Epizyme Doses First Patient in Five-Arm Phase 2 Study for First-in-Class EZH2 Inhibitor Tazemetostat (EPZ-6438) in Relapsed or Refractory Non-Hodgkin Lymphoma

Epizyme, Inc. EPZM, a clinical stage biopharmaceutical company creating novel epigenetic therapies for cancer patients, announced today that it has dosed the first patient in the phase 2 trial of its lead clinical candidate, tazemetostat (EPZ-6438) in patients with relapsed or refractory non-Hodgkin lymphoma (NHL). This five-arm study will enroll up to 150 patients with germinal center diffuse large B cell lymphoma (DLBCL) or follicular lymphoma, stratified into those expressing mutant EZH2 and those expressing wild type EZH2, as well as patients with non-germinal center DLBCL. "Results from our ongoing phase 1 trial that we presented at the International Congress on Malignant Lymphoma on June 20 show tazemetostat produced durable objective responses in heavily pre-treated patients with relapsed or refractory NHL, with an acceptable safety and tolerability profile," said Peter Ho, M.D., Ph.D., Chief Development Officer, Epizyme. "With the initiation of this phase 2 trial, we look forward to making significant progress in evaluating the potential of tazemetostat in targeted sub-populations of NHL." About the Tazemetostat Phase 2 Program The phase 2 NHL trial is a five-arm, multi-center, international study that will assess the safety and activity of tazemetostat in patients with relapsed or refractory non-Hodgkin lymphoma. The study will enroll up to 30 patients in each arm, prospectively stratified for EZH2 mutation status and cell-of-origin, assuming each arm of the study achieves its primary response rate goal in its first stage. The five study arms are enrolling relapsed/refractory patients with: Germinal center DLBCL with mutant EZH2 Germinal center DLBCL with wild-type EZH2 Follicular lymphoma with mutant EZH2 Follicular lymphoma with wild-type EZH2 Non-germinal center DLBCL A second planned phase 2 trial of tazemetostat in adult patients with INI1-deficient solid tumors is expected to initiate later in 2015. A phase 1 study in pediatric patients with INI1-deficient solid tumors is also expected to start later in 2015. The Company also plans to initiate additional clinical evaluations of tazemetostat, including a combination with R-CHOP in patients with DLBCL, and a combination with a B-cell signaling agent or other emerging targeted therapies for B-cell lymphomas.