Wednesday, May 4, 2005

Genentech Announces Webcast Discussions of Data Presented at ASCO; Phase III Breast Cancer Studies to be Presented at Educational Session

South San Francisco, Calif. -- May 4, 2005 --

Genentech, Inc. (NYSE:DNA) invites investors, the media and the general public to listen to audio webcasts discussing data presented at the American Society of Clinical Oncology (ASCO).

The Company also announced that ASCO has scheduled a special educational session titled, "Advances in Monoclonal Antibodies for Breast Cancer," on Monday, May 16 from 1:15 p.m. to 2:45 p.m. Eastern Time to discuss recent advances in early-stage and metastatic breast cancer. During the session, data from randomized Phase III studies of Herceptin plus chemotherapy as an adjuvant therapy in early-stage HER2-positive breast cancer and from a Phase III study of Avastin plus chemotherapy in first-line metastatic breast cancer will be presented.

Due to the extensive number of data presentations, Genentech will host two webcast discussions. The live webcasts can be accessed by going to Genentech's website at http://www.gene.com.

The first webcast will begin at 3:00 p.m. Pacific Time on May 14, 2005 and will be archived until 5:00 p.m. Pacific Time on May 21, 2005. An audio telephone replay will also be available beginning at 8:00 p.m. Pacific Time on May 14, 2005 through 5:00 p.m. Pacific Time on May 21, 2005. Access numbers for this replay are: 1-800-642-1687 (U.S./Canada) and 1-706-645-9291 (international); Conference ID number is 5733737.

The second webcast will begin at 4:00 p.m. Pacific Time on May 16, 2005 and will be archived until 5:00 p.m. Pacific Time on May 23, 2005. An audio telephone replay will also be available beginning at 9:00 p.m. Pacific Time on May 16, 2005 through 5:00 p.m. Pacific Time on May 23, 2005. Access numbers for this replay are: 1-800-642-1687 (U.S./Canada) and 1-706-645-9291 (international); Conference ID number is 5958818.

Genentech is a leading biotechnology company that discovers, develops, manufactures, and commercializes biotherapeutics for significant unmet medical needs. A considerable number of the currently approved biotechnology products originated from, or are based on, Genentech science. Genentech manufactures and commercializes multiple biotechnology products directly in the United States, and receives royalties or other income from companies that are licensed to market its products outside of the United States. The company has headquarters in South San Francisco, Calif., and is traded on the New York Stock Exchange under the symbol DNA. For additional information about the company, please visit http://www.gene.com.