Epizyme Testing New Mesothelioma Treatment with Phase Two Clinical Trial

Illustration of mesothelioma research

Epizyme, Inc. is starting a new phase two clinical trial using tazemetostat as a treatment for patients with mesothelioma cancer. Tazemetostat is a first-in-class EZH2 inhibitor.

Several types of clinical trials exist, but preclinical findings have showed mesothelioma cancer, especially mesothelioma characterized by BAP1 loss of function, might be sensitive to EZH2 inhibitors.

Tazemetostat will be evaluated as a monotherapy in 67 patients across the U.S., United Kingdom, and France through oral administration at a dose of 800 mg two times a day. But first, 12 patients with relapsed or refractory mesothelioma cancer will be evaluated to determine the drug’s safety and pharmacokinectic profile.

Then 55 patients with relapsed or refractory mesothelioma cancer characterized by BAP1 loss-of-function will be treated in a two-stage study. Disease control rate will be measured after 12 weeks. Overall response rate, progression-free survival, duration of response, and overall survival will also be tested.

“Mesothelioma remains a cancer that is very difficult to treat and has an extremely poor prognosis,” said Medical Oncologist at Memorial Sloan Kettering Cancer Center Marjorie Zauderer, M.D.

About 12,000 people each year are diagnosed with mesothelioma cancer. Forty to 60% have tumors with BAP1 loss-of-function. These patients usually only have eight to 14 months left to live at the time of diagnosis.

According to Dr. Zauderer, “The overwhelming majority of patients are refractory to or relapse following first-line treatment with chemotherapy leaving them with no approved treatment options.”

Although a number of experimental treatments exist, the only approved drug for mesothelioma treatment is premetrexed combined with cisplatin or carboplatin.

“Patient dosing in this phase two study marks another milestone for Epizyme and the expansion of our clinical development program into a new cancer indication for which there is significant medical need,” said Executive Vice President and Chief Medical Officer at Epizyme Peter Ho, M.D., Ph.D.

According to Dr. Ho, “With this study, Epizyme now has four registration-supporting monotherapy trials underway with tazemetostat, and plans for two combination trails to be initiated later this year.”

Epizyme’s continued trials will include a combination with R-CHOP in collaboration with the Lymphoma Study Association, as well as one with atezolizumab in collaboration with Genentech.

“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.” said Dr. Zauderer.