EXHIBIT 99


OSI PHARMACEUTICALS ANNOUNCES $150 MILLION PRIVATE OFFERING OF CONVERTIBLE
SUBORDINATED NOTES

     MELVILLE, N.Y., Jan 24, 2002 (BW HealthWire) -- OSI Pharmaceuticals, Inc.
     (NASDAQ: OSIP) announced today that it intends to offer, subject to
     market and other conditions, $150 million of Convertible Subordinated
     Notes (plus an additional amount of $30 million to cover over-allotments,
     if any), due 2009, for purchase by qualified institutional buyers under
     Rule 144A of the Securities Act of 1933. The Notes would be convertible
     into OSI Pharmaceutical's Common Stock at the option of holder, at a
     price to be determined. The offering is expected to close on or about
     February 4, 2002. OSI Pharmaceuticals will agree to file a registration
     statement for the resale of the Notes and the shares of Common Stock
     issuable upon conversion of the Notes within 90 days after the closing of
     the offering.

     Use of the expected net proceeds of the offering may include continued
     development of our product pipeline, licensing and acquisition
     opportunities that add oncology products and late stage drug candidates,
     and general corporate purposes.

     This news release shall not constitute an offer to sell or a solicitation
     of an offer to buy, nor shall there be any sale of these securities in
     any state or jurisdiction in which such an offer, solicitation or sale
     would be unlawful prior to registration or qualification under the
     securities law of any such state or jurisdiction.

     The Notes and the Common Stock issuable upon conversion of the Notes have
     not been registered under the Securities Act, or any state securities
     laws, and are being offered only to qualified institutional buyers in
     reliance on Rule 144A under the Securities Act. Unless so registered, the
     Notes and Common Stock issued upon conversion of the Notes may not be
     offered or sold in the United States, except pursuant to an exemption
     from the registration requirements of the Securities Act and applicable
     state securities laws.

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

     CONTACT:     OSI Pharmaceuticals, Inc.
                  Kathy Galante, 631/962-2000
                  Corporate Communications
                  or
                  Burns McClellan (representing OSI)
                  Jonathan M. Nugent (investors)
                  Kathy Jones, Ph.D. (media)
                  212/213-0006



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