BRIEF—Biogen and Eisai terminate MS collaboration

The Japanese subsidiary of US biotech major Biogen and Japanese drugmaker Eisai have terminated the Japan co-promotion agreement that has been in place since January 2018 for Biogen Japan's multiple sclerosis (MS) treatments, effective March 31, 2023.

The medicines involved are: Tecfidera (dimethyl fumarate), Tysabri (natalizumab, genetic recombinant) and Avonex (interferon beta 1a, genetic recombinant).

The companies have been jointly engaged in promotional activities for MS treatments in Japan.

However, since a certain objective has been achieved regarding penetration of the products into the Japanese market, the companies decided to terminate this co-promotion agreement.

As a result, Biogen Japan will have full responsibility for all operations related to the products after a transition period between the two companies.

Upon termination of this agreement, Biogen will pay Eisai $31 million.

This termination agreement does not impact any of the other agreements between Biogen and Eisai.