Eisai’s Alzheimer’s disease skin patch falls short of FDA approval

Japanese drug company Eisai‘s (TYO:4523) bid to extend the patent life of its blockbuster Alzheimer’s drug Aricept with a new skin patch formulation has been dealt a blow by the U.S. Food and Drug Administration.

Eisai’s drug partner Teikoku Pharma has received a complete response letter from the FDA stating that the agency cannot approve the drug’s application. Eisai said the FDA’s requirements relate mainly to formulation and usage. Eisai said the companies will work with the FDA to assess the agency’s concerns and determine the next steps.

Aricept tablets, which Eisai makes at a plant in North Carolina’s Research Triangle Park, are a major seller for Eisai and most of the drug’s revenue comes from the United States where annual sales are $2.5 billion, according to IMS Health. Aricept’s patent expired last November and the company has been working to add new indications and formulations of the drug. Last August, the company launched a new higher dose tablet as an additional dosing option for patients with moderate to severe Alzheimer’s. The skin patch was also expected to help maintain sales of the product.

News of the FDA response to the skin patch comes as a generics company moves closer to marketing a generic version of Aricept. Mumbai, India-based pharmaceutical company Wockhardt said Monday it has received FDA approval to market Donepezil, a generic Aricept tablet. The company expects to launch Donepezil on May 8.