XOMA 052 Phase 1 Data to be Presented At European Association for the Study of Diabetes Annual Meeting

BERKELEY, Calif., July 15, 2008 (PRIME NEWSWIRE) -- XOMA Ltd. (Nasdaq:XOMA), a leader in the discovery and development of antibody therapeutics, today announced that results from two ongoing Phase 1 studies of XOMA 052 in Type 2 diabetes will be presented at the 44th European Association for the Study of Diabetes (EASD) Annual Meeting that will be held in Rome, Italy on September 7-11, 2008.

The oral presentation, titled "XOMA 052, an Anti-IL-1beta Antibody, in a Double-Blind, Placebo-Controlled, Dose Escalation Study of the Safety and Pharmacokinetics in Patients with Type 2 Diabetes Mellitus - A New Approach to Therapy" will examine safety and pharmacokinetics of XOMA 052 in addition to certain markers of activity such as hemoglobin A1c and C-reactive protein.

In the two studies, XOMA 052 was well tolerated without any evidence of serious drug-related adverse events. Clearance of XOMA 052 was consistent with that of a human antibody with a terminal half-life of 15-21 days. This drug profile, when combined with XOMA 052's high binding affinity of 300 femtomolar, could support potential dosing of once per month or longer in Type 2 diabetes patients.

By including secondary measures of anti-diabetic and anti-inflammatory activity, the studies may also provide proof-of-concept for XOMA 052 in multiple diseases, including diabetes, rheumatoid arthritis, gout, and other diseases. The studies were designed to enroll up to 72 Type 2 diabetes patients in total.

The EASD presentation will be given at 10:45 a.m. CEST on Monday, September 8, 2008 in Da Vinci Hall at the Nuova Fiera di Roma conference and exhibition center in Rome, Italy.

An abstract of the oral presentation scheduled for September 8, 2008 is available and can be viewed on the EASD Web site at www.easd.org.

About XOMA 052

XOMA 052 is a potent monoclonal antibody with the potential to improve the treatment of patients with a wide variety of inflammatory diseases. XOMA 052 binds strongly to interleukin-1beta (IL-1 beta), a pro-inflammatory cytokine that is involved in the development of diabetes, rheumatoid arthritis, gout, and other diseases. By binding IL-1beta, the drug blocks the activation of the IL-1 receptor, thereby preventing the cellular signaling events that produce inflammation. XOMA 052 is a humanized IgG2 antibody with a half-life of 15 to 21 days and binding affinity to human IL-1beta of 300 fM. Based on its binding properties, specificity to IL-1beta and half-life, XOMA 052 may provide convenient dosing of once per month or longer.

XOMA 052 is currently being developed for acute, chronic and orphan indications, including its evaluation in two Phase 1 clinical studies in Type 2 diabetes. XOMA 052 could prove to be a disease-modifying therapy for diabetes by addressing inflammation as an underlying cause of the epidemic disease, whereas current therapies focus almost exclusively on improving the body's ability to produce and respond to insulin.

The two randomized, placebo-controlled, double-blind Phase 1 studies of XOMA 052 in Type 2 diabetes were designed to assess safety and pharmacokinetics, and include measures of systemic inflammation, Hemoglobin A1c and other diabetes readings. Each study, one in Europe and one in the US, will enroll up to 36 patients in six cohorts and involves single-dose intravenous administration and dose-escalation by cohort. The U.S. study includes two additional parts that will investigate single-dose subcutaneous and multi-dose intravenous administration in up to 36 additional patients.

Based on the Phase 1 Type 2 diabetes studies, XOMA plans to initiate in 2008 clinical studies of XOMA 052 in rheumatoid arthritis, acute gout, and systemic juvenile idiopathic arthritis (sJIA).

The central role of the IL-1 pathway in multiple diseases has been clinically validated by several inhibitors of the IL-1 pathway in development and by two FDA approved therapies based on IL-1 blockade. These disease indications include rheumatoid arthritis, sJIA, gout, Muckle-Wells syndrome, and others.

About XOMA

XOMA is a leader in the discovery, development and manufacture of therapeutic antibodies. The Company's expanding pipeline includes XOMA 052, an anti-IL-1 beta antibody, and XOMA 629, a synthetic antimicrobial peptide compound derived from bactericidal/permeability-increasing protein.

XOMA's proprietary development pipeline is primarily funded by multiple revenue streams resulting from the licensing of its antibody technologies, product royalties, development collaborations, and biodefense contracts. XOMA's technologies and experienced team have contributed to the success of marketed antibody products, including RAPTIVA(r) (efalizumab) for chronic moderate to severe plaque psoriasis, LUCENTIS(r) (ranibizumab injection) for wet age-related macular degeneration and CIMZIA(r) (certolizumab pegol) for Crohn's disease.

The Company has a premier antibody discovery and development platform that incorporates leading antibody phage display libraries and XOMA's proprietary Human Engineering(tm) and bacterial cell expression technologies. Bacterial cell expression 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.

In addition to developing its own products, XOMA develops products with premier pharmaceutical companies including Novartis AG, Schering-Plough Research Institute and Takeda Pharmaceutical Company Limited. XOMA has a fully integrated product development infrastructure, extending from pre-clinical science to approval, and a team of 330 employees at its Berkeley location. For more information, please visit http://www.xoma.com.

Certain statements contained herein relating to product development such as the timing of clinical trials and the meaning of study data, 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 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
          Greg Mann
          510-204-7270
          mann@xoma.com

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

Released July 15, 2008