OSI Pharmaceuticals to Present at the Lazard Capital Markets Annual Life Sciences Conference on Wednesday, November 30th

The presentation will be webcast live and may be accessed byvisiting OSI's website at www.osip.com. A replay of the webcast willalso be available on the Company's website until Wednesday, December14, 2005.

About OSI Pharmaceuticals

OSI Pharmaceuticals is committed to "shaping medicines andchanging lives" by discovering, developing and commercializinghigh-quality and novel pharmaceutical products that extend life orimprove the quality of life for patients with cancer, eye diseases,and diabetes. The Company operates through three business teams, (OSI)Oncology, (OSI) Eyetech and (OSI) Prosidion. (OSI) Oncology is focusedon developing molecular targeted therapies designed to change theparadigm of cancer care. (OSI) Eyetech specializes in the developmentand commercialization of novel therapeutics to treat diseases of theeye. (OSI) Prosidion is committed to the generation of novel, targetedtherapies for the treatment of type 2 diabetes and obesity. OSI'sflagship product, Tarceva(R) (erlotinib), is the first drug discoveredand developed by OSI to obtain FDA approval and the only EGFRinhibitor to have demonstrated the ability to improve survival in bothnon-small cell lung cancer and pancreatic cancer patients. OSI marketsTarceva through partnerships with Genentech, Inc. in the United Statesand with Roche throughout the rest of the world. Macugen(R)(pegaptanib sodium injection) is approved in the United States for thetreatment of neovascular age-related macular degeneration. OSIcommercializes Macugen in partnership with Pfizer Inc. For additionalinformation about OSI, please visit http://www.osip.com.

This news release contains forward-looking statements. Thesestatements are subject to known and unknown risks and uncertaintiesthat may cause actual future experience and results to differmaterially from the statements made. Factors that might cause such adifference include, among others, the completion of clinical trials,the FDA review process and other governmental regulation, OSI's andits collaborators' abilities to successfully develop and commercializedrug candidates, competition from other pharmaceutical companies, theability to effectively market products, and other factors described inOSI Pharmaceuticals' filings with the Securities and ExchangeCommission.