Epizyme, Inc., a commercial-stage biopharmaceutical company, discovers, develops, and commercializes novel epigenetic medicines for patients with cancer and other diseases in the United States. The company offers Tazemetostat for the treatment of metastatic or locally advanced epithelioid sarcoma for adults and pediatric patients. It also develops R-CHOP in front-line patients with high risk diffuse large B-cell lymphoma; and PARP inhibitor in patients with PARPi-resistant solid tumors, such as castration-resistant prostate cancer, small cell lung cancer, and others. In addition, the company develops Tazemetostat in patients with INI1-negative tumors in adults and pediatrics; PRMT5 inhibitor for patients with solid tumors; and PRMT1 inhibitor. It has collaboration agreements with Roche Molecular Systems, Inc.; Lymphoma Academic Research Organization; Eisai Co. Ltd.; HUTCHMED (China) Limited; and Roche Sequencing Solutions, Inc. The company was incorporated in 2007 and is headquartered in Cambridge, Massachusetts. As of August 11, 2022, Epizyme, Inc. operates as a subsidiary of Ipsen Biopharmaceuticals, Inc..