates for use by patients. If we encounter delays or difficulties in establishing or maintaining relationships with contractors to produce, package or distribute our finished products, if they are unable to meet our needs, if they are not approved by the regulatory authorities, or if they fail to adhere to applicable manufacturing standards, the introduction of our products into the market and the subsequent

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sales of these products would be negatively affected, and our profit margins and our ability to develop and deliver products on a timely and competitive basis may be negatively affected.

Our suppliers may not be able to provide us with sufficient quantities of materials that we may need to manufacture our products.

     We rely on outside suppliers to provide us with specialized chemicals and reagents that we use to manufacture our drugs. In order to manufacture Riquent LJP 1082 and our other drug candidates in sufficient quantities for our clinical trials and possible commercialization, our suppliers will be required to provide us with an adequate supply of chemicals and reagents. Our ability to obtain these chemicals and reagents is subject to the following risks:

	•		our suppliers may not be able to increase their own manufacturing capabilities in order to provide us with a sufficient amount of material for our use,
	•		some of our suppliers may be required to pass FDA inspectioninspections or validations or to obtain other regulatory approvals of their manufacturing facilities or processes, and they may be delayed or unable to do so,
	•		the materials that our suppliers use to manufacture the chemicals and reagents that they provide us may be costly or in short supply, and
	•		there may beare a limited number of suppliers that are able to provide us with the chemicals or reagents that we use to manufacture our drugs.

     If we are unable to obtain sufficient quantities of chemicals or reagents, the introduction of anyour ability to produce products for clinical studies and, therefore, to introduce products into the market on a

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timely and thecompetitive basis, will be impeded. The subsequent sales of anyour products, would be negatively affected,if any, and our profit margins and our ability to develop and deliver products on a timely and competitive basis may also be negatively affected.

An interruption in the operation of our sole manufacturing facility could disrupt our operations.

     We have only one drug manufacturing facility. A significant interruption in the operation of this facility, whether as a result of a natural disaster or other causes, could significantly impair our ability to manufacture drugs for our clinical trials or possible commercialization.

Even if we receive regulatory approval for our product candidates, we will be subject to ongoing regulatory obligations and review.

     Following any regulatory approval of our product candidates, we will be subject to continuing regulatory obligations such as safety reporting requirements and additional post-marketing obligations, including regulatory oversight of the promotion and marketing of our products. In addition, we and any third-party manufacturers will be required to adhere to regulations setting forth current good manufacturing practices. These regulations cover all aspects of the manufacturing, testing, quality control and record keeping relating to our product candidates. Furthermore, we and any third-party manufacturers will be subject to periodic inspection by regulatory authorities. These inspections may result in compliance issues that would require the expenditure of financial or other resources to address. If we or any third-party manufacturers that we may engage fail to comply with applicable regulatory requirements, we may be subject to fines, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

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The size of the market for our potential products is uncertain.

     We estimate that the number of people who suffer from lupus in the United States and Europe is approximatelypotentially more than 1,000,000 and that those with renal impairment, which Riquent is designed to treat, is approximately 300,000. With respect to antibody-mediated thrombosis, which LJP 1082 is designed to treat, we estimate that there are approximately 1,000,000 to 2,000,000 patients in the United States and Europe. For example, within the estimated antibody-mediated thrombosis patient population, we believe that antiphospholipid antibodies contributed to approximately 10% of the approximate 4,000,000 strokes in the United States in 2002. However, there is limited information available regarding the actual size of these patient populations. In addition, it is uncertain whether the results from previous or future clinical trials of our drug candidates will be observed in broader patient populations, and the number of patients who may benefit from our drug candidates may be significantly smaller than the estimated patient populations. Furthermore, management of patients with renal disease by specialists other than nephrologists and immunologists is likely to reduce our ability to access patients who may benefit from Riquent.

Any regulatory approvals that we may obtain for our product candidates may be limited and subsequent issues regarding safety or efficacy could cause us to remove products from the market.

     If the FDA or foreign regulatory authorities grant approval of any of our drug candidates, the approval may be limited to specific conditions or patient populations, or limited with respect to its distribution, including to specified facilities or physicians with special training or experience. The imposition of any of these restrictions or other restrictions on the marketing and use of Riquent could adversely affect any future sales of Riquent. Furthermore, even if a drug candidate is approved, it is possible that a subsequent issue regarding its safety or efficacy would require us to remove the drug from the market.

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Our drugs may not achieve market acceptance.

     Even if Riquent or our other drug candidates receive regulatory approval, patients and physicians may not readily accept our proposed methods of treatment. In order for Riquent or our other drug candidates to be commercially successful, we will need to increase the awareness and acceptance of our drug candidates among physicians, patients and the medical community. Riquent is designed to be administered weekly by intravenous injection. It is possible that providers and patients may resist an intravenously administered therapeutic. It is also possible that physician treatment practices may change and that the use of other drugs, either newly approved or currently on the market for other conditions, may become widely utilized by clinicians for the treatment of patients with lupus and reduce the potential use of Riquent in this patient population. In addition, if we are unable to manufacture drugs at an acceptable cost, physicians may not readily prescribe drugs that we may manufacture due to cost-benefit considerations when compared to other methods of treatment. If we are unable to achieve market acceptance for approved products, our revenues and potential for profitability will be negatively affected.

We lack experience in marketing products for commercial sale.

     In order to commercialize any drug candidate approved by the FDA, we must either develop marketing and sales programs or enter into marketing arrangements with others. If we cannot do either of these successfully, we will not generate meaningful sales of any products that may be approved. If we develop our own marketing and sales capabilities, we will be required to employ a sales force, establish and staff a customer service department, and create or identify distribution channels for our drugs. We will compete with other companies that have experienced and well-funded marketing and sales operations. In addition, if we establish our own sales and distribution

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capabilities, we may experience delays and expenditures and have difficulty in gaining market acceptance offor our drug candidates. We currently have no marketing arrangements with others. There can be no guarantee that, if we desire to, we will be able to enter into any marketing agreements on favorable terms, if at all, or that any such agreements will result in payments to us. If we enter into co-promotion or other marketing and sales arrangements with other companies, any revenues that we may receive will be dependent on the efforts of others. There can be no guarantee that these efforts will be successful.

We may not earn as much income as we hope due to possible changes in healthcare reimbursement policies.

     The continuing efforts of government and healthcare insurance companies to reduce the costs of healthcare may reduce the amount of income that we can generate from sales of future products.products, if any. For example, in certain foreign markets, pricing and profitability of prescription drugs are subject to government control. In the United States, we expect that there will continue to be a number of federal and state proposals to implement similar government controls. In addition, an increasing emphasis on managed care in the United States will continue to put pressure on drug manufacturers to reduce prices. Price control initiatives could reduce the revenue that we receive for any products we may develop and sell in the future.

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We have a history of losses and may not become profitable.

     We have incurred operating losses each year since our inception in 1989 and had an accumulated deficit of approximately $192.4$232.9 million as of December 31, 2003.2004. We expect to incur substantial losses each year for at least the next several years as we seek regulatory approval, conduct additional clinical trials of our drug candidates, seek regulatory approval, and continue our research, clinical development, and manufacturing and marketing activities. In addition, assuming we ultimately receive favorable clinical results and FDA approval for Riquent LJP 1082 or our other drug candidates, we will be required to develop commercial manufacturing capabilities and salesmarketing and marketingsales programs which may result in substantial additional losses. To achieve profitability we must, among other matters, complete the development of our products, obtain all necessary regulatory approvals and establish commercial manufacturing, marketing and sales capabilities. The amount of losses and the time required by us to reach sustained profitability are highly uncertain and we may never achieve profitability. We do not expect to generate revenues from the sale of Riquent, if approved, or our other products, if any, in the near term, and we may never generate product revenues.

Our success in developing and marketing our drug candidates depends significantly on our ability to obtain patent protection for Riquent LJP 1082 and any other developed products. In addition, we will need to successfully preserve our trade secrets and operate without infringing on the rights of others.

     We depend on patents and other unpatented intellectual property to prevent others from improperly benefiting from products or technologies that we may have developed. As of December 31, 2003,2004, we owned 101100 issued patents and 8485 pending patent applications, covering various technologies and drug candidates including Riquent and LJP 1082.Riquent. There can be no assurance, however, that any additional patents will be issued, that the scope of any patent protection will be sufficient to protect us or our technology, or that any current or future issued patent will be held valid if subsequently challenged. There is a substantial backlog of biotechnology patent applications at the United States Patent and Trademark Office that may delay the review and issuance of any patents. The patent position of biotechnology firms like ours is highly uncertain and involves complex legal and factual questions, and no consistent policy has emerged regarding the breadth of claims covered in biotechnology patents or the protection afforded by these patents. Currently, we have a number of patent applications pending in the United States relating

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to our technology, as well as foreign counterparts to some of our United States patent applications. We intend to continue to file applications as we believebelieved appropriate for patents covering both our products and processes. There can be no assurance that patents will be issued from any of these applications, or that the scope of any issued patents will protect our technology.

     We do not necessarily know if others, including competitors, have patents or patent applications pending that relate to compounds or processes that overlap or compete with our intellectual property.property or which may affect our freedom to operate. We are aware of one familycertain families of United States patents and patent applications that containscontain claims covering subject matter that may conflict with some of our key patents and patent applications, and any such conflict may affect our ability to develop, manufacture and sell our products in the future. We have conducted investigations into the patent families to determine what impact, if any, the patent families could have on our continued development, manufacture and, if approved by the FDA, sale of our drug candidates, including Riquent. Based on our investigations to date, we currently do not believe that these patent families are likely to impede the advancement of our drug candidates, including Riquent. However, there can be no assurance that upon our further investigation, these patent families or other patents will not ultimately be found to impact the advancement of our drug candidates, including Riquent. If the United States Patent and Trademark Office or any foreign counterpart issues or has issued patents containing competitive or conflicting claims, and if these claims are valid, the protection provided by our existing patents or any future patents that may be issued could be significantly reduced, and our ability to prevent competitors from developing

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products or technologies identical or similar to ours could be negatively affected. In addition, there can be no guarantee that we would be able to obtain licenses to these patents on commercially reasonable terms, if at all, or that we would be able to develop or obtain alternative technology. Our failure to obtain a license to a technology or process that may be required to develop or commercialize one or more of our drug candidates may have a material adverse effect on our business. In addition, we may have to incur significant expenses and management time in defending or enforcing our patents.

     We also rely on unpatented intellectual property such as trade secrets and improvements, know-how, and continuing technological innovation. While we seek to protect these rights, it is possible that:

	•		others, including competitors, will develop inventions relevant to our business,
	•		our confidentiality agreements will be breached, and we willmay not have, or be successful in obtaining, adequate remedies for such a breach, or
	•		our trade secrets will otherwise become known or be independently discovered by competitors.

     We could incur substantial costs in defending suits that others might bring against us for infringement of intellectual property rights or in prosecuting suits that we might bring against others to protect our intellectual property rights.

The technology underlying our products is uncertain and unproven.

     All of our product development efforts are based on unproven technologies and therapeutic approaches that have not been widely tested or used. To date, no products that use our technology have been commercialized. Riquent and LJP 1082The FDA has not determined that we have not been proven Riquent to be safe and effective in humans, and the technology on which they areit is based has been used only in our pre-clinical tests and clinical trials. Application of our technology to antibody-mediated diseases other than lupus and antibody-mediated thrombosis is in earlier research stages. Clinical trials of Riquent and LJP 1082 may be viewed as a test of our entire approach to developing therapies for antibody-mediated diseases. If Riquent or LJP 1082 does not work as intended, or if the data from our clinical trials indicates that Riquent or LJP 1082 is not safe and effective, the applicability of our technology for successfully treating antibody-mediated diseases will be highly uncertain. As a result, there is a significant risk that our therapeutic approaches will not prove to be successful, and there can be no guarantee that our drug discovery technologies will result in any commercially successful products.

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Future clinical trials may be delayed or halted.

     Future clinical trials of Riquent or LJP 1082, trials of drugs related to these drugs, or clinical trials of other drug candidates may be delayed or halted. During the development of Riquent, our Phase 2/3 clinical study, in collaboration with Abbott Laboratories, was terminated before planned patient enrollment was completed. Future trials may be delayed or halted for various reasons, including:

	•		the products are not effective,
	•		patients experience severe side effects during treatment,
	•		the trials are not conducted in accordance with applicable clinical practices,
	•		patients do not enroll in the studies at the rate we expect, or
	•		supplies of drug product are not sufficient to treat the patients in the studies.

If any future trials are delayed or halted, we may incur significant additional expenses, which could have a severe negative effect on our business.

Our research and development and operations depend in part on key employees. Losing these employees would have a negative effect on our product development and operations.

     We are highly dependent on the principal members of our scientific and management staff, the loss of whose services would delay the achievement of our research and development objectives. This is because our key personnel, including Steven Engle, Dr. Matthew Linnik, Dr. Paul Jenn and Dr. Andrew Wiseman, have been involved in the development of Riquent LJP 1082 and other drug candidates for several years and have unique knowledge of our drug candidates and of the technology on which they are based. In addition, we will be required to rely on other key members of our senior management team, including Bruce Bennett, Dr. Kenneth Heilbrunn, Bruce Bennett, Josefina Elchico and William Welch, to assist us with growth and expansion into areas requiring additional expertise, such as clinical trials, regulatory approvals, manufacturing, marketing and sales. We expect that we will continue to require additional management personnel, and that our existing management personnel will be required to develop additional expertise.

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Retaining our current personnel and recruiting additional personnel will be critical to our success.

     Retaining our current key personnel and recruiting additional qualified personnel to perform research and development, clinical development, manufacturing, marketing and sales will be critical to our success. Because competition for experienced scientific, clinical, manufacturing, marketing and sales personnel among numerous pharmaceutical and biotechnology companies and research and academic institutions is intense, we may not be able to attract and retain these people. If we cannot attract and retain qualified people, our ability to conduct necessary clinical trials and to develop and sell ourpotential products may be negatively affected because, for instance, the trials may not be conducted properly, or the manufacturing or sales of our products may be delayed. In addition, we rely on consultants and advisors to assist us in formulating our research and development, clinical, regulatory, manufacturing, marketing and sales strategies. All of our consultants and advisors have outside employment and may have commitments or consulting or advisory contracts with other entities that may limit their ability to contribute to our business.

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Our freedom to operate our business or profit fully from sales of our products may be limited if we enter into collaborative agreements.

     We may seek to collaborate with pharmaceutical companies to gain access to their research, drug development, manufacturing, marketing, sales and financial resources. However, we may not be able to negotiate arrangements with any collaborative partners on favorable terms, if at all. Any collaborative relationships that we enter into may include restrictions on our freedom to operate our business or may limit the sales of our products. If a collaborative arrangement is established, the collaborative partner may discontinue funding any particular program or may, either alone or with others, pursue alternative technologies or develop alternative drug candidates for the diseases we are targeting. Competing products, developed by a collaborative partner or to which a collaborative partner has rights, may result in the collaborative partner withdrawing support as to all or a portion of our technology.

     Without collaborative arrangements, we must fund our own research, development, manufacturing, marketing and sales activities, which would accelerate the depletion of our cash and require us to develop our own manufacturing, marketing and sales capabilities. Therefore, if we are unable to establish and maintain collaborative arrangements and if other sources of cash are not available, we would experience a material adverse effect on our ability to develop products and, if developed and approved, to manufacture, market and sell them successfully.

Because a number of companies compete with us, many of which have greater resources than we do, and because we face rapid changes in technology in our industry, we cannot be certain that our products will be accepted in the marketplace or capture market share.

     Competition from domestic and foreign biotechnology companies, large pharmaceutical companies and other institutions is intense and is expected to increase. A number of companies and institutions are pursuing the development of pharmaceuticals in our targeted areas, many of which are very large, and have financial, technical, sales and distribution and other resources substantially greater than ours. The greater resources of these competitors could enable them to develop competing products more quickly than we are able to, and to market any competing product more quickly or effectively so as to make it extremely difficult for us to develop a share of the market for our products. These competitors also include companies that are conducting clinical trials and pre-clinical studies for the treatment of lupus and thrombosis.lupus. Our competitors may develop or obtain regulatory approval for products more rapidly than we do. If, before the FDA approves Riquent, if ever, the FDA were to approve a drug other than Riquent for the same indication that Riquent is designed to treat, and such drug therefore received marketing exclusivity under the Orphan Drug Act, the FDA may be prevented from approving Riquent. Also, the biotechnology and pharmaceutical industries are subject to rapid changes in technology. Our competitors may develop and market technologies and products that are more effective or less costly than those being developed by us, or that would render our technology and proposed products obsolete or noncompetitive.

The use of Riquent LJP 1082 andor other potential products in clinical trials, as well as the sale of any approved products, may expose us to lawsuits resulting from the use of these products.

     The use and possible sale of Riquent LJP 1082 andor other potential products may expose us to legal liability and generate negative publicity if we are subject to claims that our products harmed people. These claims might be made directly by patients, pharmaceutical companies, or others. We currently maintain $10.0 million of product liability insurance for claims arising from the use of our products in clinical trials. However, product liability insurance is becoming increasingly expensive, and thereexpensive. In addition, in the event of any commercialization of any of our products, we will likely need to obtain additional insurance, which will increase our insurance expenses. There can be no guarantee that we will be able to maintain insurance or that insurance can be acquired at a reasonable cost, in sufficient amounts, or with broad enough coverage to protect us against possible losses. Furthermore, it is possible that our financial resources would be insufficient to

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satisfy potential product liability or other claims. A successful

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product liability claim or series of claims brought against us could negatively impact our business reputation and financial condition.

We face environmental liabilities related to certain hazardous materials used in our operations.

     Due to the nature of our manufacturing processes, we are subject to stringent federal, state and local laws governing the use, handling and disposal of certain materials and wastes. We may have to incur significant costs to comply with environmental regulations if and when our manufacturing increases to commercial volumes. Current or future environmental laws may significantly affect our operations because, for instance, our production process may be required to be altered, thereby increasing our production costs. In our research and manufacturing activities, we use radioactive and other materials that could be hazardous to human health, safety or the environment. These materials and various wastes resulting from their use are stored at our facility pending ultimate use and disposal. The risk of accidental injury or contamination from these materials cannot be eliminated. In the event of such an accident, we could be held liable for any resulting damages, and any such liability could exceed our resources. Although we maintain general liability insurance, we do not specifically insure against environmental liabilities.

II. Risk Factors Related Specifically To Our Stock

Our common stock price is volatile and may decline even if our business is doing well.

     The market price of our common stock has been and is likely to continue to be highly volatile. Recent corporate events have caused our stock price to be particularly volatile. Market prices for securities of biotechnology and pharmaceutical companies, including ours, have historically been highly volatile, and the market has from time to time experienced significant price and volume fluctuations that are unrelated to the operating performance of particular companies. The following factors, among others, can have a significant effect on the market price of our securities:

	•		actions or decisions by the FDA and other comparable agencies,
	•		our clinical trial results,
	•		announcements of technological innovations or new therapeutic products by us or others,
	•		developments in patent or other proprietary rights,
	•		public concern as to the safety of drugs discovered or developed by us or others,
	•		future sales of significant amounts of our common stock by existingus or our stockholders,
	•		developments concerning potential agreements with collaborators,
	•		comments by securities analysts and general market conditions, and
	•		government regulation.regulation, including any legislation that may impact the price of any commercial products that we may seek to sell.

The realization of any of the risks described in these “Risk Factors” could have a negative effect on the market price of our common stock.

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In the future, our stock may be removed from listing on the Nasdaq quotation system and may not qualify for listing on any stock exchange, in which case it may be difficult to find a market in our stock.

     If our stock is no longer traded on a national trading market, it may be more difficult for you to sell shares that you own, and the price of the stock may be negatively affected. Currently, our securities are traded on the Nasdaq National Market. Nasdaq has several continued listing requirements, including a minimum-trading price. Previously, we have received notice from Nasdaq that our stock price fell below this minimum trading price.price which is subject to change from time to time. Although we have since come back into compliance with this Nasdaq requirement, it is possible that we will fall out of compliance with this and/or other Nasdaq continued listing criteria at some point in the future. Failure to comply with any one of several Nasdaq requirements may cause our stock to be removed from listing on Nasdaq. Should this happen, we may not be able to secure listing on other exchanges or quotation systems. This would have a negative effect on the price and liquidity of our stock.

Future sales of our stock by existingour stockholders could negatively affect the market price of our stock and make it more difficult for us to sell stock in the future.stock.

     Sales of our common stock in the public market, or the perception that such sales could occur, could result in a drop in the market price of our securities and make it more difficult for us to complete future equity financings on acceptable terms, if at all.securities. As of December 31, 2003,February 16, 2005, there were:

	•		Approximately 51,052,18573,686,547 shares of common stock that have been issued in registered offerings or were otherwise freely tradable in the public markets.
	•		Approximately 72,34872,303 shares of common stock eligible for resale in the public market pursuant to SEC Rule 144.
	•		7,476,6458,904,328 shares of common stock that may be issued on the exercise of outstanding stock options granted under our various stock option plans at a weighted average exercise price of $4.79$4.43 per share.
	•		Approximately 9,200,000876,266 shares of common stock reserved for future issuance pursuant to awards granted under our equity incentive stock option and employee stock purchase plans, which shares are covered by effective registration statements under the Securities Act of 1933, as amended (the “Securities Act”).
	•		Pursuant to a registration statement on Form S-3 filed on December 10, 2002, we registered an aggregate amount of $125,000,000 of our common stock for issuance from time to time. As of December 31, 2003,February 16, 2005, there was $102,587,500$53,937,500 of our common stock available for future issuance. After giving effect to the recent sale of 10.0 million shares of our common stock, there is an aggregate amount of $71,087,500 of our common stock available for future issuance pursuant to the registration statement.

     We cannot estimate the number of shares of common stock that may actually be resold in the public market because this will depend on the market price for our common stock, the individual circumstances of the sellers and other factors. We also have a number of institutional stockholders that own significant blocks of our common stock. If these stockholders sell significant portions of their holdings in a relatively short time, for liquidity or other reasons, the market price of our common stock could drop significantly.

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Failure to achieve and maintain effective internal controls in accordance with Section 404 of the Sarbanes-Oxley Act could have a material adverse effect on our business and stock price.

     Section 404 of the Sarbanes-Oxley Act requires us to evaluate annually the effectiveness of our internal controls over financial reporting as of the end of each fiscal year beginning in 2004 and to include a management report assessing the effectiveness of our internal controls over financial reporting in all annual reports beginning with this annual report on Form 10-K for the fiscal year ended December 31, 2004. Section 404 also requires our independent registered public accounting firm to attest to, and report on, management’s assessment of our internal controls over financial reporting. We have evaluated our internal controls over financial reporting as of December 31, 2004 in order to comply with Section 404 and have concluded that our disclosure controls and procedures are effective. In addition, our independent registered public accounting firm has reported on our assertion with respect the effectiveness of our internal controls over financial reporting as of December 31, 2004. However, if we fail to maintain the adequacy of our internal controls, as such standards are modified, supplemented or amended from time to time, we cannot assure you that we will be able to conclude in the future that we have effective internal controls over financial reporting in accordance with Section 404. If we fail to achieve and maintain a system of effective internal controls, it could have a material adverse effect on our business and stock price.

Anti-takeover devices may prevent changes in our management.

     We have in place several anti-takeover devices, including a stockholder rights plan, which may have the effect of delaying or preventing changes in our management or deterring third parties from seeking to acquire significant positions in our common stock. For example, one anti-takeover device provides for a board of directors that is separated into three classes, with their terms in office staggered over three year periods. This has the effect of delaying a change in control of our board of directors without the cooperation of the incumbent board. In addition, our bylaws require stockholders to give us written notice of any proposal or director nomination within a specified period of time prior to the annual stockholder meeting, establish certain qualifications for a person to be elected or appointed to the board of directors during the pendency of certain business combination transactions, and do not allow stockholders to call a special meeting of stockholders.

     We may also issue shares of preferred stock without further stockholder approval and upon terms that our board of directors may determine in the future. The issuance of preferred stock could have the effect of making it more difficult for a third party to acquire a majority of our outstanding stock, and the holders of such preferred stock could have voting, dividend, liquidation and other rights superior to those of holders of our common stock.

We do not pay dividends and this may negatively affect the price of our stock.

     We have not paid any cash dividends since our inception and do not anticipate paying any cash dividends in the foreseeable future. The future price of our common stock may be negatively affected by the fact that we have not paid dividends.

Item 2. Properties.

     We lease two adjacent buildings in San Diego, California covering a total of approximately 54,000 square feet. One building contains our research and development laboratories and clinical manufacturing facilities and the other contains our corporate offices and warehouse. Both building leases expire in July 2004.2009. Each lease includes an option to extend the term of the lease for an additional five years and each is subject to an escalation clause that provides for annual rent increases. We have exercised our option to extend the lease for an additional five years on the corporate offices and warehouse lease and anticipate that we will exercise the option to extend on the other lease as well. We also lease approximately 1,500 square feet of

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laboratory space in San Diego, California for research and development purposes. This lease, which was extended in August 2003,February 2005, expires in May 2004. We anticipate that we will extend the lease term through the end of 2004.November 2005. We believe that these facilities will be adequate to meet our needs for the near term. Over the longer term, management believes that additional space can be secured at commercially reasonable rates.

Item 3. Legal Proceedings.

     We are not currently a party to any legal proceedings.

Item 4. Submission of Matters to a Vote of Security Holders.

     No matters were submitted to a vote of security holders during the three-month period ended December 31, 2003.2004.

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PART II

Item 5. Market For Registrant’s Common Equity and Related Stockholder Matters.

Information About Our Common Stock

     Our common stock trades on the Nasdaq National Market under the symbol “LJPC.” Set forth below are the high and low sales prices for our common stock for each full quarterly period within the two most recent fiscal years.

     We have never paid dividends on our common stock and we do not anticipate paying dividends in the foreseeable future. The number of record holders of our common stock as of March 10, 2004February 25, 2005 was approximately 337.356.

Information About Our Equity Compensation Plans

     Information regarding the securities authorized for issuance under our equity compensation plans required by Item 5 is incorporated by reference from our definitive proxy statement for the 20042005 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission no later than 120 days after the end of the fiscal year ended December 31, 2003.2004.

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Item 6. Selected Financial Data.

     The following Selected Financial Data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in Item 7 belowbeginning at page 46 and the consolidated financial statements of the Company and related notes thereto beginning at page F-1F-2 of this report.

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Quarterly Results of Operations

     The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 20032004 and 20022003 (in thousands except per share data):

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

Recent Developments in 2004 to Date

     On February 18, 2003,16, 2004, we announced initial results fromthat our Phase 3 clinical trial ofNew Drug Application (“NDA”) for RiquentÒ (abetimus sodium), our clinical drug candidate for the treatment of lupus renal disease. Althoughdisease, had been accepted for review by the trial did not reach statistical significance for its primary endpoint, time to renal flare,United States Food and Drug Administration (the “FDA”). Our NDA submission was prepared on our understanding that the Phase 3FDA could potentially approve Riquent on the basis of our clinical trial results demonstrated that lupus patients treated with Riquent had significantly lower levels of antibodies to dsDNA than patients treated with a placebo. Data fromor under the Phase 3 and Phase 2/3 studies demonstrated that lupus patients with sustained reductions in antibodies to dsDNA experienced fewer renal flares. In these two studies, two and four times as many Riquent-treated patients had sustained reductions compared with placebo-treated patients.

     On May 5, 2003, we announced that, based on our discussions with the FDA, we planned to complete an NDA for Riquent around the end of 2003.

     In addition to closing our Riquent-related clinical trials, in May 2003 we reduced the size of our organization by 24 positions, including certain management positions. We began to realize the cost savings from these actions in the third quarter of 2003.

     On June 16, 2003, we announced the HRQOL results from our Phase 3 clinical trial of Riquent. Patients in our Phase 3 trial with sustained reductions in antibodies to dsDNA reported improved HRQOL and had a lower risk of Major SLE flare compared with patients who did not have sustained reductions. A Major SLE flare was defined as the occurrence of any one of the following events due to the manifestation of active SLE: treatment with HDCC or initiation or increase in treatment with other identified immunosuppressive agents; hospitalization; or death. Similar results were also seen in our Phase 2/3 trial. We believe that these results support the pathogenicity or disease-causing ability of antibodies to dsDNA in lupus patients.

     On July 24, 2003, we announced that, based on recent discussions with the FDA, we may pursue an accelerated approval for Riquent under theregulation known as Subpart H regulation.H. Under Subpart H, drugs in development for serious, life-threatening diseases with an unmet medical need can be approved on an accelerated basis if the FDA determines that the effect of the drug on a surrogate endpoint is reasonably likely to predict clinical benefit and that a post-marketing clinical trial can be successfully completed following drug approval which confirms the clinical benefit. As previously announced, in our Phase 3 and Phase 2/3 trials, patients treated with Riquent had significantly reduced levels of antibodies to dsDNAdouble-stranded DNA (“dsDNA”) compared with patients treated with placebo.

     On August 2, 2004, we announced that we had reached a written agreement with the Cardio-Renal Division of the FDA under a special protocol assessment concerning a trial that is designed to meet the requirements of a post-marketing clinical benefit trial which would have to be conducted if Riquent were to be approved under Subpart H and that we had initiated the trial. The special protocol assessment process is a formal procedure that results in a written agreement between a company and the FDA that documents the design and planned analysis of a study used in support of a regulatory submission. Agreements reached under the special protocol assessment process are generally binding except in circumstances where public health concerns are raised or when there are significant changes in medical science or practice.

     Based on the data that we submitted in our NDA, we expected that the FDA would notify us in mid-October of its decision regarding the approvability of Riquent. On October 14, 2004, we announced that we had received a letter from the FDA indicating that Riquent is approvable, but that an additional, randomized, double-blind study demonstrating the clinical benefit of Riquent would need to be completed prior to approval. The FDA letter indicated that the successful completion of the clinical trial that we initiated in August 2004 would appear to satisfy this requirement.

     On November 23, 2004, we provided an update on our clinical and regulatory activities concerning Riquent. We announced that the clinical trial that we initiated in August 2004 was evaluating doses of 100 mg and 300 mg of Riquent over a 12-month period in lupus patients with a history of renal disease. We are currently recruiting patients in 37 of approximately 60 planned clinical trial sites in the United States. We also announced that we were conducting an additional study to evaluate higher doses of Riquent for use in the multi-dose study. To date, this additional study, conducted in healthy volunteers, has evaluated single doses of 600 mg in one group and 1200 mg in another group treated with Riquent or placebo. Both dose levels of Riquent appeared to be well tolerated and we may test additional dose levels in connection with this trial. Based on previous studies of Riquent, we believe that some lupus patients may benefit from higher doses of Riquent. Once the dosing study is completed, we plan to review the data from the study with the FDA and may choose to study additional doses of Riquent in the trial that we initiated in August 2004.

     Our November 2004 announcement also noted that we had met with the European Agency for the Evaluation of Medicinal Products (the “EMEA”) which had designated two countries to lead the review of our European regulatory filing and that, due to the efforts involved

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in our ongoing discussions with the FDA, we anticipated a delay in filing our Marketing Authorization Application (“MAA”) for Riquent in Europe. We also announced that, while our discussions with the FDA were ongoing, we had taken steps to control certain costs associated with our research, development and other activities. Finally, we announced that, since receiving the approvable letter from the FDA in October 2004, we and the FDA had met twice to discuss the approvable letter and data concerning Riquent and that we had two additional meetings scheduled.

     Since our November 2004 announcement, we completed three additional meetings with the FDA regarding the approvable letter and whether the FDA would consider approving Riquent under Subpart H. During our discussions with the FDA, we have provided the FDA with additional evidence in support of the potential efficacy of Riquent and with information that we believe supports a determination that antibodies to dsDNA are an appropriate surrogate endpoint for lupus renal disease and that the magnitude of the effect of Riquent on antibodies to dsDNA is reasonably likely to predict clinical benefit, which is a requirement for any potential approval under Subpart H. Many of the analyses of data from our clinical trials of Riquent were conducted on a retrospective basis and the relevant medical literature would support the use of the level of antibodies to dsDNA as a surrogate endpoint that would be reasonably likely to predict clinical benefit.

     On August 13, 2003,p values reported are nominal, without adjustment for multiple comparisons. While we announced that we had completed a public offering of 8,150,000 shares of our common stock. The net proceeds that we received from the offering, after expenses, were approximately $20.9 million.

     On December 2, 2003, we announced the discovery of novel, orally-active small molecules for the treatment of autoimmune diseases and acute and chronic inflammatory disorders. Our scientists have generated highly selective inhibitors of SSAO (“semicarbazide-sensitive amine oxidase”), an enzyme that has been implicatedare in inflammatory responses in many tissues and organs. Preclinical studies in animal models of multiple sclerosis, rheumatoid arthritis and acute inflammation have shown that treatment with our inhibitors both maintained function and reduced disease activity compared with placebo treatment.

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     On December 16, 2003, we announced that we had submitted our NDA for Riquent with the FDA.

     On February 16, 2004, we announced that our NDA for Riquent had been accepted for review by the FDA. The acceptance of the NDA by the FDA indicates that the NDA is sufficiently complete to permit a substantive review of the application. Further discussions with the FDA will be needed to clarify whether any additional supportive information or studies will be required to supportregarding the approvalpossibility of the NDA. The FDA will determine whether to approve Riquent, either on the basis of our clinical trial results orapproval under Subpart H, andwe are continuing the conditions of any approval,clinical benefit study that we initiated in August 2004 in order to satisfy the additional trial requirement set forth in the FDA’s October 2004 approvable letter. In the event that the FDA approves Riquent under Subpart H, we expect that we would continue the ongoing trial as a post-marketing benefit trial, which would need to be completed after it has reviewedapproval.

     We currently expect to continue our NDA. We are currently in discussiondiscussions with the FDA about the design and timing of a post-marketing clinical trial that would be required ifregarding possible Subpart H approval, is pursued. We also are currently meeting with European regulatory authorities to discuss potential next steps for Riquent in Europe. Therealthough there can be no guarantee that any future meetings with the FDA and other regulatory agencies can be held in a timely manner, or at all, or that our meetings with themthe FDA will result in our being ableeliminate or change the current FDA requirement that we conduct an additional trial for Riquent prior to continue to develop Riquent. If for any reason our development efforts as to Riquent are terminated, it would have a material adverse effect on our business and future prospects.further consideration of possible approval.

     On February 26, 2004,2, 2005, we announced that we had completed a public offering of 8,695,65312,250,000 shares of our common stock. The net proceeds that we received from the offering,to us, after expenses, were approximately $25.6$15.8 million.

     On March 5, 2004, we announced that the underwriter for the recently completed public offering purchased an additional 1,304,347 shares at the initial offering price per share pursuant to the over-allotment option granted to the underwriter in connection with the offering. The net proceeds that we received from the sale of the over-allotment shares were approximately $3.9 million.

     On March 11, 2004, we announced additional analyses of data from our Phase 3 and Phase 2/3 trials of Riquent. The data showed that after one year of treatment, the number of lupus patients with a reduction in proteinuria of at least 50% from baseline was greater in the Riquent-treated group than in the placebo-treated group. Additional details regarding this announcement can be found under the heading “Additional findings from the Phase 3 and Phase 2/3 trials,” on page 12 of this report.

Overview

     Since our inception in May 1989, we have devoted substantially all of our resources to the research and development of technology and potential drugs to treat antibody-mediated diseases. We have never generated any revenue from product sales and have relied on public and private and public investors,offerings of securities, revenue from collaborative agreements, equipment financings and interest income on invested cash balances for our working capital. DependingBased on the results of the FDA’s recent review of our NDA, and depending on the outcome of the FDA’s review of our NDA, ourfurther discussions with the FDA and other regulatory agencies and our continuing analysis of the data from our clinical trials of Riquent, our research and development expenses may increase significantly in the futurefuture. For example, we have initiated a clinical trial of Riquent that the FDA has indicated appears to satisfy the requirement that we conduct an additional randomized, double-blind study. In addition, our research and development expenses may increase if we are required to conductinitiate any additional clinical studies to demonstrate the safety and efficacy of Riquent or if we increase our commercialization activities of Riquent, development of LJP 1082, or efforts to developrelated any additional drug candidates. If we obtain Subpart H approval, our expenses may significantly increase if we increase our commercial-scale manufacturing capabilities or our marketing and sales activities. Our activities to date are not as broad in depth or scope as the activities we may undertake in the future, and our historical operations and the financial information included in this report are not necessarily indicative of our future operating results or financial condition.

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     We expect our net loss to fluctuate from quarter to quarter as a result of the timing of expenses incurred and the revenues earned from any potential collaborative arrangements we may establish. Some of these fluctuations may be significant. As of December 31, 2003,2004, our accumulated deficit was approximately $192.4$232.9 million.

     Our business is subject to significant risks, including, but not limited to, our clear need for additional financing, the risks inherent in research and development efforts, including clinical trials, uncertainties associated with both obtaining and enforcing patents and with the potential enforcement of the patent rights of others, the lengthy, expensive and uncertain process of seeking regulatory approvals, uncertainties associated with both obtaining and enforcing patents, the potential enforcement of the patent rights of others against us, uncertainties regarding government reforms and ofregarding product pricing and reimbursement levels, technological change, and competition, manufacturing uncertainties, our lack of marketing experience, and the uncertainty of receiving future revenue from product sales or other sources such as collaborative relationships, and the uncertainty of future profitability and the clear need for additional financing.profitability. Even if our product candidates appear promising at an early stage of development, they may not reach the market for numerous reasons, including the possibilities that the products will be ineffective or unsafe during clinical trials, will fail to receive necessary regulatory approvals, will be difficult to manufacture on a large scale, will be uneconomical to market or will be precluded from commercialization by the proprietary rights of third parties or competing products.

Critical Accounting Policies and Estimates

     The discussion and analysis of our financial condition and results of operations are based on our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States. The preparation of these consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. We evaluate our estimates on an ongoing basis, including those related to patent costs and income taxes. We base our estimates on historical experience and on other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from these estimates under different assumptions or conditions.

     We believe the following critical accounting policy affects the significant judgments and estimates used in the preparation of our consolidated financial statements (see noteNote 1 to our consolidated financial statements).

     Impairment and useful lives of long-lived assets.

     We regularly review our long-lived assets for impairment. Our long-lived assets include costs incurred to file our patent applications. We evaluate the recoverability of long-lived assets by measuring the carrying amount of the assets against the estimated undiscounted future cash flows associated with them. At the time such evaluations indicate that the future undiscounted cash flows of certain long-lived assets are not sufficient to recover the carrying value of such assets, the assets are adjusted to their fair values. The estimation of the undiscounted future cash flows associated with long-lived assets requires judgment and assumptions that could differ materially from the actual results. While we believe our current and historical operating and cash flow losses are indicators of impairment, we believe the future cash flows to be received from the long-lived assets will exceed the assets’ carrying value, and accordingly we have not recognized any material impairment losses through December 31, 2003.2004.

     Costs related to successful patent applications are amortized using the straight-line method over the lesser of the remaining useful life of the related technology or the remaining

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patent life, commencing on the date the patent is issued. Legal costs and expenses incurred in

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connection with pending patent applications have been capitalized. We expense all costs related to abandoned patent applications. If we elect to abandon any of our currently issued or unissued patents, the related expense could be material to our results of operations for the period of abandonment. The estimation of useful lives for long-lived assets requires judgment and assumptions that could differ materially from the actual results. In addition, our results of operations could be materially impacted whenif we begin amortizing the costs related to unissued patents.

Results of Operations

Years Ended December 31, 2004, 2003 2002 and 20012002

     Research and Development Expense. Our research and development expense decreasedincreased slightly to $32.4$33.2 million for the year ended December 31, 2004 from $32.4 million in 2003 and decreased from $37.7 million in 20022002. The increase in research and increaseddevelopment expenses in 2004 from $23.2 million2003 was primarily due to the purchase of raw materials, which we expect to use in 2001.the production of validation lots of Riquent in 2005. We expect to use the validation lots in connection with our ongoing clinical trial and for other purposes. This increase was mostly offset by decreases in costs incurred for clinical studies of Riquent, including the open-label follow-on clinical trial of Riquent which was closed in April 2003 and the unblinding and analysis of the data from the Phase 3 trial of Riquent in the first quarter of 2003. The decrease in research and development expensesexpense in 20032004 from 2002 was primarily due to a decrease in expenses related to the Phase 3 clinical trial of Riquent which was completed in December 2002, the open-label follow-on clinical trial of Riquent which was initiated in July 2002 and closed in April 2003, and the Phase 1/2 clinical trial of LJP 1082 which was completed in October 2002. This decrease wasThese decreases were partially offset by an increase in personnel costs including the restructuring charges recorded in May 2003 of $0.3 million for 19 research and development employees. The increase in research and development expense in 2003 from 2001 was primarily due to the cost of the open-label follow-on clinical trial for Riquent which was initiated in July 2002 and closed in April 2003, as well as anthe increase in personnel costs as discussedfrom the purchase of raw materials noted above.

     Research and development expense of $32.4$33.2 million for the year ended December 31, 20032004 consisted of $27.1$29.0 million for lupus research and development related expense, $3.1$1.6 million for thrombosis research and development related expense and $2.2$2.6 million for other research and development related expense. Total lupus related research and development expense consisted primarily of salaries and other costs related to research, manufacturing and clinical personnel, clinical research organization fees, investigator fees, contract clinical research associate fees, clinical lab fees andraw materials for the production of Riquent for validation lots, fees for consulting and professional outside services.services, clinical research organization fees, depreciation expense and lease expense. Total thrombosis related research and development expense consisted primarily of salaries for research and development personnel, raw materials for the production of LJP 1082 for research purposes and depreciation expense. Total other research and development expense consisted primarily of salaries for research and development personnel, research supplies, lease expense and lease expense.fees for consulting and professional outside services.

     Our research and development expense may increase significantly in the future iffuture. For example, we are required to initiate an additionalhave initiated a clinical trial of Riquent that the FDA has indicated appears to satisfy the requirement that we conduct an additional randomized, double-blind study. This study is expected to involve approximately 500 to 600 patients, cost at least $60 million, and take several years to complete. Additionally, our research and development expenses may increase significantly if we initiate commercialization activities forany additional clinical studies of Riquent, if we increase our development activities of LJP 1082 or increase ourrelated to the development of additional drug candidates.candidates or, if we obtain Subpart H approval, we increase our commercial-scale manufacturing capabilities.

     General and Administrative Expense. Our general and administrative expense of $6.9increased to $7.6 million for the year ended December 31, 2003 remained consistent with 2002 and increased2004 from $4.3$6.9 million in 2001.2003 and 2002. The

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increase in general and administrative expense in 20032004 as compared to 20012003 and 2002 was due to an increase in headcountconsulting and administrative infrastructure to support increased clinical trial, manufacturingprofessional fees for pre-marketing, intellectual property and research and developmentother administrative activities. General and administrative expense may increase in the future to support clinical trials and possible increases in commercialization, clinical trial, manufacturing and research and development, manufacturing and commercialization activities.

     Interest Income and Expense. Our interest income decreased to $0.7$0.4 million for the year ended December 31, 2004 from $0.7 million in 2003 fromand $1.4 million in 2002 and $2.8 million in 2001.2002. The decrease in interest income in 20032004 was due to lower average interest rates on our investments and lower average balances of cash and short-term investments as compared to 20022003 and 2001.2002. Interest

45

expense increased to $210,000was $0.2 million for the year ended December 31, 2004, $0.2 million in 2003 fromand $51,000 in 2002 and $30,000 in 2001.2002. The higher interest expense in 2004 and 2003 as compared to 2002 and 2001 was due to new notes payable obligations entered into in 2004 and 2003 to finance equipment purchases.

     Net Operating Loss and Research Tax Credit Carryforwards. At December 31, 2003,2004, we had available net operating loss carryforwards and research tax credit carryforwards of approximately $182.9$220.8 million and $10.0$11.7 million, respectively, for federal income tax purposes, which will begin to expire in 2005 unless utilized. Approximately $1.4$2.2 million of the federal net operating loss carryforward is set to expire in 2005 unless utilized and approximately $0.1 million of the federal research tax credit carryforward is set to expire in 2005 unless utilized. At December 31, 2003,2004, we had available net operating loss carryforwards and research tax credit carryforwards of approximately $67.1$93.4 million and $5.0$6.2 million, respectively, for California income tax purposes, which will begin to expire in 20042009 unless utilized. Approximately $0.3 million of the California net operating loss carryforward is set to expire in 2004 and approximately $0.7 million is set to expire in 2005,2009 unless utilized.

Liquidity and Capital Resources

     From inception through December 31, 2003,2004, we have incurred a cumulative net loss of approximately $192.4$232.9 million and have financed our operations through privatepublic and publicprivate offerings of securities, revenues from collaborative agreements, equipment financings and interest income on invested cash balances. From inception through December 31, 2003,2004, we had raised $228.1$258.1 million in net proceeds from sales of equity securities.

     At December 31, 2003,2004, we had $32.1$23.1 million in cash, cash equivalents and short-term investments, as compared to $52.7$32.1 million at December 31, 2002.2003. Our working capital at December 31, 20032004 was $28.9$17.5 million, as compared to $46.5$28.9 million at December 31, 2002.2003. The decrease in cash, cash equivalents and short-term investments resulted from the use of our financial resources to fund our manufacturing and clinical trials,trial activities and research and development efforts, manufacturing activities and for other general corporate purposes, partially offset by net proceeds of $20.9$29.4 million we received from the sale of 8,150,000an aggregate of 10,000,000 shares of our common stock in August 2003.February and March 2004. We invest our cash in corporate and United States government-backed securities, money market funds and debt instruments.instruments of financial institutions and corporations with strong credit ratings. As of December 31, 2003,2004, we classified all of our investments as available-for-sale securities because we expect to sell them in order to support our current operations regardless of their maturity date.dates. As of December 31, 2003,2004, available-for-sale securities and cash equivalents of $14.6$11.5 million have stated maturity dates of one year or less and $16.1$10.2 million have maturity dates after one year.

     As of December 31, 2003,2004, we had acquired an aggregate of $13.3$15.1 million in property and equipment, of which $0.2$0.1 million and $3.0$3.5 million of equipment is financed under capital lease and notes payable obligations, respectively. In addition, we lease our office and laboratory facilities and certain equipment under operating leases. We have also entered into a $1.4 million purchase commitment with a potential third party manufacturer of materials for Riquent. The

50

purpose of the agreement is to qualify the manufacturer as a manufacturer that we could use in the commercial production of Riquent if we obtain regulatory approval. The agreement includes a cancellation fee of $0.4 million. We have also entered into non-cancelable purchase commitments for an aggregate of $0.8 million with third-party manufacturers of materials to be used in the production of our validation lots of Riquent. In addition, in December 2004, we entered into an agreement with a third-party to provide clinical trial services, requiring a $0.2 million advance upon execution of the agreement. We intend to use our current financial resources to fund our obligationobligations under thisthese purchase commitment.commitments. In the future, we may have additional increases toincrease our investments in property and equipment if we expand our research and development and manufacturing facilities and capabilities.

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     During the period ended December 31, 2004, we entered into three additional note payable obligations for $189,000, $132,000, and $157,000, the proceeds of which we used to finance the purchase of equipment. In June 2004, we exercised an option to extend a lease for additional research space for nine months, which we extended for an additional nine months in February 2005. In July 2004, we exercised an option to extend the leases for our research and development laboratories, clinical manufacturing facilities and office space for an additional five years. The following table summarizes our contractual obligations at December 31, 2003,2004. Long-term debt and the effect suchcapital lease obligations are expected to have on our liquidity and cash flows in future periods:

     We have no current means of generating cash flow from operations. Our lead drug candidate, Riquent, will not generate revenues, if at all, until it has received regulatory approval and has been successfully manufactured, marketed and sold. This process, if completed, could take a significant amount of time. Our other drug candidates are much less developed than Riquent. There can be no assurance that our product development efforts with respect to Riquent or any other drug candidate will be successfully completed, that required regulatory approvals will be obtained or that any product, if introduced, will be successfully marketed or achieve commercial acceptance. Accordingly, we must continue to rely on outside sources of financing to meet our capital needs for the foreseeable future.

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     We will continue to seek capital through any appropriatenumber of means, including issuance ofby issuing our equity securities and establishment of additionalby establishing one or more collaborative arrangements. However, there can be no assurance that additional financing will be available to us on acceptable terms, if at all, and our negotiating position in capital-raising efforts may worsen as we continue to use existing resources or if the development of Riquent is delayed or terminated. There is also no assurance that we will be able to enter into further collaborative relationships.

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

     We invest our excess cash in interest-bearing investment-grade securities which we sell from time to time to support our current operations. We do not utilize derivative financial instruments, derivative commodity instruments or other market risk sensitive instruments, positions or transactions in any material fashion. Although the investment-grade securities which we hold are subject to changes in the financial standing of the issuer of such securities, we do not believe that we are subject to any material risks arising from the maturity dates of the debt instruments or changes in interest rates because the interest rates of the securities in which we invest that have a maturity date greater than one year are reset periodically within time periods not exceeding 49 days. We currently do not invest in any securities that are materially and directly affected by foreign currency exchange rates or commodity prices.

Item 8. Financial Statements and Supplementary Data.

     The financial statements and supplementary data required by this item can be foundis set forth above under the caption “Quarterly Results of Operations” on page 4145 and at the end of this report beginning on page F-1.F-2 and is incorporated herein by reference.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

     None.

Item 9A. Controls and Procedures.

     (a)  As of the end of the period covered by this annual report on Form 10-K, we carried out an evaluation, under the supervision andOur management, with the participation of our management, including our principal executive officer and principal financial officer, ofofficers, has evaluated the effectiveness of the design and operation of our disclosure controls and procedures.procedures as of December 31, 2004. Based upon thaton this evaluation, our principal executive officer and principal financial officer haveofficers concluded that theseour disclosure controls and procedures are effective in timely alerting them to material information relating to La Jolla Pharmaceutical Company required to be included in our periodic SEC filings.

     (b)  There were no changeseffective. The evaluation did not identify any change in our internal controlcontrols over financial reporting that occurred during our most recent fiscalthe quarter ended December 31, 2004 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

4852

Management Report on Internal Control Over Financial Reporting

     Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rule 13a-15(f) or 15d-15(f) promulgated under the Securities Exchange Act of 1934 as a process designed by, or under the supervision of, our principal executive and principal financial officers and effected by our board of directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that:

	•	Pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets;
	•	Provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures are being made only in accordance with authorizations of our management and directors; and
	•	Provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on our financial statements.

     Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

     Our management assessed the effectiveness of our internal control over financial reporting as of December 31, 2004. In making this assessment, our management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in Internal Control-Integrated Framework.

     Based on our assessment, management concluded that, as of December 31, 2004, our internal control over financial reporting is effective based on those criteria.

     Our independent registered public accounting firm that audited our consolidated financial statements included in this annual report on Form 10-K has issued an audit report on our assessment of our internal control over financial reporting. This report appears below.

Item 9B. Other Information.

Report Of Independent Registered Public Accounting Firm On Internal Control Over Financial Reporting

The Board of Directors and Stockholders
La Jolla Pharmaceutical Company

     We have audited management’s assessment, included in the accompanying Management Report on Internal Control over Financial Reporting, that La Jolla Pharmaceutical Company maintained effective internal control over financial reporting as of December 31, 2004, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring

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Organizations of the Treadway Commission (the COSO criteria). La Jolla Pharmaceutical Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting. Our responsibility is to express an opinion on management’s assessment and an opinion on the effectiveness of the company’s internal control over financial reporting based on our audit.

     We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, evaluating management’s assessment, testing and evaluating the design and operating effectiveness of internal control, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

     A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

     Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

     In our opinion, management’s assessment that La Jolla Pharmaceutical Company maintained effective internal control over financial reporting as of December 31, 2004, is fairly stated, in all material respects, based on the COSO criteria. Also, in our opinion, La Jolla Pharmaceutical Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2004, based on the COSO criteria.

     We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated balance sheets of La Jolla Pharmaceutical Company as of December 31, 2004 and 2003, and the related consolidated statements of operations, stockholders’ equity, and cash flows for each of the three years in the period ended December 31, 2004 of La Jolla Pharmaceutical Company and our report dated February 28, 2005 expressed an unqualified opinion thereon.

	/s/ ERNST & YOUNG LLP

San Diego, California
February 28, 2005

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PART III

Item 10. Directors and Executive Officers of the Registrant.

     Except for information concerning our executive officers, which is included under the caption “Executive Officers of the Registrant” beginning on page 2324 of this report, the information required by Item 10 is incorporated by reference to our definitive proxy statement for the 2004our 2005 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission no later than 120 days after the close of the fiscal year ended December 31, 2003.2004.

Item 11. Executive Compensation.

     The information required by Item 11 is incorporated by reference to our definitive proxy statement for the 2004our 2005 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission no later than 120 days after the close of the fiscal year ended December 31, 2003.2004.

Item 12. Security Ownership of Certain Beneficial Owners and Management.

     The information required by Item 12 is incorporated by reference to our definitive proxy statement for the 2004our 2005 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission no later than 120 days after the close of the fiscal year ended December 31, 2003.2004.

Item 13. Certain Relationships and Related Transactions.

     None.

Item 14. Principal Accountant Fees and Services.

     The information required by Item 14 is incorporated by reference to our definitive proxy statement for the 2004our 2005 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission no later than 120 days after the close of the fiscal year ended December 31, 2003.2004.

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PART IV

Item 15. Exhibits and Financial Statement Schedules, and Reports on Form 8-K.Schedules.

(a)

(a) Documents filed as part of this report.

1.

Financial Statements.

Consolidated financial statements. The following consolidated financial statements of La Jolla Pharmaceutical Company are included in Item 8: