Eisai Co., Ltd.
Biogen Japan Ltd.

Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Biogen Japan Ltd. (Headquarters: Tokyo, President and Representative Director: Shinichi Torii, “Biogen Japan”) announced that the companies have commenced co-promotion of Biogen Japan's multiple sclerosis treatments TECFIDERA® (dimethyl fumarate), TYSABRI® (natalizumab, genetic recombinant) and AVONEX® (interferon beta 1a, genetic recombinant) in Japan as of today.

Based on the provisions of the agreement, the two companies will jointly conduct promotional activities at the clinical facilities for which they are responsible and provide information on appropriate use. There will be no change to the manufacturing or logistic systems, and Biogen Japan books sales of the products.

An autoimmune disease of the central nervous system, multiple sclerosis is a serious, chronic, progressive disease accompanied by inflammation. It affects cognitive function, mental and social functions as well as physical functions. With multiple sclerosis, lesions are found widely throughout the central nervous system such as the brain, spinal cord and optic nerves, and depending on where these lesions occur, a diverse range of symptoms appear including visual impairment, impaired movement and sensation, as well as abnormal gait. As such, it can take several years to reach a conclusive diagnosis, and it is a disease with significant unmet medical needs. The incidence of multiple sclerosis in Japan is reported as 10.8 to 14.4 per 100,000.1

Eisai Representative Corporate Officer, Japan Business and CIO Hideki Hayashi commented, “Eisai considers neurology a strategic therapeutic area of focus and possesses rich experience and knowledge in neurology products such as Aricept® and Fycompa®. Leveraging these strengths, we hope to maximize the benefits for multiple sclerosis patients and their families.”

Biogen Japan President and Representative Director Shinichi Torii commented, “Biogen is a leading company in multiple sclerosis, and approximately 40% of multiple sclerosis patients worldwide use Biogen's medicines. By co-promoting with Eisai who has strong networks in the field of neurology, we believe we can reliably deliver multiple sclerosis treatments to patients who need them.”

Media Inquiries

<Notes to editors>

1.About Multiple Sclerosis Treatments TECFIDERA, TYSABRI and AVONEX

TECFIDERA (dimethyl fumarate) is an orally-administered medicine for the treatment of relapsing forms of multiple sclerosis, including relapse-remitting multiple sclerosis, the most common type of multiple sclerosis. TECFIDERA was approved in Japan for the prevention of relapse and for delaying the accumulation of physical disability in multiple sclerosis in December 2016, and was launched in February 2017. First approved in 2013 in the United States, TECFIDERA is currently approved in 54 countries (as of August 2016). TECFIDERA is widely used in the United States and countries in Europe as a first-line treatment, and the number of patients who have been treated with TECFIDERA worldwide to date reached 250,000.
TYSABRI (natalizumab, genetic recombinant) is a humanized monoclonal anti-α4 integrin antibody and a disease modifying drug. TYSABRI was approved in Japan for the prevention of relapse and delaying the accumulation of physical disability in multiple sclerosis in March 2014, and was launched in June of the same year. TYSABRI has been approved in over 77 countries worldwide (as of April 2016) including the United States and countries in Europe, and the number of patients who have been treated with TYSABRI worldwide reached 167,000.
AVONEX (interferon beta 1a, genetic recombinant) was approved in Japan for relapse prevention of multiple sclerosis in July 2006, and was launched in November of the same year. In December 2013 a pen formulation was approved and subsequently launched in June 2014.

2.About Eisai

Eisai Co., Ltd. is a leading global research and development-based pharmaceutical company headquartered in Japan. We define our corporate mission as “giving first thought to patients and their families and to increasing the benefits health care provides,” which we call our human health care (hhc) philosophy. With approximately 10,000 employees working across our global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to realize our hhc philosophy by delivering innovative products to address unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology.
For more information about Eisai Co., Ltd., please visit Window).

3.About Biogen Japan

At Biogen, our mission is clear: we are pioneers in neuroscience. Biogen discovers, develops and delivers worldwide innovative therapies for people living with serious neurological and neurodegenerative diseases. Founded in 1978 as one of the world's first global biotechnology companies by Charles Weissman and Nobel Prize winners Walter Gilbert and Phillip Sharp, today Biogen has the leading portfolio of medicines to treat multiple sclerosis; has introduced the first and only approved treatment for spinal muscular atrophy; and is focused on advancing neuroscience research programs in Alzheimer's disease and dementia, neuroimmunology, movement disorders, neuromuscular disorders, pain, ophthalmology, neuropsychiatry, and acute neurology. Biogen also manufactures and commercializes biosimilars of advanced biologics. We routinely post information that may be important to investors on our website at To learn more, please visit and follow us on social media – Twitter, LinkedIn, Facebook, YouTube.

Biogen Japan is a subsidiary of Biogen in the U.S. Biogen Japan, as the Japan affiliate of one of the oldest independent biotechnology companies, started its operation in Japan in 2000. To learn more about Biogen Japan, please visit

  • 1

    Kinoshita M, Obata K, Tanaka M. Latitude has more significant impact on prevalence of multiple sclerosis than ultraviolet level or sunshine duration in Japanese population. Neurol Sci. 2015;36(7):1147-51.