Epizyme Enters Worldwide Strategic Partnership with Eisai Inc. for Cancer Therapeutics Targeting EZH2 Epigenetic Enzyme; Epizyme will Receive $6 Million Upfront and May Earn More than $200 Million

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Epizyme, Inc. announced today a worldwide partnership with Eisai Co., Ltd., Tokyo, Japan to discover, develop and commercialize therapeutics targeting EZH2, an epigenetic enzyme, for the treatment of lymphoma and other cancers in genetically-defined patients. Under the terms of the agreement, Epizyme will receive $6M in upfront and initial milestone payments, and may earn more than $200M in additional research, development and sales milestones, and up to double-digit royalties. Additionally, Eisai will fund 100 percent of R&D through human proof-of-concept, at which point Epizyme has the right to opt into a profit share and co-commercialization arrangement for the United States.

"Eisai is committed to bringing epigenetic therapeutics to cancer patients," said Takashi Owa, Ph.D., President, Oncology Product Creation Unit, Eisai Product Creation Systems. "Epizyme’s proprietary product platform; leadership in determining the oncogenic role of EZH2 in genetically-defined cancers; and success in discovering novel, potent, and selective small molecule inhibitors of histone methyltransferases (HMTs), an important epigenetic target class, led us to them as the partner of choice in epigenetic drug discovery."

“Our partnership with Eisai reflects our shared belief in the therapeutic potential of this area and is an important element in the ongoing execution of our strategy to build a leading new biopharma company by bringing innovative personalized therapeutics to genetically-defined cancer patients,” commented Robert Gould, Ph.D., President and CEO of Epizyme. “The US profit share and co-commercialization option is a key element of our strategy to discover, develop and also to commercialize epigenetic medicines.”

About Epizyme

Epizyme is leading the discovery and development of small molecule histone methyltransferase (HMT) inhibitors, a new class of targeted therapeutics for the treatment of genetically-defined cancer patients based on breakthroughs in the field of epigenetics. Genetic alterations in the HMTs are strongly associated with the underlying causes of multiple human diseases, including cancer. Epizyme’s patient-driven approach represents the future of personalized therapeutics by creating better medicines for the right patients more quickly and at lower cost than traditional approaches. www.epizyme.com

About Eisai Co., Ltd.

Eisai Co., Ltd. is a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Through a global network of research facilities, manufacturing sites and marketing subsidiaries, Eisai actively participates in all aspects of the worldwide healthcare system. www.eisai.com

Contact:

Epizyme: MacDougall Biomedical Communications Chris Erdman or Jennifer Conrad, 781-235-3060 or Eisai: Media Inquiries: Suzanne Grogan, 201-746-2083 suzanne_grogan@eisai.com or Investor Inquiries: Alex Scott, 201-746-2177