Eisai Co., Ltd. (Headquarters: Tokyo, President & CEO: Haruo Naito, “Eisai”) announced today that it has exercised its option to jointly develop and commercialize its clinical candidates for Alzheimer's disease (AD) with Biogen Idec (Headquarters: Massachusetts, the United States, CEO: George A. Scangos) in Japan. The option was included as part of Eisai's collaboration agreement with Biogen Idec, which was announced in March 2014.

Based on the agreement, Eisai and Biogen Idec will co-develop Eisai's investigational next generation AD treatment candidates E2609, a BACE inhibitor, and BAN2401, an anti-amyloid beta (Aβ) protofibril antibody, in major markets, such as the United States, the European Union and now Japan. The companies will also co-promote the products following marketing approval. Both companies will share overall costs, including research and development expenses incurred in Japan. Eisai will book all sales for E2609 and BAN2401 following marketing approval and launch, and profits will be shared between the companies. Also, in accordance with the execution of this option, Eisai will receive from Biogen Idec an additional one-time payment as well as the right to receive additional development milestone payments.

Leveraging the synergy between Eisai's knowledge in the field of AD and Biogen Idec's strength in neurodegenerative diseases, the companies are working together to effectively and efficiently develop E2609 and BAN2401 in order to deliver promising treatments to patients around the world as soon as possible.

[ Please refer to the following notes for further information on E2609, BAN2401 and Biogen Idec. ]

Media Inquiries:

Public Relations Department,
Eisai Co., Ltd.


< Notes to editors >

1. About E2609

E2609, discovered in-house by Eisai, is an investigational next-generation oral candidate for the treatment of AD that is believed to inhibit BACE, a key enzyme in the production of Aβ. By inhibiting BACE, E2609 decreases Aβ proteins in the brain, potentially improving symptoms and slowing disease progression. Currently, E2609 is undergoing preparations to enter Phase Ⅱ clinical trials.

2. About BAN2401

BAN2401 is a humanized monoclonal antibody that is the result of a strategic research alliance between Eisai and BioArctic Neuroscience AB to identify a potential immunotherapy for AD. BAN2401 is believed to selectively bind to, neutralize and eliminate soluble, toxic Aβ aggregates that are thought to contribute to the neurodegenerative process in AD. As such, BAN2401 has the potential to have an immunomodulatory effect that may suppress the progression of the disease. Eisai obtained the global rights to study, develop, manufacture and market BAN2401 for the treatment of AD pursuant to an agreement concluded with BioArctic Neuroscience AB in December 2007. Currently, the compound is undergoing Phase Ⅱ clinical trials.

3. About Biogen Idec

Through cutting-edge science and medicine, Biogen Idec discovers, develops and delivers to patients worldwide innovative therapies for the treatment of neurodegenerative diseases, hemophilia and autoimmune disorders. Founded in 1978, Biogen Idec is the world's oldest independent biotechnology company. Patients worldwide benefit from its leading multiple sclerosis therapies. For product labeling, press releases and additional information about the Company, please visit http://www.biogenidec.com.