Epizyme Presents Updated Phase 2 Data at the 2019 ASH Annual Meeting Supporting Planned Tazemetostat NDA Submission for Follicular Lymphoma

Epizyme, Inc. (Nasdaq: EPZM), a late-stage biopharmaceutical company developing novel epigenetic therapies, today reported positive, mature data at the 2019 American Society of Hematology (ASH) Annual Meeting from its ongoing Phase 2 trial of tazemetostat, an oral EZH2 inhibitor, as a monotherapy for patients with follicular lymphoma (FL), both with or without EZH2 activating mutations, who have received at least two prior lines of systemic therapy.

The data show that treatment with tazemetostat demonstrated meaningful clinical activity as assessed by both investigators and an Independent Review Committee (IRC), and was generally well tolerated in both FL patients with EZH2 activating mutations (n=45) and FL patients with wild-type EZH2 (n=54). The IRC assessment was conducted for inclusion in Epizyme’s planned NDA submission to the U.S. Food and Drug Administration (FDA) in December 2019.

As assessed by the IRC, as of an August 9, 2019 data cutoff date, tazemetostat treatment resulted in:

• Objective response rate (ORR) of 69% for patients with an EZH2 mutation and 35% for patients with wild-type EZH2
• Median duration of response of 11 months for patients with an EZH2 mutation and 13 months for patients with wild-type EZH2
• Median progression-free survival of 14 months for patients with an EZH2 mutation and 11 months for patients with wild-type EZH2
• Overall survival has not yet been reached for either FL patient population

“Follicular lymphoma remains an incurable disease today, and it’s essential that patients be able to receive treatment for an extended period of time,” said Dr. Shefali Agarwal, chief medical officer of Epizyme. “We believe the clinically meaningful benefit of tazemetostat seen across both FL patient populations in this trial, along with its continued tolerability, are impressive findings. We are particularly pleased with the robust response rates, extended durability and consistency of data as assessed by investigators and independent reviewers. These data support tazemetostat’s potential to make a difference for FL patients, and we look forward to submitting our NDA for both patient populations later this month.”