XOMA Corp - Annual Report: 2008 (Form 10-K)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the fiscal year ended December 31, 2008

OR

For the transition period from                      to                     

Commission File No. 0-14710

XOMA Ltd.

(Exact name of registrant as specified in its charter)

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

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

Common Shares, U.S. $0.0005 par value

Preference Share Purchase Rights

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act.    Yes  ¨    No  x

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

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    x

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

Large Accelerated Filer  ¨    Accelerated Filer  x     Non-Accelerated filer  ¨    Smaller reporting company  ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act of 1934).    Yes  ¨    No  x

The aggregate market value of voting shares held by non-affiliates of the registrant is $223,028,144 as of June 30, 2008

Number of Common Shares outstanding as of March 6, 2009: 142,244,227

DOCUMENTS INCORPORATED BY REFERENCE:

Portions of the Company’s Proxy Statement for the Company’s 2009 Annual General Meeting of Shareholders are incorporated by reference into Part III of this Report.

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XOMA Ltd.

2008 FORM 10-K ANNUAL REPORT

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PART I

Overview

XOMA Ltd. (“XOMA” or the “Company”), a Bermuda company, is a leading biopharmaceutical company focused on the discovery, development and manufacture of therapeutic antibodies and other agents designed to treat inflammatory, autoimmune, infectious and oncological diseases. XOMA uses its expertise, technologies and capabilities to build a product pipeline that includes multiple proprietary and collaborative development programs. The Company’s lead product candidate is XOMA 052, a potent monoclonal antibody with the potential to improve the treatment of patients with a wide variety of diseases in which inflammation is either the cause or plays a significant role.

XOMA has multiple revenue streams and generates revenues from product royalties, technology licenses, development collaborations and biodefense contracts. The Company receives royalties on three approved products, RAPTIVA^®, which is marketed globally for the treatment of chronic moderate-to-severe plaque psoriasis, LUCENTIS^®, which is marketed globally for the treatment of neovascular (wet) age-related macular degeneration, and CIMZIA^®, which is approved in the U.S. and Switzerland for the treatment of Crohn’s disease. XOMA has established on-going technology licensing programs for certain of its proprietary technologies, which have attracted numerous significant licensees including Pfizer Inc. (“Pfizer”). The Company’s development collaborations include arrangements with Takeda Pharmaceutical Company Limited (“Takeda”), Schering-Plough Research Institute (“SPRI”) and Novartis AG (“Novartis”). XOMA’s biodefense initiatives currently include a $65 million multiple-year contract with the National Institute of Allergy and Infectious Diseases (“NIAID”) to support XOMA’s ongoing development of drug candidates toward clinical trials in the treatment of botulism poisoning.

The Company has a premier antibody discovery and development platform that includes six commercial antibody phage display libraries and XOMA’s proprietary Human Engineering^™ and bacterial cell expression technologies. Our Human Engineering^™ technology was used in development of XOMA 052 and certain other antibody products. Bacterial cell expression technology is a key biotechnology for the discovery and manufacture of antibodies and other proteins. Thus far, more than 50 pharmaceutical and biotechnology companies have signed bacterial cell expression licenses with XOMA.

Strategy

We are advancing a pipeline of biotherapeutic products using our proven expertise, technologies and capabilities from antibody discovery through product development. We seek to expand our pipeline by developing proprietary products and technologies, collaborating with pharmaceutical and biotechnology companies and providing contract services to government agencies responsible for biodefense. We fund a portion of our development activities through multiple revenue streams, including product royalties, technology licenses, collaborations and biodefense contracts. The principal elements of our strategy are to:

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In January of 2009, XOMA announced a workforce reduction of approximately 42 percent, or 144 employees, a majority of which were employed in manufacturing and related support functions. This decision was made based on the challenging economic conditions and a decline in forecasted contract manufacturing demand in 2009. We expect an annualized reduction of approximately $27 million in cash expenditures when changes are completed in the second quarter of 2009. Upon completion of the workforce reduction on March 17, 2009, we expect to have approximately 200 employees to develop XOMA 052, develop and license proprietary products and technology, and continue fully funded antibody discovery and development activities in collaboration with our pharmaceutical partners and under biodefense contracts with the U.S. government. We will maintain our pilot scale manufacturing plant. XOMA expects to record a charge in the first quarter of 2009 of approximately $3 million for severance and other costs related to the workforce reduction.

Proprietary Products

As part of our strategy, we are focusing our technology and resources on advancing the emerging proprietary pipeline. Below is a summary of our proprietary products:

We are currently conducting two Phase 1 clinical trials in Type 2 diabetes patients, one in the U.S. and one in Europe. In September of 2008, we announced interim data from the Phase 1 clinical trials which indicate support for a novel anti-inflammatory approach to Type 2 diabetes treatment that may preserve insulin-producing cells. Although these Phase 1 studies were designed to test drug safety and pharmacokinetics, rather than efficacy, we believe these studies are important additions to other published medical research indicating that decreasing inflammation may reduce disease progression in diabetes. We plan to advance our Phase 1 clinical testing of XOMA 052 in Type 2 diabetes and initiate a major Phase 2 Type 2 diabetes study in the third quarter of 2009.

In addition to our Phase 1 clinical trials in Type 2 diabetes patients, we initiated a Phase 2a pharmacokinetic study of XOMA 052 in rheumatoid arthritis in the first quarter of 2009. Depending on resources and timing, we may initiate additional small XOMA 052 “proof-of-concept” trials in other indications in 2009.

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Partnership Products

XOMA partners with world-class organizations in research and development of new antibody products. Below is a list of current activities through such collaborations:

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Royalties and Technology Licenses

Royalties

XOMA earns mid- and low-single digit royalties on the following three marketed antibody products:

In October of 2008, the FDA announced that it had approved labeling changes, including a Boxed Warning, to highlight the risks of life-threatening infections, including progressive multifocal leukoencephalopathy (“PML”), with the use of RAPTIVA^®. In November of 2008, Genentech announced that it had issued a Dear Healthcare Provider letter to inform dermatologists and neurologists of a second case of PML which resulted in the death of a 73-year old patient who had received RAPTIVA^® for approximately four years. In February of 2009, the European Medicines Agency (“EMEA”) announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and that its Committee for Medicinal Products for Human Use (“CHMP”) has concluded that the benefits of RAPTIVA^® no longer outweigh its risks and EMD Serono Inc., the company that markets RAPTIVA^® in Canada (“EMD Serono”), announced that, in consultation with Health Canada, the Canadian health authority (“Health Canada”), it will suspend marketing of RAPTIVA^® in Canada. Also in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^®.

In January of 2009, Novartis announced that LUCENTIS^® was approved in Japan for the treatment of neovascular (wet) age-related macular degeneration.

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In January of 2009, UCB announced that the FDA had issued a Complete Response Letter relating to the Biologics License Application (“BLA”) of CIMZIA^® for the treatment of rheumatoid arthritis. As a prerequisite for approval of CIMZIA^®, UCB announced in February of 2009 that the FDA requires further analysis of existing data and a new safety update and that no additional studies are needed to fulfill the FDA’s request. UCB is working with the FDA to fulfill its request and anticipates a full response will be submitted in the second quarter of 2009.

Technology Licenses

Below is a summary of certain proprietary technologies owned by us and available for licensing to other companies:

We have granted over 50 licenses to biotechnology and pharmaceutical companies to use our patented and proprietary technologies relating to bacterial expression of recombinant pharmaceutical products. Bacterial antibody expression is also a key technology used in multiple systems for high-throughput screening of antibody domains. Expression of antibodies by phage display technology, for example, depends upon the expression and secretion of antibody domains from bacteria as properly folded, functional proteins.

Under the terms of our license agreement with Pfizer, signed in 2007, we received an up-front, non-dilutive cash payment of $30.0 million and, in 2008, we received two milestone payments relating to two different products, including a payment of $0.5 million for the initiation of a Phase 3 clinical trial. We are also eligible for additional milestone, royalty and other fees on future sales of all products subject to this license.

Current licensees include but are not limited to the following companies:

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These licenses are sometimes associated with broader agreements which may include expanded license rights, cell line development and process development.

We also have access to certain intellectual property rights and services that augment our existing integrated antibody technology platform and development capabilities and further compress product development timelines. This broad antibody technology platform and expertise is available for building our antibody product pipeline as well as those of our collaborators.

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Proprietary Product Summary:

The following table describes important information related to certain products on which we may earn royalties or that we are currently developing:

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Product Available for Out-Licensing

In an effort to focus our resources on our XOMA 052 program, we have designated XOMA 629 as available for out-licensing. XOMA 629 is a topical anti-bacterial formulation of a peptide derived from BPI, a key part of the protective human immune system. XOMA was developing XOMA 629 as a possible treatment for superficial skin infections, including impetigo and the eradication of staphylococcus aureus, including MRSA.

Financial and Legal Arrangements of Product Collaborations, Licensing and Other Arrangements

Current Agreements

Genentech

In April of 1996, we entered into a collaboration agreement with Genentech for the development of RAPTIVA^®. In March of 2003, we entered into amended agreements which called for us to share in the development costs and to receive a 25% share of future U.S. operating profits and losses and a royalty on sales outside the U.S. The amended agreements also called for Genentech to finance our share of development costs up until first FDA marketing approval via a convertible subordinated loan, and our share of pre-launch marketing and sales costs via an additional commercial loan facility. Under the loan agreement, upon FDA approval of the product, which occurred in October of 2003, we elected to pay $29.6 million of the development loan in convertible preference shares, which are convertible into approximately 3.8 million common shares at a price of $7.75 per common share. The commercial loan was repaid in cash in two installments in 2004.

In January of 2005, we announced a restructuring of our arrangement with Genentech on RAPTIVA^®. Under the restructured arrangement, we are entitled to receive mid-single digit royalties on worldwide sales of RAPTIVA^® in all indications. The previous cost and profit sharing arrangement for RAPTIVA^® in the U.S. was discontinued and Genentech is responsible for all operating and development costs associated with the product. In addition, the outstanding balance on our development loan was extinguished.

In December of 1998, we licensed our bacterial cell expression technology to Genentech, which utilized it in the development of LUCENTIS^® for the treatment of neovascular (wet) age-related macular degeneration. LUCENTIS^® was approved by the FDA in June of 2006, the European Union in January of 2007 and Japan in January of 2009. We are entitled to receive a low-single digit royalty on worldwide sales of LUCENTIS^®.

UCB

In December of 1998, we licensed our bacterial cell expression technology to Celltech Therapeutics Ltd., now UCB Celltech, a branch of UCB, which utilized it in the development of CIMZIA^® for the treatment of moderate-to-severe Crohn’s disease in adults who have not responded to conventional therapies and for the treatment of rheumatoid arthritis. CIMZIA^® was approved by the FDA in April of 2008 and in Switzerland in September of 2007 for the treatment of Crohn’s disease. The FDA is currently considering UCB’s application to market CIMZIA^® for the treatment of rheumatoid arthritis. We are entitled to receive a low-single digit royalty on worldwide sales of CIMZIA^®.

Novartis

In November of 2008, we restructured our product development collaboration with Novartis, which involves six development programs including the HCD122 program. HCD122, which is a fully human anti-CD40 antagonist antibody intended as a treatment for B-cell mediated diseases, including malignancies and autoimmune diseases, is currently in Phase 1 and Phase 2 clinical trials in several indications. The investigational drug is in a Phase 1b-2a clinical trial for the treatment of lymphoma and a Phase 1 clinical trial for the treatment of multiple myeloma. The antibody has a dual mechanism of action that involves inhibition of CD40-ligand mediated growth and survival while recruiting immune effector cells to kill CD40-expressing tumor cells through a process known as antibody-dependent cellular cytotoxicity (ADCC). CD40, a member of the tumor necrosis factor, or TNF, family of antigens, is a cell surface antigen expressed in B-cell malignancies and involved in a broad variety of immune and inflammatory responses.

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Under the restructured agreement, Novartis made a payment to us of $6.2 million in cash; reduced our existing debt by $7.5 million; will fully fund all future research and development expenses; may pay potential milestones of up to $14.0 million and double-digit royalty rates for two ongoing product programs, including HCD122; and has provided us with options to develop or receive royalties on four additional programs. In exchange, Novartis has control over the HCD122 program and the additional ongoing program, as well as the right to expand the development of these programs into additional indications outside of oncology. As part of the agreement, Novartis has paid us for all project costs incurred after July 1, 2008.

The collaboration between XOMA and Novartis (then Chiron Corporation) began in 2004 with the signing of an exclusive, worldwide, multi-product agreement to develop and commercialize multiple antibody products for the treatment of cancer. We shared expenses and revenues, generally on a 70-30 basis, with our share being 30 percent. Financial terms included initial payments to us in 2004 totaling $10.0 million and a note agreement, secured by our interest in the collaboration, to fund up to 75 percent of our share of expenses beginning in 2005. In the first quarter of 2007, the mutual obligations of XOMA and Novartis to work together on an exclusive basis in oncology expired, except with respect to existing collaborative product development projects.

In December of 2008, we entered into a Manufacturing and Technology Transfer Agreement with Novartis, effective July 1, 2008. Under this agreement, XOMA has been engaged by Novartis to perform research and development, process development, manufacturing and technology transfer activities with respect to the ongoing product programs now controlled by Novartis under the restructured product development collaboration. The work performed by XOMA under this agreement is fully funded by Novartis.

Schering-Plough

In May of 2006, we entered into a fully funded collaboration agreement with the SPRI division of Schering-Plough Corporation for therapeutic monoclonal antibody discovery and development. Under the agreement, SPRI will make up-front, annual maintenance and milestone payments to us, fund our research and development activities related to the agreement and pay royalties on sales of products resulting from the collaboration. During the collaboration, we will discover therapeutic antibodies against multiple targets selected by SPRI using multiple human antibody phage display libraries, may optimize antibodies through affinity maturation or other protein engineering, may use our proprietary Human Engineering^™ technology to humanize antibody candidates generated by hybridoma techniques, perform preclinical studies to support regulatory filings, develop cell lines and production processes and produce antibodies for initial clinical trials. SPRI selected the first target at the inception of the agreement and, in December of 2006, exercised its right to initiate the additional discovery and development programs.

Schering-Plough/AVEO Pharmaceuticals, Inc. (“AVEO”)

In April of 2006, we entered into an agreement with AVEO to utilize our Human Engineering^™ technology to humanize AV-299, AVEO’s novel anti-HGF antibody, under which AVEO paid us an up-front license fee and development milestones. In addition, we will receive royalties on sales of products resulting from the agreement. Under this agreement we created four Human Engineering^™ versions of the original AV-299, all of which met design goals and from which AVEO selected one as its lead development candidate. In September of 2006, as a result of the successful humanization of AV-299, we entered into a second agreement with AVEO to manufacture and supply AV-299 in support of early clinical trials. Under the agreement, we created AV-299 production cell lines, conducted process and assay development, and performed Good Manufacturing Practices (“cGMP”) manufacturing activities. AVEO retains all development and commercialization rights to AV-299 and is responsible to pay XOMA annual maintenance fees, additional development milestones and royalties if certain targets are met.

In April of 2007, Schering-Plough Corporation, acting through its SPRI division, entered into a research, development and license agreement with AVEO concerning AV-299 and other anti-HGF molecules. In connection with the aforementioned license agreement, AVEO has assigned its entire right, title and interest in, to and under its manufacturing agreement with XOMA to SPRI.

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Takeda

In November of 2006, we entered into a fully funded collaboration agreement with Takeda for therapeutic monoclonal antibody discovery and development. Under the agreement, we will discover and optimize therapeutic antibodies against multiple targets selected by Takeda. Takeda will make up-front, annual maintenance and milestone payments to us, fund our research and development and manufacturing activities for preclinical and early clinical studies and pay royalties on sales of products resulting from the collaboration. Takeda will be responsible for clinical trials and commercialization of drugs after an Investigational New Drug (“IND”) submission and is granted the right to manufacture once a product enters into Phase 2 clinical trials.

In September of 2008, we initiated new therapeutic antibody programs under our existing collaboration with Takeda. The new programs add to the multiple discovery and development programs already being advanced through the collaboration.

In addition, in February of 2009 we expanded our existing collaboration to provide Takeda with access to multiple antibody technologies, including a suite of research and development technologies and integrated information and data management systems. We received a $29.0 million expansion fee, of which $23.2 million was received in cash in February of 2009 and the remainder was witheld for payment to the Japanese taxing authority. In addition, we expect to pay approximately $1.5 million of additional expenses to Takeda related to the agreement. We may receive potential milestones and royalties on sales of antibody products in the future.

NIAID

In March of 2005, we were awarded a $15.0 million competitive bid contract from NIAID to develop three anti-botulinum neurotoxin monoclonal antibodies. Under this contract, we created production cell lines using our proprietary antibody expression systems, built Master and Manufacturer’s Working Cell Banks, developed production processes and produced initial quantities of the three antibodies. The contract was performed over an 18-month period and was 100% funded with federal funds from NIAID under Contract No. HHSN266200500004C. Final acceptance of the project was received in October of 2006.

In July of 2006, we were awarded a $16.3 million contract funded with federal funds from NIAID under Contract No. HHSN266200600008C/N01-Al-60008 to produce monoclonal antibodies for the treatment of botulism to protect United States citizens against the harmful effects of botulinum neurotoxins used in bioterrorism. Under this contract, we have created and produced an innovative injectable product comprised of three anti-type A botulinum neurotoxin monoclonal antibodies to support entry into Phase 1 safety human clinical trials. The work is being performed on a cost plus fixed fee basis, per the terms of the contract, over a three-year period.

In September of 2008, we were awarded a third contract for $65 million funded with federal funds from NIAID under Contract No. HHSN272200800028C to continue development of our anti-botulinum antibody product candidates, including XOMA 3AB and additional product candidates. As part of the new contract, we will develop, evaluate and produce the clinical supplies to support an IND filing with the FDA and conduct preclinical studies required to support human clinical trials.

Recently Terminated Agreements

Lexicon

In November of 2008, we terminated our collaboration agreement with Lexicon Pharmaceuticals, Inc. (“Lexicon”), which was entered into in June of 2005 to jointly develop and commercialize antibody drugs for certain targets discovered by Lexicon. The collaboration was designed to combine Lexicon’s target discovery and biotherapeutics capabilities with our antibody generation, process development and manufacturing expertise to accelerate the development and commercialization of novel therapeutic antibodies.

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Incyte

In July of 2008, our license agreement with Incyte Corporation (“Incyte”) expired including the remaining 125,000 warrants held by Incyte to purchase our common shares at $6.00 per share. This agreement was entered into in July of 1998 whereby we obtained an exclusive (even as to Incyte), freely sublicenseable, worldwide license to all of Incyte’s patent rights relating to BPI. In exchange, we agreed to pay Incyte a royalty on sales of BPI products covered by the license, up to a maximum of $11.5 million and we made a $1.5 million advance royalty payment, one-half in cash and one-half in our common shares.

Research and Development

Our research and development expenses currently include costs of personnel, supplies, facilities and equipment, consultants, third party costs and other expenses related to preclinical and clinical testing. In 2008, our research and development expenses were $82.6 million compared with $66.2 million in 2007 and $52.1 million in 2006.

Our research and development activities can be divided into those related to our internal projects and those related to collaborative and contract arrangements, which are reimbursed by our customers. In 2008, research and development expenses related to internal projects were $58.5 million compared with $45.8 million in 2007 and $32.0 million in 2006. In 2008, research and development expenses related to collaborative and contract arrangements were $24.1 million compared with $20.4 million in 2007 and $20.1 million in 2006. Refer to Item 7: Results of Operations: Research and Development Expenses for further information regarding our research and development expenses.

Competition

The biotechnology and pharmaceutical industries are subject to continuous and substantial technological change. Competition in the areas of recombinant DNA-based and antibody-based technologies is intense and expected to increase as new technologies emerge and established biotechnology firms and large chemical and pharmaceutical companies continue to advance in the field. A number of these large pharmaceutical and chemical companies have enhanced their capabilities by entering into arrangements with or acquiring biotechnology companies or entering into business combinations with other large pharmaceutical companies. Many of these companies have significantly greater financial resources, larger research and development and marketing staffs and larger production facilities than ours. Moreover, certain of these companies have extensive experience in undertaking preclinical testing and human clinical trials. These factors may enable other companies to develop products and processes competitive with or superior to ours. In addition, a significant amount of research in biotechnology is being carried out in universities and other non-profit research organizations. These entities are becoming increasingly interested in the commercial value of their work and may become more aggressive in seeking patent protection and licensing arrangements. Furthermore, many companies and universities tend not to announce or disclose important discoveries or development programs until their patent position is secure or, for other reasons, later; as a result, we may not be able to track development of competitive products, particularly at the early stages. There can be no assurance that developments by others will not render our products or technologies obsolete or uncompetitive.

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Without limiting the foregoing, we are aware of the following competitors for the products and candidates shown in the table below. This table is not intended to be representative of all existing competitors in the market:

Regulatory

Our products are subject to comprehensive preclinical and clinical testing requirements and to approval processes by the FDA and by similar authorities in other countries. Our products are primarily regulated on a product-by-product basis under the United States Food, Drug and Cosmetic Act and Section 351(a) of the Public Health Service Act. Most of our human therapeutic products are or will be classified as biologic products. Approval of a biologic for commercialization requires licensure of the product and the manufacturing facilities. The review of therapeutic biologic products is carried out by the FDA’s Center for Drug Evaluation and Research, the body that also reviews drug products.

The FDA regulatory process is carried out in several phases. Prior to beginning human clinical testing of a proposed new biologic product, an IND is filed with the FDA. This document contains scientific information on the proposed product, including results of testing of the product in animal and laboratory models. Also included is information on manufacturing the product and studies on toxicity in animals and a clinical protocol outlining the initial investigation in humans.

The initial stage of clinical testing, Phase 1, ordinarily encompasses safety, pharmacokinetic and pharmacodynamic evaluations. Phase 2 testing encompasses investigation in specific disease states designed to provide preliminary efficacy data and additional information on safety. Phase 3 studies are designed to further establish clinical safety and efficacy and to provide information allowing proper labeling of the product following approval. Phase 3 studies are most commonly multi-center, randomized, placebo-controlled trials in which rigorous statistical methodology is applied to clinical results. Other designs may also be appropriate in specific circumstances.

Following completion of clinical trials, a BLA is submitted to the FDA to request marketing approval. Internal FDA committees are formed that evaluate the application, including scientific background information, animal and laboratory efficacy studies, toxicology, manufacturing facility and clinical data. During the review process, a dialogue between the FDA and the applicant is established in which FDA questions are raised and additional information is submitted. During the final stages of the approval process, the FDA generally requests presentation of clinical or other data before an FDA advisory committee, at which point, some or all of such data may become available. Also, during the later stages of review, the FDA conducts an inspection of the manufacturing facility to

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establish that the product is made in conformity with good manufacturing practice. If all outstanding issues are satisfactorily resolved and labeling established, the FDA issues a license for the product and for the manufacturing facility, thereby authorizing commercial distribution.

The FDA has substantial discretion in both the product approval process and the manufacturing approval process. It is not possible to predict at what point, or whether, the FDA will be satisfied with our submissions or whether the FDA will raise questions which may delay or preclude product approval or manufacturing facility approval. As additional clinical data is accumulated, it will be submitted to the FDA and may have a material impact on the FDA product approval process. Given that regulatory review is an interactive and continuous process, we have adopted a policy of limiting announcements and comments upon the specific details of the ongoing regulatory review of our products, subject to our obligations under the securities laws, until definitive action is taken. There can be no assurance any of the products we have under development will be developed successfully, obtain the requisite regulatory approval or be successfully manufactured or marketed.

In Europe, most of our human therapeutic products are or will be classified as biological medicinal products which are assessed through a centralized procedure by the EMEA. The EMEA coordinates the evaluation and supervision of medicinal products throughout the European Union and the European Economic Area. The assessment of the Marketing Authorization Application (“MA”) is carried out by a Rapporteur and a Co-Rapporteur appointed by the CHMP, which is the expert scientific committee of the EMEA.

The Rapporteur and Co-Rapporteur are drawn from the CHMP membership representing member states of the European Union. In addition to their responsibility for undertaking scientific assessments of an application for a MA, the Rapporteur and the Co-Rapporteur liaise with the applicant on behalf of the CHMP in an effort to provide answers to queries raised by the CHMP. Their assessment report(s) is circulated to and considered by the full CHMP membership, leading to the production ultimately of a CHMP opinion which is transmitted to the applicant and the European Commission. The final decision on the grant of a MA is made by the European Commission as the licensing authority of the European Community (“Community”). Under Community law, a positive decision issued by the European Commission represents the grant of a MA. Such an authorization allows a medicinal product to be placed on the European market. Upon the grant of an MA in the European Union, certain member states require pricing approval before the product can be placed into commercial distribution.

Under Community law, the applicant may request grant of a MA under exceptional circumstances if comprehensive data on the efficacy and safety of the drug, under normal conditions of use cannot be provided because its intended indications are encountered so rarely (such as in the case of a medicinal product intended for treating an orphan disease) that comprehensive evidence cannot reasonably be collected, the present state of scientific knowledge will not allow comprehensive information to be collected, or it would be against generally accepted medical ethics to collect comprehensive information. The Rapporteur, Co-Rapporteur and the other CHMP members will assess the justification/data submitted for exceptional circumstances as part of the overall assessment of the benefit/risk of the application. It is up to the CHMP, during the review, to ultimately decide on whether grant of a MA under exceptional circumstances is justified on the evidence before them. Approval under exceptional circumstances is subject to a requirement for specific procedures related to safety and results of its use and is reviewed annually to reassess the risk-benefit balance of the product. Once approval is granted, the product can be marketed under the single European MA in all member states of the European Union and the European Economic Area. Consistent with the single MA, the labeling for Europe is identical throughout all member states except that all labeling must be translated into the local language of the country of intended importation and in relation to the content of the so called “blue box” on the outer packaging in which locally required information may be inserted.

Orphan drugs are those intended for use in rare diseases or conditions. As a result of the high cost of development and the low return on investment for rare diseases, governments provide regulatory and commercial incentives for the development of drugs for small disease populations. In the United States, the term “rare disease or condition” means any disease or condition which affects less than 200,000 persons in the United States.

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Applications for United States orphan drug status are evaluated and granted by the Office of Orphan Products Development (“OOPD”) of the FDA. In the United States, orphan drugs are subject to the standard regulatory process for marketing approval but are exempt from the payment of user fees for licensure, receive market exclusivity for a period of seven years and some tax benefits, and are eligible for OOPD grants. In Europe, orphan medicinal products are those intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition affecting not more than five in 10,000 persons in the Community. The EMEA’s Committee for Orphan Medicinal Products (“COMP”) reviews applications seeking orphan designation. If the European Commission agrees with a positive assessment made by COMP, then the product will receive a positive designation through adoption of a decision by the European Commission. Orphan medicinal products are exempt from fees for protocol assistance and scientific advice from the Scientific Advice Working Party during development, reduction or exemption of MA and other fees, and ten-year market exclusivity upon granting of a MA in respect of the approved clinical indication. Moreover, manufacturers may be eligible for grants or other financial incentives from the Community and Member States programs.

Patents and Trade Secrets

Patent and trade secret protection is important to our business and our future will depend in part on our ability to obtain patents, maintain trade secret protection and operate without infringing on the proprietary rights of others. As a result of our ongoing activities, we hold and have filed applications for a number of patents in the United States and internationally to protect our products and important processes. We also have obtained or have the right to obtain exclusive licenses to certain patents and applications filed by others. However, the patent position of biotechnology companies generally is highly uncertain and no consistent policy regarding the breadth of allowed claims has emerged from the actions of the U.S. Patent and Trademark Office (“Patent Office”) with respect to biotechnology patents. Accordingly, no assurance can be given that our patents will afford protection against competitors with similar technologies, or others will not obtain patents claiming aspects similar to those covered by our patent applications.

We have established a portfolio of patents related to our bacterial expression technology, including claims to novel promoter sequences, secretion signal sequences, compositions, methods for expression and secretion of recombinant proteins from bacteria, including immunoglobulin gene products, and improved methods and cells for expression of recombinant protein products. U.S. Patent No. 5,028,530 directed to expression vehicles containing an araB promoter, host cells and processes for regulated expression of recombinant proteins expired in July of 2008. U.S. Patent Nos. 5,576,195 and 5,846,818 are related to DNA encoding a pectate lyase signal sequence, recombinant vectors, host cells and methods for production and externalization of recombinant proteins. U.S. Patent Nos. 5,595,898, 5,698,435 and 5,618,920 address secretable immunoglobulin chains, DNA encoding the chains and methods for their recombinant production. U.S. Patent Nos. 5,693,493, 5,698,417 and 6,204,023 relate to methods for recombinant production/secretion of functional immunoglobulin molecules. U.S. Patent Nos. 7,094,579 and 7,396,661 relate to eukaryotic signal sequences and their use in methods for prokaryotic expression of recombinant proteins. U.S. Patent No. 6,803,210 relates to improved bacterial host cells that are deficient in one or more of the active transport systems for an inducer of an inducible promoter, such as arabinose for an araB promoter, and methods for the use of such cells for the production of recombinant proteins. Most of the more important European patents in this portfolio expired in July of 2008 or earlier.

We have also established a portfolio of patent applications related to our mammalian expression technology, including U.S. Patent No. 7,192,737, related to methods for increasing the expression of recombinant polypeptides using expression vectors containing multiple copies of a transcription unit encoding a polypeptide of interest.

We have established a portfolio of patents and applications related to our Human Engineering^™ technology, including U.S. Patent No. 5,766,886, directed to methods of modifying antibody variable domains to reduce immunogenicity. Related patents and applications are directed to antibodies engineered according to our patented methods. We believe that our patented Human Engineering^™ technology provides an attractive alternative to other humanization technologies.

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If certain patents issued to others are upheld or if certain patent applications filed by others issue and are upheld, we may require certain licenses from others in order to develop and commercialize certain potential products incorporating our technology. There can be no assurance that such licenses, if required, will be available on acceptable terms.

Where appropriate, we also rely on trade secrets to protect aspects of our technology. However, trade secrets are difficult to protect. We protect our proprietary technology and processes, in part, by confidentiality agreements with our employees, consultants and collaborators. These parties may breach these agreements, and we may not have adequate remedies for any breach. Our trade secrets may otherwise become known or be independently discovered by competitors. To the extent that we or our consultants or collaborators use intellectual property owned by others, we may have disputes with our collaborators or consultants or other third parties as to the rights in related or resulting know-how and inventions.

International Operations

We believe that, because the pharmaceutical industry is global in nature, international activities will be a significant part of our future business activities and that, when and if we are able to generate income, a substantial portion of that income will be derived from product sales and other activities outside the United States.

A number of risks are inherent in international operations. Foreign regulatory agencies often establish standards different from those in the United States. An inability to obtain foreign regulatory approvals on a timely basis could have an adverse effect on our international business, financial condition and results of operations. International operations may be limited or disrupted by the imposition of government controls, export license requirements, political or economic instability, trade restrictions, changes in tariffs, restrictions on repatriating profits, taxation or difficulties in staffing and managing international operations. In addition, our business, financial condition and results of operations may be adversely affected by fluctuations in currency exchange rates. There can be no assurance that we will be able to successfully operate in any foreign market.

Financial information regarding the geographic areas in which we operate is included in Note 1 to the Financial Statements: Segment and Geographic Information.

Concentration of Risk

In 2008, Genentech, Novartis and SPRI each provided more than 10% of our total revenues, none of which represent a related party to XOMA. These key customers accounted for 81% of our total revenues in 2008 and represented 64% of the accounts receivable balance at December 31, 2008. NIAID accounted for an additional 28% of the accounts receivable balance at December 31, 2008. The loss of one or more of these customers could have a material adverse effect on our business and financial condition.

In 2007, Pfizer, Genentech, SPRI and NIAID each provided more than 10% of our total revenues, none of which represent a related party to XOMA. These key customers accounted for approximately 99% of our accounts receivable balance at December 31, 2007. In 2006, Genentech and NIAID each provided more than 10% of our total revenues. These key customers accounted for approximately 39% of the accounts receivable balance at December 31, 2006. SPRI accounted for an additional 45% of the accounts receivable balance at December 31, 2006.

Organization

We were incorporated in Delaware in 1981 and became a Bermuda company effective December 31, 1998, when we completed a shareholder-approved corporate reorganization, changing our legal domicile from Delaware to Bermuda and our name to XOMA Ltd. When referring to a time or period before December 31, 1998, or when the context so requires, the terms “Company” and “XOMA” refer to XOMA Corporation, a Delaware corporation and the predecessor of XOMA Ltd.

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Employees

On January 15, 2009, the Company announced a workforce reduction of approximately 42 percent or 144 employees, a majority of which were employed in manufacturing and related support functions. This decision was based on a decrease in forecasted contract manufacturing demand in 2009.

As of March 6, 2009, we employed approximately 335 full-time employees (none of which are unionized) at our facilities, principally in Berkeley, California, and, due to the workforce reduction, expect to have approximately 200 employees as of March 17, 2009. Our employees are primarily engaged in clinical, process development, research and product development, and in executive, business development, finance and administrative positions. We consider our employee relations to be excellent.

Available Information

For information on XOMA’s investment prospects and risks, please contact Investor Relations and Corporate Communications at (800) 246-9662 or by sending an e-mail message to investorrelations@xoma.com. Our principal executive offices are located at 2910 Seventh Street, Berkeley, California 94710, U.S.A. Our telephone number is (510) 204-7200.

The following information can be found on our website at http://www.xoma.com or can be obtained free of charge by contacting our Investor Relations Department:

We intend to satisfy the applicable disclosure requirements regarding amendments to, or waivers from, provisions of our Code of Ethics by posting such information on our website.

The following risk factors and other information included in this annual report should be carefully considered. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us also may impair our business operations. If any of the following risks occur, our business, financial condition, operating results and cash flows could be materially adversely affected.

Because our product candidates are still being developed, we will require substantial funds to continue; we cannot be certain that funds will be available and, if they are not available, we may have to take actions that could adversely affect your investment and may not be able to continue as a going concern.

While our refocused business strategy will reduce capital expenditures and other operating expenses, we will need to commit substantial funds to continue development of our product candidates and we may not be able to obtain sufficient funds on acceptable terms, or at all. If adequate funds are not available, we may have to raise additional funds in a manner that may dilute or otherwise adversely affect the rights of existing shareholders,

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curtail or cease operations, or file for bankruptcy protection in extreme circumstances. We have spent, and we expect to continue to spend, substantial funds in connection with:

We finance our operations primarily through our multiple revenue streams resulting from the licensing of our antibody technologies, product royalties, development collaborations and biodefense contracts, and sales of XOMA’s common shares. Based on current spending levels, anticipated revenues, collaborator funding and other sources of funding we believe to be available, we estimate that we have sufficient cash resources to meet our anticipated net cash needs through the next twelve months, excluding a potential acceleration of debt due to an anticipated decline in RAPTIVA^® royalty revenue in 2009. Any significant revenue shortfalls, increases in planned spending on development programs or more rapid progress of development programs than anticipated, as well as the unavailability of anticipated sources of funding, could shorten this period. We expect sales of RAPTIVA^® to decline significantly as a result of recent events, and we anticipate that as a consequence we will be in violation of or default under the relevant provisions of our loan from Goldman Sachs during the second or third quarter of this year. In the event we are not able to restructure the terms of our loan from Goldman Sachs and otherwise maintain at least twelve months of cash resources, there will be substantial doubt as to our ability to continue as a going concern. If adequate funds are not available, we will be required to delay, reduce the scope of, or eliminate one or more of our product development programs and further reduce personnel-related costs. Progress or setbacks by potentially competing products may also affect our ability to raise new funding on acceptable terms. As a result, we do not know when or whether:

Cash balances and operating cash flow are influenced primarily by the timing and level of payments by our licensees and development partners, as well as by our operating costs.

Our independent registered public accountants have indicated there is substantial doubt as to our ability to continue as a going concern.

Our independent registered public accounting firm has included in their report for our fiscal year ended December 31, 2008 a qualification with respect to our ability to continue as a going concern. Our consolidated financial statements have been prepared on the basis of going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. If we became unable to continue as a going concern, we would have to liquidate our assets and the values we receive for our assets in liquidation could be significantly lower than the values at which they are carried on our consolidated financial statements. The inclusion of a going concern qualification in our independent registered public accounting firm’s audit opinion for the year ended December 31, 2008 may materially adversely affect our share price and our ability to raise new capital.

Global credit and financial market conditions may reduce our ability to access capital and cash and could negatively impact the value of our current portfolio of cash equivalents or short-term investments and our ability to meet our financing objectives.

Traditionally, we have funded a large portion of our research and development expenditures through raising capital in the equity markets. Recent events, including failures and bankruptcies among large commercial and

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investment banks, have led to considerable declines and uncertainties in these and other capital markets and may lead to new regulatory and other restrictions that may broadly affect the nature of these markets. These circumstances could severely restrict the raising of new capital by companies such as us in the future.

Recent volatility in the financial markets has also created liquidity problems in investments previously thought to bear a minimal risk. For example, money market fund investors, including us, have in the past been unable to retrieve the full amount of funds, even in highly-rated liquid money market accounts, upon maturity. An inability to retrieve funds from money market and similar short-term investments as they mature in the future could have a material and adverse impact on our business, results of operations and cash flows. As of December 31, 2008, we have received the full amount of proceeds from matured money market fund investments.

Our cash and cash equivalents are maintained in highly liquid investments with remaining maturities of 90 days or less at the time of purchase. Our short-term investments consist primarily of readily marketable debt securities with remaining maturities of more than 90 days at the time of purchase. While as of the date of this filing, we are not aware of any downgrades, material losses, or other significant deterioration in the fair value of our cash equivalents or short-term investments since December 31, 2008, no assurance can be given that further deterioration in conditions of the global credit and financial markets would not negatively impact our current portfolio of cash equivalents or short-term investments or our ability to meet our financing objectives.

Our level of leverage and debt service obligations could adversely affect our financial condition.

As of December 31, 2008, we had approximately $63.3 million of indebtedness outstanding, including $12.9 million with Novartis and $50.4 million with Goldman Sachs Specialty Lending Holdings, Inc. (“Goldman Sachs”). We may not be able to generate cash sufficient to pay the principal of, interest on and other amounts due in respect of our indebtedness when due. We may also incur additional debt that may be secured.

In connection with our original collaboration with Novartis, Novartis extended a loan to us (through our U.S. subsidiary) to fund up to 75% of our expenses thereunder, of which $12.9 million was outstanding as of December 31, 2008. The loan bears interest at an annual rate of six-month LIBOR plus 2%, which was equal to 3.85% at December 31, 2008, and any unpaid principal amount together with accrued and unpaid interest is due and payable in full in June of 2015. This loan is secured by a pledge of our interest in the collaboration. Although the collaboration was restructured in November of 2008 and we may not draw any additional funds under the loan facility, we remain liable for amounts previously borrowed under this facility.

In November of 2006, XOMA (US) LLC entered into a five-year, $35.0 million term royalty-based loan facility with Goldman Sachs and borrowed the full amount thereunder. In May of 2008, this term loan facility was replaced with a new five-year term royalty-based loan facility. The loan bears interest at an annual rate equal to the greater of six-month LIBOR or 3%, plus a margin of 8.5%. As of December 31, 2008, the interest rate on this loan was 12.3%. The outstanding balance of the new facility as of December 31, 2008 was $50.4 million.

The new Goldman Sachs loan is guaranteed by XOMA and secured by the payment rights relating to RAPTIVA^®, LUCENTIS^® and CIMZIA^® . So long as this loan is outstanding, these assets will not be available to XOMA or any other lender to secure future indebtedness.

Our level of debt and debt service obligations could have important effects on us and our investors. These effects may include:

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Our ability to satisfy our debt obligations will depend upon our future operating performance and the availability of refinancing debt. If we are unable to service our debt and fund our business, we may be forced to reduce or delay capital expenditures, seek additional debt financing or equity capital, restructure or refinance our debt or sell assets. We cannot assure you that we would be able to obtain additional financing, refinance existing debt or sell assets on satisfactory terms or at all. In particular, although we may prepay our debt to Goldman Sachs at any time, in order to do so we would be required to pay certain specified prepayment premiums if prepaid within the first four years which we may not have sufficient funds to pay or which may be prohibitively high under the circumstances at the time we would otherwise choose to repay such debt.

Because we expect the royalty payments we receive on sales of RAPTIVA^® to decline significantly, we anticipate that we will be in violation of or default under our debt to Goldman Sachs if we cannot successfully restructure the terms of this debt.

Our loan agreement with Goldman Sachs includes provisions that allow the lenders to accelerate our obligation to repay the debt or to pursue other remedies against us in certain circumstances. For example, the terms of this debt include a financial covenant that requires us to maintain a specified ratio of royalties collected to interest payable and another covenant that requires quarterly U.S. and outside-the-U.S. sales of RAPTIVA^® and LUCENTIS^® to exceed certain specified minimum levels. This means that our ability to comply with these requirements is dependent on continued sales by Genentech, UCB and their partners of these products at adequate levels, and any significant reduction in such sales could cause us to violate or be in default under these provisions, which could result in acceleration of our obligation to repay this debt.

In February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union, EMD Serono announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada and the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. We expect sales of RAPTIVA^® to decline significantly as a result of these and other related events, and we anticipate that as a consequence we will be in violation of or default under the relevant provisions of this loan during the second or third quarter of this year. We are currently in discussions with the lenders regarding a restructuring of the terms of this loan to address the effects of these developments. However, there can be no assurance that we will reach agreement with the lenders on acceptable terms, or at all, as a result of these discussions.

If the trading price of our common shares fails to comply with the continued listing requirements of The NASDAQ Global Market, we would face possible delisting, which would result in a limited public market for our common shares and make obtaining future debt or equity financing more difficult for us.

NASDAQ-listed companies are subject to delisting for, among other things, failure to maintain a minimum closing bid price per share of $1.00 for 30 consecutive business days. The closing price per share of our common shares was below $1.00 for 13 consecutive business days during November and December of 2008 and has been below $1.00 since December 9, 2008. NASDAQ has temporarily suspended the minimum bid price requirement in

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response to current market conditions. This suspension is currently set to expire on April 20, 2009. Although NASDAQ had informally indicated that it may extend this suspension, there can be no assurance that it will do so.

If we do not continue to comply with the continued listing requirements for The NASDAQ Global Market, then NASDAQ may provide written notification regarding the delisting of our securities. At that time, we would have the right to request a hearing to appeal the NASDAQ determination and would also have the option to apply to transfer our securities to The NASDAQ Capital Market.

We cannot be sure that our price will comply with the requirements for continued listing of our common shares on The NASDAQ Global Market, or that any appeal of a decision to delist our common shares will be successful. If our common shares lose their status on The NASDAQ Global Market and we are not successful in obtaining a listing on The NASDAQ Capital Market, our common shares would likely trade in the over-the-counter market.

If our shares were to trade on the over-the-counter market, selling our common shares could be more difficult because smaller quantities of shares would likely be bought and sold, transactions could be delayed, and security analysts’ coverage of us may be reduced. In addition, in the event our common shares are delisted, broker-dealers have certain regulatory burdens imposed upon them, which may discourage broker-dealers from effecting transactions in our common shares, further limiting the liquidity thereof. These factors could result in lower prices and larger spreads in the bid and ask prices for common shares.

Such delisting from The NASDAQ Global Market or future declines in our share price could also greatly impair our ability to raise additional necessary capital through equity or debt financing, and could significantly increase the ownership dilution to shareholders caused by our issuing equity in financing or other transactions. Consent under the Exchange Control Act 1972 (and its related regulations) has been obtained from the Bermuda Monetary Authority for the issue and transfer of our shares, notes and other securities to and between non-residents of Bermuda for exchange control purposes, but this consent is conditional on our shares remaining listed on an appointed stock exchange. We cannot assure you that the Bermuda Monetary Authority will give the same or a similar consent in the event our common shares are no longer listed on The NASDAQ Global Market or another appointed stock exchange. In the absence of such a general consent, specific consents of the Bermuda Monetary Authority would be required for certain issues and transfers of our shares, notes and other securities.

Because all of our product candidates are still being developed, we have sustained losses in the past and we expect to sustain losses in the future.

We have experienced significant losses and, as of December 31, 2008, we had an accumulated deficit of $785.1 million.

For the year ended December 31, 2008, we had a net loss of approximately $45.2 million or $0.34 per common share (basic and diluted). For the year ended December 31, 2007, we had a net loss of approximately $12.3 million or $0.10 per common share (basic and diluted).

Our ability to achieve profitability is dependent in large part on the success of our development programs, obtaining regulatory approval for our product candidates and entering into new agreements for product development, manufacturing and commercialization, all of which are uncertain. Our ability to fund our ongoing operations is dependent on the foregoing factors and on our ability to secure additional funds. Because our product candidates are still being developed, we do not know whether we will ever achieve sustained profitability or whether cash flow from future operations will be sufficient to meet our needs.

We may issue additional equity securities and thereby materially and adversely affect the price of our common shares.

We are authorized to issue, without shareholder approval, 1,000,000 preference shares, of which 2,959 were issued and outstanding as of March 6, 2009, which may give other shareholders dividend, conversion, voting, and

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liquidation rights, among other rights, which may be superior to the rights of holders of our common shares. In addition, we are authorized to issue, generally without shareholder approval, up to 210,000,000 common shares, of which 142,244,227 were issued and outstanding as of March 6, 2009. If we issue additional equity securities, the price of our common shares may be materially and adversely affected. On October 21, 2008, we entered into a common share purchase agreement with Azimuth Opportunity, Ltd. (“Azimuth”), pursuant to which we obtained a committed equity line of credit facility under which we may sell up to $60 million of our registered common shares to Azimuth over a 24-month period, subject to certain conditions and limitations. As of March 6, 2009, we have sold 7,932,432 common shares under this facility for aggregate gross proceeds of $7.5 million.

The financial terms of future collaborative or licensing arrangements could result in dilution of our share value.

Funding from collaboration partners and others has in the past and may in the future involve issuance by us of our shares. Because we do not currently have any such arrangements, we cannot be certain how the purchase price of such shares, the relevant market price or premium, if any, will be determined or when such determinations will be made. Any such issuance could result in dilution in the value of our issued and outstanding shares.

Our share price may be volatile and there may not be an active trading market for our common shares.

There can be no assurance that the market price of our common shares will not decline below its present market price or that there will be an active trading market for our common shares. The market prices of biotechnology companies have been and are likely to continue to be highly volatile. Fluctuations in our operating results and general market conditions for biotechnology stocks could have a significant impact on the volatility of our common share price. We have experienced significant volatility in the price of our common shares. From January 1, 2008 through March 6, 2009, our share price has ranged from a high of $3.37 to a low of $0.48. Factors contributing to such volatility include, but are not limited to:

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Our therapeutic product candidates have not received regulatory approval. If these product candidates do not receive regulatory approval, neither our third party collaborators nor we will be able to manufacture and market them.

Our product candidates cannot be manufactured and marketed in the United States and other countries without required regulatory approvals. The United States government and governments of other countries extensively regulate many aspects of our product candidates, including:

In the United States, the FDA regulates pharmaceutical products under the Federal Food, Drug, and Cosmetic Act and other laws, including, in the case of biologics, the Public Health Service Act. At the present time, we believe that most of our product candidates will be regulated by the FDA as biologics. Initiation of clinical trials requires approval by health authorities. Clinical trials involve the administration of the investigational new drug to healthy volunteers or to patients under the supervision of a qualified principal investigator. Clinical trials must be conducted in accordance with FDA and International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (“ICH”) Good Clinical Practices and the European Clinical Trials Directive under protocols that detail the objectives of the study, the parameters to be used to monitor safety and the efficacy criteria to be evaluated. Other national, foreign and local regulations may also apply. The developer of the drug must provide information relating to the characterization and controls of the product before administration to the patients participating in the clinical trials. This requires developing approved assays of the product to test before administration to the patient and during the conduct of the trial. In addition, developers of pharmaceutical products must provide periodic data regarding clinical trials to the FDA and other health authorities, and these health authorities may issue a clinical hold upon a trial if they do not believe, or cannot confirm, that the trial can be conducted without unreasonable risk to the trial participants. We cannot assure you that U.S. and foreign health authorities will not issue a clinical hold with respect to any of our clinical trials in the future.

The results of the preclinical studies and clinical testing, together with chemistry, manufacturing and controls information, are submitted to the FDA and other health authorities in the form of a new drug application for a pharmaceutical product, and in the form of a BLA for a biological product, requesting approval to commence commercial sales. In responding to a new drug application or an antibody license application, the FDA or foreign health authorities may grant marketing approvals, request additional information or further research, or deny the application if it determines that the application does not satisfy its regulatory approval criteria. Regulatory approval of a new drug application, BLA, or supplement is never guaranteed, and the approval process can take several years and is extremely expensive. The FDA and foreign health authorities have substantial discretion in the drug and biologics approval processes. Despite the time and expense incurred, failure can occur at any stage, and we could encounter problems that cause us to abandon clinical trials or to repeat or perform additional preclinical, clinical or manufacturing-related studies.

Changes in the regulatory approval policy during the development period, changes in, or the enactment of additional regulations or statutes, or changes in regulatory review for each submitted product application may cause delays in the approval or rejection of an application. State regulations may also affect our proposed products. The FDA has substantial discretion in both the product approval process and manufacturing facility approval process and, as a result of this discretion and uncertainties about outcomes of testing, we cannot predict at what point, or whether, the FDA will be satisfied with our or our collaborators’ submissions or whether the FDA will raise questions which may be material and delay or preclude product approval or manufacturing facility approval. As we accumulate additional clinical data, we will submit it to the FDA, and such data may have a material impact on the FDA product approval process.

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Even once approved, a product may be subject to additional testing or significant marketing restrictions or its approval may be withdrawn.

Even if the FDA, the European Commission or another regulatory agency approves a product candidate for marketing, the approval may impose ongoing requirements for post-approval studies, including additional research and development and clinical trials, and the FDA, European Commission or other regulatory agency may subsequently withdraw approval based on these additional trials

Even for approved products such as RAPTIVA^®, LUCENTIS^® and CIMZIA^®, the FDA, European Commission or other regulatory agency may impose significant restrictions on the indicated uses, conditions for use, labeling, advertising, promotion, marketing and/or production of such product. For example, in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^®.

Furthermore, a marketing approval of a product may be withdrawn by the FDA, the European Commission or another regulatory agency based, for example, on subsequently-arising safety concerns. In February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and that the CHMP has concluded that the benefits of RAPTIVA^® no longer outweigh its risks because of safety concerns, including the occurrence of PML in patients taking the medicine.

The FDA, European Commission and other agencies also may impose various civil or criminal sanctions for failure to comply with regulatory requirements, including withdrawal of product approval.

We face uncertain results of clinical trials of our potential products.

Our potential products, including XOMA 052 and XOMA 3AB, will require significant additional research and development, extensive preclinical studies and clinical trials and regulatory approval prior to any commercial sales. This process is lengthy and expensive, often taking a number of years. As clinical results are frequently susceptible to varying interpretations that may delay, limit or prevent regulatory approvals, the length of time necessary to complete clinical trials and to submit an application for marketing approval for a final decision by a regulatory authority varies significantly. As a result, it is uncertain whether:

For example, in 2003, we completed two Phase 1 trials of XOMA 629, a BPI-derived topical peptide compound targeting acne, evaluating the safety, skin irritation and pharmacokinetics. In January of 2004, we announced the initiation of Phase 2 clinical testing in patients with mild-to-moderate acne. In August of 2004, we announced the results of a Phase 2 trial with XOMA 629 gel. The results were inconclusive in terms of clinical benefit of XOMA 629 compared with vehicle gel. In 2007, after completing an internal evaluation of this program, we chose to reformulate and focus development efforts on the use of this reformulated product candidate in superficial skin infections, including impetigo and the eradication of staphylococcus aureus, including MRSA. In the fourth quarter of 2008, we decided to curtail all spending on XOMA 629 in response to current economic conditions and to focus our financial resources on XOMA 052.

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The timing of the commencement, continuation and completion of clinical trials may be subject to significant delays relating to various causes, including scheduling conflicts with participating clinicians and clinical institutions, difficulties in identifying and enrolling patients who meet trial eligibility criteria, and shortages of available drug supply. Patient enrollment is a function of many factors, including the size of the patient population, the proximity of patients to clinical sites, the eligibility criteria for the trial, the existence of competing clinical trials and the availability of alternative or new treatments. In addition, we will conduct clinical trials in foreign countries in the future which may subject us to further delays and expenses as a result of increased drug shipment costs, additional regulatory requirements and the engagement of foreign clinical research organizations, as well as expose us to risks associated with foreign currency transactions insofar as we might desire to use U.S. dollars to make contract payments denominated in the foreign currency where the trial is being conducted.

All of our product candidates are prone to the risks of failure inherent in drug development. Preclinical studies may not yield results that would satisfactorily support the filing of an IND (or a foreign equivalent) with respect to our product candidates. Even if these applications would be or have been filed with respect to our product candidates, the results of preclinical studies do not necessarily predict the results of clinical trials. Similarly, early-stage clinical trials in healthy volunteers do not predict the results of later-stage clinical trials, including the safety and efficacy profiles of any particular product candidates. In addition, there can be no assurance that the design of our clinical trials is focused on appropriate indications, patient populations, dosing regimens or other variables which will result in obtaining the desired efficacy data to support regulatory approval to commercialize the drug. Preclinical and clinical data can be interpreted in different ways. Accordingly, FDA officials or officials from foreign regulatory authorities could interpret the data in different ways than we or our partners do, which could delay, limit or prevent regulatory approval.

Administering any of our products or potential products may produce undesirable side effects, also known as adverse effects. Toxicities and adverse effects that we have observed in preclinical studies for some compounds in a particular research and development program may occur in preclinical studies or clinical trials of other compounds from the same program. Such toxicities or adverse effects could delay or prevent the filing of an IND (or a foreign equivalent) with respect to such products or potential products or cause us to cease clinical trials with respect to any drug candidate. In clinical trials, administering any of our products or product candidates to humans may produce adverse effects. These adverse effects could interrupt, delay or halt clinical trials of our products and product candidates and could result in the FDA or other regulatory authorities denying approval of our products or product candidates for any or all targeted indications. The FDA, other regulatory authorities, our partners or we may suspend or terminate clinical trials at any time. Even if one or more of our product candidates were approved for sale, the occurrence of even a limited number of toxicities or adverse effects when used in large populations may cause the FDA to impose restrictions on, or stop, the further marketing of such drugs. Indications of potential adverse effects or toxicities which may occur in clinical trials and which we believe are not significant during the course of such clinical trials may later turn out to actually constitute serious adverse effects or toxicities when a drug has been used in large populations or for extended periods of time. Any failure or significant delay in completing preclinical studies or clinical trials for our product candidates, or in receiving and maintaining regulatory approval for the sale of any drugs resulting from our product candidates, may severely harm our reputation and business.

Given that regulatory review is an interactive and continuous process, we maintain a policy of limiting announcements and comments upon the specific details of regulatory review of our product candidates, subject to our obligations under the securities laws, until definitive action is taken.

Certain of our technologies are relatively new and are in-licensed from third parties, so our capabilities using them are unproven and subject to additional risks.

We license technologies from third parties. These technologies include but are not limited to phage display technologies licensed to us in connection with our bacterial cell expression technology licensing program. However, our experience with some of these technologies remains relatively limited and, to varying degrees, we

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are still dependent on the licensing parties for training and technical support for these technologies. In addition, our use of these technologies is limited by certain contractual provisions in the licenses relating to them and, although we have obtained numerous licenses, intellectual property rights in the area of phage display are particularly complex. If the owners of the patent rights underlying the technologies we license do not properly maintain or enforce those patents, our competitive position and business prospects could be harmed. Our success will depend in part on the ability of our licensors to obtain, maintain and enforce our licensed intellectual property. Our licensors may not successfully prosecute the patent applications to which we have licenses, or our licensors may fail to maintain existing patents. They may determine not to pursue litigation against other companies that are infringing these patents, or they may pursue such litigation less aggressively than we would. Our licensors may also seek to terminate our license, which could cause us to lose the right to use the licensed intellectual property and adversely affect our ability to commercialize our technologies, products or services.

Our present and future revenues rely significantly on sales of products marketed and sold by others.

Currently, our revenues rely significantly upon sales of RAPTIVA^® and LUCENTIS^®, in which we have only royalty interests. RAPTIVA^® was approved by the FDA on October 27, 2003, for the treatment of chronic moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. Genentech and Merck Serono, Genentech’s international marketing partner for RAPTIVA^®, are responsible for the marketing and sales effort in support of this product. In September of 2004, Merck Serono announced that RAPTIVA^® had received approval for use in the European Union and the product was launched in several European Union countries in the fourth quarter of 2004. LUCENTIS^® was approved by the FDA on June 30, 2006, for the treatment of age-related macular degeneration. Genentech and Novartis, Genentech’s international marketing partner for LUCENTIS^®, are responsible for the marketing and sales effort in support of this product. We also receive revenues from sales of CIMZIA^® in the U.S. and Switzerland, in which we only have a royalty interest, and royalties received therefrom through December 31, 2008 have been immaterial. CIMZIA^® was approved by the FDA on April 22, 2008 for the treatment of moderate-to-severe Crohn’s disease in adults who have not responded to conventional therapies. In March of 2008, UCB announced that the CHMP of the EMEA had rejected UCB’s appeal following CHMP’s previously-announced refusal of UCB’s marketing authorization application for CIMZIA^® in the treatment of Crohn’s disease. UCB is responsible for the marketing and sales effort in support of this product. We have no role in marketing and sales efforts, and Genentech, Merck Serono, Novartis and UCB do not have an express contractual obligation to us regarding the marketing or sales of RAPTIVA^®, LUCENTIS^® or CIMZIA^®.

Successful commercialization of RAPTIVA^®, LUCENTIS^® and CIMZIA^® is subject to a number of risks, including, but not limited to:

For example, in February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and EMD Serono has announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada. Merck Serono has stated

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that it will work closely with the European health authorities to undertake all necessary measures to comply with the EMEA recommendation. Also in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that, based on the medical information available for these cases, it believes that RAPTIVA^® increases the risk of PML and that prolonged exposure to RAPTIVA^® or older age may further increase this risk. Genentech has also stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^®. We expect sales of RAPTIVA^® to decline significantly as a result of these events.

According to Genentech, United States sales of RAPTIVA^® during 2008 were $108 million, compared with $107 million and $90 million during 2007 and 2006, respectively. According to Merck Serono, sales of RAPTIVA^® outside of the U.S. during 2008 were approximately $134 million, compared with $106 million and $70 million during 2007 and 2006, respectively. According to Genentech, U.S. sales of LUCENTIS^® were $875 million during 2008 compared with $815 million and $380 million during 2007 and 2006, respectively. According to Novartis, sales of LUCENTIS^® outside the United States were $886 million in 2008 compared with $393 million and $27 million during 2007 and 2006, respectively. According to UCB, worldwide sales of CIMZIA^® were approximately $13 million during 2008.

Given our current reliance on RAPTIVA^® and LUCENTIS^® as principal sources of revenues, any material adverse developments with respect to the commercialization of RAPTIVA^® or LUCENTIS^® may cause our revenues to decrease and may cause us to incur additional losses in the future.

We do not know whether there will be, or will continue to be, a viable market for the products in which we have an ownership or royalty interest.

Although RAPTIVA^® was approved in the United States in October of 2003 and in the European Union in 2004 and LUCENTIS^® was approved in the United States in June of 2006, in the European Union in January of 2007 and in Japan in January of 2009, their acceptance in the marketplace may not continue. Although CIMZIA^® was approved in the United States in April of 2008 and in Switzerland in September of 2007, it may not be accepted in the marketplace. Furthermore, even if other products in which we have an interest receive approval in the future, they may not be accepted in the marketplace. In addition, we or our collaborators or licensees may experience difficulties in launching new products, many of which are novel and based on technologies that are unfamiliar to the healthcare community. We have no assurance that healthcare providers and patients will accept such products, if developed. For example, physicians and/or patients may not accept a product for a particular indication because it has been biologically derived (and not discovered and developed by more traditional means) or if no biologically derived products are currently in widespread use in that indication. Similarly, physicians may not accept a product, such as RAPTIVA^®, LUCENTIS^® or CIMZIA^®, if they believe other products to be more effective or are more comfortable prescribing other products.

Safety concerns may also arise in the course of on-going clinical trials or patient treatment as a result of adverse events or reactions. For example, in February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and EMD Serono has announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada. Merck Serono has stated that it will work closely with the European health authorities to undertake all necessary measures to comply with the EMEA recommendation. Also in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that, based on the medical information available for these cases, it believes that RAPTIVA increases the risk of PML and that prolonged exposure to RAPTIVA^® or older age may further increase this risk. Genentech has also stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^® and that it will likely see a reduction in demand for RAPTIVA^® in the future. We expect demand for RAPTIVA^® to decline significantly as a result of these events.

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Furthermore, government agencies, as well as private organizations involved in healthcare, from time to time publish guidelines or recommendations to healthcare providers and patients. Such guidelines or recommendations can be very influential and may adversely affect the usage of any products we may develop directly (for example, by recommending a decreased dosage of a product in conjunction with a concomitant therapy or a government entity withdrawing its recommendation to screen blood donations for certain viruses) or indirectly (for example, by recommending a competitive product over our product). Consequently, we do not know if physicians or patients will adopt or use our products for their approved indications.

We or our third party collaborators or licensees may not have adequate manufacturing capacity sufficient to meet market demand.

Genentech is responsible for manufacturing or arranging for the manufacturing of commercial quantities of RAPTIVA^® and LUCENTIS^®. UCB is responsible for manufacturing or arranging for the manufacturing of commercial quantities of CIMZIA^®. Should Genentech or UCB have difficulty in providing manufacturing capacity to produce these products in sufficient quantities, we do not know whether they will be able to meet market demand. If not, we will not realize revenues from the sales of these products. If any of our product candidates are approved, because we have never commercially introduced any pharmaceutical products, we do not know whether the capacity of our existing manufacturing facilities can be increased to produce sufficient quantities of our products to meet market demand. Also, if we or our third party collaborators or licensees need additional manufacturing facilities to meet market demand, we cannot predict that we will successfully obtain those facilities because we do not know whether they will be available on acceptable terms. In addition, any manufacturing facilities acquired or used to meet market demand must meet the FDA’s quality assurance guidelines.

Our agreements with third parties, many of which are significant to our business, expose us to numerous risks.

Our financial resources and our marketing experience and expertise are limited. Consequently, our ability to successfully develop products depends, to a large extent, upon securing the financial resources and/or marketing capabilities of third parties.

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Because our collaborators and licensees are independent third parties, they may be subject to different risks than we are and have significant discretion in determining the efforts and resources they will apply related to their agreements with us. If these collaborators and licensees do not successfully develop and market these products, we may not have the capabilities, resources or rights to do so on our own. We do not know whether our collaborators or licensees will successfully develop and market any of the products that are or may become the subject of one of our collaboration or licensing arrangements. In particular, each of these arrangements provides for funding solely by our collaborators or licensees. Furthermore, our contracts with NIAID contain numerous standard terms and conditions provided for in the applicable federal acquisition regulations and customary in many government contracts. Uncertainty exists as to whether we will be able to comply with these terms and conditions in a timely manner, if at all. In addition, given our relative lack of experience in programs under contract with government agencies, we are uncertain as to the extent of NIAID’s demands and the flexibility that will be granted to us in meeting those demands.

Even when we have a collaborative relationship, other circumstances may prevent it from resulting in successful development of marketable products.

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Although we continue to evaluate additional strategic alliances and potential partnerships, we do not know whether or when any such alliances or partnerships will be entered into.

Products and technologies of other companies may render some or all of our products and product candidates noncompetitive or obsolete.

Developments by others may render our products, product candidates, or technologies obsolete or uncompetitive. Technologies developed and utilized by the biotechnology and pharmaceutical industries are continuously and substantially changing. Competition in the areas of genetically engineered DNA-based and antibody-based technologies is intense and expected to increase in the future as a number of established biotechnology firms and large chemical and pharmaceutical companies advance in these fields. Many of these competitors may be able to develop products and processes competitive with or superior to our own for many reasons, including that they may have:

These factors may enable others to develop products and processes competitive with or superior to our own or those of our collaborators. In addition, a significant amount of research in biotechnology is being carried out in universities and other non-profit research organizations. These entities are becoming increasingly interested in the commercial value of their work and may become more aggressive in seeking patent protection and licensing arrangements. Furthermore, many companies and universities tend not to announce or disclose important discoveries or development programs until their patent position is secure or, for other reasons, later; as a result, we may not be able to track development of competitive products, particularly at the early stages. Positive or negative developments in connection with a potentially competing product may have an adverse impact on our ability to raise additional funding on acceptable terms. For example, if another product is perceived to have a competitive advantage, or another product’s failure is perceived to increase the likelihood that our product will fail, then investors may choose not to invest in us on terms we would accept or at all.

The examples below pertain to competitive events in the market which we review quarterly and are not intended to be representative of all existing competitive events. Without limiting the foregoing, we are aware that:

XOMA 052

XOMA has initiated clinical testing of XOMA 052, a potent anti-inflammatory monoclonal antibody targeting IL-1 beta, in Type 2 diabetes patients. It is possible that other companies may be developing other products based on the same therapeutic target as XOMA 052 and that these products may prove more effective than XOMA 052. We are aware that:

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XOMA 3AB

RAPTIVA^®

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LUCENTIS^®

In addition to LUCENTIS^®, there are two other FDA-approved therapies to treat macular degeneration: Pfizer’s and OSI Pharmaceuticals, Inc.’s Macugen^® and Novartis’ and QLT Inc.’s Visudyne^®. LUCENTIS^® also competes with Genentech’s cancer drug Avastin^®.

CIMZIA^®

In addition to CIMZIA^®, there are two other FDA-approved anti-TNF therapies to treat moderate-to-severe active Crohn’s disease in adults: Johnson & Johnson’s Remicade^® (infliximab) and Abbott Laboratories’ Humira^® (adalimumab).

Manufacturing risks and inefficiencies may adversely affect our ability to manufacture products for ourselves or others.

To the extent we continue to provide manufacturing services for our own benefit or to third parties, we are subject to manufacturing risks. Additionally, unanticipated fluctuations in customer requirements have led and may continue to lead to manufacturing inefficiencies. We must utilize our manufacturing operations in compliance with regulatory requirements, in sufficient quantities and on a timely basis, while maintaining acceptable product quality and manufacturing costs. Additional resources and changes in our manufacturing processes may be required for each new product, product modification or customer or to meet changing regulatory or third party requirements, and this work may not be successfully or efficiently completed. In addition, to the extent we continue to provide manufacturing services, our fixed costs, such as facility costs, would be expected to increase, as would necessary capital investment in equipment and facilities.

Manufacturing and quality problems may arise in the future to the extent we continue to perform these services for our own benefit or for third parties. Consequently, our development goals or milestones may not be achieved in a timely manner or at a commercially reasonable cost, or at all. In addition, to the extent we continue to make investments to improve our manufacturing operations, our efforts may not yield the improvements that we expect.

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Because many of the companies we do business with are also in the biotechnology sector, the volatility of that sector can affect us indirectly as well as directly.

As a biotechnology company that collaborates with other biotech companies, the same factors that affect us directly can also adversely impact us indirectly by affecting the ability of our collaborators, partners and others we do business with to meet their obligations to us and reduce our ability to realize the value of the consideration provided to us by these other companies.

For example, in connection with our licensing transactions relating to our bacterial cell expression technology, we have in the past and may in the future agree to accept equity securities of the licensee in payment of license fees. The future value of these or any other shares we receive is subject both to market risks affecting our ability to realize the value of these shares and more generally to the business and other risks to which the issuer of these shares may be subject.

As we do more business internationally, we will be subject to additional political, economic and regulatory uncertainties.

We may not be able to successfully operate in any foreign market. We believe that, because the pharmaceutical industry is global in nature, international activities will be a significant part of our future business activities and that, when and if we are able to generate income, a substantial portion of that income will be derived from product sales and other activities outside the United States. Foreign regulatory agencies often establish standards different from those in the United States, and an inability to obtain foreign regulatory approvals on a timely basis could put us at a competitive disadvantage or make it uneconomical to proceed with a product or product candidate’s development. International operations and sales may be limited or disrupted by:

If we and our partners are unable to protect our intellectual property, in particular our patent protection for our principal products, product candidates and processes, and prevent its use by third parties, our ability to compete in the market will be harmed, and we may not realize our profit potential.

We rely on patent protection, as well as a combination of copyright, trade secret, and trademark laws to protect our proprietary technology and prevent others from duplicating our products or product candidates. However, these means may afford only limited protection and may not:

Because of the length of time and the expense associated with bringing new products to the marketplace, we and our partners hold and are in the process of applying for a number of patents in the United States and abroad

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to protect our product candidates and important processes and also have obtained or have the right to obtain exclusive licenses to certain patents and applications filed by others. However, the mere issuance of a patent is not conclusive as to its validity or its enforceability. The United States Federal Courts or equivalent national courts or patent offices elsewhere may invalidate our patents or find them unenforceable. In addition, the laws of foreign countries may not protect our intellectual property rights effectively or to the same extent as the laws of the United States. If our intellectual property rights are not adequately protected, we may not be able to commercialize our technologies, products, or services, and our competitors could commercialize our technologies, which could result in a decrease in our sales and market share that would harm our business and operating results. Specifically, the patent position of biotechnology companies generally is highly uncertain and involves complex legal and factual questions. The legal standards governing the validity of biotechnology patents are in transition, and current defenses as to issued biotechnology patents may not be adequate in the future. Accordingly, there is uncertainty as to:

We have established an extensive portfolio of patents and applications, both United States and foreign, related to our BPI-related product candidates, including novel compositions, their manufacture, formulation, assay and use. We have also established a portfolio of patents, both United States and foreign, related to our bacterial cell expression technology, including claims to novel promoter sequences, secretion signal sequences, compositions and methods for expression and secretion of recombinant proteins from bacteria, including immunoglobulin gene products. Most of the more important European patents in our bacterial cell expression patent portfolio expired in July of 2008.

If certain patents issued to others are upheld or if certain patent applications filed by others issue and are upheld, we may require licenses from others in order to develop and commercialize certain potential products incorporating our technology or we may become involved in litigation to determine the proprietary rights of others. These licenses, if required, may not be available on acceptable terms, and any such litigation may be costly and may have other adverse effects on our business, such as inhibiting our ability to compete in the marketplace and absorbing significant management time.

Due to the uncertainties regarding biotechnology patents, we also have relied and will continue to rely upon trade secrets, know-how and continuing technological advancement to develop and maintain our competitive position. All of our employees have signed confidentiality agreements under which they have agreed not to use or disclose any of our proprietary information. Research and development contracts and relationships between us and our scientific consultants and potential customers provide access to aspects of our know-how that are protected generally under confidentiality agreements. These confidentiality agreements may be breached or may not be enforced by a court. To the extent proprietary information is divulged to competitors or to the public generally, such disclosure may adversely affect our ability to develop or commercialize our products by giving others a competitive advantage or by undermining our patent position.

Litigation regarding intellectual property can be costly and expose us to risks of counterclaims against us.

We may be required to engage in litigation or other proceedings to protect our intellectual property. The cost to us of this litigation, even if resolved in our favor, could be substantial. Such litigation could also divert management’s attention and resources. In addition, if this litigation is resolved against us, our patents may be

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declared invalid, and we could be held liable for significant damages. In addition, we may be subject to a claim that we are infringing another party’s patent. If such claim is resolved against us, we or our collaborators may be enjoined from developing, manufacturing, selling or importing products, processes or services unless we obtain a license from the other party. Such license may not be available on reasonable terms, thus preventing us from using these products, processes or services and adversely affecting our revenue.

Even if we or our third party collaborators or licensees bring products to market, we may be unable to effectively price our products or obtain adequate reimbursement for sales of our products, which would prevent our products from becoming profitable.

If we or our third party collaborators or licensees succeed in bringing our product candidates to the market, they may not be considered cost-effective, and reimbursement to the patient may not be available or may not be sufficient to allow us to sell our products on a competitive basis. In both the United States and elsewhere, sales of medical products and treatments are dependent, in part, on the availability of reimbursement to the patient from third-party payors, such as government and private insurance plans. Third-party payors are increasingly challenging the prices charged for pharmaceutical products and services. Our business is affected by the efforts of government and third-party payors to contain or reduce the cost of healthcare through various means. In the United States, there have been and will continue to be a number of federal and state proposals to implement government controls on pricing. In addition, the emphasis on managed care in the United States has increased and will continue to increase the pressure on the pricing of pharmaceutical products. We cannot predict whether any legislative or regulatory proposals will be adopted or the effect these proposals or managed care efforts may have on our business.

Healthcare reform measures and other statutory or regulatory changes could adversely affect our business.

The pharmaceutical and biotechnology industries are subject to extensive regulation, and from time to time legislative bodies and governmental agencies consider changes to such regulations that could have significant impact on industry participants. For example, in light of certain highly-publicized safety issues regarding certain drugs that had received marketing approval, the U.S. Congress is considering various proposals regarding drug safety, including some which would require additional safety studies and monitoring and could make drug development more costly. We are unable to predict what additional legislation or regulation, if any, relating to safety or other aspects of drug development may be enacted in the future or what effect such legislation or regulation would have on our business.

The business and financial condition of pharmaceutical and biotechnology companies are also affected by the efforts of governments, third-party payors and others to contain or reduce the costs of healthcare to consumers. In the United States and various foreign jurisdictions there have been, and we expect that there will continue to be, a number of legislative and regulatory proposals aimed at changing the healthcare system, such as proposals relating to the reimportation of drugs into the U.S. from other countries (where they are then sold at a lower price) and government control of prescription drug pricing. The pendency or approval of such proposals could result in a decrease in our share price or limit our ability to raise capital or to obtain strategic collaborations or licenses.

We are exposed to an increased risk of product liability claims.

The testing, marketing and sales of medical products entails an inherent risk of allegations of product liability. In the event of one or more large, unforeseen awards of damages against us, our product liability insurance may not provide adequate coverage. A significant product liability claim for which we were not covered by insurance would have to be paid from cash or other assets. To the extent we have sufficient insurance coverage, such a claim would result in higher subsequent insurance rates. In addition, product liability claims can have various other ramifications including loss of future sales opportunities, increased costs associated with replacing products, and a negative impact on our goodwill and reputation, which could also adversely affect our business and operating results.

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The loss of key personnel, including our Chief Executive Officer, could delay or prevent achieving our objectives.

Our research, product development and business efforts could be adversely affected by the loss of one or more key members of our scientific or management staff, particularly our executive officers: Steven B. Engle, our Chairman, Chief Executive Officer and President; Fred Kurland, our Vice President, Finance and Chief Financial Officer; Patrick J. Scannon, M.D., Ph.D., our Executive Vice President and Chief Biotechnology Officer; and Christopher J. Margolin, our Vice President, General Counsel and Secretary. We currently have no key person insurance on any of our employees.

We may not realize the expected benefits of our initiatives to reduce costs across our operations.

We are pursuing and may continue to pursue a number of initiatives to reduce costs across our operations, including workforce reductions. In January of 2009, we implemented a workforce reduction of approximately 42% in order to improve our cost structure. We expect an annualized reduction of approximately $27 million in cash expenditures when changes are completed in the second quarter of 2009 and to record a charge in the first quarter of 2009 of approximately $3 million for severance and other costs related to the workforce reduction. We anticipate that we will incur some level of restructuring charges through the remainder of 2009 as we continue to implement these cost reduction initiatives.

We may not realize some or all of the expected benefits of our current and future initiatives to reduce costs. In addition to restructuring or other charges, we may experience disruptions in our operations as a result of these initiatives.

Because we are a relatively small biopharmaceutical company with limited resources, we may not be able to attract and retain qualified personnel.

Our success in developing marketable products and achieving a competitive position will depend, in part, on our ability to attract and retain qualified scientific and management personnel, particularly in areas requiring specific technical, scientific or medical expertise. We had approximately 335 employees as of March 6, 2009, and due to a workforce reduction, we expect to have approximately 200 employees as of March 17, 2009. We anticipate that we will require additional experienced executive, accounting, research and development, legal, administrative and other personnel in the future. There is intense competition for the services of these personnel, especially in California. Moreover, we expect that the high cost of living in the San Francisco Bay Area, where our headquarters and manufacturing facilities are located, may impair our ability to attract and retain employees in the future. If we do not succeed in attracting new personnel and retaining and motivating existing personnel, our operations may suffer and we may be unable to implement our current initiatives or grow effectively.

Calamities, power shortages or power interruptions at our Berkeley headquarters and manufacturing facility could disrupt our business and adversely affect our operations, and could disrupt the businesses of our customers.

Our principal operations are located in Northern California, including our corporate headquarters and manufacturing facility in Berkeley, California. In addition, many of our collaborators and licensees are located in California. All of these locations are in areas of seismic activity near active earthquake faults. Any earthquake, terrorist attack, fire, power shortage or other calamity affecting our facilities or our customers’ facilities may disrupt our business and could have material adverse effect on our business and results of operations.

We may be subject to increased risks because we are a Bermuda company.

Alleged abuses by certain companies that have changed their legal domicile from jurisdictions within the United States to Bermuda have created an environment where, notwithstanding that we changed our legal

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domicile in a transaction that was approved by our shareholders and fully taxable to our company under United States law, we may be exposed to various prejudicial actions, including:

We do not know whether any of these things will happen, but if implemented one or more of them may have an adverse impact on our future operations or our share price.

It may be difficult to enforce a judgment obtained against us because we are a foreign entity.

We are a Bermuda company. All or a substantial portion of our assets, including substantially all of our intellectual property, may be located outside the United States. As a result, it may be difficult for shareholders and others to enforce in United States courts judgments obtained against us. We have irrevocably agreed that we may be served with process with respect to actions based on offers and sales of securities made hereby in the United States by serving Christopher J. Margolin, c/o XOMA Ltd., 2910 Seventh Street, Berkeley, California 94710, our United States agent appointed for that purpose. Uncertainty exists as to whether Bermuda courts would enforce judgments of United States courts obtained in actions against us or our directors and officers that are predicated upon the civil liability provisions of the United States securities laws or entertain original actions brought in Bermuda against us or such persons predicated upon the United States securities laws. There is no treaty in effect between the United States and Bermuda providing for such enforcement, and there are grounds upon which Bermuda courts may not enforce judgments of United States courts. Certain remedies available under the United States federal securities laws may not be allowed in Bermuda courts as contrary to that nation’s policy.

Our shareholder rights agreement or bye-laws may prevent transactions that could be beneficial to our shareholders and may insulate our management from removal.

In February of 2003, we adopted a new shareholder rights agreement (to replace the shareholder rights agreement that had expired), which could make it considerably more difficult or costly for a person or group to acquire control of us in a transaction that our Board of Directors opposes.

Our bye-laws:

These provisions of our shareholders rights agreement and our bye-laws, alone or in combination with each other, may discourage transactions involving actual or potential changes of control, including transactions that otherwise could involve payment of a premium over prevailing market prices to holders of common shares, could limit the ability of shareholders to approve transactions that they may deem to be in their best interests, and could make it considerably more difficult for a potential acquirer to replace management.

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None.

Our corporate headquarters and development and manufacturing facilities are located in Berkeley and Emeryville, California. We currently lease five buildings, and space in a sixth building, which house our research and development laboratories, manufacturing facilities and office space. A separate technology development and pilot scale manufacturing facility is owned by us.

On January 15, 2009, the Company announced a workforce reduction of approximately 42 percent or 144 employees, a majority of which were employed in manufacturing and related support functions. This decision was based on a decrease in forecasted contract manufacturing demand in 2009. As a result, we are temporarily suspending operations in four of our leased buildings. Our leases on these four buildings expire in the period from 2011 to 2014 and total minimum lease payments due from January of 2009 until expiration of the leases are $7.2 million. We are currently evaluating our options as to the future use of these leased spaces.

We will maintain our technology development and pilot scale manufacturing facility, and two leased buildings will house our research and development laboratories and office space. Subject to future manufacturing demand, we believe that these three facilities will be suitable and adequate for our current level of operations and anticipated growth in the near future.

In 2008, we produced multiple anti-botulinum neurotoxin antibodies, sufficient quantities of XOMA 052 for planned studies and numerous other small-scale development runs, pursuant to a drug manufacturing license obtained from the State of California. We also have an Investigational Medicinal Products (“IMP”) Certification from the Medicines and Healthcare Products Regulatory Agency of the United Kingdom which permits production of clinical trial materials for use in the European Union.

In September of 2004, XOMA (US) LLC entered into a collaboration with Aphton for the treatment of gastrointestinal and other gastrin-sensitive cancers using anti-gastrin monoclonal antibodies. In May of 2006, Aphton filed for bankruptcy protection under Chapter 11, Title 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the District of Delaware, No. 06-10510 (CSS). XOMA (US) LLC filed a proof of claim in the proceeding, as an unsecured creditor of Aphton, for approximately $594,000. Aphton and the Official Committee of Unsecured Creditors filed a Proposed Plan of Reorganization that would result in a liquidation of Aphton. The creditors have voted in favor of the plan, and the bankruptcy court has confirmed it. It is not presently known what, if any, distributions will be made to holders of unsecured claims. There were no developments material to XOMA in the United States Bankruptcy Court proceedings involving Aphton during the year ended December 31, 2008.

No matters were brought to a vote of our shareholders in the quarter ended December 31, 2008.

Supplementary Item: Executive Officers of the Registrant

Our executive officers and their respective ages, as of December 31, 2008, and positions are as follows:

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Effective August 8, 2008, J. David Boyle II, then the Company’s Vice President, Finance and Chief Financial Officer, resigned. The Company appointed a new Vice President, Finance and Chief Financial Officer, Fred Kurland, effective December 28, 2008.

The Board of Directors elects all officers annually. There is no family relationship between or among any of the officers or directors.

Business Experience

Mr. Engle is XOMA’s Chairman, Chief Executive Officer and President. He has more than 25 years of executive leadership and biotechnology and pharmaceutical industry experience. Prior to joining XOMA in 2007, he served as Chairman of the Board and Chief Executive Officer of La Jolla Pharmaceutical Company, a publicly-held biopharmaceutical company focused on the research and development of therapeutic products for autoimmune and antibody-mediated diseases. He joined La Jolla Pharmaceutical Company in 1993, became President and a Director in 1994, Chief Executive Officer in 1995, and Chairman of the Board in 1997. Prior to joining La Jolla, he held executive-level positions at Cygnus Therapeutic Systems, a developer of drug delivery systems, and Micro Power Systems, Inc., a manufacturer of high technology products, including medical devices. He began his professional career with the Strategic Decisions Group and the Stanford Research Institute. Mr. Engle is a graduate of the University of Texas with B.S. and M.S. degrees in Electrical Engineering, with a focus in biomedical engineering.

Dr. Scannon is one of our founders and has served as a Director since our formation. Dr. Scannon became Executive Vice President and Chief Biotechnology Officer in May of 2006. Previously he was our Chief Scientific and Medical Officer beginning in March of 1993, served as our as Vice Chairman, Scientific and Medical Affairs from April of 1992 to March of 1993 and our President from our formation until April of 1992. In 2007, Dr. Scannon was invited to join the newly formed National Biodefense Science Board, reporting to the Secretary for the Department of Health and Human Services. In 2007, he also became a member of the Board of Directors for Pain Therapeutics, Inc, a biopharmaceutical company. He serves on the Defense Sciences Research Council for the Defense Advanced Research Projects Agency (DARPA) and on the Threat Reduction Advisory Committee for the Department of Defense. From 1979 until 1981, Dr. Scannon was a clinical research scientist at the Letterman Army Institute of Research in San Francisco. A Board-certified internist, Dr. Scannon holds a Ph.D. in organic chemistry from the University of California, Berkeley and an M.D. from the Medical College of Georgia.

Mr. Kurland is our Vice President, Finance and Chief Financial Officer. He joined XOMA on December 29, 2008. Mr. Kurland is responsible for directing the Company’s financial strategy, accounting, financial planning and investor relations functions. He has more than 30 years of experience in biotechnology and pharmaceutical companies including Aviron/MedImmune, Protein Design Labs and Syntex/Roche. Prior to joining XOMA, Mr. Kurland served as Chief Financial Officer of Bayhill Therapeutics, Inc., Corcept Therapeutics Incorporated and Genitope Corporation. From 1998 to 2002, Mr. Kurland served as Senior Vice President and Chief Financial Officer of Aviron, acquired by MedImmune in 2001 and developer of FluMist. From 1996 to 1998, he was Vice President and Chief Financial Officer of Protein Design Labs, Inc., an antibody design company, and from 1995 to 1996, he served as Vice President and Chief Financial Officer of Applied Immune Sciences, Inc. Mr. Kurland also held a number of financial management positions at Syntex Corporation, a pharmaceutical company acquired by Roche, including Vice President and Controller between 1991 and 1995. He received his J.D. and M.B.A. degrees from the University of Chicago and his B.S. degree from Lehigh University.

Mr. Margolin is our Vice President, General Counsel and Secretary and heads our technology licensing function. During his time with the Company, Mr. Margolin has been responsible for the legal and intellectual property function and, at various times, the business development, human resources and licensing functions. Prior to joining us in 1991, Mr. Margolin was a corporate attorney holding several different executive legal positions for Raychem Corporation, an international high technology company, for 11 years. From 1975 to 1980, he was a division counsel for TRW Inc. and from 1972 to 1975, he was an associate at the law firm of McCutchen, Black, Verleger and Shea in Los Angeles. Mr. Margolin holds a B.A. from Princeton University, a J.D. from the University of Pennsylvania and an M.B.A. from the University of California, Los Angeles.

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PART II

Market for Registrant’s Common Equity

Our common shares trade on the NASDAQ Global Market under the symbol “XOMA.” The following table sets forth the quarterly range of high and low reported sale prices of our common shares on the NASDAQ Global Market for the periods indicated:

On March 6, 2009, there were 2,640 shareholders of record of our common shares, one of which was Cede & Co., a nominee for Depository Trust Company (“DTC”). All of the common shares held by brokerage firms, banks and other financial institutions as nominees for beneficial owners are deposited into participant accounts at DTC and are therefore considered to be held of record by Cede & Co. as one shareholder.

Dividend Policy

We have not paid dividends on our common shares. We currently intend to retain any earnings for use in the development and expansion of our business. We, therefore, do not anticipate paying cash dividends on our common shares in the foreseeable future.

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Performance Graph

The following graph compares the five-year cumulative total shareholder return for XOMA common stock with the comparable cumulative return of certain indices. The graph assumes $100 invested on the same date in each of the indices. Returns of the company are not indicative of future performance.

FIVE-YEAR PERFORMANCE GRAPH

Debt and Equity Issuances

On October 21, 2008, we entered into a common share purchase agreement (the “Purchase Agreement”) with Azimuth Opportunity Ltd. (“Azimuth”), pursuant to which we obtained a committed equity line of credit facility (the “Facility”) under which we may sell up to $60 million of our registered common shares to Azimuth over a 24-month period, subject to certain conditions and limitations. We are not obligated to utilize any of the $60 million Facility and remain free to enter other financing transactions. Pursuant to the terms of the Purchase Agreement, we determine, in our sole discretion, the timing, dollar amount and floor price per share of each draw down under the Facility, subject to certain conditions and limitations. The number and price of shares sold in each draw down are determined by a contractual formula designed to approximate fair market value, less a discount which may range from 2.65% to 6.65%. If the daily volume weighted average price of our common shares falls below a threshold price of $1.00 on any trading day during a draw down period, Azimuth will not be required to purchase the pro-rata portion of common shares allocated to that day. However, at its election, Azimuth may buy the pro-rata portion of shares allocated to that day at the threshold price less a negotiated discount. The Purchase Agreement also provides that from time to time and in our sole discretion, we may grant Azimuth the right to exercise one or more options to purchase additional common shares during each draw down pricing period for the amount of shares based upon the maximum option dollar amount and the option threshold price specified by us. Shares under the Facility are sold pursuant to a prospectus which forms a part of a registration statement declared effective by the Securities and Exchange Commission on May 29, 2008. From the

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inception of the Facility in October of 2008 through December 31, 2008, we have sold 7,932,432 common shares under the Facility for aggregate gross proceeds of $7.5 million, and $52.5 million remains available under the Facility. This includes the sale of 4.0 million shares under the Facility in December of 2008 that Azimuth agreed to purchase notwithstanding that the relevant volume weighted average prices were under the threshold price of $1.00. Under the terms of the Purchase Agreement, we negotiated a discount rate of 8.86% for this draw down. Prior to the successful conclusion of such negotiations, Azimuth was not obligated to purchase such shares, and there can be no assurance that they would agree to do so again if similar circumstances were to arise in the future. Offering expenses incurred through December 31, 2008 related to this Facility were $0.3 million. The proceeds are being used for general corporate purposes.

In February of 2006, we completed an exchange offer with holders of our 6.5% convertible senior notes due 2012 in which we exchanged $60.0 million aggregate principal amount of our New Notes for all $60.0 million aggregate principal amount of our then outstanding convertible senior notes due 2012. We also issued an additional $12.0 million of New Notes to the public for cash at a public offering price of 104% of principal, or $12.5 million. The New Notes were initially convertible into approximately 38.4 million common shares at a conversion rate of 533.4756 of common shares per $1,000 principal amount of New Notes, which is equivalent to a conversion price of approximately $1.87 per common share.

For the year ended December 31, 2006, $27.5 million of 6.5% Convertible SNAPs_SM due 2012 (the “New Notes”) were converted into 18,262,264 common shares including 3,602,879 shares related to the additional interest payment feature of the notes. During the first quarter of 2007, $42.0 million of New Notes were voluntarily converted by holders through March 7, 2007, at which time we announced that we had elected to automatically convert 100% of the remaining $2.5 million of New Notes outstanding. As a result, 25,640,187 shares were issued to effect the conversion of the principal balances. Additionally, we issued 1,889,317 shares and $5.2 million in cash to satisfy the remaining additional interest payment feature related to these converted New Notes.

During the first quarter of 2007, we eliminated the remaining balance of convertible debt issued in February of 2006. For the year ended December 31, 2007, we incurred $0.2 million in interest expense related to our convertible debt, amortized $0.1 million in debt issuance costs, premium and discount, and recognized $6.1 million in interest expense related to the revaluation of the embedded derivative.

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The following table contains our selected financial information including consolidated statement of operations and consolidated balance sheet data for the years 2004 through 2008. The selected financial information has been derived from our audited consolidated financial statements. The selected financial information should be read in conjunction with Item 8: Financial Statements and Supplementary Data and Item 7: Management’s Discussion and Analysis of Financial Condition and Results of Operations included in this Annual Report. The data set forth below is not necessarily indicative of the results of future operations.

We have paid no dividends in the past five years.

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Overview

We are a leader in the discovery, development and manufacture of therapeutic antibodies and other agents designed to treat inflammatory, autoimmune, infectious and oncological diseases. Our proprietary development pipeline includes XOMA 052, an anti-IL-1 beta antibody, XOMA 3AB, a biodefense anti-botulism antibody candidate, and five antibodies in preclinical development. Our proprietary development pipeline is funded by multiple revenue streams resulting from the licensing of our antibody technologies, product royalties, development collaborations and biodefense contracts, and sales of XOMA’s common shares. Our technologies and experienced team have contributed to the success of marketed antibody products, including RAPTIVA^® (efalizumab) for chronic moderate-to-severe plaque psoriasis, LUCENTIS^® (ranibizumab injection) for (wet) age-related macular degeneration and CIMZIA^® (certolizumab pegol, CDP870) for Crohn’s disease.

We have a premier antibody discovery and development platform that includes six antibody phage display libraries and our proprietary Human Engineering^™ and bacterial cell expression technologies. Our bacterial cell expression technology is a key biotechnology for the discovery and manufacturing of antibodies and other proteins. Thus far, more than 50 pharmaceutical and biotechnology companies have signed bacterial cell expression licenses with us.

In addition to developing our own potential products, we develop products for premier pharmaceutical companies including Novartis AG (“Novartis”), Takeda Pharmaceutical Company Limited (“Takeda”) and Schering-Plough Research Institute (“SPRI”). In the first quarter of 2009, we announced the expansion of our collaboration with Takeda under which Takeda will have access to multiple antibody technologies, including a suite of research and development technologies and integrated information and data management systems. We have a fully integrated product development infrastructure, extending from preclinical science to manufacturing.

Our ability to fund ongoing operations is dependent on the progress of our proprietary development pipeline, specifically XOMA 052 and XOMA 3AB. We are currently conducting two Phase 1 clinical trials of XOMA 052 in Type 2 diabetes patients, one in the U.S. and one in Europe. In September of 2008, we announced interim data from the Phase 1 clinical trials which indicate support for a novel anti-inflammatory approach to Type 2 diabetes treatment that may preserve insulin-producing cells. XOMA 052 potentially addresses inflammation as an underlying cause of diabetes by targeting IL-1 beta, a master signaling protein which triggers

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inflammatory pathways in the body. Although these Phase 1 studies were designed to test drug safety and pharmacokinetics, rather than efficacy, we believe these studies are important additions to the other medical research indicating that decreasing inflammation may reduce disease progression in diabetes. We plan to advance our Phase 1 clinical testing of XOMA 052 in Type 2 diabetes and initiate a major Phase 2 Type 2 diabetes study in the third quarter of 2009. We have been approached by several companies offering to collaborate on our testing and development of XOMA 052 for Type 2 diabetes and will seek to enter into a collaboration by the end of 2009.

We have also received promising results from our testing of XOMA 052 for use in other indications. Based on these results, we initiated a Phase 2a pharmacokinetic study of XOMA 052 in rheumatoid arthritis in the first quarter of 2009. Depending on resources and timing, we may initiate additional small XOMA 052 “proof-of-concept” trials in other indications in 2009.

In the near-term, our ability to fund ongoing operations is also dependent on worldwide sales of RAPTIVA^®, which we developed under a collaboration agreement with Genentech, Inc. (“Genentech”), and LUCENTIS^®, for which Genentech licensed our bacterial cell expression technology. Genentech is responsible for the manufacturing, marketing and sales effort in support of these products. In previous quarters, we disclosed that we expected royalty revenues from sales of LUCENTIS^® outside the U.S. to decrease due to the expiration in July of 2008 of most of the more important European patents in our bacterial cell expression patent portfolio. In the fourth quarter of 2008, Genentech confirmed that LUCENTIS^® is currently produced in the United States for worldwide distribution. Based on this information, we expect Genentech to continue to pay royalties on worldwide sales of LUCENTIS^®, for so long as the product continues to be produced in the United States, through the expiration of the related U.S. patents at the end of 2014.

In October of 2008, the FDA announced that it had approved labeling changes, including a Boxed Warning, to highlight the risks of life-threatening infections, including progressive multifocal leukoencephalopathy (“PML”), with the use of RAPTIVA^®. In November of 2008, Genentech announced that it had issued a Dear Healthcare Provider letter to inform dermatologists and neurologists of a second case of PML which resulted in the death of a 73-year old patient who had received RAPTIVA^® for approximately four years. In February of 2009, the European Medicines Agency (“EMEA”) announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and that its Committee for Medicinal Products for Human Use (“CHMP”) has concluded that the benefits of RAPTIVA^® no longer outweigh its risks and EMD Serono Inc., the company that markets RAPTIVA^® in Canada (“EMD Serono”), announced that, in consultation with Health Canada, the Canadian health authority (“Health Canada”), it will suspend marketing of RAPTIVA^® in Canada. Also in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^®. These adverse events have consequences under our term loan with Goldman Sachs Specialty Lending Holdings, Inc. (“Goldman Sachs”), as detailed in Liquidity and Capital Resources.

We began receiving royalty revenues in the first quarter of 2008 from sales of CIMZIA^®, which was approved in the U.S. in April of 2008 and Switzerland in September of 2007. UCB Celltech, a branch of UCB S.A. (“UCB”) licensed our bacterial cell expression technology in the development of this product and is responsible for the marketing and sales effort in support of CIMZIA^®.

Our initial biodefense anti-botulism antibody candidate, XOMA 3AB, is a multi-antibody product that targets the most potent of the botulinum toxins, Type A. Our anti-botulism program was recently expanded to include additional product candidates and is the first of its kind to combine multiple human antibodies to target a broad spectrum of the most toxic botulinum toxins, including the three most toxic serotypes of botulism, Types A, B and E. The antibodies are designed to bind to each toxin and enhance the clearance of the toxin from the body. The use of multiple antibodies increases the likelihood of clearing the harmful toxins by providing specific protection against each toxin type. In September of 2008, we were awarded our third contract from the National

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Institute of Allergy and Infectious Diseases (“NIAID”), a part of the National Institutes of Health (“NIH”), to support our ongoing development of XOMA 3AB and additional product candidates toward clinical trials in the treatment of botulism poisoning. This brings the program’s total to nearly $100 million.

We also have the ability to generate cash flow from funded research and development and other development activities. We are developing a number of products, both proprietary and under collaboration agreements with other companies and may enter into additional arrangements. Our objective in development collaborations is to leverage our existing development infrastructure to broaden and strengthen our proprietary product pipeline thereby diversifying our development risk and gaining financial support from our collaboration partners.

In January of 2009, we announced a workforce reduction of approximately 42 percent, or 144 employees, a majority of which were employed in manufacturing and related support functions. This decision was made based on the challenging economic conditions and a decline in forecasted manufacturing demand in 2009. We expect an annualized reduction of approximately $27 million in cash expenditures when changes are completed in the second quarter of 2009. Upon completion of the workforce reduction on March 17, 2009, we expect to remain staffed with approximately 200 employees to develop XOMA 052, develop and license proprietary products and technology, and continue fully funded antibody discovery and development activities with our pharmaceutical partners in collaborations and the U.S. government in biodefense. We will also maintain our pilot scale manufacturing plant with some full scale capability. XOMA expects to record a charge in the first quarter of 2009 of approximately $3 million for severance and other costs related to the workforce reduction.

We incurred negative cash flow from operations in four of the past five years and expect to remain in this position until sufficient cash flow can be generated from XOMA 052 partnering agreements, technology licensing, biodefense contracts with the government and various development collaboration arrangements, or until we achieve additional regulatory approvals and commence commercial sales of additional products. The timing and likelihood of additional approvals is uncertain and there can be no assurance that approvals will be granted or that cash flow from product sales will be sufficient to fully fund operations.

Critical Accounting Estimates

The accompanying discussion and analysis of our financial condition and results of operations are based upon our consolidated financial statements and the related disclosures, which have been prepared in accordance with accounting principles generally accepted in the United States. The preparation of these financial statements requires us to make estimates, assumptions and judgments that affect the reported amounts in our consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various 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 from these estimates under different assumptions or conditions.

We believe the following policies to be the most critical to an understanding of our financial condition and results of operations because they require us to make estimates, assumptions and judgments about matters that are inherently uncertain.

Revenue Recognition

Revenue is generally recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed and determinable; and (4) collectibility is reasonably assured. Determination of criteria (3) and (4) is based on management’s judgments regarding the nature of the fee charged for products or services delivered and the collectibility of those fees. Allowances are established for estimated uncollectible amounts, if any.

We recognize revenue from license and collaboration arrangements, contract services, product sales and royalties. Our revenue arrangements with multiple elements are divided into separate units of accounting if

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certain criteria are met, including whether the delivered element has stand-alone value to the customer and whether there is objective and reliable evidence of the fair value of the undelivered items. The consideration we receive is allocated among the separate units based on their respective fair values and the applicable revenue recognition criteria are applied to each of the separate units. Advance payments received in excess of amounts earned are classified as deferred revenue until earned.

License and Collaborative Fees

Revenue from non-refundable license, technology access or other payments under license and collaborative agreements, with cost and profit-sharing arrangements, where we have a continuing obligation to perform is recognized as revenue over the expected period of the continuing performance obligation. We estimate the performance period at the inception of the arrangement and reevaluate it each reporting period. This reevaluation may shorten or lengthen the period over which the remaining revenue is recognized. Changes to these estimates are recorded on a prospective basis.

Milestone payments under collaborative and other arrangements are recognized as revenue upon completion of the milestone events, once confirmation is received from the third party and collectibility is reasonably assured. This represents the culmination of the earnings process because we have no future performance obligations related to the payment. Milestone payments that require a continuing performance obligation on our part are recognized over the expected period of the continuing performance obligation. Amounts received in advance are recorded as deferred revenue until the related milestone is completed.

Contract Revenue

Contract revenue for research and development involves our providing research and development for manufacturing processes for collaborative partners, biodefense contracts or others. Revenue for certain contracts is accounted for by a proportional performance, or output based, method where performance is based on estimated progress toward elements defined in the contract. The amount of contract revenue and related costs recognized in each accounting period are based on estimates of the proportional performance during the period. Adjustments to estimates based on actual performance are recognized on a prospective basis and do not result in reversal of revenues should the estimate to complete be extended.

In addition, revenue related to certain research and development contracts is billed based on actual costs incurred by XOMA related to the contract, multiplied by full-time equivalent (“FTE”) rates plus a mark-up. The FTE rates are developed based on our best estimates of labor, materials and overhead costs. For certain contracts, the FTE rates are agreed upon at the beginning of the contract and are subject to review or audit by the contracting party at any time.

For example, in the third quarter of 2008, the NIH completed an audit of the Company’s 2007 actual data and developed billing rates for the period from January of 2007 to June of 2009 to be used for all of the Company’s government contracts, including Contract No. HHSN26620060008C/N01-A1-60008l (“NIAID 2”). While the audited NIH rates are considered final for 2007 billings, these NIH rates are considered provisional for the period from January of 2008 to June of 2009 and thus are subject to future audits at the discretion of NIAID’s contracting office. In September of 2008, XOMA retroactively applied these NIH rates to the invoices from 2007 through the third quarter of 2008 resulting in an adjustment to decrease revenue by $2.7 million. The adjustment increased the Company’s loss from operations and net loss for the year ended December 31, 2008 by $2.7 million. The adjustment also increased basic and diluted net loss per common share by $0.02 for the year ended December 31, 2008. As the NIH audit only covered 2007 actual data, which differs significantly from 2006 actual data primarily due to a 22% increase in headcount from 2006 to 2007, management has determined that the original provisional rates are more reflective of 2006 actual data than the 2007 actual data. Based on this understanding, the parties agreed to not adjust the 2006 billings with the provision that those billings are subject to future NIH audit at the discretion of the NIAID contracting office.

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Up-front fees are recognized ratably over the expected benefit period under the arrangement. Given the uncertainties of research and development collaborations, significant judgment is required to determine the duration of the arrangement. We have $13.2 million of deferred up-front fees related to two research and collaboration agreements that are being amortized over a range of two to five years.

Royalty Revenue

Royalty revenue and royalty receivables are generally recorded in the periods these royalties are earned, in advance of collection. The royalty revenue and receivables in these instances are based upon communication with collaborative partners, historical information and forecasted sales trends. Under some of our agreements with licensees that include receipt of royalty revenue, we do not have sufficient historical information to estimate royalty revenues or receivables in the period that these royalties are earned. For these contracts, we record royalty revenue upon receipt of a royalty statement or cash.

In previous quarters, we disclosed that we expected royalty revenues from sales of LUCENTIS^® outside the U.S. to decrease due to the expiration in July of 2008 of most of the more important European patents in our bacterial cell expression patent portfolio. In the fourth quarter of 2008, Genentech confirmed that LUCENTIS^® is currently produced in the United States for worldwide distribution. Based on this information, we expect Genentech to continue to pay royalties on worldwide sales of LUCENTIS^®, for so long as the product continues to be produced in the United States, through the expiration of the related U.S. patents at the end of 2014. This information, obtained in the fourth quarter of 2008, resulted in an adjustment to increase third quarter royalty revenues by $0.7 million.

Research and Development Expenses

We expense research and development expenses as incurred. Research and development expenses consist of direct and research-related allocated overhead costs such as facilities costs, salaries and related personnel costs, and material and supply costs. In addition, research and development expenses include costs related to clinical trials to validate our testing processes and procedures and related overhead expenses. Expenses resulting from clinical trials are recorded when incurred based in part on estimates as to the status of the various trials. From time to time, research and development expenses may include up-front fees and milestones paid to collaborative partners for the purchase of rights to in-process research and development. Such amounts are expensed as incurred. The timing of up-front fees and milestone payments in the future may cause variability in our future research and development expenses.

Share-Based Compensation

On January 1, 2006, we adopted SFAS 123 (revised 2004), “Share-Based Payment” (“SFAS 123R”), which requires the measurement and recognition of compensation expense for all share-based payment awards made to our employees and directors, including employee share options and employee share purchases related to the Employee Share Purchase Plan (“ESPP”), on estimated fair values.

Under SFAS 123R, we elected to use the modified prospective transition method. Under this method, we are required to record compensation expense for all awards granted or modified after the date of adoption and the unvested portion of previously granted awards that remained outstanding at the date of adoption. To estimate the value of an award, we use the Black-Scholes option pricing model. This model requires inputs such as expected life, expected volatility and risk-free interest rate. Further, the forfeiture rate also impacts the amount of aggregate compensation. These inputs are subjective and generally require significant analysis and judgment to develop. While estimates of expected life, volatility and forfeiture rate are derived primarily from our historical data, the risk-free rate is based on the yield available on United States Treasury zero-coupon issues. We review our valuation assumptions quarterly and, as a result, it is likely we will change our valuation assumptions used to value share based awards granted in future periods.

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Income Taxes

We account for uncertain tax positions in accordance with FASB Interpretation No. 48, “Accounting for Uncertainty in Income Taxes” (“FIN 48”), an interpretation of SFAS No. 109, “Accounting for Income Taxes” (“SFAS 109”). The application of income tax law and regulations is inherently complex. Interpretations and guidance surrounding income tax laws and regulations change over time. As such, changes in our subjective assumptions and judgments can materially affect amounts recognized in our financial statements.

SFAS 109 provides for the recognition of deferred tax assets if realization of such assets is more likely than not. Based upon the weight of available evidence, which includes our historical operating performance and carryback potential, we have determined that total deferred tax assets should be fully offset by a valuation allowance.

Results of Operations

Revenues

Total revenues in 2008 were $68.0 million, compared with $84.3 million in 2007 and $29.5 million in 2006 as shown in the table below (in thousands):

License and collaborative fees in 2008 were $16.4 million, compared with $36.5 million in 2007 and $2.8 million in 2006. These revenues include up-front and milestone payments related to the out-licensing of our products and technologies and other agreements where we have cost and profit-sharing arrangements, such as with our collaboration partner Novartis. The primary source of license and collaborative fees in 2008 related to the restructuring of our product development collaboration with Novartis, which involved six development programs including the HCD122 program. Under the restructured agreement, we recognized a collaborative fee of $13.7 million in exchange for giving Novartis control over the HCD122 program and an additional program, as well as the right to expand the development of these programs into additional indications outside of oncology. We also recognized $1.7 million in up-front fees and annual maintenance fees relating to various out-licensing arrangements. In addition, we recognized four milestone payments totaling $1.0 million, including two milestone payments from Pfizer Inc. (“Pfizer”) relating to two different products, including the payment of $0.5 million for the initiation of a Phase 3 clinical trial. The generation of future revenues related to license fees and other collaborative arrangements is dependent on our ability to attract new licensees to our bacterial cell expression and other technologies and new collaboration partners.

The primary source of license and collaborative fees for 2007 related to payments received from Pfizer and an existing technology partner totaling $31.3 million. These payments represented initial license fees for which no remaining obligation of the Company existed. In addition, $4.3 million in revenue was recognized during the first quarter of 2007 representing the unamortized revenue from a $10.0 million up-front collaboration fee received in connection with our collaboration with Novartis in February of 2004. In February of 2007, we announced that pursuant to the terms of our collaboration agreement with Novartis, the mutual exclusivity obligation to conduct antibody discovery, development and commercialization work in oncology had ended. The expiration of this mutual obligation had no impact on the existing collaboration projects which had reached the development stage and the parties could continue to collaborate on a non-exclusive basis. Prior to the expiration of the exclusivity period, the up-front fee was being amortized over the expected five-year term of the exclusivity provision, or at a rate of $0.5 million per quarter.

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License and collaborative fees recognized in 2006 primarily related to the recognition of $2.0 million from an up-front collaboration fee in connection with our Novartis collaboration.

Contract and other revenue was $30.5 million in 2008 compared with $31.1 million in 2007 and $16.3 million in 2006. These revenues include agreements where we provide contracted research and development and manufacturing services to our collaboration partners, including Takeda, SPRI, Novartis and NIAID. Contract and other revenue recognized in 2008 includes $4.2 million related to our NIAID Contract No. HHSN272200800028C (“NIAID 3”), which was awarded in September of 2008, and $6.6 million relating to our Manufacturing and Technology Transfer Agreement with Novartis signed in December of 2008, and effective from July of 2008. We also recognized $10.8 million in revenue in 2008 from our agreement with SPRI, compared with $5.7 million in 2007, and $4.4 million in revenue in 2008 from our agreement with Takeda, compared with $3.1 million in 2007. These increases in contract and other revenue were offset by decreases in revenue recognized from our NIAID 2 contract from $11.3 million in 2007 to $1.3 million in 2008, and on our AVEO Pharmaceuticals, Inc. (now with SPRI and referred to herein together as “SPRI/AVEO”) contract from $8.0 million in 2007 to $3.2 million in 2008. These decreases are primarily due to the Company nearing the end of contracted service arrangements with NIAID 2 and SPRI/AVEO. Contract revenue for 2008 also includes an adjustment for NIAID 2 to decrease revenue by $2.7 million due to a change in billing rates, as detailed above in the Critical Accounting Estimates: Contract Revenue section. We expect to continue to generate revenue in 2009 related to our NIAID 3 contract, which is a $65 million multiple-year contract, our 2008 Novartis contract and our existing agreements with SPRI and Takeda, the latter of which we initiated new therapeutic antibody programs in September of 2008.

The increase in contract and other revenue of $14.7 million for 2007 compared to 2006 was primarily due to increased activities on our contracts with SPRI/AVEO, SPRI, Takeda and NIAID 2. This increase was partially offset by the completion of our NIAID Contract No. HHSN26620050004C (“NIAID 1”) in October of 2006, which was entered into in March of 2005. Contract and other revenues recognized in 2006 related to contracts entered into in 2006 with SPRI, Taligen Therapeutics, Inc. (“Taligen”), Cubist Pharmaceuticals, Inc. (“Cubist”) and SPRI/AVEO and contract work performed under NIAID 1 and NIAID 2.

We defer revenue until all requirements under our revenue recognition policy are met. In 2008, we deferred $17.5 million of revenue from five contracts including SPRI, Takeda and Novartis and recognized $18.4 million in revenue from the five contracts. In 2007, we deferred $23.3 million of revenue from five contracts including SPRI, SPRI/AVEO and Takeda and recognized $22.2 million in revenue from the five contracts including amortization of $4.3 million of the $10.0 million in up-front payments received from Novartis related to our February of 2004 oncology collaboration contract. In 2006, we deferred $25.2 million of revenue from eight contracts including SPRI, NIAID, Takeda and Taligen and recognized $16.1 million of revenue from the eight contracts, including the amortization of the Novartis up-front payments.

The following table shows the activity in deferred revenue for the years ended December 31, 2008, 2007 and 2006 (in thousands):

Of the $17.2 million balance in deferred revenue at December 31, 2008, $9.1 million is expected to be earned over the next year and the remaining $8.1 million is expected to be earned over the next five years. Future amounts may be impacted by additional consideration received, if any, under existing or any future licensing or other collaborative arrangements as well as changes in the estimated period of obligation or services to be provided under the arrangements.

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Revenue from royalties was $21.1 million in 2008 compared with $16.7 million in 2007 and $10.3 million in 2006. This includes royalties of $6.5 million from U.S. sales of RAPTIVA^® in 2008, compared with $6.4 million and $5.4 million during 2007 and 2006, respectively, and royalties of $5.7 million from sales of RAPTIVA^® outside the U.S. in 2008, compared with $4.2 million and $2.8 million during 2007 and 2006, respectively. In addition, royalties earned on U.S sales of LUCENTIS^® were $4.4 million in 2008, compared with $4.1 million and $1.9 million during 2007 and 2006, respectively, and royalties earned on sales of LUCENTIS^® outside the U.S. were $4.4 million in 2008, compared with $1.9 million and $0.1 million during 2007 and 2006, respectively.

The increase in royalty revenues from 2006 through 2008 resulted from higher sales of LUCENTIS^® and RAPTIVA^® in the U.S. and worldwide. According to Genentech, U.S sales of RAPTIVA^® during 2008 were $108 million, compared with $107 million and $90 million during 2007 and 2006, respectively. According to Merck Serono, sales of RAPTIVA^® outside of the U.S. during 2008 were approximately $134 million, compared with $106 million and $70 million during 2007 and 2006, respectively. According to Genentech, U.S. sales of LUCENTIS^® were $875 million during 2008 compared with $815 million and $380 million during 2007 and 2006, respectively. According to Novartis, sales of LUCENTIS^® outside the United States were $886 million in 2008 compared with $393 million and $27 million during 2007 and 2006, respectively.

In previous quarters, we disclosed that we expected royalty revenues from sales of LUCENTIS^® outside the U.S. to decrease due to the expiration in July of 2008 of most of the more important European patents in our bacterial cell expression patent portfolio. In the fourth quarter of 2008, Genentech confirmed that LUCENTIS^® is currently produced in the United States for worldwide distribution, and as a result we recorded an adjustment to increase third quarter royalty revenues by $0.7 million. We expect Genentech to continue to pay royalties on worldwide sales of LUCENTIS^®, for so long as the product continues to be produced in the United States, through the expiration of the related U.S. patents at the end of 2014. Therefore we expect royalty revenues from sales of LUCENTIS^® worldwide to increase in 2009. In addition, in January of 2009, Novartis announced that LUCENTIS^® was approved in Japan for the treatment of (wet) age-related macular degeneration.

In October of 2008, the FDA announced that it had approved labeling changes, including a Boxed Warning, to highlight the risks of life-threatening infections, including PML, associated with the use of RAPTIVA^®. In the fourth quarter of 2008, royalty revenues from U.S. sales of RAPTIVA^® decreased by approximately 10%; however, we are unable to determine at this point in time if the decline in sales was linked to the Boxed Warning.

In February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union and that the CHMP has concluded that the benefits of RAPTIVA^® no longer outweigh its risks and EMD Serono Inc. announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada. Also in February of 2009, the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. Genentech has stated that it is working with the FDA to determine appropriate next steps, which may include significant restrictions in the use of, or suspension or withdrawal of regulatory approval for, RAPTIVA^®. We expect royalties from sales of RAPTIVA^® to decline significantly as a result of these and other related events.

In addition, UCB announced in April of 2008 that CIMZIA^® received FDA approval for the treatment of Crohn’s disease. CIMZIA^® was approved in Switzerland for the treatment of Crohn’s disease in September of 2007. UCB provides CIMZIA^® related sales and royalty statements to us within 60 days of the end of each quarter. Due to the lack of sufficient historical information, royalties received on sales of CIMZIA^® are recorded upon receipt of the royalty statement until we establish sufficient historical information on which to estimate related royalty revenues. During 2008, royalties received from sales of CIMZIA^® were not material; however we expect sales to increase in 2009.

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Research and Development Expenses

Biopharmaceutical development includes a series of steps, including in vitro and in vivo preclinical testing, and Phase 1, 2 and 3 clinical studies in humans. Each of these steps is typically more expensive than the previous step, but actual timing and the cost to us depends on the product being tested, the nature of the potential disease indication and the terms of any collaborative arrangements with other companies. After successful conclusion of all of these steps, regulatory filings for approval to market the products must be completed, including approval of manufacturing processes and facilities for the product. Our research and development expenses currently include costs of personnel, supplies, facilities and equipment, consultants, third party costs and other expenses related to preclinical and clinical testing.

In 2008, our research and development expenses were $82.6 million compared with $66.2 million in 2007 and $52.1 million in 2006. The $16.4 million increase in 2008 compared with 2007 primarily reflects increased spending on development of XOMA 052, including Phase 1 clinical trials, and to a lesser extent XOMA 629. In addition, we increased spending on our contracts with Novartis, SPRI, NIAID 3 and Takeda. Research and development expenses also increased in 2008 related to the preclinical development of five antibodies, XOMA 3AB and upgrades made to our manufacturing plant. These increases were partially offset by a decrease in spending on NIAID 2 and SPRI/AVEO-related contract activities, due to the Company nearing the end of contracted service arrangements.

The $14.1 million increase in 2007 compared with 2006 primarily reflects increased spending on development of XOMA 052, including the initiation of Phase 1 clinical trials, and on the development of XOMA 629. In addition, we increased spending on our contracts with NIAID 2, SPRI/AVEO, SPRI and Takeda, partially offset by a decrease in spending on NIAID 1 due to the Company nearing the end of the contracted service arrangement.

We recorded $34.4 million in research and development salaries and employee related expenses in 2008 compared with $31.5 million in 2007 and $22.8 million in 2006. Included in these expenses for 2008 were $32.1 million for salaries and benefits and $2.3 million for share-based compensation, which is a non-cash expense, compared with $27.9 million and $1.0 million, respectively, in 2007, and $21.1 million and $0.5 million, respectively, in 2006. The $2.9 million increase in salaries and employee related expenses in 2008 as compared to 2007 primarily relates to increased headcount.

Partially offsetting the 2008 increase in salaries and employee related expenses is a decrease in bonus expense for 2008 to zero compared with $2.6 million in 2007 and $1.2 million in 2006. In efforts to control spending and manage the Company’s cash balance, the Company decided not to pay bonuses for 2008. The Bonus Compensation Plan (“BCP”) was implemented in 2007 and provides performance-based bonuses to be paid to employees that did not qualify under the Management Incentive Compensation Plan (“MICP”) or CEO Incentive Compensation Plan (“CICP”, collectively “Incentive Plans”). See Results of Operations: Share-Based Compensation for further discussion of our share-based compensation expense for 2008.

We expect a decrease in salaries and employee related expenses in 2009 as a result of the workforce reduction and our decision, at this time, to not award merit increases in 2009. We expect the workforce reduction announced in January of 2009 will be completed by the second quarter of 2009. A charge of approximately $3 million is expected in the first quarter of 2009 for severance and other costs related to the workforce reduction.

Our research and development activities can be divided into earlier stage programs and later stage programs. Earlier stage programs include molecular biologics, process development, pilot-scale production and preclinical testing. Also included in earlier stage programs are costs related to excess manufacturing capacity, which we expect to decrease in 2009 as a result of the workforce reduction. Later stage programs include clinical testing, regulatory affairs and manufacturing clinical supplies. The costs associated with these programs approximate the following (in thousands):

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Our research and development activities can also be divided into those related to our internal projects and those projects related to collaborative and contract arrangements. The costs related to internal projects versus collaborative and contract arrangements approximate the following (in thousands):

In 2008, one development program (Novartis) accounted for more than 10% but less than 20% of our total research and development expenses and one development program (XOMA 052) accounted for more than 20% but less than 30% of our total research and development expenses. No development program accounted for more than 30% of our total research and development expenses in 2008. In 2007, two development programs (XOMA 052 and NIAID) each individually accounted for more than 10% but less than 20% of our total research and development expenses. In 2006, three development programs (Novartis, NIAID and XOMA 052) each individually accounted for more than 10% but less than 20% of our total research and development expenses. No development program accounted for more than 20% of our total research and development expenses in 2007 or 2006.

We currently anticipate a decrease in our research and development spending in 2009. In the fourth quarter of 2008, we narrowed the focus of our research and development efforts to XOMA 052, and away from our other programs. In 2009, we plan to complete Phase 1 clinical testing of XOMA 052 in Type 2 diabetes, which includes three studies. We also plan to initiate a major Phase 2 study in Type 2 diabetes in the third quarter of 2009. We have been approached by several companies offering to collaborate on our testing and development of XOMA 052 and will seek to enter into a collaboration by the end of 2009. We also initiated a Phase 2a pharmacokinetic study in rheumatoid arthritis in the first quarter of 2009, and plan to conduct XOMA 052 “proof-of-concept” trials in other indications in 2009.

As a result of the workforce reduction in January of 2009, we are temporarily suspending operations in four of our leased buildings. We expect capital costs to decrease in 2009, as compared to 2008.

Future research and development spending may also be impacted by potential new licensing or collaboration arrangements, as well as the termination of existing agreements. Beyond this, the scope and magnitude of future research and development expenses are difficult to predict at this time.

General and Administrative Expenses

General and administrative expenses include salaries and related personnel costs, facilities costs and professional fees. In 2008, general and administrative expenses were $24.1 million compared with $20.6 million in 2007 and $18.1 million in 2006. The $3.5 million increase in general and administrative expenses in 2008 as compared with 2007 was primarily related to a $1.2 million increase in legal fees supporting our technology licensing and collaboration agreements as well as the protection of our intellectual property, a $1.1 million increase in spending related to the marketing and communication of our technology and proprietary products to potential corporate partners and investors, a $0.9 million increase in consulting fees primarily related to employee training and system implementation and a net increase in salaries and related expenses of $0.6 million.

The increase in general and administrative expenses of $2.5 million in 2007 compared with 2006 primarily relates to increased compensation costs, including an increase in share-based compensation, which is a non-cash expense, related to the CEO transition in the third quarter of 2007 and an increase in bonus awards, including the implementation of BCP, as detailed above in the Results of Operations: Research and Development Expenses section.

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We recorded $13.3 million in general and administrative salaries and employee related expenses in 2008 compared with $12.7 million in 2007 and $9.6 million in 2006. Included in these amounts were $10.7 million for salaries and benefits and $2.6 million for share-based compensation, which is a non-cash expense, in 2008, compared with $9.5 million and $1.9 million, respectively, in 2007, and $8.3 million and $0.5 million, respectively, in 2006. The $0.6 million increase in salaries and employee related expenses in 2008 as compared to 2007 primarily relates to increased headcount.

Partially offsetting the 2008 increase in salaries and employee related expenses is a decrease in bonus expense for 2008 to zero compared with $1.4 million in 2007 and $0.8 million in 2006. In the fourth quarter of 2008, the Company decided not to pay 2008 bonuses in an effort to control spending and manage the Company’s cash balance. Based on this information, the 2008 bonus accrual was reversed in the fourth quarter of 2008. See Results of Operations: Share-Based Compensation for further discussion of our share-based compensation expense for 2008.

We expect a decrease in salaries and employee related expenses in 2009 as a result of the workforce reduction and our decision, at this time, to not award merit increases in 2009. We expect the workforce reduction announced in January of 2009 will be completed by the second quarter of 2009. A charge of approximately $3 million is expected to be recorded in the first quarter of 2009 for severance and other costs related to the workforce reduction.

As a result of the workforce reduction in January of 2009, we are temporarily suspending operations in four of our leased buildings. Our leases on these four buildings expire in the period from 2011 to 2014 and total minimum lease payments due from January of 2009 until expiration of the leases are $7.2 million. In addition, the net book value of fixed assets potentially subject to write down as a result of the workforce reduction is approximately $12.5 million as of December 31, 2008. We are currently evaluating our options as to the future use of these leased spaces.

Other Income (Expense)

Investment and interest income was $0.9 million in 2008 compared with $1.9 million in 2007 and $1.7 million in 2006. Investment and interest income consists primarily of interest earned on our cash and investment balances. The differences between 2008, 2007, and 2006 balances resulted from varying average cash balances and interest rates.

Interest expense was $7.7 million in 2008 compared with $11.6 million and $12.9 million in 2007 and 2006, respectively. The decrease in interest expense of $3.9 million in 2008 compared to 2007 is due to the elimination of our convertible debt in 2007, which represented $6.1 million of interest expense in 2007 from the revaluation to fair value of the embedded derivative on our convertible debt related to the additional interest feature, partially offset by an increase in interest expense related to the higher principal balance and interest rate associated with our new term loan facility with Goldman Sachs.

The decrease in interest expense from 2006 to 2007 of $1.3 million includes a decrease in interest expense recorded relating to the revaluation of the embedded derivative of $0.8 million and a decrease in interest expense on our convertible debt of $3.2 million, offset by an increase in interest expense on our Goldman Sachs loan of $2.9 million.

Interest expense for 2009 is expected to decrease compared to 2008 due to the repayment of $8.9 million of principal on our Novartis note and $4.6 million of principal paid on our Goldman Sachs term loan in the fourth quarter of 2008. The decrease in interest expense from this principal reduction is expected to be slightly offset by the increase in the principal balance and the interest rate on our new Goldman Sachs term loan in the fourth quarter of 2008. This anticipated decrease may be offset by additional interest expense in the event we obtain new financing.

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Income Taxes

We have recorded cumulative gross deferred tax assets of $214.7 million and $205.6 million at December 31, 2008 and 2007, respectively, principally attributable to the timing of the deduction of certain expenses associated with certain research and development expenses, net operating loss and other carryforwards. We also recorded corresponding valuation allowances of $214.7 million and $205.6 million at December 31, 2008 and 2007, respectively, to offset these deferred tax assets, as management cannot predict with reasonable certainty that the deferred tax assets to which the valuation allowances relate will be realized.

As of December 31, 2008, we had federal net operating loss carryforwards of approximately $159.5 million to offset future taxable income. We also had federal research and development tax credit carryforwards of approximately $10.5 million. If not utilized, these carryforwards will begin to expire in 2009. Our activities in Ireland and the adoption of FIN 48 in 2007 have allowed us to record previously unrecorded net operating losses related to our Irish subsidiary. These net operating losses are subject to a full valuation allowance. The availability of our net operating loss and tax credit carryforwards may be subject to substantial limitation if it is determined that our ownership has changed by more than 50% over a three-year period.

We had $0.4 million of income tax benefit for 2008 relating to refundable credits. There was no income tax expense for 2007 and 2006.

In February of 2009, we expanded our existing collaboration with Takeda to provide Takeda with access to multiple antibody technologies, including a suite of research and development technologies and integrated information and data management systems. We received a $29.0 million expansion fee, of which $5.8 million was witheld for payment to the Japanese taxing authority and will be included in income tax expense in 2009.

Share-Based Compensation

In October of 2007, our Board of Directors (the “Board”) approved a company-wide grant of options to purchase common shares. The purpose of the grant was to improve the level of employee ownership in the business by using existing share-based option plans to bring the Company in line with competitive industry levels. Of the total 6,635,000 options granted, 5,185,000 options were made subject to shareholder approval of a commensurate increase in the number of shares available for the grant of options under the Company’s existing share option plans. In addition, all options granted in February of 2008 as part of our annual compensation plan were subject to the aforementioned shareholder approval. As of December 31, 2007, the 5,185,000 shares from October of 2007 were not included in any of the options outstanding disclosures, options granted disclosures, or share-based compensation expense as they were not deemed granted for accounting purposes until shareholder approval was obtained in May of 2008.

In May of 2008, our shareholders approved the increase in the number of shares available for issuance under our existing share option plans. Upon shareholder approval, we recognized share-based compensation expense for the 5,185,000 share options granted in October of 2007 and the company-wide grant of 3,521,300 share options from February of 2008.

These shares vest according to our standard four-year vesting schedule which provides for 25% cliff vesting on the first year anniversary of the legal date of grant and monthly vesting of the remaining 75% of shares over the next three years. For accounting purposes, the expense related to the cliff vesting feature will be recognized from May of 2008 through the first corresponding anniversary of the legal grant date. We expect our share-based compensation expense to continue to be higher than prior periods over the four-year vesting period related to these options.

During the year ended December 31, 2008, we recognized $4.9 million in share-based compensation expense compared with $2.9 million in 2007 and $1.0 million in 2006. The increase of $2.0 million relates to annual grants in February of 2008 and the grant in October of 2007. At December 31, 2008, there was $11.1 million of unrecognized share-based compensation expense related to unvested share options with a weighted-average remaining recognition period of 2.9 years.

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Liquidity and Capital Resources

Cash, cash equivalents and short-term investments at December 31, 2008 was $10.8 million compared with $38.6 million and $46.4 million at December 31, 2007 and 2006, respectively. Net cash used in operating activities was $33.0 million in 2008, compared with net cash provided of $4.5 million in 2007. The $37.5 million increase in cash used for operations from 2007 to 2008 included a net loss of $45.2 million offset by non-cash adjustments of $16.1 million, primarily related to depreciation and share-based compensation. In addition, receivables increased by $4.6 million in 2008 primarily related to work performed on the NIAID 3, Novartis, SPRI and Takeda contracts, offset by a decrease in work performed on the SPRI/AVEO contract. Deferred revenue decreased by $0.9 million primarily related to a decrease in deferred revenue on the SPRI contract of $2.7 million due to amortization of up-front fees and a decrease in advance billings. This decrease was partially offset by an increase in deferred revenue of $1.5 million related to advance billings on the Novartis contract signed in December of 2008. Accrued liabilities decreased by $3.3 million primarily related to the reversal of the 2008 bonus accrual in the fourth quarter when the Company decided it would not pay the 2008 bonuses. Accounts payable increased by $3.0 million due to the Company paying vendors on longer terms and other liabilities increased by $2.1 million related to the NIAID 2 billing adjustment (as detailed above in the Critical Accounting Estimates: Contract Revenue section) for which a credit was provided to the NIH to be applied to future work performed on the NIAID 2 contract. During 2008, we collected $58.5 million in outstanding accounts receivable related to our revenue streams and made payments of $35.6 million relating to payroll, $4.0 million for the 2007 annual bonus and $65.8 million relating to payment of vendors.

We expect a decrease in net cash used for operating activities in 2009. During 2008, we substantially increased our spending on XOMA 052. We have been approached by several companies offering to collaborate on our testing and development of XOMA 052 and will seek to enter into such a collaboration by the end of 2009. We expect decreases in payroll expense and manufacturing-related expense in 2009 as a result of the workforce reduction, for which we expect to record a charge of approximately $3 million for severance and other costs. Our collaboration costs are fully funded by contract revenues from collaborators, including SPRI, Takeda and Novartis. Our biodefense costs are fully funded by the U.S. Government through our NIAID contracts.

In February of 2009 we expanded our existing collaboration to provide Takeda with access to multiple antibody technologies, including a suite of research and development technologies and integrated information and data management systems. We received a $29.0 million expansion fee, of which $23.2 million was received in cash in February of 2009 and the remainder was witheld for payment to the Japanese taxing authority. In addition, we expect to pay approximately $1.5 million of additional expenses to Takeda related to the agreement. We may receive potential milestones and royalties on sales of antibody products in the future.

Cash provided by operations for 2007 consisted of a net loss of $12.3 million with non-cash add-backs for depreciation and amortization of $6.2 million, the revaluation of our embedded derivative of $6.1 million, equity-related compensation of $4.2 million, and the amortization of debt issuance costs and the premium or discount on convertible notes of $0.6 million, as well as a net increase in liabilities of $4.5 million, which was partially offset by cash payments for the additional interest feature of our convertible debt of $5.2 million and $0.4 million of accrued interest on convertible debt and other interest bearing obligations. During the year ended December 31, 2007, we made payments of $6.6 million for interest on our convertible debt, $3.1 million for interest on our Goldman Sachs term loan, and $1.0 million for our Incentive Plans. In October of 2007, the Board of Directors approved amendments to the Incentive Plans eliminating the provisions requiring payments to be made partly in Common Shares and beginning in 2008, bonuses awarded under the incentive plans are paid entirely in cash.

Cash used in operations in 2006 consisted of a net loss of $51.8 million with non-cash add-backs for the revaluation of our embedded derivative of $6.9 million, depreciation and amortization of $5.1 million, equity-related compensation of $2.1 million and accrued interest of $1.2 million, along with a net increase in liabilities of $9.0 million partially offset by an increase in assets of $6.8 million. During 2006, we made payments of $2.7 million for debt issuance costs on our convertible debt of which $2.0 million related to cash used in operations, $3.8 million for interest on our convertible debt and $1.1 million for our Incentive Plans.

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Net cash provided by investing activities was $3.2 million in 2008, compared with net cash used in investing activities for 2007 and 2006 of $8.8 million and $8.4 million, respectively. Cash provided by investing activities for 2008 consisted of net sales and maturities of investments of $14.8 million, slightly offset by the transfer to restricted cash of $3.5 million relating to our new facility with Goldman Sachs and purchases of fixed assets of $8.1 million, primarily relating to lab and production equipment. Net cash used in investing activities for 2007 and 2006 consisted of purchases of property and equipment of $9.5 million and $8.5 million, respectively, and net proceeds from short-term investments of $2.3 million and $4.4 million, respectively. In addition, $1.7 million was transferred to restricted cash in 2007 and $4.3 million was transferred to restricted cash in 2006. We expect the reduction in our manufacturing-related operations, as part of the workforce reduction, to be completed by the second quarter of 2009. As a result, we expect capital costs to decrease in 2009 as compared to 2008.

Net cash provided by (used in) financing activities in 2008, 2007 and 2006 was $16.8 million, $(1.2 million) and $48.9 million, respectively. The increase in cash provided by financing activities in 2008 as compared to 2007 of $18.0 million is due to the refinancing of our original facility with Goldman Sachs in May of 2008, which netted proceeds of approximately $30.9 million, partially offset by a principal payment of $8.2 million against the outstanding balance of the original facility with Goldman Sachs in the first quarter of 2008. In addition, principal payment of $4.6 million was made on the new Goldman Sachs facility and $8.9 million was paid on our Novartis note in the fourth quarter of 2008. We also received proceeds of $7.6 million from the issuance of common shares related to draws made on our equity line of credit facility entered into in October of 2008 with Azimuth Opportunity, Ltd. (“Azimuth”).

Financing activities in 2007 included a $4.7 million principal repayment on our Goldman Sachs term loan, offset by additional borrowings of $2.8 million on our Novartis note and $0.7 million in proceeds received from the issuance of common shares. Financing activities in 2006 consisted of borrowings of $35.0 million from our original term loan with Goldman Sachs, partially offset by $1.5 million in debt issuance costs, $12.5 million in proceeds received from the issuance of convertible notes, partially offset by $0.5 million in debt issuance costs, a $3.0 million advance on our line-of-credit with Novartis and $0.4 million in proceeds received from the issuance of common shares.

Goldman Sachs Term Loan

In November of 2006, XOMA (US) LLC entered into a five-year, $35.0 million term loan facility (“the original facility”) with Goldman Sachs and borrowed the full amount thereunder. Indebtedness under the original facility incurred interest at an annual rate equal to six-month LIBOR plus 5.25% and was secured by all rights to receive payments due to the Company relating to RAPTIVA^®, LUCENTIS^® and CIMZIA^®.

In May of 2008, we entered into a five-year, $55.0 million amended and restated term loan facility with Goldman Sachs (the “new facility”) refinancing the original facility and borrowed the full amount thereunder. Indebtedness under the new facility bears interest at an annual rate equal to the greater of (x) six-month LIBOR or (y) 3.0%, plus 8.5% and is subject to reset on April 1 and October 1 of each year. As of December 31, 2008, the interest rate was 12.3%. The debt is secured by all rights to receive payments due to the Company relating to RAPTIVA^®, LUCENTIS^®, and CIMZIA^®. Payments received by XOMA in respect of these payment rights, in addition to a standing reserve equal to the next semi-annual interest payment, are held in a custodial account which is classified as restricted cash. This cash account and the interest earned thereon can be used solely for the payment of the semi-annual interest amounts due on April 1 and October 1 of each year and, at that time, amounts in excess of the interest reserve requirement may be used to pay down principal or be distributed back to us, at the discretion of Goldman Sachs. We may prepay indebtedness under the facility at any time, subject to certain prepayment premiums if prepaid during the first four years.

We are required to comply with certain covenants including a ratio of royalties collected to interest payable and a requirement that quarterly U.S. and outside-the-U.S. sales of RAPTIVA^® and LUCENTIS^® exceed certain specified minimum levels and we were in compliance with these covenants as of December 31, 2008. Our ability

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to comply with these covenants is dependent on continued sales by Genentech, UCB and their partners of these products at adequate levels, and any significant reduction in such sales could cause us to violate or be in default under these provisions, which could result in acceleration of our obligation to repay this debt.

In February of 2009, the EMEA announced that it has recommended suspension of the marketing authorization of RAPTIVA^® in the European Union, EMD Serono announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada and the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. We expect sales of RAPTIVA^® to decline significantly as a result of these and other related events, and we anticipate that as a consequence we will be in violation of or default under the relevant provisions of the new facility during the second or third quarter of this year. We are currently in discussions with the lenders regarding a restructuring of the terms of the new facility to address the effects of these developments. However, there can be no assurance that we will reach agreement with the lenders on acceptable terms, or at all, as a result of these discussions.

At December 31, 2008, the outstanding principal amount under the new facility totaled $50.4 million and the balance in restricted cash was $8.6 million relating to this facility. On April 1, 2009, the next payment date under the loan, the outstanding principal balance of the loan may be reduced, at the discretion of the lenders, by as much as $8 million, should the lenders choose to apply a portion of the restricted cash balance to the repayment of outstanding principal. This potential reduction in principal, if it were to occur, would take into account our interest payment due on April 1, 2009, estimated fourth quarter 2008 royalty receipts and amounts required to remain in restricted cash for the estimated interest payment due on October 1, 2009.

Debt issuance costs under the new facility of $2.0 million are being amortized on a straight-line basis over the five-year life of the loan and are disclosed as current and long-term debt issuance costs on the balance sheet. Proceeds from the new facility were used to pay the outstanding principal and accrued interest under the original facility, certain fees and expenses in connection with the new facility and for general corporate purposes.

Novartis Note

In May of 2005, we executed a secured note agreement with Chiron Corporation (now Novartis). Under the note agreement, Novartis agreed to make semi-annual loans to us to fund up to 75% of our research and development and commercialization costs under the collaboration arrangement, not to exceed $50.0 million in aggregate principal amount. Any unpaid principal amount together with accrued and unpaid interest shall be due and payable in full on June 21, 2015, the tenth anniversary date of the advance date on which the first loan was made. Interest on the unpaid balance of the principal amount of each loan shall accrue at six-month LIBOR plus 2%, which was equal to 3.85% at December 31, 2008, and is payable semi-annually in June and December of each year. Additionally, the interest rate resets in June and December of each year. At our election, the semi-annual interest payments can be added to the outstanding principal amount, in lieu of a cash payment, as long as the aggregate principal amount does not exceed $50.0 million and we have made this election for all interest payments thus far. Loans under the note agreement are secured by our interest in the collaboration with Novartis, including any payments owed to us thereunder.

In November of 2008, we restructured our product development collaboration with Novartis. Under the restructured agreement, we received $13.7 million in consideration of which $7.5 million was in the form of a debt reduction on our existing loan facility with Novartis, in exchange for giving Novartis control over the HCD122 program and an additional ongoing program. In addition, we made a principal payment on our Novartis note of $1.4 million in November of 2008. Pursuant to this restructuring, no additional borrowings will be made by XOMA on our Novartis note.

At December 31, 2008, the outstanding principal balance under this note agreement totaled $12.9 million and for the years ended December 31, 2008, 2007 and 2006 we incurred, and added to the principal balance of the note, interest expense of $1.2 million, $1.3 million and $1.0 million, respectively.

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Equity Line of Credit

On October 21, 2008, we entered into a common share purchase agreement (the “Purchase Agreement”) with Azimuth, pursuant to which we obtained a committed equity line of credit facility (the “Facility”) under which we may sell up to $60 million of our registered common shares to Azimuth over a 24-month period, subject to certain conditions and limitations. We are not obligated to utilize any of the $60 million Facility and remain free to enter other financing transactions. Pursuant to the terms of the Purchase Agreement, we determine, in our sole discretion, the timing, dollar amount and floor price per share of each draw down under the Facility, subject to certain conditions and limitations. The number and price of shares sold in each draw down are determined by a contractual formula designed to approximate fair market value, less a discount which may range from 2.65% to 6.65%. If the daily volume weighted average price of our common shares falls below a threshold price of $1.00 on any trading day during a draw down period, Azimuth will not be required to purchase the pro-rata portion of common shares allocated to that day. However, at its election, Azimuth may buy the pro-rata portion of shares allocated to that day at the threshold price less a negotiated discount. The Purchase Agreement also provides that from time to time and in our sole discretion, we may grant Azimuth the right to exercise one or more options to purchase additional common shares during each draw down pricing period for the amount of shares based upon the maximum option dollar amount and the option threshold price specified by us. Shares under the Facility are sold pursuant to a prospectus which forms a part of a registration statement declared effective by the Securities and Exchange Commission on May 29, 2008. From the inception of the Facility in October of 2008 through December 31, 2008, we have sold 7,932,432 common shares under the Facility for aggregate gross proceeds of $7.5 million, and $52.5 million remains available under the Facility. This includes the sale of 4.0 million shares under the Facility in December of 2008 that Azimuth agreed to purchase notwithstanding that the relevant volume weighted average prices were under the threshold price of $1.00. Under the terms of the Purchase Agreement, we negotiated a discount rate of 8.86% for this draw down. Prior to the successful conclusion of such negotiations, Azimuth was not obligated to purchase such shares, and there can be no assurance that they would agree to do so again if similar circumstances were to arise in the future. Offering expenses incurred through December 31, 2008 related to this Facility were $0.3 million. The proceeds are being used for general corporate purposes.

Convertible Debt

In February of 2006, we completed an exchange offer with holders of our 6.5% convertible senior notes due 2012 in which we exchanged $60.0 million aggregate principal amount of our new 6.5% Convertible SNAPs_SM due 2012 (the “New Notes”) for all $60.0 million aggregate principal amount of our then outstanding convertible senior notes due 2012. We also issued an additional $12.0 million of New Notes to the public for cash at a public offering price of 104% of principal, or $12.5 million. The New Notes were initially convertible into approximately 38.4 million common shares at a conversion rate of 533.4756 of common shares per $1,000 principal amount of New Notes, which is equivalent to a conversion price of approximately $1.87 per common share.

We separately accounted for the additional interest payment feature of the New Notes as an embedded derivative instrument, which was measured at fair value and classified on the balance sheet with the convertible debt. Changes in the fair value of the embedded derivative were recognized in earnings as a component of other income (expense). The initial fair value of the derivative was subtracted from the carrying value of the debt, reflected as a debt discount, which was amortized as interest expense using the effective interest method through the date the notes were scheduled to mature, and separately reported as a derivative liability.

The additional New Notes were issued to the initial purchasers for net proceeds of $11.8 million. Debt issuance costs related to the New Notes of approximately $0.7 million were being amortized on a straight-line basis over the original 72-month life of the notes. Additional debt issuance costs of $2.0 million, related to the modification of the existing debt, were expensed as incurred with $1.1 million expensed during the quarter ended March 31, 2006.

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At the time of note conversion, unamortized discount, premium and debt issuance costs related to the converted notes was charged to shareholder’s equity.

For the year ended December 31, 2006, $27.5 million of New Notes were converted into 18,262,264 common shares including 3,602,879 shares related to the additional interest payment feature of the notes. As of December 31, 2006, we had elected to pay all additional interest owed in common shares. We recorded a $6.9 million charge to interest expense during the year ended December 31, 2006, as a result of an increase in the fair value of the embedded derivative on our convertible debt including $4.8 million related to the additional interest feature of the converted notes. The remaining principal for the New Notes was $44.5 million as of December 31, 2006.

During the first quarter of 2007, $42.0 million of New Notes were voluntarily converted by holders through March 7, 2007, at which time we announced that we had elected to automatically convert 100% of the remaining $2.5 million of New Notes outstanding. As a result, during the quarter 25,640,187 shares were issued to effect the conversion of the principal balances. Additionally, we issued 1,889,317 shares and $5.2 million in cash to satisfy the remaining additional interest payment feature related to these converted New Notes. We recorded a $6.1 million charge to interest expense during the first quarter of 2007 as a result of the revaluation of the embedded derivative related to the additional interest feature of the convertible notes.

For the years ended December 31, 2007 and 2006, we incurred $0.2 million and $3.4 million, respectively, in interest expense on our convertible debt. Additionally, we amortized a net of $0.1 million and $1.0 million in debt issuance costs, premium and discount for the years ended December 31, 2007 and 2006, respectively. There were no balances recorded in 2008 relating to the convertible debt, as it was eliminated in the first quarter of 2007.

We have incurred significant operating losses and negative cash flows from operations since our inception. At December 31, 2008, we had cash, cash equivalents and short-term investments of $10.8 million, restricted cash of $9.5 million and working capital of $11.7 million. During 2009, we expect to continue using our cash, cash equivalents and short-term investments to fund ongoing operations. Additional licensing, antibody discovery collaboration agreements and financing arrangements may positively impact our cash balances. Based on anticipated spending levels, revenues, collaborator funding and other sources of funding we believe to be available, we estimate that we have sufficient cash resources to meet our anticipated net cash needs through the next twelve months, excluding a potential acceleration of the Goldman Sachs debt due to an anticipated decline in RAPTIVA^® royalties in 2009, as discussed above. Any significant revenue shortfalls, increases in planned spending on development programs or more rapid progress of development programs than anticipated, as well as the unavailability of anticipated sources of funding, could shorten this period. We expect sales of RAPTIVA^® to decline significantly as a result of recent events, and we anticipate that as a consequence we will be in violation of or default under the relevant provisions of our loan from Goldman Sachs during the second or third quarter of this year. In the event we are not able to restructure the terms of our loan from Goldman Sachs and otherwise maintain at least twelve months of cash resources, there will be substantial doubt as to our ability to continue as a going concern. Progress or setbacks by potentially competing products may also affect our ability to raise new funding on acceptable terms. If adequate funds are not available, we have developed contingency plans that may require us to delay, reduce the scope of, or eliminate one or more of our product development programs and further reduce personnel-related costs.

Our independent registered public accounting firm has included in their report for our fiscal year ended December 31, 2008 a qualification with respect to our ability to continue as a going concern. Our consolidated financial statements have been prepared on the basis of going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. If we became unable to continue as a going concern, we would have to liquidate our assets and the values we receive for our assets in liquidation could be significantly lower than the values at which they are carried on our consolidated financial statements. The inclusion of a going concern qualification in our independent registered public accounting firm’s audit opinion for the year ended December 31, 2008 may materially adversely affect our share price and our ability to raise new capital.

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Commitments and Contingencies

Purchase Obligations

In September of 2007, we entered into a five-year purchase agreement for custom cell culture medium for use in our research and development activities. Under the terms of the agreement we are obligated to meet certain annual purchase commitments. These commitments are included in the schedule of contractual obligations below:

Schedule of Contractual Obligations

Payments by period due under contractual obligations at December 31, 2008 are as follows (in thousands):

In addition to the above, we have committed to make potential future “milestone” payments to third parties as part of licensing and development programs. Payments under these agreements become due and payable only upon the achievement of certain developmental, regulatory and/or commercial milestones. Because it is uncertain if and when these milestones will be achieved, such contingencies, aggregating up to $79.0 million have not been recorded on our consolidated balance sheet. We are unable to determine precisely when and if our payment obligations under the agreements will become due as these obligations are based on milestone events, the achievement of which is subject to a significant number of risks and uncertainties.

Although operations are influenced by general economic conditions, we do not believe that inflation had a material impact on financial results for the periods presented. We believe that we are not dependent on materials or other resources that would be significantly impacted by inflation or changing economic conditions in the foreseeable future.

Recent Accounting Pronouncements

Fair Value Measurements

In October 2008, the FASB issued FSP 157-3 Determining Fair Value of a Financial Asset in a Market That Is Not Active (FSP 157-3). FSP 157-3 clarified the application of SFAS No. 157 in an inactive market. It demonstrated how the fair value of a financial asset is determined when the market for that financial asset is inactive. FSP 157-3 was effective upon issuance, including prior periods for which financial statements had not been issued. The implementation of this standard did not have a material impact on our financial statements. See Note 1: Fair Value of Financial Instruments to the Consolidated Financial Statements for information and related disclosures regarding our fair value measurements.

Accounting for Advance Payments for Goods or Services to Be Used in Future Research and Development

In June of 2007, the Emerging Issues Task Force issued EITF Issue 07-03, “Accounting for Advance Payments for Goods or Services to Be Used in Future Research and Development” (“EITF 07-03”). EITF 07-03

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addresses the diversity which exists with respect to the accounting for the non-refundable portion of a payment made by a research and development entity for future research and development activities. Under EITF 07-03, an entity would defer and capitalize non-refundable advance payments made for research and development activities until the related goods are delivered or the related services are performed. EITF 07-03 was effective for fiscal years beginning after December 15, 2007 and interim periods within those years. The adoption of EITF 07-03 did not have a material impact on our financial statements.

Accounting for Collaborative Agreements

In December of 2007, the EITF reached a consensus on EITF Issue 07-01 “Accounting for Collaborative Agreements” (“EITF 07-01”). EITF 07-01 defines collaborative arrangements and establishes reporting requirements for transactions between participants and third parties in a collaborative arrangement. EITF 07-01 prohibits companies from applying the equity method of accounting to activities performed outside a separate legal entity by a virtual joint venture. Instead, revenues and costs incurred with third parties in connection with the collaborative arrangement should be presented gross or net by the collaborators based on the criteria in EITF Issue No. 99-19, “Reporting Revenue Gross as a Principal versus Net as an Agent”, and other applicable accounting literature. The consensus should be applied to collaborative arrangements in existence at the date of adoption using a modified retrospective method that requires reclassification in all periods presented for those arrangements still in effect at the transition date, unless that application is impracticable. The consensus is effective for fiscal years beginning after December 15, 2008. The adoption of EITF 07-01 is not expected to have a material impact on the Company’s financial statements.

Subsequent Events

Workforce Reduction

In January of 2009, we announced a workforce reduction of approximately 42 percent, or 144 employees, a majority of which were employed in manufacturing and related support functions. This decision was made based on the challenging economic conditions and a decline in forecasted contract manufacturing demand in 2009. We expect an annualized reduction of approximately $27 million in cash expenditures when changes are completed in the second quarter of 2009. Upon completion of the workforce reduction, we expect to remain staffed with approximately 200 employees to develop XOMA 052, develop and license proprietary products and technology, and continue fully funded antibody discovery and development activities with our pharmaceutical partners in collaborations and the U.S. government in biodefense. We are temporarily suspending operations in four of our leased buildings. Our leases on these four buildings expire in the period from 2011 to 2014 and total minimum lease payments due from January of 2009 until expiration of the leases are $7.2 million. We are currently evaluating our options as to future use of these leased spaces. We will maintain our pilot scale manufacturing plant with some full scale capability.

Approval of LUCENTIS^® in Japan

In January of 2009, Novartis announced that LUCENTIS^® received approval in Japan for the treatment of (wet) age-related macular degeneration. We are entitled to receive low single-digit royalties on worldwide sales of LUCENTIS^®.

Expansion of Collaboration with Takeda

In February of 2009, we expanded our existing collaboration with Takeda to provide Takeda with access to multiple antibody technologies, including a suite of research and development technologies and integrated information and data management systems. We received a $29.0 million expansion fee, of which $23.2 million was received in cash in February of 2009 and the remainder was witheld for payment to the Japanese taxing authority. In addition, we expect to pay approximately $1.5 million of additional expenses to Takeda related to the agreement. We may receive potential milestones and royalties on sales of antibody products in the future.

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EMEA and Health Canada Recommendations and FDA Warning Regarding RAPTIVA^®

In February of 2009, the EMEA announced that it recommended suspension of the marketing authorization of RAPTIVA^® in the European Union, EMD Serono announced that, in consultation with Health Canada, it will suspend marketing of RAPTIVA^® in Canada, and the FDA issued a public health advisory concerning three confirmed reports, and one possible report, of PML in patients using RAPTIVA^®. We are entitled to receive mid-single digit royalties on worldwide sales of RAPTIVA^®. We expect sales of RAPTIVA^® to decline significantly as a result of these and other related events.

Forward-Looking Information and Cautionary Factors That May Affect Future Results

Certain statements contained herein related to the sufficiency of our cash resources, levels of future revenues, losses, expenses and cash, future sales of approved products, as well as other statements related to current plans for product development and existing and potential collaborative and licensing relationships, or that otherwise relate to future periods, are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These statements are based on assumptions that may not prove accurate. Actual results could differ materially from those anticipated due to certain risks inherent in the biotechnology industry and for companies engaged in the development of new products in a regulated market. Among other things, the period for which our cash resources are sufficient could be shortened if expenditures are made earlier or in larger amounts than anticipated or are unanticipated, if anticipated revenues or cost sharing arrangements do not materialize, if funds are not otherwise available on acceptable terms; revenue levels may be other than as expected if sales of approved products are lower than expected; losses may be other than as expected for any of the reasons affecting revenues and expenses; expense levels and cash utilization may be other than as expected due to unanticipated changes in our research and development programs; and the sales efforts for approved products may not be successful if the parties responsible for marketing and sales fail to meet their commercialization goals, due to the strength of the competition, if physicians do not adopt the product as treatment for their patients or if remaining regulatory approvals are not obtained. These and other risks, including those related to the results of preclinical testing; the timing or results of pending and future clinical trials (including the design and progress of clinical trials; safety and efficacy of the products being tested; action, inaction or delay by the United States Food and Drug Administration (“FDA”), European or other regulators or their advisory bodies; and analysis or interpretation by, or submission to, these entities or others of scientific data); changes in the status of existing collaborative relationships; the ability of collaborators and other partners to meet their obligations; our ability to meet the demand of the United States government agency with which we have entered our government contracts; competition; market demands for products; scale-up and marketing capabilities; availability of additional licensing or collaboration opportunities; international operations; share price volatility; our financing needs and opportunities; uncertainties regarding the status of biotechnology patents; uncertainties as to the costs of protecting intellectual property; and risks associated with our status as a Bermuda company, are described in more detail in Item 1A: Risk Factors.

Interest Rate Risk

Our exposure to market rate risk for changes in interest rates relates primarily to our investment portfolio and our loan facilities. By policy, we make our investments in high quality debt securities, limit the amount of credit exposure to any one issuer and limit duration by restricting the term of the instrument. We generally hold investments to maturity, with a weighted average portfolio period of less than twelve months. We do not invest in derivative financial instruments.

We hold interest-bearing instruments that are classified as cash, cash equivalents and short-term investments. Fluctuations in interest rates can affect the principal values and yields of fixed income investments. If interest rates in the general economy were to rise rapidly in a short period of time, our fixed income investments could lose value.

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The following table presents the amounts and related weighted average interest rates of our cash and investments at December 31, 2008 and 2007 (in thousands, except interest rate):

Due to the adverse developments in the credit markets in 2008, we may experience reduced liquidity with respect to some of our investments. Our investments are generally held to maturity, with a weighted average portfolio period of less than twelve months. However, if the need arose to liquidate such securities before maturity, we may experience losses on liquidation.

We have the ability and intent to hold our debt securities to maturity when they will be redeemed at full par value. Accordingly, we consider any unrealized losses to be temporary and have not recorded an impairment charge during the year ended December 31, 2008.

In November of 2006, we entered into a five-year senior term loan facility with Goldman Sachs in the aggregate amount of $35.0 million with the principal due at maturity. In May of 2008, this facility was replaced with a new loan facility of $55.0 million, for which we borrowed the full amount thereunder. As of December 31, 2008, $50.4 million remains outstanding under the new facility. Interest on the new facility is charged at a rate of the greater of (x) USD six-month LIBOR or (y) 3.0%, plus 8.5%, which was 12.3% at December 31, 2008.

As of December 31, 2008, we have an outstanding principal balance on our note with Novartis of $12.9 million, which is due in 2015. The interest rate on this note is charged at a rate of USD six-month LIBOR plus 2%, which was 3.85% at December 31, 2008. No further borrowing is available under this facility.

The variable interest rates related to our long-term debt instruments are based on LIBOR. We estimate that a hypothetical 100 basis point change in interest rates could increase or decrease our interest expense by approximately $642,000 on an annualized basis.

The following consolidated financial statements of the registrant, related notes and report of independent registered public accounting firm are set forth beginning on page F-1 of this report.

Not applicable.

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Under the supervision and with the participation of our management, including our Chairman, Chief Executive Officer and President and our Vice President, Finance and Chief Financial Officer, we conducted an evaluation of our disclosure controls and procedures, as such term is defined under Rule 13a-15(e) promulgated under the Securities Exchange Act of 1934, as amended, as of the end of the period covered by this report. Our disclosure controls and procedures are intended to ensure that the information we are required to disclose in the reports that we file or submit under the Securities Exchange Act of 1934 is (i) recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms and (ii) accumulated and communicated to our management, including the Chairman, Chief Executive Officer and President and Vice President, Finance and Chief Financial Officer, as the principal executive and financial officers, respectively, to allow timely decisions regarding required disclosures. Based on this evaluation, our Chairman, Chief Executive Officer and President and our Vice President, Finance and Chief Financial Officer concluded that our disclosure controls and procedures were effective as of the end of the period covered by this report.

We continue to enhance internal financial controls and staffing consistent with the requirements of the Sarbanes-Oxley Act of 2002. Apart from this, there were no changes in our internal controls over financial reporting during 2008 that have materially affected, or are reasonably likely to materially affect, our internal controls over financial accounting.

Management’s Report on Internal Control over Financial Reporting

Management, including our Chairman, Chief Executive Officer and President and our Vice President, Finance and Chief Financial Officer, is responsible for establishing and maintaining adequate internal control over financial reporting (as such term is defined in Exchange Act Rules 13a-159f). The Company’s internal control system was designed to provide reasonable assurance to the Company’s management and board of directors regarding the preparation and fair presentation of published financial statements in accordance with accounting principles generally accepted in the United States.

Management assessed the effectiveness of our internal control over financial reporting as of December 31, 2008. In making this assessment, 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 we believe that, as of December 31, 2008, our internal control over financial reporting is effective based on those criteria.

The Company’s internal control over financial reporting as of December 31, 2008, has been audited by Ernst & Young, LLP, the independent registered public accounting firm who also audited the Company’s consolidated financial statements. Ernst & Young’s attestation report on the Company’s internal control over financial reporting follows.

Changes in Internal Control over Financial Reporting

Our management, including our Chairman, Chief Executive Officer and President and our Vice President, Finance and Chief Financial Officer, has evaluated any changes in our internal control over financial reporting that occurred during the quarter ended December 31, 2008, and has concluded that there was no change during such quarter that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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Report of Independent Registered Public Accounting Firm

The Board of Directors and Shareholders of XOMA Ltd.:

We have audited XOMA Ltd.’s internal control over financial reporting as of December 31, 2008, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (the COSO criteria). XOMA Ltd.’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 included in the accompanying Management’s Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on 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, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, 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, XOMA Ltd. maintained, in all material respects, effective internal control over financial reporting as of December 31, 2008, 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 XOMA Ltd. as of December 31, 2008 and 2007 and the related consolidated statements of operations, shareholders’ equity (net capital deficiency) and cash flows for each of the three years in the period ended December 31, 2008 of XOMA Ltd., and our report dated March 10, 2009 expressed an unqualified opinion thereon that included an explanatory paragraph regarding XOMA Ltd.’s ability to continue as a going concern.

/s/ ERNST & YOUNG LLP

Palo Alto, California

March 10, 2009

None.

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PART III

Certain information regarding our executive officers required by this Item is set forth as a Supplementary Item at the end of Part I of this Form 10-K (pursuant to Instruction 3 to Item 401(b) of Regulation S-K). The Company’s Code of Ethics applies to all employees, officers and directors including the Chairman, Chief Executive Officer and President, the Vice President, Finance and Chief Financial Officer and Chief Accounting Officer, and is posted on the Company’s website at www.xoma.com. Other information required by this Item will be included in the Company’s proxy statement for the 2009 Annual General Meeting of Shareholders, under the sections labeled “Item 1—Election of Directors” and “Compliance with Section 16(a) of the Securities Exchange Act of 1934”, and is incorporated herein by reference.

Information required by this Item will be included in the sections labeled “Compensation of Executive Officers”, “Summary Compensation Table”, “Plan-Based Awards”, “Outstanding Equity Awards”, “Option Exercises and Share Vested Table”, “Pension Benefits”, “Non-Qualified Deferred Compensation” and “Director Compensation” appearing in our proxy statement for the 2009 Annual General Meeting of Shareholders, and is incorporated herein by reference.

Information required by this Item will be included in the sections labeled “Share Ownership” and “Equity Compensation Plan Information” appearing in our proxy statement for the 2009 Annual General Meeting of Shareholders, and is incorporated herein by reference.

Information required by this Item will be included in the section labeled “Transactions With Related Persons” appearing in our proxy statement for the 2009 Annual General Meeting of Shareholders, and is incorporated herein by reference.

Information required by this Item will be included in the section labeled “Item 2—Appointment of Independent Auditors” appearing in our proxy statement for the 2009 Annual General Meeting of Shareholders, and is incorporated herein by reference.

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PART IV

All financial statements of the registrant referred to in Item 8 of this Report on Form 10-K.

All financial statements schedules have been omitted because the required information is included in the consolidated financial statements or the notes thereto or is not applicable or required.

See “Index to Exhibits” on page i of this report.

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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on this 11^th day of March 2009.

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