Eisai say FDA approves higher dose Aricept

Eisai Co and Pfizer Inc said they won U.S. regulatory approval for a higher dose once-daily version of Aricept, a drug that treats Alzheimer disease.

Eisai, Japan's No. 4 drugmaker, said in March it expected annual U.S. sales of the drug, its flagship product, to fall 60 percent to $800 million from $2 billion between 2011 and 2013 with the expiration of its patent for the drug looming.

The U.S. Federal Drug Administration approved a 23 mg tablet version of the drug, which treats moderate-to-severe Alzheimer's. About 3.5 million Americans over the age of 65 suffer from the disease.

(Reporting by Phil Wahba; editing by Carol Bishopric)