Astellas to acquire all Maxygen's equity interests in Perseid for $76.0 million

Maxygen, Inc. (Nasdaq:MAXY) today announced that Astellas Pharma Inc. has exercised its option to purchase all of Maxygen's equity interests in Perseid Therapeutics LLC at the current exercise price of $76.0 million.

Under the terms of the companies' 2009 joint venture arrangement, Maxygen transferred substantially all of its protein pharmaceutical programs and related assets and research and development personnel to Perseid and granted Astellas an option to acquire all of Maxygen's ownership interest in Perseid at specified exercise prices that increased each quarter over the term of the option, which was scheduled to expire on September 18, 2012.

"Astellas' decision to exercise this option represents another important milestone in Maxygen's on-going efforts to maximize the value of its portfolio of assets," said James Sulat, Maxygen's Chief Executive Officer. "It also represents the culmination of an extraordinary effort on the part of the staff at Perseid Therapeutics to demonstrate the value of its programs and the MolecularBreeding^TM directed evolution platform to Astellas," continued Mr. Sulat.

The closing of the acquisition transaction is subject to Maxygen and Astellas entering into a definitive agreement for the acquisition by Astellas of the preferred units of Perseid held by Maxygen and review and clearance of the transaction by U.S. regulatory authorities. Maxygen's stockholders approved the acquisition in 2009 as part of the joint venture arrangement. The parties expect the transaction to close in the second quarter of 2011. Upon consummation of the acquisition transaction, Perseid will become a wholly-owned subsidiary of Astellas and Maxygen will have no further interests or obligations with respect to the business and operations of Perseid, except for the provision of limited transition services between the companies.