December 13, 2005
OSI Pharmaceuticals, Inc.
58 South Service Road
Melville, NY 11747
Ladies and Gentlemen
OSI Pharmaceuticals, Inc. ("you" or the "Borrower" has requested that J.P. Morgan Securities Inc.
("JPMorgan"), agree to structure, arrange and syndicate a senior revolving credit facility in an aggregate amount
of $75,000,000 for the Borrower, and that JPMorgan Chase Bank, N.A. "Chase") commit to provide the
$75,000,000 senior secured credit facility (the "Facility") and to serve as administrative agent for the Facility.
JPMorgan is pleased to advise you that it is willing to act as exclusive arranger for the Facility.
Furthermore (a) Chase is pleased to advise you of its commitment to provide the entire amount of the Facility,
and (b) JPMorgan is pleased to advise you of its agreement to uses commercially reasonable efforts to assemble
a syndicate of financial institutions as recommended to JPMorgan and Chase by you and as identified by
JPMorgan and Chase in consultation with you, to participate in the Facility, in each case upon the terms and
subject to the conditions set forth in this commitment letter (the "Commitment Letter") and in the Term Sheet
attached hereto (the "Term Sheet").
It is agreed that Chase will act as the sole and exclusive administrative agent, and that JPMorgan will act as the
sole and exclusive Lead Arranger and Bookrunner (in such capacities, the "Lead Arranger") for the Facility:
provided that the commitments of Chase to act as administrative agent and to provide a portion of the Facility
may be assumed by an affiliated bank and JPMorgan may assign some or all of its rights and delegate some or all
of its responsibilities hereunder to one of its affiliates. You agree that no other agents, co-agents or arrangers will
be appointed, no other titles will be awarded and no compensation (other than that expressly contemplated by
the Term Sheet and the Fee Letter referred to below) will be paid in connection w