Interim Results from an Ongoing Phase 2 Multicenter Study of Tazemetostat, an EZH2 Inhibitor, in Patients with Relapsed or Refractory (R/R) Diffuse Large B-Cell Lymphoma (DLBCL)

Background: R/R DLBCL remains an area of unmet medical need and treatments with novel mechanisms of action are urgently needed. Germinal center DLBCLs depend on the histone methyltransferase EZH2 to perpetuate a less-differentiated state and EZH2 activating mutations may be oncogenic drivers in a subset of patients (pts). Inhibition of EZH2 reprograms abnormal cell growth, leading to cell death or differentiation, and subsequent tumor regression. Tazemetostat, a potent, selective, oral EZH2 inhibitor has shown antitumor activity in a phase 1 study that included DLBCL pts with mutated (mt) or wild type (wt) EZH2 tumors, which provides rationale for further investigation of its single agent activity. This open-label, multicenter phase 2 study is evaluating tazemetostat in pts with either mt or wt EZH2 R/R DLBCL or follicular lymphoma (Grade 1-3b); results of an interim analysis of DLBCL pts treated with tazemetostat, as monotherapy or in combination with prednisolone are presented.