XOMA Receives $4 Million for Sale of Royalty Interest in CIMZIA(R)

BERKELEY, Calif., Aug. 18, 2010 (GLOBE NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA), a leader in the discovery and development of therapeutic antibodies, announced today that it has sold its royalty interest in CIMZIA(R) (certolizumab pegol) marketed by UCB S.A. for $4 million to an undisclosed buyer. The manufacture of CIMZIA is covered by a license to XOMA's Bacterial Cell Expression technology. The licensed U.S. patents will expire in 2014. CIMZIA is a pegylated antibody fragment that targets tumor necrosis factor alpha. It is approved in the U.S. to treat Crohn's disease and rheumatoid arthritis.

"The sale of our royalty interest in CIMZIA provides non-dilutive funding to support the development of XOMA 052 for Type 2 diabetes and other diseases and our preclinical programs," said Steven B. Engle, Chairman and CEO of XOMA.

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 with cardiovascular biomarkers, Type 1 diabetes, and
      with potential for the treatment of a wide range of inflammatory
      conditions. XOMA 052 also has demonstrated positive clinical benefit in
      a proof-of-concept trial for the treatment of vision-threatening uveitis
      of Behcet's disease.
  --  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 (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 225 employees at its Berkeley, California location. For more information, please visit http://www.xoma.com.

The XOMA Ltd. logo is available at https://www.globenewswire.com/newsroom/prs/?pkgid=5960

Safe Harbor Statement

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 generally unstable nature of current economic and financial market conditions; 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); availability of additional collaborative and licensing opportunities; 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 uncertainties regarding the status of biotechnology patents; uncertainties as to the cost of protecting intellectual property; 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.
          Company and Investor Contact:
          Carol DeGuzman
          510-204-7270
          deguzman@xoma.com

          Canale Communications
          Media Contact:
          Carolyn Hawley
          619-849-5375
          carolyn@canalecomm.com

Released August 18, 2010