Epizyme Falls as Investors Take in Disappointing Phase II Data

Published: Jun 16, 2017

Epizyme Falls as Investors Take in Disappointing Phase II Data June 15, 2017
By Alex Keown, BioSpace.com Breaking News Staff

CAMBRIDGE, Mass. – Epizyme Inc. ’s tazemetostat, an experimental Phase II treatment for lymphomas, showed a 29 percent overall response rate in patients with diffuse large B-cell lymphoma (DLBCL), but that fell below investors’ expectations, which caused share prices to tumble on Wednesday.

On June 14, Epizyme released interim data showing tazemetostat, a first-in-class, oral EZH2 inhibitor, resulted in a clinically meaningful benefit in patients with follicular lymphoma with EZH2 activating mutations. Those patients showed a 92 percent objective response rate. However, it was when it came to patients with diffuse large B-cell lymphoma with EZH2 mutations that the trial fell below what investors were hoping to see. The company said those patients saw a 29 percent ORR, which fell below the 40 percent mark analysts and investors had been expecting in the in DLBCL group, according to Endpoints. Matthew Eckler, an analyst with RBC, had predicted ORR could range between 33 and 50 percent, Endpoints added.

While the stock dropped on Wednesday, it appears to be making a turnaround this morning. Share prices are up more than two points from $10.10 to $12.80.

Follicular Lymphoma, an indolent form of non-Hodgkin lymphoma (NHL), is considered to be incurable. Approximately 25,000 patients in the U.S. and major European countries are diagnosed with FL every year, of which an estimated 15 to 20 percent have an EZH2 mutation. There are no approved treatments indicated for patients with FL with an EZH2 mutation. In April, tazemetostat received Fast Track Designation for the treatment of patients with relapsed or refractory follicular lymphoma, either wild type EZH2 or with EZH2 activating mutations.

DLBCL is an aggressive form of NHL that once diagnosed, typically requires immediate treatment. Approximately 45,000 patients are diagnosed with DLBCL in the U.S. and major European countries every year. Among patients with germinal center DLBCL, an estimated 15 to 20 percent have an EZH2 mutation.

Franck Morschhauser, lead investigator of the Phase II study, said he was excited by the results of the Phase II trial and believes tazemetostat can play a significant role in treatment of patients.

“I am also encouraged by the level of activity in DLBCL patients with EZH2 mutations, especially in light of the bleak prognosis associated with advanced disease. Tazemetostat has demonstrated a uniquely tolerable safety profile, and I look forward to further exploring its full benefit in patients with relapsed or refractory FL and DLBCL as the data mature,” Morschhauser said in a statement.

Rob Bazemore, chief executive officer of Epizyme, also hailed the interim findings of the Phase II trial, saying they represent an important step forward in the company’s tazemetostat program. With anti-tumor activity being observed across all groups of the study, Bazemore said the reactions are consistent with what the company had been expecting.

“The activity we have observed in patients with an EZH2 mutation exceeds what we have seen so far with wild-type EZH2, consistent with our scientific hypothesis, and we are encouraged by both the objective responses and durability of responses in FL and DLBCL,” Bazemore said in a statement.

Epizyme will continue to move forward with the Phase II trial and expects to meet with the U.S. Food and Drug Administration later this year to move the drug forward through the next round of clinical trials and possibly to commercialization.

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