XOMA Issued Two New U.S. Patents for Methods of Treating Type 2 Diabetes and Inflammatory Diseases Using Interleukin-1 Beta Antibodies

Key Additions to XOMA's Intellectual Property Portfolio for Its Lead Proprietary Product Candidate Which May Have Broad Commercial Utility in Multiple Disease Areas

BERKELEY, Calif., April 13, 2010 (GLOBE NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA), a leader in the discovery and development of therapeutic antibodies, announced that the U.S. Patent and Trademark Office has issued two new patents that significantly expand the company's intellectual property portfolio relating to its anti-inflammatory antibody, XOMA 052, that targets interleukin-1 beta (IL-1 beta). One of the patents covers methods of treating Type 2 diabetes with high affinity antibodies and antibody fragments that bind to IL-1 beta, including XOMA 052. The high affinity antibodies, such as XOMA 052, offer potential advantages in Type 2 diabetes because they may provide greater potency, less frequent dosing, reduced dose levels, and manufacturing efficiencies.

Additional claims in this patent relate to methods of reducing or preventing complications or conditions associated with Type 2 diabetes including retinopathy, renal failure, wound healing and cardiovascular disease, with these high affinity IL-1 beta antibodies. The patent also includes claims that relate to methods of treatment of Type 2 diabetes with high affinity IL-1 beta antibodies in conjunction with additional agents.

A second patent covers methods of treating IL-1 related inflammatory diseases, including rheumatoid arthritis and osteoarthritis, with XOMA 052 and other antibodies and antibody fragments with similar binding properties for human interleukin-1 beta (IL-1 beta).

The patents expire in 2027 (U.S. 7,695,718) and 2026 (U.S. 7,695,717), respectively. With these patents, the intellectual property portfolio for XOMA 052 includes four issued patents in the U.S. and one granted patent in Europe. Additional applications are pending in the U.S. and other countries.

"It is remarkable that targeting one component of the IL-1 pathway, as we have with our high affinity IL-1 beta antibody XOMA 052, may address a broad range of diseases that have inflammation as a common disease cause," said Steven B. Engle, XOMA's Chairman and Chief Executive Officer. "The issuance of these patents highlights XOMA's innovative research with IL-1 beta antibodies and in particular our pioneering role in applying IL-1 beta targeting to the treatment of Type 2 diabetes."

Diabetes and Cardiovascular Disease

The incidence of Type 2 diabetes is growing, with 23.6 million Americans, or 7.8% of the population, diagnosed with the disease, according to the Centers for Disease Control and Prevention. The total cost of diabetes is estimated to be $174 billion annually in the U.S., and the average medical expenditure for people with diabetes is estimated to be 2.3 times higher than for those without diabetes.

The American Heart Association estimates that 81 million people in the U.S. have one or more forms of cardiovascular disease, including high blood pressure, coronary heart disease, stroke or heart failure. It is the leading cause of death in the U.S. and worldwide. Direct and indirect costs of cardiovascular disease in the U.S. are estimated to be $503.2 billion annually.

About IL-1 and XOMA 052

The concept of targeting the IL-1 pathway in some inflammatory diseases has been clinically validated by three FDA-approved therapies, one for rheumatoid arthritis, and two for cryopyrin-associated periodic syndromes (CAPS). These and other IL-1 targeting products are currently in clinical development to address significant unmet medical needs including the treatment of Type 1 diabetes, Type 2 diabetes, cardiovascular disease, rheumatoid arthritis and gout.

XOMA is conducting two Phase 2 clinical trials of XOMA 052 in patients with Type 2 diabetes and a Phase 2 trial in Type 1 diabetes. The Phase 2 trials follow a successful 98 patient Phase 1 program in Type 2 diabetes patients in which XOMA 052 was shown to be well-tolerated, demonstrated evidence of biological activity in diabetes measures and cardiovascular biomarkers, and had a half-life that may provide convenient dosing of once per month or less frequently.

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 Institute of
      Allergy and Infectious Diseases of the National Institutes of Health
      (Contract # HHSN266200600008C).

  --  A preclinical pipeline with candidates in development for several
      diseases.

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

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.

Forward-Looking Statements

Certain statements contained herein concerning product development and capabilities of XOMA's technologies 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 generally unstable nature of current economic conditions; the results of discovery research 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 and licensing relationships; the ability of collaborators, licensees and other third parties 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.

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CONTACT:  XOMA Ltd.
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