OSI Pharmaceuticals Names Gary M. Clark, Ph.D. Senior Director, Biostatistics and Data Management.

Business Editors & Health/Medical Writers

MELVILLE, N.Y.--(BW HealthWire)--March 5, 2002

OSI Pharmaceuticals, Inc. (NASDAQ: OSIP) announced today that Gary M. Clark, Ph.D., has joined the Company as Senior Director of Biostatistics and Data Management.

Dr. Clark will report to Nicole Onetto, MD, Executive Vice President, Oncology at OSI Pharmaceuticals.

Dr. Clark, 56, will oversee all of OSI's biostatistics and data management activities on OSI's growing pipeline of oncology candidates, including Tarceva(TM) (OSI-774), which is currently in Phase III clinical trials in non-small cell lung and pancreatic cancers.

"We are very excited about having someone of Gary's caliber leading our biometrics group," stated Nicole Onetto, MD. "Gary's extensive theoretical knowledge, practical experience and expertise will be a tremendous benefit to OSI as we expand our oncology development and commercialization capabilities."

Prior to joining OSI, Dr. Clark most recently served three years at Baylor College of Medicine as Associate Director of the Breast Center and Professor of Medicine. Dr. Clark's previous positions included Professor of Medicine, Department of Medicine/Oncology at the University of Texas Health Science Center at San Antonio, Director of the Biostatistics, Data Processing and Data Management Shared Resource of the San Antonio Cancer Institute, and Associate Professor, Department of Biometry, University of Kansas Medical Center. Dr. Clark studied at the University of Washington where he received his Master's degree and Doctorate in Biomathematics. Dr. Clark is a world recognized oncology researcher, and has significantly contributed to the field of prognostic factors in breast cancer. He has received many prestigious awards throughout his career and serves on several peer-reviewing committees.

OSI Pharmaceuticals is a leading biotechnology company primarily focused on the discovery, development and commercialization of innovative products for the treatment of cancer. OSI has built a pipeline of discovery programs and drug candidates addressing major, unmet medical needs in cancer and selected opportunities, including diabetes, arising from the Company's extensive drug discovery research programs that represent significant commercial opportunities outside of cancer. OSI's most advanced drug candidate, Tarceva(TM) (OSI-774), a small molecule inhibitor of the EGFR gene, is currently in Phase III clinical trials for lung and pancreatic cancers.

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 preclinical 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 party reimbursement, and other factors described in OSI Pharmaceuticals' filings with the Securities and Exchange Commission.

Additional information on OSI Pharmaceuticals is available at www.osip.com