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Eisai Completes Acquisition of AkaRx, Inc. in the United States

ý. (Headquarters: Tokyo, President and CEO: Haruo Naito, “Eisai”) today announced that Eisai Inc., the Companys U.S. subsidiary, acquired all shares of AkaRx, Inc. (Headquarters: New Jersey, U.S., CEO: Dr. Robert E. Desjardins, “AkaRx”) on January 6, 2010 (U.S. Eastern Standard Time).

As a result, all procedures to acquire AkaRx as announced by Eisai on December 18, 2009 (Japan time) have now been completed. The buyout price of this acquisition is US$255 million.

With the completion of the acquisition, AkaRx has become a wholly-owned subsidiary of Eisai Inc. while Eisai has obtained the exclusive worldwide rights to develop, market, and manufacture AKR-501 (current research code: E5501).

Eisai will continue to expedite the development of the compound with the aim of providing a new treatment option to patients with thrombocytopenia to make contributions toward addressing their unmet medical needs and increasing their benefits.

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