Epizyme Reports Positive Updated Interim Data from Phase 2 Study of Tazemetostat in Patients With Relapsed or Refractory Follicular Lymphoma at the Congress of the European Hematology Association (EHA)

  • Consistently High Responses in Patients with an EZH2 Activating Mutation
  • Durable Clinical Responses and Progression-Free Survival Observed in Patients With or Without an EZH2 Activating Mutation
  • Company to Host Investor Conference Call Today at 8:30 a.m. EDT

CAMBRIDGE, Mass., June 15, 2018 (GLOBE NEWSWIRE) — Epizyme, Inc. (NASDAQ:EPZM), a clinical-stage company developing novel epigenetic therapies, announced positive interim data from an ongoing Phase 2 study of its lead candidate tazemetostat, a potent, selective, orally available EZH2 inhibitor, as a monotherapy for patients with relapsed or refractory follicular lymphoma (FL). The data, presented today at the 23rd Congress of the European Hematology Association (EHA) in Stockholm, show that tazemetostat demonstrated meaningful clinical activity and was generally well tolerated in these heavily pre-treated patients.

Interim data as of May 1, 2018 included 82 evaluable patients across two cohorts, prospectively assigned by EZH2 status. In the EZH2 activating mutation cohort (n=28), an objective response rate (ORR) of 71 percent was observed; 11 percent of patients achieved a complete response (CR), and 61 percent achieved a partial response (PR). Twenty-nine percent achieved stable disease (SD) as best response; of those, 21 percent are still on study with the potential to respond. All patients in this cohort experienced reduction in tumor burden, and no patients experienced progressive disease (PD) as best response. At the time of this analysis, the median progression-free survival (PFS) was 49 weeks and the median duration of response (DOR) was 32 weeks, and both endpoints continue to mature.

In the fully-enrolled cohort of FL patients with wild-type (WT) EZH2 (n=54), the ORR was 33 percent; six percent achieved a CR, and 28 percent achieved a PR. An additional 31 percent of patients achieved SD as best response, including one patient who is still receiving treatment. At the time of this analysis, the median PFS was 30 weeks and median DOR was 76 weeks.  The median DOR figure continues to mature, with more than half of the responders still on therapy.

“I am impressed by the sustained clinical activity and the good tolerability of tazemetostat in this heavily pre-treated patient population. This is important for patients with relapsed or refractory follicular lymphoma, as both the response rates and durations of response usually tend to decrease with each successive line of treatment,” said Gilles Salles, M.D., Ph.D., at the University Hospital of Lyon France, and president of the Lymphoma Study Association (LYSA) cooperative group. “I believe tazemetostat has the potential to fill a significant unmet need for these patients and continued investigation of tazemetostat as single agent or in combination with other agents is warranted.”

Updated interim clinical activity findings are as follows:

Best Response FL with EZH2
FL with EZH2 WT
Evaluable for efficacy on May 1, 2018 n =28 n =54
Median Prior Lines of Therapy 3 4
Objective Response Rate (CR + PR) 71% (20) 33% (18)
Complete Response (CR) 11% (3) 6% (3)
Partial Response (PR) 61% (17) 28% (15)
Stable Disease (SD) 29% (8) 31% (17)
SD study drug ongoing 21% (6) 2% (1)
Progressive Disease (0) 31% (17)
Median Progression-Free Survival (PFS)
48.6+ weeks* 29.9 weeks
Median Duration of Response (DOR)
32.3+ weeks* 76.0+ weeks*
Patients with Response Ongoing 55% (11) 56% (10)
*median not yet reached; data continue to mature
includes discontinued patients with response ongoing at time of discontinuation

This ongoing global, multi-center Phase 2 study is assessing the safety and efficacy of 800 mg of tazemetostat, administered orally twice daily, in adult patients who had received at least two prior therapies. The two cohorts represented in the interim assessment included patients with an EZH2 activating mutation or those with WT EZH2. The primary endpoint is ORR, defined as CR and PR. Secondary endpoints include PFS, DOR and safety/tolerability.

Tazemetostat was generally well tolerated in this study. Interim safety results at the time of this analysis show only six percent of FL patients discontinued treatment due to treatment-related adverse events (AEs).  AEs of Grade 3 or higher were reported across 17 percent of patients, the most frequent of which included thrombocytopenia, anemia, asthenia and fatigue.

“Today’s interim update underscores our belief that tazemetostat may be an important therapeutic candidate in relapsed or refractory follicular lymphoma and may play a key role in the treatment landscape, regardless of mutational status,” said Robert Bazemore, president and chief executive officer of Epizyme. “The patients who are participating in this study deserve our gratitude. At Epizyme, we are dedicated to continuing our work with the global investigator community to resolve the partial clinical hold and complete enrollment in this study, in an effort to bring tazemetostat to people living with follicular lymphoma.”

Investor Conference Call Reminder
Epizyme will host an investor conference call and webcast today at 8:30 a.m. EDT to discuss interim clinical activity and tolerability data from adult patients with relapsed or refractory FL who are receiving tazemetostat in the company’s ongoing Phase 2 study. To participate in the call, please dial (877) 844-6886 (domestic) or (970) 315-0315 (international) and refer to conference ID 4869637. A live webcast will be available in the investor section of the company’s website at www.epizyme.com. The webcast will be archived on the website for 60 days.

About Follicular Lymphoma (FL)
An estimated 40,000 people in the U.S. and EU5 are treated for FL each year. FL is an incurable and deadly form of cancer that is most frequently treated with multiple lines of systemic chemotherapy. As a result, there remains a significant need for an effective, convenient and tolerable medicine that patients can take for long durations.

About the Tazemetostat Clinical Trial Program
Tazemetostat, a first-in-class EZH2 inhibitor, is currently being studied as a monotherapy in ongoing Phase 1 and 2 programs in certain molecularly defined solid tumors, including epithelioid sarcoma (ES) and other INI1-negative tumors; both follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) forms of non-Hodgkin lymphoma (NHL); mesothelioma and combination studies in DLBCL.

About Epizyme, Inc.
Epizyme, Inc. is a clinical-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 is also 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 relating to the Company’s ability to resume enrollment in its tazemetostat trials and the timing of such resumption, and the impact of the safety finding on enrollment of patients in ongoing and future trials of tazemetostat following the lifting of the partial clinical hold and the resumption of enrollment; 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; expectations for regulatory approvals to conduct trials or to market products; 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.


Erin Graves, Epizyme, Inc.
(617) 500-0615

Jason Fredette, Epizyme, Inc.
(617) 500-0623

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