Item 8.01. Other Events.
On June 18, 2009, OSI Pharmaceuticals, Inc. ("OSI") received a second, non-final office action notice from the U.S. Patent and Trademark Office ("U.S. PTO") regarding OSI's application for a reissue of OSI's composition of matter patent for TarcevaŽ (erlotinib), U.S. Patent No. 5,747,498 (the '498 patent). Other than the rejection of two claims as being indefinite due to the improper format of the claims (i.e., unmatched brackets), there were no patentability rejections of the claimed subject matter over prior art. The office action also sets forth a rejection of all claims based upon a defective oath or declaration. OSI is responding to the U.S. PTO's comments and remains optimistic that it will have the reissue process substantially completed by the end of 2009.

-2-

---