June 20, 2016
By Mark Terry, BioSpace.com Breaking News Staff
Epizyme , headquartered in Cambridge, Massachusetts, announced very preliminary data from its ongoing Phase II clinical trial of tazemetostat in non-Hodgkin lymphoma (NHL) patients. The data is very early, what the company’s chief executive officer, Robert Bazemore, calls an “early snapshot,” which also means that as promising as it is, a lot more works needs to be done.
Of the 270 patients planned for the trial, only 82 have been enrolled, and only a very small percentage have received treatment for more than five months. A single patient has been on it longer than eight months.
What the company reported is the impact on 47 patients, and safety in 82 patients. The patients either have diffuse large-B cell lymphoma (DLBCL) or follicular lymphoma (FL). They also have failed at least two prior rounds of treatment. Some of the patients have a mutation for an enzyme called EZH2, which is the drug’s target, and some do not.
So far, the drug has a favorable safety profile in all patients. The most common side effects were nausea, asthenia, thrombocytopenia, neutropenia and fatigue.
Bloomberg summed up the findings, writing, “Among 47 patients whose disease data were available, four had their tumors eliminated and nine saw tumor shrinkage. … One patient whose tumor shrank has since started seeing regrowth, according to slides that will be presented at the American Society of Hematology Meeting on Lymphoma Biology in Colorado Springs, Colorado. Among 82 patients for whom safety data were available, 2 percent stopped taking tazemetostat because of drug-related side effects.”
“These numbers are nothing to jump up and down about,” said Robert Chen, a hematologist and assistant professor at the City of Hope National Medical Center in Duarte, California, to Xconomy. He does find one of the study groups interesting. In that group, all three patients with FL and EZH2 mutations responded to the drug. But he suggests healthy skepticism, saying, “You might just be lucky getting three out of three responses. It’s too early … time will tell.”
The company believes that the overall improvement rate will get better as the trial progresses. Which it’s going to need, given the market. “Unless the overall response rate is greater than 50 percent,” says Chen, [the drug] is not going to make it in the [NHL] space.”
“Patients with relapsed or refractory NHL are often faced with limited treatment options, particularly those who are highly refractory or whose disease is multiply relapsed as we have seen in this study population,” said Franck Morschhauser, with the Centre Hospitalier Regional Universitaire de Lille, France, and principle investigator of the study, in a statement. “These patients are in need of new therapeutic options, and while these data are early, we are encouraged and look forward to further understanding the impact that tazemetostat could have on patients as the trial proceeds.”
Epizyme has two drugs in clinical trials. Aside from tezemetostat, it has pinometostat, which it splits rights to with Summit, New Jersey-based Celgene . In March 2015, Epizyme bought the rights back to tazemetostat from Japanese company Eisai.
Xconomy writes, “Often a bigger partner walks away from a drug because of disappointing results. But Bazemore, in a previous interview with Xconomy, said oncology wasn’t a top priority for Eisai at the time, and the drug ‘wasn’t moving as quickly and aggressively as we thought it could be.’”
