XOMA Elects Charles J. Fisher, M.D. to Board of Directors

BERKELEY, Calif., July 26, 2007 (PRIME NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA) today announced the election of Charles J. Fisher, M.D. to its board of directors. Dr. Fisher will replace Arthur Kornberg, M.D., a member of XOMA's board of directors since 1984, who chose not to stand for reelection at the Company's last annual general meeting of shareholders.

"Dr. Fisher is a seasoned industry veteran and a distinguished clinical researcher," commented Jack Castello, chairman of the board of directors, president and chief executive officer of XOMA. "His experience in clinical development, regulatory affairs and commercialization strategy will be particularly important to XOMA's continued effort to grow its pipeline of new product candidates. We look forward to his expert insight and counsel."

"On behalf of the Board of Directors, I also wish to express our gratitude to Dr. Kornberg for his service and dedication to XOMA," Mr. Castello added. "His visionary perspective has benefited the company tremendously through the years."

Charles J. Fisher, M.D. is Chief Medical Officer and Executive Vice President of Clinical and Regulatory Affairs at Cardiome Pharma Corp. He has more than 20 years of leadership experience in clinical research and drug development and, during his earlier academic career, served as Principal Investigator of numerous clinical trials. Prior to Cardiome Pharma Corp., Dr. Fisher was divisional Vice President of Global Pharmaceutical Development at Abbott Laboratories Limited, responsible for the global development of pharmaceuticals, biologics and drug coated medical devices. Prior to Abbott Laboratories Limited, he was an Executive Director and Clinical Research Fellow at Eli Lilly & Co, where he led the scientific team in the development and regulatory approval of Xigris(r) (drotrecogin alfa (activated)) for the treatment of severe sepsis. Dr. Fisher also held professor and director positions at numerous academic institutions before joining industry, including the University of Manitoba, the University of California at Davis Medical Center, Case Western Reserve University and the Cleveland Clinic Foundation where he was Professor and Head of Critical Care Medicine.

Dr. Fisher is a Fellow of the American College of Physicians, American College of Chest Physicians, American College of Critical Care Physicians, American College of Emergency Physicians, and the American Academy of Emergency Medicine. An international thought leader in sepsis, Dr. Fisher has authored 88 peer-reviewed manuscripts and has been a reviewer for 14 journals. He obtained his medical degree from Michigan State University. He completed his internship and residency at the University of California, UC Davis Medical Center and fellowship training at the University of Manitoba.

About XOMA

XOMA is a leader in the discovery, development and manufacture of therapeutic antibodies, with a therapeutic focus that includes cancer and immune diseases. XOMA has royalty interests in RAPTIVA(r) (efalizumab), a monoclonal antibody product marketed worldwide (by Genentech, Inc. and Merck Serono S.A.) to treat moderate-to-severe plaque psoriasis, and LUCENTIS(r) (ranibizumab injection), a monoclonal antibody product marketed worldwide (by Genentech and Novartis AG) to treat neovascular (wet) age-related macular degeneration.

The company has built a premier antibody discovery and development platform that includes access to seven of the leading commercially available antibody phage display libraries and XOMA's proprietary Human Engineering(tm) and bacterial cell expression (BCE) technologies. More than 45 companies have signed BCE licenses. XOMA's development collaborators include Lexicon Pharmaceuticals, Inc., Novartis, Schering-Plough Research Institute and Takeda Pharmaceutical Company Limited. With a fully integrated product development infrastructure, XOMA's product development capabilities extend from preclinical sciences to product launch. For more information, please visit the company's website at www.xoma.com.

Certain statements contained herein that 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 the results of discovery research and 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 FDA, European or other regulators or their advisory bodies; and analysis or interpretation by, or submission to, these entities or others of scientific data); uncertainties regarding the status of biotechnology patents; uncertainties as to the cost of protecting intellectual property; changes in the status of the existing collaborative and licensing relationships; the ability of collaborators, licensees and other third parties to meet their obligations; market demand for products; scale up and marketing capabilities; competition; international operations; share price volatility; XOMA's financing needs and opportunities and risks associated with XOMA's status as a Bermuda company, are described in more detail in XOMA's most recent annual report on Form 10-K and in other SEC filings. Consider such risks carefully in considering XOMA's prospects.

CONTACT:  XOMA Ltd.
          Investor Relations and Corporate Communications
          Greg Mann
          510-204-7270
          mann@xoma.com

Released July 26, 2007