Eisai wins patent extension in Japan for blockbuster Alzheimer's drug Aricept

Japanese drug major Eisai (TYO: 4523) says that the Supreme Court of Japan has turned down a petition filed by generic drug manufacturers with regards to an Intellectual Property High Court ruling to maintain a decision to grant an extension for the Aricept (donepezil hydrochloride) patent in relation to severe Alzheimer's disease.

Aricept is the world’s leading Alzheimer’s drug and generated fiscal 2010/11 sales of around $3.9 billion, or around 40% of Eisai’s revenues. However, the drug is now facing generic completion, notably from India’s Ranbaxy Laboratories, and has seen the branded product’s price tumble 70% after the copy product came to the US market in February.

As a result of the patent expiry for Aricept in the USA, Eisai has already announced a major restructuring program to reduce its workforce by around 20% across all US functions, eliminating about 600 positions (The Pharma Letter March 9).