Current Status of the Development Programs of New Indications and Formulations for Aricept(R) for Enhancing Patient Value

Eisai Co., Ltd. (Headquarters: Tokyo, President & CEO: Haruo Naito, "Eisai") and Eisai Corporation of North America (Headquarters: Woodcliff Lake, NJ, Chairman and CEO Hajime Shimizu) are currently focusing on three clinical development programs for the company's major product Aricept(R) (donepezil hydrochloride tablets) to further contribute to patients with Alzheimer's disease. As progress in those programs has been made, Eisai announces the status as follows:

1. Sustained Release Tablets

Eisai has completed a Phase III study of Aricept 23 mg sustained release (SR) in patients with moderate to severe Alzheimer's disease. Aricept 23 mg SR is being developed to increase clinical benefits while maintaining a favorable safety profile compared to currently marketed Aricept 10 mg immediate release.

Based on the preliminary review of the data from this Phase III study, Eisai plans to submit a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA) in August or September 2009.

2. Pediatric Use

Eisai filed a Proposed Pediatric Study Request (PPSR), an application that proposes a rationale and study design for pediatric studies, with the U.S. FDA in February 2009 to evaluate the clinical benefits of donepezil in children with attention impairment following cancer treatment. Eisai received a notice from the U.S. FDA that there were insufficient grounds to issue a Written Request to obtain pediatric exclusivity. Eisai plans to complete the ongoing studies to provide important information on this therapeutic approach for an underserved patient population currently with limited treatment options.

3. Transdermal Patch Formulation

Clinical trials of a once-a-week transdermal patch formulation of donepezil, which include a bioequivalence study compared to the currently marketed formulation of donepezil, are currently being conducted by Teikoku Pharma USA, Inc. in the United States. An NDA submission to the U.S. FDA is planned for the middle of fiscal year 2009 based on the results of the clinical trials. Eisai is working on this new formulation of donepezil based on agreements with Teikoku Seiyaku Co., Ltd. and its U.S. subsidiary, Teikoku Pharma USA, Inc.

About Aricept

Aricept is the first and only prescription medication approved by the U.S. Food and Drug Administration for mild, moderate and severe dementia of the Alzheimer's type. This indication is supported by evidence-based medicine backed by numerous well-controlled clinical studies of AD in all stages and settings among thousands of patients that demonstrated that Aricept improves cognition and delays functional decline.

Aricept is well tolerated, but may not be for everyone. People at risk for stomach ulcers or who take certain other medicines should tell their doctors because serious stomach problems, such as bleeding, may get worse. Some people who take Aricept may experience fainting. Some people may have nausea, vomiting, diarrhea, bruising, or not sleep well. Some people may have muscle cramps or loss of appetite or may feel tired. In studies these were usually mild and temporary.

About Eisai Co., Ltd.

Eisai Co., Ltd. is a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Through a global network of research facilities, manufacturing sites and marketing subsidiaries, Eisai actively participates in all aspects of the worldwide health care system. Eisai employs approximately 10,000 employees worldwide.

About Eisai Corporation of North America

Eisai Corporation of North America is a wholly-owned subsidiary of Eisai Co., Ltd. and supports the activities of its operating companies in North America. These operating companies include: Eisai Research Institute of Boston, Inc., a discovery operation with strong organic chemistry capabilities; Morphotek, Inc., a biopharmaceutical company specializing in the development of therapeutic monoclonal antibodies; Eisai Medical Research Inc., a clinical development group; Eisai Inc., a commercial operation with manufacturing and marketing/sales functions; and Eisai Machinery U.S.A., which markets and maintains pharmaceutical manufacturing machinery.