EISAI INITIATES PROCEDURES TO ACQUIRE AkaRx Inc. IN THE UNITED STATES

Eisai Co., Ltd. (Headquarters: Tokyo, President and CEO: Haruo Naito, "Eisai") today announced that the Company will initiate procedures to acquire AkaRx, Inc. (Headquarters: New Jersey, U.S., CEO: Robert E. Desjardins, "AkaRx"). As a result of the acquisition, AkaRx will become a subsidiary of Eisai Inc., Eisai’s U.S. subsidiary. The buyout price has been set at US$255 million (approximately ¥22.7 billion, converted yen at 89 to the US$).

Eisai obtained an option right to acquire AkaRx through the Company’s acquisition of MGI PHARMA, INC. ("MGI") in January 2008, as well as a development and license agreement relating to AKR-501 (current research code: E5501). Eisai has expressed its intention to exercise this option, and will acquire all of AkaRx’s capital stock to make it a wholly-owned subsidiary of Eisai Inc. as well as the exclusive worldwide rights to develop, market and manufacture AKR-501. The Company plans to consummate this acquisition on or before January 8, 2010.

AKR-501 is a pharmacological agonist of the receptors of thrombopoietin (TPO), which stimulates platelet production, and is expected to demonstrate its effects in various diseases associated with thrombocytopenia. Eisai is currently conducting Phase II clinical studies of the compound in the U.S. for idiopathic thrombocytopenic purpura (ITP) and thrombocytopenia associated with liver diseases, and has confirmed POC (Proof of Concept) in the clinical studies for ITP. In addition, Eisai will explore its potential as a treatment for cancer chemotherapy-induced thrombocytopenia.

ITP is a disorder that causes a variety of bleeding symptoms due to a decrease in platelet count caused by the destruction of blood platelets as a result of the production of autoantibodies against platelets. The number of patients with the disorder is estimated to be approximately 800,000 (Japan, U.S., major European countries, China, and India). It is known that, in patients with liver diseases, decrease in platelet count as a complication resulting from deficient TPO production causes bleeding tendency, and in many patients with hepatitis C, interferon-induced thrombocytopenia could lead to the cessation of their interferon therapy. If successfully developed, Eisai expects that AKR-501 will provide a new

treatment option for patients with thrombocytopenia, as well as increase its contributions to patients in China, India and other countries with a high incidence of hepatitis.

Through this acquisition, Eisai will further enhance its portfolio of pipeline products, and will make contributions towards increasing benefits of patients and their families by addressing the unmet medical needs.

In accordance with the acquisition, Eisai has revised its full-year consolidated business forecast for the fiscal year ending March 31, 2010, (April 1, 2009 to March 31, 2010) as outlined below.

1. Revised full-year consolidated business forecast for the fiscal year ending March 31, 2010 (April 1, 2009 to March 31, 2010)

(unit: million yen)

TO VIEW THE BUSINESS FORECAST DIAGRAM - PLEASE SEE ATTACHED PRESSRELEASE IN PDF FORMAT.