Eisai Inc. and Pfizer Inc announced today that the U.S. Food and Drug Administration (FDA) has accepted for review Eisai's New Drug Application (NDA) for once daily 23 mg Aricept® (donepezil HCl extended release) tablets for the treatment of moderate to severe Alzheimer's disease (AD). This new higher dose formulation contains 23 mg of donepezil HCl in an extended release, matrix-type tablet with a delivery system that allows for gradual release of the drug. The NDA is based on a head-to-head clinical study comparing the 23 mg Aricept extended release tablet to the currently marketed once daily 10 mg Aricept® (donepezil HCl) immediate release tablet. More than 1400 patients with moderate to severe Alzheimer's disease were enrolled in this global study.

Acceptance of the NDA indicates that the FDA has found the company's submission to be sufficiently complete to review. Eisai and Pfizer believe this new formulation will potentially provide physicians, patients and their families with another option for the management of Alzheimer's disease.

About Aricept® (donepezil HCl) tablet

Aricept is the first and only prescription medication approved by the FDA for the treatment of all stages of AD -- mild, moderate and severe dementia of the Alzheimer's type. This indication is supported by evidence-based medicine, with numerous well-controlled clinical studies of AD in all stages and multiple settings among thousands of patients, demonstrating that Aricept improves cognition and slows the decline of overall function. Aricept is currently available in 5 mg and 10 mg immediate release tablets, dosed once daily. It is co-promoted in the United States by Eisai Inc. and Pfizer Inc.

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.

  For full prescribing information, please visit www.aricept.com.

  About Eisai

Eisai Inc. is a wholly-owned subsidiary of Eisai Corporation of North America. Established in 1995 and ranked among the top-20 U.S. pharmaceutical companies (based on retail sales), the company began marketing its first product in the United States in 1997 and has rapidly grown to become a fully integrated pharmaceutical business with fiscal year 2008 (year ended March 31, 2009) sales of approximately $3.7 billion. Eisai Inc.'s areas of commercial focus include neurology, gastrointestinal disorders and oncology/critical care. The company serves as the U.S. pharmaceutical operation of Eisai Co., Ltd., a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Headquartered in Woodcliff Lake, New Jersey, Eisai Inc. has several R&D facilities in Massachusetts, New Jersey and North Carolina, as well as manufacturing facilities in Maryland and North Carolina. For more information about Eisai, please visit www.eisai.com.

*On October 1, 2009, Eisai Research Institute of Boston, Inc. (established in 1987) and Eisai Medical Research Inc. (established in 2002) were merged into Eisai Inc.

  About Pfizer
  Pfizer Inc: Working Together for a Healthier World™

At Pfizer, we apply science and our global resources to improve health and well-being at every stage of life. We strive to set the standard for quality, safety and value in the discovery, development and manufacturing of medicines for people and animals. Our diversified global health care portfolio includes human and animal biologic and small molecule medicines and vaccines, as well as nutritional products and many of the world's best-known consumer products. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as the world's leading biopharmaceutical company, we also collaborate with health care providers, governments and local communities to support and expand access to reliable, affordable health care around the world. For more than 150 years, Pfizer has worked to make a difference for all who rely on us. To learn more about our commitments, please visit us at www.pfizer.com.

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SOURCE: Eisai Inc.

CONTACT: For Media Inquiries: Judee Shuler, Eisai Inc.,
+1-201-746-2241, or Sally Beatty, Pfizer Inc, +1-212-733-6566, or For Investor
Inquiries: Bob Laverty, Eisai Inc., +1-201-746-2265, or Jennifer Davis, Pfizer
Inc, +1-212-733-0717

Web Site: http://www.eisai.com/