Epizyme Announces FDA Acceptance of Investigational New Drug Application for Tazemetostat in Mesothelioma

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Epizyme, Inc. (NASDAQ: EPZM), a clinical stage biopharmaceutical company creating novel epigenetic therapies for people with cancer, today announced that the U.S. Food and Drug Administration has accepted the company’s Investigational New Drug (IND) application for tazemetostat for the treatment of adults with mesothelioma characterized by BAP1 loss-of-function. In the third quarter of this year, the company plans to initiate a phase 2 study in patients with mesothelioma.

“We are moving quickly to expand the tazemetostat clinical program into mesothelioma, adding to our ongoing studies in non-Hodgkin lymphoma and certain genetically defined solid tumors,” said Robert Bazemore, President and Chief Executive Officer, Epizyme. “We believe that tazemetostat has the potential to treat multiple types of cancer in patients who have limited treatment options. We look forward to starting the mesothelioma phase 2 study later this year.”

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. Emerging preclinical findings from published reports suggest that mesothelioma, and particularly mesothelioma characterized with BAP1 loss of function, may be sensitive to EZH2 inhibition¹.

Mesothelioma characterized by BAP1 loss of function accounts for 40-60 percent of the approximately 12,000 new mesothelioma cases each year in major markets^2-5.

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

The company has announced plans to initiate additional clinical evaluations of tazemetostat in 2016, including a combination with R-CHOP in patients with diffuse large B-cell lymphoma (DLBCL) and a combination with an immune checkpoint inhibitor in NHL.

About Epizyme, Inc.
Epizyme, Inc. is a clinical stage biopharmaceutical company creating novel epigenetic therapeutics for cancer patients. Epizyme has built a proprietary product platform that the Company uses to create small molecule inhibitors of a 96-member class of enzymes known as histone methyltransferases, or HMTs. HMTs 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 HMTs, 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 and connect with us on Twitter at @EpizymeRx.

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 or expansion of ongoing 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, development progress of the Company’s companion diagnostics, 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-K 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.

¹ LaFave, LM, et. al. “Loss of BAP1 function leads to EZH2-dependent transformation”; Nature Medicine; Published online 05 October 2015.
² Arzt et al., Pathol. Oncol. Res. 2014.
³ Bott et al., Nature Genetics 2011.
⁴ American Cancer Society
⁵ Park EK Envi Health Perspectives 2011.