Epizyme, Inc. is a clinical-stage biopharmaceutical company. The Company discovers, develops and plans to commercialize epigenetic therapies for cancer patients. The Company is engaged in the discovery and development of novel epigenetic therapies for cancer patients. The Company develops small molecule inhibitors of a class of enzymes known as histone methyltransferases (HMTs). The Company develops small molecule inhibitors of other chromatin modifying proteins (CMPs). The Company's lead product candidate, tazemetostat, is a potent and selective inhibitor of the enhancer of zeste homolog 2 (EZH2) histone methyltransferases (HMT), an enzyme that plays an important role in various cancers. The Company is evaluating tazemetostat in a Phase II study in adults with relapsed or refractory non-Hodgkin lymphoma (NHL), and one Phase I study in children with molecularly defined solid tumors. The Company owns the global development and commercialization rights to tazemetostat outside of Japan.