CAMBRIDGE, Mass., Aug. 11, 2016 (GLOBE NEWSWIRE) -- Epizyme, Inc. (NASDAQ:EPZM), a clinical-stage biopharmaceutical company creating novel epigenetic therapies, today announced that the first patient has been dosed in the Company’s global phase 2 study evaluating tazemetostat, a first-in-class EZH2 inhibitor, for the treatment of adults with mesothelioma characterized by BAP1 loss-of-function.

“Mesothelioma remains a cancer that is very difficult to treat and has an extremely poor prognosis,” said Marjorie Zauderer, M.D., medical oncologist at Memorial Sloan Kettering Cancer Center. “The overwhelming majority of patients are refractory to or relapse following first-line treatment with chemotherapy leaving them with no approved treatment options. The preclinical data demonstrating that EZH2 inhibition may play a role in the treatment of mesothelioma is promising, and I look forward to exploring the potential for tazemetostat as a targeted agent for patients with this devastating disease.”

Mesothelioma affects nearly 12,000 people each year in major markets, of which 40 to 60% have tumors characterized by BAP1 loss-of-function. The median overall survival for all patients with mesothelioma generally ranges from eight to 14 months from the time of diagnosis. The most commonly used first-line treatment consists of cisplatin or carboplatin combined with pemetrexed, which is the only drug approved (2004) for the treatment of mesothelioma¹.

“Patient dosing in this phase 2 study marks another milestone for Epizyme and the expansion of our clinical development program into a new cancer indication for which there is a significant medical need,” said Peter Ho, M.D., Ph.D., Executive Vice President and Chief Medical Officer, Epizyme. “With this study, Epizyme now has four registration-supporting monotherapy trials underway with tazemetostat, and plans for two combination trials to be initiated later this year.”

Phase 2 Study Design
The international, open-label, phase 2 study will evaluate tazemetostat as a monotherapy in a total of 67 patients at multiple sites in the United States, United Kingdom and France. Tazemetostat is orally administered at a dose of 800 mg twice-daily. The safety and pharmacokinetic profile of tazemetostat will first be evaluated in 12 patients with relapsed or refractory mesothelioma regardless of BAP1 status. Subsequently, a total of 55 patients with relapsed or refractory mesothelioma characterized by BAP1 loss-of-function will be treated using a two-stage study design. The primary endpoint of the study is disease control rate (complete response, partial response or stable disease) at 12 weeks. Secondary endpoints include overall response rate, progression-free survival, duration of response and overall survival.

EZH2 Inhibition in Mesothelioma
Tazemetostat is a first-in-class small molecule inhibitor of EZH2 created by Epizyme using its proprietary drug development platform. Aberrant EZH2 activity results in misregulation of genes that control cell proliferation and has been associated with a diverse set of human cancers. Preclinical findings from published reports suggest that mesothelioma, and particularly mesothelioma characterized by BAP1 loss of function, may be sensitive to EZH2 inhibition². Mesothelioma characterized by BAP1 loss of function accounts for 40 to 60 percent of the approximately 12,000 new mesothelioma cases each year in major markets^3-6.

About the Tazemetostat Clinical Trial Program
Tazemetostat, a first-in-class EZH2 inhibitor, is currently being studied in ongoing phase 2 programs in non-Hodgkin lymphoma (NHL), certain genetically defined solid tumors, including INI1-negative and SMARCA4-negative tumors and synovial sarcoma, and mesothelioma.

The company plans to initiate additional clinical trials of tazemetostat in 2016, including a combination with R-CHOP in collaboration with the Lymphoma Study Association and a combination with Tecentriq™ (atezolizumab) in collaboration with Genentech, a member of the Roche Group, both in patients with diffuse large B-cell lymphoma.

About Epizyme, Inc.
Epizyme, Inc. is a clinical-stage biopharmaceutical company creating novel epigenetic therapeutics for people with cancer. Epizyme has built a proprietary product platform to create small molecule inhibitors of chromatin modifying proteins (CMPs), such as histone methyltransferases (HMTs). CMPs are part of the system of gene regulation, referred to as epigenetics, that controls gene expression. Genetic alterations can result in changes to the activity of CMPs, making them oncogenic (cancer-causing). By focusing on the genetic drivers of cancers, Epizyme's targeted science seeks to match the right medicines with the right patients. 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," "plans," "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, 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 or the results of future trials, expectations for regulatory approvals, whether the Company's collaborations will be successful, availability of funding sufficient for 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 or companion diagnostics and other factors discussed in the "Risk Factors" section of our Form 10-Q most recently filed with the SEC, and in our 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. 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. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to the date hereof.

Tecentriq™ is a trademark of Genentech, Inc., (South San Francisco, CA, USA), a member of the Roche Group.

¹ Beebe-Dimmer, et al. ASCO Annual Meeting 2015
² LaFave, LM, et al. "Loss of BAP1 function leads to EZH2-dependent transformation"; Nature Medicine; 2015
³ Arzt, et al. Pathol. Oncol. Res. 2014
⁴ Bott, et al. Nature Genetics 2011
⁵ American Cancer Society
⁶ Park, EK. Envi Health Perspectives 2011