Sunday, Jun 1, 2003

Genentech Reports Additional Data from BioOncology Pipeline at ASCO

Phase I Data on Omnitarg (pertuzumab) in Solid Tumors and First Study of Tarceva (erlotinib HCl) and Avastin (bevacizumab) Combination Presented

Chicago -- June 1, 2003 --

Genentech, Inc. (NYSE: DNA) today announced preliminary positive data from a Phase I study of Omnitarg™ (pertuzumab), formerly known as rhuMAb-2C4, and a Phase I/II study of Tarceva™ (erlotinib, HCl) in combination with Avastin™ (bevacizumab, rhuMAb-VEGF) in non-small cell lung cancer patients. These data were presented at the 39th annual meeting of the American Society of Clinical Oncology (ASCO).

Phase I Trial Evaluates Omnitarg (rhuMAb-2C4) in Solid Tumors (Abstract # 771)
David Agus, M.D. of Cedars-Sinai Medical Center reported on results from a Phase I study designed to evaluate the safety profile and clinical activity of Omnitarg in 21 patients with previously-treated, relapsed metastatic solid tumor cancers. Patients in the study received treatment with Omnitarg at doses ranging from 0.5 mg/kg to 15 mg/kg.

Partial responses were observed in 14 percent of patients (3/21) and an additional 38 percent of patients (8/21) achieved stable disease in this study. The investigators concluded that Omnitarg was well-tolerated at doses up to 15 mg/kg, as a majority of adverse events were Grade 1 and 2, with the most frequently reported adverse events being vomiting, nausea, fatigue, rash, anemia, abdominal pain, and diarrhea. There were two Grade 3 or 4 adverse events reported as drug-related: gastrointestinal bleeding in a patient with pre-existing tears in the esophagus and a patient who experienced a drop in left ventricular activity following a myocardial infarction.

"The development of Omnitarg is based on years of research conducted by Genentech and others into the mechanisms by which the HER pathway signals tumors to grow and metastasize, as well as our extensive clinical experience with Herceptin and Tarceva," said Susan D. Hellmann, M.D., M.P.H., Genentech's executive vice president, Development and Product Operations, and chief medical officer. "We are encouraged to observe that patients with multiple tumor types in this early dose-ranging Phase I study experienced partial responses or disease stabilization, demonstrating that Omnitarg may be a potentially active therapy."

Based on these data, Phase II trials evaluating Omnitarg have been initiated in advanced ovarian cancer, hormone-refractory prostate cancer and HER2-negative metastatic breast cancer (conducted by Roche). An additional Phase II trial in non-small cell lung cancer is scheduled to begin in 2003.

Omnitarg is a monoclonal antibody and the first in a new class of agents known as HER dimerization inhibitors (HDIs). It was developed to bind to the HER2 receptor and block the interaction between HER2 and other HER family members (HER1/EGFR, HER2, HER3, and HER4). Therefore it is designed to target tumors that have normal, rather than overexpressed levels of the HER2 protein.

Phase I/II Study of Tarceva and Avastin Yields Initial Promising Results (Abstract #2521)
In one of the first clinical trials to combine two targeted therapies to potentially inhibit activity of distinct signaling pathways, Edward Mininberg, M.D. of the University of Texas, MD Anderson Cancer Center presented preliminary data from a Phase I/II study of nine patients with recurrent non-small cell lung cancer. All patients were treated with a combination of Tarceva, a small molecule that targets the HER1 receptor (also known as EGFR), and the monoclonal antibody Avastin that targets VEGF (vascular endothelial growth factor), a central mediator of angiogenesis.

To date, nine patients have been enrolled in the ongoing study and six are evaluable for response. According to the investigators, two of the six patients experienced partial responses to the combined therapy at six weeks. Early data also show the treatment combination was well tolerated, with no unexpected adverse events.

In addition to the Avastin/Tarceva combination in non-small cell lung cancers, exploratory clinical studies are underway with an Avastin/Tarceva combination in renal cell (kidney) cancer and a Herceptin/Tarceva study in metastatic breast cancer, with additional studies being planned.

Leaders in Oncology
Genentech has established a broad oncology portfolio of innovative targeted therapies, including the first two monoclonal antibodies approved to treat cancer in the United States. Led by Rituxan® (Rituximab) and Herceptin® (Trastuzumab), the number one and number eight oncology therapies in the United States, respectively, the BioOncology portfolio includes product candidates in clinical trials for eight of the ten most lethal cancers. Phase III trials of Avastin, an angiogenesis inhibitor and Tarceva, a small molecule directed at the HER1/EGFR pathway, are ongoing in several solid tumor indications. Phase II trials of Omnitarg, a monoclonal antibody directed at the HER pathway have been initiated or are planned in four solid tumor cancers. Earlier stage programs are leveraging Genentech's world-leading expertise in targeting additional components of the HER2 and angiogenesis pathways, as well as pathways that instruct cancer cells to commit suicide, i.e., apoptosis, to broaden its portfolio of targeted cancer therapies.

About Genentech
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 originated from or are based on Genentech science. Genentech manufactures and commercializes ten biotechnology products 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. For press releases and additional information about the company, please visit http://www.gene.com.