FOR IMMEDIATE RELEASE
April 1, 2020
Eisai Co., Ltd.
SEIKAGAKU CORPORATION

Eisai and Seikagaku Enter into Agreement for the Co-development and Marketing
Alliance of SI-613, a Treatment of Osteoarthritis, in China
Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Seikagaku Corporation(Headquarters: Tokyo, President: Ken Mizutani, “Seikagaku”) announced today that the companies
have entered into an agreement for the co-development and marketing alliance in China for SI-613(diclofenac conjugated sodium hyaluronate), a therapeutic agent for osteoarthritis discovered bySeikagaku.
On the basis of this agreement, the companies will jointly develop SI-613 in China for a treatment ofknee osteoarthritis. After obtaining approval, Seikagaku will supply products to Eisai, and Eisai will be
responsible for distribution. The companies will cover an equal share of the development cost, andEisai will pay Seikagaku the upfront payment, and development as well as sales milestones.
Osteoarthritis is a disease caused by the articular cartilage damage due to aging and other factors,
leading to inflammation and pain, which result in impaired quality of life (QOL). Knee osteoarthritis is
one of the most frequent cases among thereof, and the number of symptomatic patients with knee
osteoarthritis in China is estimated to be approximately 47 million*1, and it is anticipated that the number
will continue to increase as the population ages.
SI-613 is diclofenac conjugated sodium hyaluronate created by Seikagaku using their proprietarydrug-binding technology to chemically bond hyaluronic acid and diclofenac (an anti-inflammatory drug).
This material has the analgesic and anti-inflammatory effects of diclofenac, which is designed to besustained-released*2 by a drug delivery system*3, in addition to the joint function improving effect ofsodium hyaluronate. Hence, it is expected that SI-613 rapidly and continuously reduces the pain andinflammation associated with osteoarthritis.
Under this agreement, Eisai aims to contribute to patients with knee osteoarthritis that is unmet
medical needs by utilizing the knowledge and networks that Eisai has cultivated through its China
business. Seikagaku will seek to maximize the value of SI-613 in China by leveraging Eisai's businessbase in China.
Through the development and commercialization of SI-613, the companies will provide newtreatment options in China for knee osteoarthritis and contribute to improving the QOL of patients.
Media Inquiries
Seikagaku Corporation
Investor Relations and Public Relations
Corporate Staff
ir@seikagaku.co.jp

Eisai Co., Ltd.
Public Relations Department
TEL : +81-(0)3-3817-5120
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<Notes to editors>
1. About Eisai Co., Ltd.
Eisai Co., Ltd. defines our corporate mission as "giving first thought to patients and their families and toincreasing 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 ofNeurology and Oncology. As a global pharmaceutical company, our mission extends to patients aroundthe world through working with key stakeholders to improve access to medicines in developing andemerging countries.
For further information on Eisai Co., Ltd., please visit https://www.eisai.com.
2. About Seikagaku Corporation
Seikagaku Corporation is an R&D-oriented pharmaceutical company that focuses on glycoscience as
an area of specialization. Since its foundation in 1947, Seikagaku has continuously focused on thepossibilities of glycoscience and developed original, beneficial pharmaceutical products and medical
devices in the fields of orthopedic disorders and ophthalmic diseases. Under a unique business modelof specializing in R&D and manufacturing without having an in-house pharmaceuticals sales division,
Seikagaku contributes to healthy and fulfilling lives for people around the world by marketing products
globally in collaboration with companies having strengths in particular countries and product areas.
For further information on Seikagaku Corporation, please visit https://www.seikagaku.co.jp/en/
3. About SI-613
SI-613 is diclofenac conjugated sodium hyaluronate created by Seikagaku using their proprietary drugbinding technology to chemically bond hyaluronic acid and diclofenac (an anti-inflammatory drug). This
material has the analgesic and anti-inflammatory effects of diclofenac, which is designed to besustained-released*2 by a drug delivery system*3, in addition to the joint function improving effects ofsodium hyaluronate. It is expected that SI-613 rapidly and continuously reduces the pain andinflammation associated with osteoarthritis (such as knee joint). Also, since this is administered directly
into the joint cavity by injection, it is considered that the amount of diclofenac systemic exposure and the riskof eliciting systemic adverse drug reaction are to be low.
In Japan, Seikagaku submitted a new drug application (“NDA”) for manufacturing and marketing approvalfor SI-613 on January 6, 2020.
###References:*1: For the estimated data regarding the number of patients with knee osteoarthritis
 Data of morbidity prevalence rate - The Prevalence of Symptomatic Knee Osteoarthritis inChina, ARTHRITIS & RHEUMATOLOGY(2016)
 Estimated data calculated from United Nations World Population Estimates - WorldPopulation Prospects, URL：http://www.un.org/en/development/desa/population/*2: Sustained release is a gradual release of the active pharmaceutical ingredients of a drug toachieve a sustained therapeutic effect.
*3: Drug delivery system (DDS) is a technology for the controlled release, targeting, and absorption
improvement of drugs.
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