September 9, 2015
Press Release
Company name: Mitsubishi Tanabe Pharma Corporation
Representative: Masayuki Mitsuka
President and Representative Director
Code number: 4508, First Section, Tokyo Stock Exchange
Contact:

Yoshifumi Mifune, General Manager,
Corporate Communications Department(Osaka: TEL: +81-6-6205-5211)(Tokyo: TEL: +81-3-6748-7664)

Biogen and Mitsubishi Tanabe Pharma Conclude a License Agreement on MT-1303,
a Therapeutic Agent for Autoimmune Diseases

Osaka, Japan, September 09, 2015 - Mitsubishi Tanabe Pharma Corporation (President &Representative Director, CEO: Masayuki Mitsuka, hereinafter, the Company) and Biogen(Headquarters: Massachusetts, U.S., CEO: George A. Scangos, hereinafter, Biogen) have concluded a
License Agreement on MT-1303, a therapeutic agent for autoimmune diseases,

discovered anddeveloped by the Company.
MT-1303 developed by the Company, is a sphingosine-1-phosphate (S1P) receptor functional
antagonist and, by inhibiting the receptor function of sphingosine-1-phosphate (S1P) receptor on thelymphocyte, keeps lymphocytes sequestered in the lymph nodes to prevent them from contributing toautoimmune reactions . Due to this mechanism, this compound may be potentially effective for various
autoimmune diseases. The Company is currently conducting clinical trials for MT-1303 for multiple
sclerosis, psoriasis, Crohn's disease and systemic lupus erythematosus in Europe and in Japan, andhas obtained results suggesting a profile possibly safer than that of the existing S1P receptor functional
antagonists. Considering these results, the Company decided to seek an alliance to accelerate
development of this drug both in Japan and overseas, to launch the drug as soon as possible and tomaximize its product value, and has concluded an agreement with Biogen, a company with anexperience in this field.
In accordance with this agreement, the Company grants to Biogen the exclusive right to develop andmarket this drug globally except in Japan and in Asia. The Company has a right to participate in
Biogen's global clinical trials as well as a co-promotion right in the United States in non-multiple
sclerosis indications. Also, the Company receives an upfront payment of $60 million from Biogen.
Moreover, the Company may receive up to $484 million in additional milestone payments according toterritories and indications. The Company will receive royalties according to the sales volume after
Biogen's marketing the product.
-1-Please note that this agreement is subject to customary closing conditions, including the expiration ofthe applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 in theUnited States, and is expected to close by the end of the calendar year

2015. Impact on theCompany's results is under investigation and will be notified later.
Mitsubishi Tanabe Pharma Corporation has identified autoimmune diseases as one of its strategicareas and will aggressively work to develop new drugs that address unmet medical needs.
EndReference
About Mitsubishi Tanabe Pharma Corporation
Mitsubishi Tanabe Pharma Corporation is a research-driven pharmaceutical company based in Osaka,
Japan. MTPC is taking on the challenge of drug discovery in the fields of autoimmune disorders, central
nervous system diseases, diabetes and kidney diseases, and vaccines. To those ends, MTPC is
strengthening its R&D pipeline. MTPC contributes to the healthier lives of people around the world
through the creation of pharmaceuticals. www.mt-pharma.co.jp/e.
About Biogen
Through cutting-edge science and medicine, Biogen discovers, develops and delivers to patientsworldwide innovative therapies for the treatment of neurodegenerative diseases, hematologicconditions and autoimmune disorders. Founded in 1978, Biogen is one of the world’s oldest
independent biotechnology companies and patients worldwide benefit from its leading multiple
sclerosis and innovative hemophilia therapies. For product labeling, press releases and additional
information about the company, please visit www.biogen.com.
Biogen Safe Harbor

This press release contains forward-looking statements, including statements about the potential
benefits and developments that may be achieved through the license agreement with Mitsubishi
Tanabe Pharma Corporation and the expected timing of the closing the transactions. Thesestatements may be identified by words such as “believe,” “expect,” “may,” “plan,” “potential,” “will”
and similar expressions, and are based on Biogen’s current beliefs and expectations. Thesestatements involve risks and uncertainties that could cause actual results to differ materially fromthose reflected in such statements. Risks and uncertainties that may cause actual results to differ
materially include, among others: uncertainty inherent in the regulatory review process andsatisfaction of other closing conditions relating to the transactions; uncertainty regarding the ability
to achieve the expected benefits from the proposed license agreement, including as a result ofrisks and uncertainties associated with drug development and commercialization, reliance on thirdparties over which Biogen may not always have full control; and other risks and uncertainties thatare described in the Risk Factors section of Biogen’s most recent annual or quarterly report filedwith the Securities and Exchange Commission. Any forward-looking statements speak only as ofthe date of this press release and Biogen assumes no obligation to update any forward-looking
statements, whether as a result of new information, future events or otherwise.
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