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EXHIBIT 5.1
[SAUL EWING LETTERHEAD]
November 1, 2000
OSI Pharmaceuticals, Inc.
106 Charles Lindbergh Blvd.
Uniondale, NY 11553
Gentlemen:
We refer to the Registration Statement on Form S-3 (the "Registration
Statement") of OSI Pharmaceuticals, Inc., a Delaware corporation (the
"Company"), to be filed with the Securities and Exchange Commission covering the
registration under the Securities Act of 1933, as amended (the "Securities
Act"), of 6,152,500 shares of common stock, par value $.01 per share, of the
Company (the "Shares").
We have examined the Registration Statement, the Certificate of
Incorporation and By-laws of the Company and such records, certificates and
other documents as we have considered necessary or appropriate for the purposes
of this Opinion.
Based on the foregoing, it is our opinion that:
1. the Company is duly organized, validly existing and in good standing
under the laws of the State of Delaware; and
2. the Shares to be issued in accordance with the terms described in the
Registration Statement have been duly authorized and, when issued in accordance
with the terms described in the Registration Statement, will be validly issued,
fully paid and non-assessable.
We hereby consent to use of our name in the Registration Statement as
counsel who will pass upon the legality of the Shares for the Company and as
having prepared this Opinion as an exhibit to the Registration Statement. In
giving the foregoing consent, we do not thereby admit that we are in the
category of person whose consent is required under Section 7 of the Securities
Act or the rules and regulations of the Securities and Exchange Commission
thereunder.
Very truly yours,
/s/ SAUL EWING LLP
