Monday, May 4, 1998

Genentech Submits Application for FDA Approval of HER2 Antibody, Herceptin

First Monoclonal Antibody for Treatment of Metastatic Breast Cancer

South San Francisco, Calif. -- May 4, 1998 --

Genentech, Inc. (NYSE:GNE) today announced completion of its submission of a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for Herceptin™ (Trastuzumab), a humanized anti-HER2 monoclonal antibody intended for the treatment of women with metastatic breast cancer who have tumors that overexpress the growth factor receptor, HER2. Herceptin is designated as a Fast Track Product by the FDA and will receive a priority review with a decision anticipated within six months.

"This Fast Track Biologics License Application represents a massive effort on the part of Genentech, the clinical trial investigators and staff, breast cancer patient advocates, researchers and the FDA to evaluate this novel treatment as rapidly as possible," said Arthur D. Levinson, Ph.D., Genentech's president and chief executive officer. "Submission of our license application to the FDA brings us another step closer to providing a new therapy which may benefit women with this aggressive form of breast cancer."

If Herceptin is approved for marketing, it will be a new biologic approach for the treatment of women with HER2-overexpressing metastatic breast cancer. HER2-overexpression affects 25-30 percent of breast cancer patients and is associated with more rapid cancer progression and shortened survival. Herceptin, the first monoclonal antibody for treatment of breast cancer, has been shown in laboratory studies to slow the growth of human breast cancer cells that overexpress HER2.

Genentech's license application to the FDA is based on the results of two recent Phase III clinical trials. The results of these trials will be presented on May 17 at the annual meeting of the American Society of Clinical Oncology (ASCO). The preliminary results of these studies were announced by Genentech in December 1997.

Approximately 1.6 million women have been diagnosed with breast cancer in the United States with 180,000 new cases diagnosed in any given year. Genentech estimates that there are approximately 164,000 women with metastatic breast cancer. Of these women, 25-30 percent have tumors that overexpress HER2 and would be candidates for this potential therapy.

Genentech, Inc. is a leading biotechnology company that discovers, develops, manufactures and markets human pharmaceuticals for significant unmet medical needs. Eleven of the currently marketed biotechnology products stem from Genentech science, seven of which Genentech markets in the United States. The company has headquarters in South San Francisco, California and is traded on the New York Stock Exchange and the Pacific Exchange under the symbol of GNE.

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