Friday, Apr 5, 2002

Genentech and Xoma Obtain Results from Xanelim(TM) (Efalizumab) Pharmacokinetic Study

South San Francisco and Berkeley, Calif. -- April 5, 2002 --

Genentech Inc. (NYSE: DNA) and XOMA Ltd. (Nasdaq: XOMA) today announced that a pharmacokinetic study conducted on Xanelim™ (efalizumab) comparing XOMA-produced material and Genentech-produced material did not achieve the pre-defined statistical definition for comparability.  The study suggested that the Genentech material achieved a slightly higher serum concentration than the XOMA material.  Genentech and XOMA will work closely with the U.S. Food and Drug Administration (FDA) to determine next steps, but this will probably delay the filing of a Biologics License Application (BLA) with the FDA for Xanelim beyond summer 2002.

“Genentech and XOMA are encouraged by the Xanelim safety and efficacy data collected to date,” said Susan D. Hellmann, M.D., M.P.H., Genentech’s executive vice president, Development and Product Operations and chief medical officer.  “We continue to enroll patients into ongoing Xanelim clinical trials, including additional studies to expose more patients to the Xanelim material being produced at Genentech for marketing after approval.  Genentech now plans to submit data from an additional ongoing efficacy study using Xanelim material produced at Genentech to the FDA and, contingent upon successful discussions with the FDA, expects to be able to submit data from this efficacy study before the end of 2002.”

During Phase III Xanelim testing, minor manufacturing modifications were made to allow for large-scale material production.  Last year the FDA requested a pharmacokinetic study to confirm the comparability of Xanelim material used in clinical trials, which was primarily produced at XOMA, and Xanelim material produced at Genentech for marketing after product approval.   As part of the Xanelim clinical program, the companies had earlier successfully completed a number of internal evaluations, including animal pharmacokinetic studies, which supported comparability of the two materials.

Xanelim is a targeted T-cell modulator that is designed to target three key processes in the cascade of events that lead to psoriasis.  These targeted processes are: (1) binding of T-cells through interactions with adhesion molecules on the endothelial cell surface; (2) migration of T-cells into the skin; and (3) activation of T-cells, all of which may be linked to the abnormal growth of skin cells and the painful, elevated scaly patches of skin (lesions) typical among psoriasis sufferers.

Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes biotherapeutics for significant unmet medical needs.  Fifteen of the currently approved biotechnology products stem from or are based on Genentech science.  Genentech manufactures and commercializes ten biotechnology products directly in the United States.  The company has headquarters in South San Francisco, California, and is traded on the New York Stock Exchange under the symbol DNA.

XOMA develops and manufactures innovative biopharmaceuticals for disease targets that include cancer, immunological and inflammatory disorders, and infectious diseases. XOMA’s programs include collaborations with Genentech, Inc. on the Xanelim™ antibody for psoriasis (Phase III), rheumatoid arthritis (Phase II) and other indications; with Baxter Healthcare Corporation to develop NEUPREX? (rBPI-21) for Crohn’s disease (Phase II) and other indications; with Millennium Pharmaceuticals, Inc. on two biotherapeutic agents, CAB2 and MLN01, for certain vascular inflammation indications (preclinical); and with Onyx Pharmaceuticals, Inc. to develop and manufacture its Onyx-015 product for various cancers (Phase II and III). Earlier-stage development programs include compounds to treat cancer, retinopathies, autoimmune diseases and infections. For more information about XOMA's pipeline and activities, please visit XOMA’s website at


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The statements made in this press release relating to the BLA filing time frame and data submission are forward-looking and the actual filing or submission time frame could differ materially.  Among other things, the BLA filing or submission could be delayed by unexpected safety or efficacy issues, manufacturing issues or additional time requirements for data analysis, BLA preparation, discussions with the FDA, slow enrollment in clinical studies or the need for additional clinical studies.


Statements made in this news release related to the timing of regulatory approval, submission of regulatory filings, progress of clinical trials and collaborative arrangements, 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 include those related to safety, efficacy and comparability of the products being studied; action, inaction or delay by the Food and Drug Administration; analysis and interpretation of scientific data; changes in the status of existing collaborative relationships; the ability of collaborators to meet their obligations and market demand for products, as well as those factors described in the preceding paragraph. These risks are discussed in XOMA’s most recent annual report on Form 10-K and in other SEC filings. Consider such risks carefully in evaluating XOMA's prospects.