XOMA Licenses ING-1 Antibody to Triton BioSystems.

CHELMSFORD, Mass. & BERKELEY, Calif. -- Agreement Accelerates Triton's Development of its Targeted Payload System for Treatment of Cancer Patients

Triton BioSystems, Inc. (Triton) and XOMA Ltd. (NASDAQ: XOMA) today announced an agreement in which Triton has in-licensed the exclusive worldwide rights to commercially use XOMA's proprietary anti-tumor Human Engineered(TM) ING-1 monoclonal antibody with Triton's Targeted Nano-Therapeutics(TM) (TNT(TM)) System. The TNT(TM) System is an innovative product that ablates tumors by using tiny magnetic spheres delivered systemically with antibodies. The tiny spheres within the tumors are induced to heat by a localized externally applied magnetic field. ING-1, a Human Engineered(TM) monoclonal antibody with high affinity to the Ep-CAM antigen is expressed in high concentrations on many adenocarcinoma tumor cells. The combination of the ING-1 antibody with the TNT(TM) System is intended to create a novel, highly selective, safe, and effective treatment for adenocarcinomas, such as breast, colorectal, lung, ovary and prostate.

"This agreement represents an important milestone in the development of Triton's TNT(TM) System," said Dr. Samuel Straface, president and CEO of Triton BioSystems. "The extensive preclinical and clinical history of ING-1 demonstrating its lack of immunogenicity in humans eliminates many of the risks we would have faced with an untested antibody. The use of ING-1 in our TNT(TM) System will enable us to rapidly enter human clinical trials and enhance our product's potential to treat a significant number of cancer patients worldwide."

The license to Triton includes U.S. and foreign patent rights related to XOMA's ING-1 and Human Engineering(TM) technologies along with several pending applications.

"After an extensive review and evaluation of anti-tumor antibodies as potential targeting agents with the TNT(TM) System, we believe ING-1 is an ideal candidate," said Dr. Howard L. Levine, Triton's Chief Technology Officer and President of BioProcess Technology Consultants, Inc. "ING-1 binds very specifically to adenocarcinoma cells, and can be manufactured using a reliable, validated process making it an excellent choice to develop the first of many products using the TNT(TM) System."

XOMA has substantial experience and broad-based capabilities in the generation and development of monoclonal antibody products. XOMA's patented Human Engineering(TM) methodology effectively yields antibodies with minimal potential for immunogenicity in humans. ING-1 was the first Human-Engineered(TM) antibody to be administered in human clinical studies. In phase I/II clinical trials ING-1 was evaluated in cancer patients with advanced adenocarcinomas of the breast, colorectal, pancreatic, gastric, esophageal, lung, ovary, and prostate.

"We are pleased that Triton has licensed our ING-1 antibody," said John L. Castello, chairman, president and chief executive officer of XOMA. "It demonstrates the value of XOMA's technologies, capabilities and experience in biopharmaceutical development. It also reinforces our vision of working with innovators such as Triton to develop innovative products to treat a variety of diseases to improve patients' quality of life."

About Triton BioSystems

Triton BioSystems, Inc, is based in Chelmsford, Massachusetts, USA, and is a private-equity owned company focused on the discovery and development of low side effect targeted therapeutics that use heat to treat cancer and other life threatening and debilitating diseases. For more information about Triton BioSystems, please visit http://www.TritonBioSystems.com/.

About XOMA

XOMA is a biopharmaceutical company focused on the development and commercialization of antibody and other protein-based biopharmaceuticals for disease targets that include cancer, immunological and inflammatory disorders, and infectious diseases. XOMA's proprietary and collaborative product development programs include: RAPTIVA(R) for moderate to severe plaque psoriasis (marketed) and other indications in collaboration with Genentech, Inc.; MLN 2222, a recombinant protein for reducing the incidence of post-operative events in coronary artery bypass graft surgery patients with Millennium Pharmaceuticals, Inc. (Phase I); C1212, an anti-CD40 antibody for treating B-cell tumors and additional product candidates in connection with the antibody oncology collaboration with Chiron Corporation (preclinical); a TPO mimetic antibody to treat chemotherapy-induced thrombocytopenia in collaboration with Alexion Pharmaceuticals, Inc. (preclinical); and several anti-gastrin product candidates in conjunction with the antibody collaboration for the treatment of gastrointestinal cancers with Aphton Corporation (preclinical). XOMA's proprietary bactericidal/permeability-increasing protein (BPI)-derived programs include NEUPREX(R), in a Phase I/II study to limit complications following pediatric cardiopulmonary bypass surgery. For more information about XOMA's product pipeline and antibody product development capabilities and technologies, please visit XOMA's website at http://www.xoma.com/.

Certain statements contained herein related to the development of the ING-1 antibody and XOMA's licensing arrangement with Triton, 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 and other risks, including those related to uncertainties regarding the status of biotechnology patents, uncertainties as to the cost of protecting intellectual property, changes in the status of existing licensing relationships, the ability of licensees and other partners to meet their obligations, the results of pre-clinical testing, the timing or results of future clinical trials (including the design and progress of clinical trials; safety and efficacy of products being tested; action, inaction or delay by the FDA, European or other regulators or their advisory bodies; and analysis and interpretation by, or submission to, these entities or others of scientific data), market demand for products, scale-up and marketing capabilities, competition, XOMA's financing needs and opportunities, share price volatility, international operations 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 its other SEC filings.