Astellas Pharma Inc. announced today the completion of its tender offer for all outstanding shares of common stock in OSI Pharmaceuticals, Inc.

The subsequent offer period announced by Astellas on June 3 expired at 12:00 midnight, New York City time, on June 7, 2010. Computershare Trust Company, N.A., the depositary for the tender offer, has advised that, as of the expiration of the subsequent offer period, a total of 57,232,357 shares had been validly tendered and not withdrawn (including shares tendered in the initial tender offer that expired on June 2, 2010). The tendered shares in total represent approximately 93% of OSI’s issued and outstanding shares. All shares validly tendered and not withdrawn have been accepted for payment.

Astellas now owns more than 90% of the issued and outstanding shares of OSI’s common stock, and intends, as promptly as practicable, to complete the acquisition of OSI through a short-form merger without a meeting of OSI’s stockholders. In the merger, each outstanding share of OSI common stock not purchased in the tender offer or otherwise owned by Astellas will be converted into the right to receive the same $57.50 consideration that was provided in the tender offer, without interest, except shares for which appraisal rights are validly asserted.

As a result of the merger, OSI will be a wholly-owned subsidiary of Astellas US Holding, Inc., a holding company owned by Astellas Pharma Inc., and OSI’s common stock will cease to be traded on the Nasdaq Global Select Market.