1 Exhibit 4.1 STOCK PURCHASE AGREEMENT OSI Pharmaceuticals, Inc. 106 Charles Lindbergh Boulevard Uniondale, NY 11553 Ladies & Gentlemen: The undersigned, Biotechnology Value Fund, L.P. (the "Investor"), hereby confirms its agreement with you as...Stock Purchase Agreement • March 1st, 2000 • Osi Pharmaceuticals Inc • In vitro & in vivo diagnostic substances • Delaware
Contract Type FiledMarch 1st, 2000 Company Industry Jurisdiction