XOMA Presents Advantages of Its Multiple Antibody Formulation Technologies at Antibody Engineering Conference

Ability to Deliver Multiple Antibodies in a Single Dose Has Potential to Increase Product Efficacy for Infectious and Other Diseases

BERKELEY, Calif., Dec. 10, 2009 (GLOBE NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA), a leader in the discovery and development of therapeutic antibodies, reported results demonstrating the advantages of its monoclonal antibody technologies in the rapid development of a first-in-class multiple antibody product candidate, XOMA 3AB. XOMA 3AB is designed to neutralize botulinum neurotoxin Type A, which causes paralysis and is a bioterror threat. The results were presented at the 20th Annual International Conference on Antibody Engineering being held December 6 to 10 in San Diego, CA.

A major problem with treating botulism and many infectious diseases is that a single antibody may not be effective in neutralizing a toxin or infectious agent, particularly when multiple strains or subtypes exist. XOMA's technologies enable it to co-formulate and deliver multiple antibodies in a single injectable solution, which facilitates delivery and has the potential to increase efficacy for infectious and other diseases. XOMA 3AB is comprised of three human antibodies that bind to unique epitopes on the botulinum A toxin, which in composite provide unprecedented potency against the toxin. XOMA is developing XOMA 3AB under existing research contracts with the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH).

This project has been funded in whole or in part with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, and Department of Health and Human Services under contract numbers HHSN266200600008C and HHSN272200800028C. Contract HHSN272200800028C was awarded in 2008 for a total of $65 million.

"These results highlight the breadth of XOMA's advanced expertise in antibody development, optimization and formulation. We are utilizing multiple technologies to provide stable products with longer shelf lives and lower costs than third generation biologics," said Patrick J. Scannon, M.D., Ph.D., XOMA's Executive Vice President and Chief Medical Officer. "For the first time, we have also solved a key quality problem in ensuring the mix and potency of multiple antibodies. Specialized assays were developed and implemented to ensure precise characterization, stability and release of this multiple antibody cocktail."

XOMA recorded revenue of $4.3 million from this botulism-related biodefense business in the nine months ended September 30, 2009. XOMA anticipates this business will generate more than $20 million in 2010.

About XOMA

XOMA discovers, develops and manufactures novel antibody therapeutics for its own proprietary pipeline as well as through license and collaborative agreements with pharmaceutical and biotechnology companies, and under its contracts with the U.S. government. The company's proprietary product pipeline includes:


 * XOMA 052, an anti-IL-1 beta antibody in Phase 2 clinical
   development for Type 2 diabetes, Type 1 diabetes and
   cardiovascular disease, with potential for the treatment of a
   wide range of inflammatory conditions
 * XOMA 3AB, an antibody candidate in pre-IND studies to neutralize
   the botulinum toxin, among the most deadly potential bioterror
   threats, under development through funding provided by the
   National Institutes of Allergy and Infectious Diseases of the
   National Institutes of Health
 * A preclinical pipeline with candidates in development for
   inflammatory, autoimmune and oncologic diseases

In addition to its proprietary pipeline, XOMA develops products with premier pharmaceutical companies including Novartis AG, Merck & Co., Inc. and Takeda Pharmaceutical Company Limited.

XOMA has multiple revenue streams resulting from the licensing of its antibody technologies, product royalties, development collaborations and biodefense contracts. XOMA's technologies have contributed to the success of marketed antibody products, including LUCENTIS(R) (ranibizumab injection) for wet age-related macular degeneration and CIMZIA(R) (certolizumab pegol) for rheumatoid arthritis and Crohn's disease.

The company has a premier antibody discovery and development platform that incorporates an unmatched collection of antibody phage display libraries and proprietary Human Engineering(TM), affinity maturation, Bacterial Cell Expression (BCE) and manufacturing technologies. BCE is a key breakthrough biotechnology for the discovery and manufacturing of antibodies and other proteins. As a result, more than 50 pharmaceutical and biotechnology companies have signed BCE licenses, and several licensed product candidates are in clinical development.

XOMA has a fully integrated product development infrastructure, extending from pre-clinical science to approval, and a team of about 200 employees at its Berkeley, California location. For more information, please visit http://www.xoma.com.

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Forward-Looking Statements

Certain statements contained herein concerning product development 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.

These risks, including those related to inability to comply with NASDAQ's continued listing requirements, the declining and generally unstable nature of current economic conditions; the results of discovery and pre-clinical 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 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; XOMA's ability to meet the demands of the United States government agency with which it has entered into its government contracts; competition; market demands for products; scale-up and marketing capabilities; availability of additional licensing or collaboration opportunities; international operations; share price volatility; XOMA's financing needs and opportunities; uncertainties regarding the status of biotechnology patents; uncertainties as to the costs of protecting intellectual property; and risks associated with XOMA's status as a Bermuda company, are described in more detail in XOMA's most recent filing on Form 10-K and in other SEC filings. Consider such risks carefully when considering XOMA's prospects.

CONTACT:  XOMA Ltd.
          Company and Investor Contact:
          Carol DeGuzman
          510-204-7270
          deguzman@xoma.com

          Porter Novelli Life Sciences
          Media Contact:
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          619-849-5375
          chawley@pnlifesciences.com