OSI Pharmaceuticals to Announce Fourth Quarter and Year-End 2008 Financial Results on February 19, 2009

OSI Pharmaceuticals, Inc. (Nasdaq: OSIP) announced today that its fourth quarter and year-end 2008 financial results will be released on February 19, 2009, after the markets close. Following the announcement, OSI’s management will host a live conference call and webcast at 5:00 p.m. Eastern Time to review the Company’s financial results, product portfolio and business developments.

To access the live webcast or the fourteen-day archive via the Internet, log on to www.osip.com. Please connect to the Company's website at least 15 minutes prior to the conference call to ensure adequate time for any software download that may be needed to access the webcast. Alternatively, please call 1-877-852-6578 (U.S.) or 1-719-325-4826 (international) to listen to the call. The conference ID number for the live call is 2105141. Telephone replay is available approximately two hours after the call through March 5, 2009. To access the replay, please call 1-888-203-1112 (U.S.) or 1-719-457-0820 (international). The conference ID number is 2105141.

About OSI Pharmaceuticals

OSI Pharmaceuticals is committed to "shaping medicine and changing lives" by discovering, developing and commercializing high-quality and novel pharmaceutical products designed to extend life and/or improve the quality of life for patients with cancer and diabetes/obesity. The Company’s oncology programs are focused on developing molecular targeted therapies designed to change the paradigm of cancer care. OSI’s diabetes/obesity efforts are committed to the generation of novel, targeted therapies for the treatment of type 2 diabetes and obesity. OSI's flagship product, Tarceva® (erlotinib), is the first drug discovered and developed by OSI to obtain FDA approval and the only EGFR inhibitor to have demonstrated the ability to improve survival in both non-small cell lung cancer and pancreatic cancer patients in certain settings. OSI markets Tarceva through partnerships with Genentech, Inc. in the United States and with Roche throughout the rest of the world. For additional information about OSI, please visit 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, the completion of clinical trials, the FDA and other foreign review processes and other governmental regulation, OSI's and its collaborators' abilities to successfully develop and commercialize drug candidates, competition from other pharmaceutical companies, the ability to effectively market products, and other factors described in OSI Pharmaceuticals' filings with the Securities and Exchange Commission.