Eisai Corporation of North America Receives Action Letter on Fospropofol Disodium Injection for Sedation in Diagnostic or Therap

Eisai Corporation of North America Receives Action Letter on Fospropofol Disodium Injection for Sedation in Diagnostic or Therapeutic Procedures; FDA's Not Approvable Letter Outlines Pathway to Potential Approval

WOODCLIFF LAKE, N.J., July 25 -- Eisai Corporation of North America today announced that it has received a not approvable letter from the U.S. Food and Drug Administration (FDA), which outlines a pathway to potential approval of fospropofol disodium for use by appropriately trained physicians. Fospropofol disodium injection has been in review at the FDA for use as an intravenous sedative-hypnotic agent for sedation in adult patients undergoing diagnostic or therapeutic procedures.

"We are confident that our continued discussions with FDA will lead to the timely approval of this important new therapy," said Mary Lynne Hedley, PhD, Executive Vice President of Eisai Corporation of North America. "We look forward to working with FDA to help ensure that appropriately trained physicians have this new option for patients. We believe that our clinical data submitted to FDA supports the approval of fospropofol disodium as a potential new option for sedation of patients undergoing important diagnostic or therapeutic procedures."

On May 7, 2008, the FDA Advisory Committee on Anesthetic and Life Support Drugs voted 6 to 3 in favor (with one abstention) of approval of fospropofol disodium injection for use as an intravenous sedative-hypnotic agent for sedation in adult patients undergoing diagnostic or therapeutic procedures. The committee recommended use of fospropofol disodium injection by healthcare providers who are appropriately trained.

About Fospropofol Disodium Injection

Fospropofol disodium injection is a proprietary prodrug of propofol that, after intravenous injection, is converted by an enzyme (alkaline phosphatase) in the body into propofol. Fospropofol disodium injection is a product candidate in development for sedation of adult patients undergoing diagnostic or therapeutic procedures.

About Eisai Corporation of North America

Eisai Corporation of North America is a wholly-owned subsidiary of Eisai Co., Ltd., a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Eisai focuses its efforts in three therapeutic areas: neurology, gastrointestinal disorders and oncology/critical care.

Eisai Corporation of North America supports the activities of its operating companies in North America, which 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. For more information about Eisai, please visit http://www.eisai.com