Saturday, May 12, 2001

OSI Pharmaceuticals, Genentech and Roche Announce Interim Clinical Data From Phase II Cancer Studies of the Anti-EGFR Therapy Tarceva® (OSI-774)

Data In Non-Small Cell Lung and Head and Neck Cancers Presented At The American Society Of Clinical Oncology (ASCO) Meeting

Uniondale, N.Y., South San Francisco, Calif. and Basel, Switzerland -- May 12, 2001 --

OSI Pharmaceuticals, Inc. (Nasdaq: OSIP), Genentech, Inc. (NYSE: DNA) and Roche announced today updated findings from two ongoing, Phase II clinical studies of the anti-cancer drug candidate Tarceva™ (OSI-774), an inhibitor of the epidermal growth factor receptor tyrosine kinase (EGFR). Clinical results presented at the 37th Annual Meeting of the American Society of Clinical Oncology (ASCO) demonstrated encouraging anti-cancer activity of Tarceva (OSI-774) and its potential utility as a single agent for the treatment of patients with refractory non-small cell lung (NSCLC) and head and neck cancer. The companies also announced that Tarceva has been chosen by the alliance as the trademark for OSI-774.

Phase II Non-Small Cell Lung Cancer Trial

Roman Perez-Soler, M.D., a lead investigator and Associate Director for Translational Research at New York University School of Medicine – Kaplan Comprehensive Cancer Center, reported data from a Phase II study of 57 evaluable patients with advanced, refractory, non-small cell lung cancer (NSCLC). Out of the 57 evaluable patients, one complete response (2 percent) and 8 partial responses (14 percent) were documented (2 unconfirmed). A total of 15 patients (26 percent) demonstrated evidence of disease stabilization for periods of three or more months. Furthermore, 28 patients (50 percent) in the study were still alive at the date of data assessment (3/30/01) with 10 patients (18 percent) having survived for over 300 days. In addition, 14 patients (25 percent) remained on study for six or more months. Median survival of patients in the study was 257 days and statistical analysis indicated a one year survival rate of 48 percent for patients in this uncontrolled study.

"The activity of Tarceva in patients with NSCLC was clearly demonstrated in this study," stated Dr. Perez-Soler. "Although this patient population is a highly selected group of stage IIIb and IV NSCLC patients who have progressed through multiple prior therapies, the information on patient survival is noteworthy. We look forward to controlled studies designed to substantiate this encouraging observation."

Qualification criteria for the open label, single agent study required failure of at least one round of platinum-based chemotherapy and to have tumors that are EGFR-positive. Tarceva (150 mg) was given orally as a single agent on a once-a-day dosing schedule. Objective clinical responses were evaluated at 8 and 12 weeks and classified as either complete responses, partial responses (>50 percent reduction in tumor size), stable disease, or progressive disease (>25 percent increase in tumor size).

Phase II Head and Neck Cancer Trial

Neil Senzer, M.D., a lead investigator and Director of Research Radiation, U.S. Oncology in Dallas, Texas, presented data from a Phase II study of 124 evaluable patients with advanced squamous cell carcinoma of the head and neck. Qualification criteria for the open label, single agent study required patients to have advanced head and neck cancer that was inoperable. Dosing and endpoints were similar to those in the NSCLC study.

Of the 124 patients, seven partial responses (1 unconfirmed) (6 percent) were observed, while 49 patients (39 percent) showed documented evidence of disease stabilization for periods of three or more months. Overall 45 percent of patients had either a response or disease stabilization. The number of partial responses is less than previously reported at last November's EORTC meeting in Amsterdam and results from the re-classification of several previously reported responses as stable disease (up to 50 percent tumor shrinkage) following third party assessment of the imaging data. Median survival of the patients in this study was 174 days, with 42 of the patients (39 percent) alive at the date of data assessment (3/28/01) and 14 patients having survived for over 300 days.

"Although data from these kinds of single agent studies in highly selected cancer patients can sometimes be over-interpreted, we are none-the-less very encouraged by these results documenting that Tarceva; is active in both of these trials," stated Colin Goddard, Ph.D., Chairman and Chief Executive Officer of OSI Pharmaceuticals.

Tarceva Safety and Tolerability Data

Preliminary analysis of the safety, tolerability and activity is ongoing and has thus far documented that Tarceva therapy can be administered to most patients with advanced cancer. Treatment has been generally well tolerated at the Phase II dose of 150 mg/day with a generally reversible acneiform rash and occasional diarrhea that responds to therapy being the most common side-effects reported to date. Consistent with other EGFR inhibitors in clinical development, rash has been the most common adverse event observed in all of the Tarceva trials. In the Phase II NSCLC study, a rash or rash related disorders were observed in 65 percent of the patients with 24 patients experiencing a mild rash and 12 patients having moderate rash and only one patient in this trial having a rash characterized as severe. The acneiform rash was more severe in the head and neck study with rash seen in approximately 72 percent of patients with 80 patients experiencing mild to moderate rash and 10 patients with documented severe rash.

"These early findings could mean a real chance for patients with NSCLC and head and neck cancer. We remain hopeful that results from further controlled clinical trials will prove beneficial to these patients who today have too few therapeutic options," said Dr. Don MacLean, Life Cycle Leader at Roche. "Tarceva; will compliment the existing Roche oncology portfolio, as it is another targeted anti-cancer treatment."

Tarceva; Comprehensive Clinical Development Program

OSI, Genentech and Roche also revealed further details of their development program for Tarceva. Genentech and Roche will initiate registration studies (Phase III) in front-line NSCLC later this year and will be responsible for the alliance program in breast cancer. OSI will initiate Phase III studies in pancreatic and refractory NSCLC and is responsible for the ongoing Phase Ib program examining the use of Tarceva with various chemotherapeutic regimens for advanced cancer patients. Genentech has opened a single agent, open label Phase II trial of Tarceva in patients with advanced breast cancer. OSI is conducting two additional Phase Ib clinical trials to determine the safety, tolerance, pharmacokinetics and preliminary anti-cancer activity of escalating doses of Tarceva in combination with carboplatin (Paraplatin®) and paclitaxel (Taxol®) in one study and gemcitabine (Gemzar®) and cisplatin (Platino®) in another study.

"Our experience in developing targeted therapies such as Rituxan and Herceptin for advanced cancer showed us that the ability of a single agent therapy to demonstrate objective responses in a heavily pre-treated patient population provides a strong rationale for randomized clinical trials that combine Tarceva; with traditional therapies and in earlier stage advanced disease," said Susan D. Hellmann, Genentech's executive vice president, Development and Product Operations and chief medical officer."

Further studies are in discussion with the U.S. National Cancer Institute's Cancer Therapy Evaluation Program (CTEP) to collaborate with OSI to conduct clinical trials in multiple tumor types including epithelial malignancies of the gastrointestinal and genitourinary tracts, gynecological malignancies and brain tumors.

OSI Pharmaceuticals is a leading biopharmaceutical company with a substantial portfolio of product opportunities for commercialization with the pharmaceutical industry. OSI's research programs are focused in the areas of cancer therapeutics, respiratory diseases, diabetes, and cosmeceuticals. OSI utilizes a comprehensive drug discovery and development capability to facilitate the rapid and cost-effective discovery and development of novel, small molecule compounds against more than 40 gene targets.

Genentech, Inc. is a leading biotechnology company that discovers, develops, manufactures and markets human pharmaceuticals for significant unmet medical needs. Fourteen of the currently approved biotechnology products stem from Genentech science. Genentech markets nine 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. Headquartered in Basel, Switzerland, Roche is one of the world's leading research-oriented healthcare groups in the fields of pharmaceuticals, diagnostics, and vitamins. Roche's products and services address prevention, diagnosis and treatment of diseases. Roche is a world leader in oncology included in its portfolio; Xeloda (breast cancer and colorectal cancer), Herceptin (breast cancer), MabThera (Non-Hodgkin's lymphoma), NeoRecormon (anemia in cancer patients), Roferon-A (leukemia, Kaposi's sarcoma, malignant melanoma), Bondronat (tumour-induced hypercalcemia), Furtulon (malignant tumours, only available in Japan) and the anti-emetic drug Kytril (used in chemotherapy induced emesis). Not all products and indications are available in all countries.

Investors may access a webcast regarding this announcement over the Internet by logging onto: http://www.osip.com or http://www.gene.com on Monday, March 14th at 3:15PM Eastern time (12:15PM Pacific time). A replay of this call will also be available until May 15th at 6:00PM Eastern time by dialing, 800-633-8284 or 858-812-6440 – call number: 18780057

Additional information on OSI Pharmaceuticals is available on the World Wide Web at http://www.osip.com

This news release contains forward-looking statements. These statements are subject to known and unknown risks and uncertainties that may cause actual future experience and results to differ materially from the statements made. Factors that might cause such a difference include, among others, uncertainties related to the identification of lead compounds, the successful pre-clinical development thereof, the completion of clinical trials, the FDA review process and other governmental regulation, pharmaceutical collaborators’ ability to successfully develop and commercialize drug candidates, competition from other pharmaceutical companies, product pricing and third part reimbursement, and other factors described in OSI Pharmaceuticals’ filings with the Securities and Exchange Commission.

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