Epizyme Submits New Drug Application to the U.S. FDA for Tazemetostat for the Treatment of Patients with Epithelioid Sarcoma

Submission Follows Productive Pre-NDA Meeting and Marks On-time Execution of First of Two NDA Submissions Planned for 2019

CAMBRIDGE, Mass.--()--Epizyme, Inc. (Nasdaq: EPZM), a late-stage biopharmaceutical company developing novel epigenetic therapies, today announced that it has submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for accelerated approval of tazemetostat for the treatment of patients with metastatic or locally advanced epithelioid sarcoma not eligible for curative surgery. Tazemetostat is an oral, first-in-class, EZH2 inhibitor discovered by Epizyme and being developed for a range of cancers and treatment settings.

This NDA submission follows a recently conducted pre-NDA meeting held with FDA, in which the Agency considered the proposed clinical package to be sufficient for inclusion with the NDA. The submission is based on updated tazemetostat efficacy and safety data from 62 patients enrolled in the epithelioid sarcoma cohort of the Phase 2 clinical trial, which will be reported in an oral presentation at the American Society of Clinical Oncology (ASCO) 2019 Annual Meeting. The company’s ongoing Phase 2 study cohort is the largest prospective clinical trial in epithelioid sarcoma with any approved or investigational anticancer treatment to date.

Epithelioid sarcoma is a rare and aggressive cancer that affects people in the prime of their lives, and we are very pleased to have recently submitted the NDA for tazemetostat for the treatment of people with this devastating cancer,” said Dr. Shefali Agarwal, chief medical officer of Epizyme. “If approved, we believe tazemetostat has the potential to change the care of patients with this disease. We are incredibly grateful to the physicians and clinical teams who have helped advance tazemetostat to this stage, and, most notably, to the patients and caregivers who have participated in our clinical trials along the way. We look forward to continuing to engage with the FDA as we work to bring tazemetostat to patients and physicians in the U.S.”

To support a full approval of tazemetostat for epithelioid sarcoma, Epizyme plans to conduct a global, randomized, controlled trial, that it expects to begin in the second half of 2019. The final design of the study is subject to alignment with FDA, and the company plans to disclose details once it has reached alignment with FDA and the NDA submission has been accepted for review. The FDA has a 60-day filing review period to determine whether the NDA is complete and acceptable for filing.

At Epizyme, our mission is to deliver new treatments for patients with cancer and other serious diseases, and today we stand one significant step closer to achieving that,” said Robert Bazemore, president and chief executive officer of Epizyme. “This submission is the culmination of years of hard work by our entire team, and I wish to congratulate them all on this accomplishment. Our epithelioid sarcoma program is strategically valuable to Epizyme and helps streamline our planned NDA submission in the fourth quarter, for patients with follicular lymphoma. Over the coming months, we have multiple anticipated clinical data and regulatory milestones, and we are well underway with commercialization readiness activities to support the potential launch of tazemetostat and our transition to a commercial-stage organization. 2019 is set to be a transformational year for Epizyme, and I am enthusiastic for our continued progress.”

About Epithelioid Sarcoma
Epithelioid sarcoma is an ultra-rare soft tissue sarcoma characterized by a loss of the protein INI1. Patients are most commonly diagnosed as young adults, between 20 and 40 years of age. Median overall survival from initial diagnosis is 30 months. Epithelioid sarcoma becomes more aggressive after recurrence or metastases, with a typical survival of less than one year for patients with metastatic disease.

About Epizyme, Inc.
Epizyme, Inc. is a late-stage biopharmaceutical company committed to rewriting treatment for cancer and other serious diseases through novel epigenetic medicines. Epizyme is broadly developing its lead product candidate, tazemetostat, a first-in-class EZH2 inhibitor, with studies underway in both solid tumors and hematological malignancies, as a monotherapy and combination therapy in relapsed and front-line disease. The company also is developing a novel G9a program with its next development candidate, EZM8266, which is targeting sickle cell disease. By focusing on the genetic drivers of disease, Epizyme's science seeks to match targeted medicines with the patients who need them. For more information, visit www.epizyme.com.

Cautionary Note on Forward-Looking Statements
Any statements in this press release about future expectations, plans and prospects for Epizyme, Inc. and other statements containing the words “anticipate," “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: uncertainties inherent in the initiation of future clinical studies and in the availability and timing of data from ongoing clinical studies; whether interim results from a clinical trial will be predictive of the final results of the trial; whether results from preclinical studies or earlier clinical studies will be predictive of the results of future trials; whether results from clinical studies will warrant meetings with regulatory authorities, submissions for regulatory approval or review by governmental authorities under the accelerated approval process; whether Fast Track Designation and Orphan Drug Designations will provide the benefits for which tazemetostat is eligible; whether the NDA submission referred to in this release will be accepted for review under the accelerated approval process or at all, or approved on a timely basis or at all; whether the company's cash resources will be sufficient to fund the company's foreseeable and unforeseeable operating expenses and capital expenditure requirements; other matters that could affect the availability or commercial potential of the company's therapeutic candidates; and other factors discussed in the "Risk Factors" section of the company's most recent Form 10-Q filed with the SEC and in the company's other filings from time to time with the SEC. In addition, the forward-looking statements included in this press release represent the company's views as of the date hereof and should not be relied upon as representing the company's views as of any date subsequent to the date hereof. The company anticipates that subsequent events and developments will cause the company's views to change. However, while the company may elect to update these forward-looking statements at some point in the future, the company specifically disclaims any obligation to do so.

Contacts

Media:
Erin Graves, (617) 500-0615
Epizyme, Inc.
media@epizyme.com

Investors:
Monique Allaire
THRUST Strategic Communications
monique@thrustsc.com

Contacts

Media:
Erin Graves, (617) 500-0615
Epizyme, Inc.
media@epizyme.com

Investors:
Monique Allaire
THRUST Strategic Communications
monique@thrustsc.com