According to a January 2020 release by Business Wire, the USFDA has awarded accelerated approval of Epizyme’s TAZVERIK™ in the treatment of advanced epithelioid sarcoma (ES).
The approval was based on the Phase II EZH-202 clinical trial (NCT02601950). Currently, TAZVERIK is the only FDA approved treatment for epithelioid sarcoma patients.
About Epithelioid Sarcoma (ES)
ES is a rare soft tissue tumor that is known to affect young adults, generally in the area of the hand and forearm.
It usually begins with a small firm growth but multiple growths may appear. ES may appear as an open ulcer that does not heal. It is generally painless at the onset. ES progresses slowly and has a tendency to reoccur, spreading along lymphatic channels.
ES has an overall survival rate of anywhere between twenty-five to seventy-eight percent.
About Phase II EZH-202 Clinical Trial
Sixty-two patients 16 years or older with metastatic ES who were not eligible for surgical removal of the sarcoma participated in the trial. The endpoint of the trial was the overall response and duration of response.
The TAZVERIK (tazemetostat) study was held at multiple facilities as a single-arm (one group a/k/a Cohort 5) open-label study. Open-label studies allow researchers and patients to know which treatment is being administered.
One of the requirements for inclusion in the study was the loss of function of the INI1 tumor-suppressor gene which distinguishes ES from other tumors. This genetic mutation is found in eighty to ninety percent of ES cases.
Each patient was administered 800 mg of TAZVERIK twice daily until unacceptable toxicity or disease progression. Tumor assessments were performed every eight weeks. Median followup was fourteen months and the median age was thirty-four months.
A complete response to the drug was seen in 1.6% of patients and 13% of patients achieved a partial response. The most common adverse events were decreased appetite, constipation, nausea, pain, and fatigue.
The most severe adverse events included hemorrahage, excess fluid around the lungs, respiratory distress, and skin infection. A response of varied proportions was seen in all patients.
A confirmatory trial will be necessary for continued approval of TAZVERIK. Epizyme is currently conducting a worldwide trial studying the combination of TAZVERIK and doxorubicin versus doxorubicin plus placebo for ES patients.
Epizyme is expanding its Phase II trial into Cohort 6 with forty-four sarcoma patients already enrolled.
The company is also conducting studies to evaluate how TAZVERIK affects liver function.
TAZVERIK is known as a methyltransferase inhibitor which is a substance that blocks specific enzymes in cell division and gene function. These enzymes may be mutated and found in some forms of cancer cells.
About Epizyme, Inc.
Epizyme, a biopharmaceutical organization responsible for the development of TAZVERIK™ (tazemetostat) is dedicated to developing treatments for cancer and serious diseases.
Epizyme is currently conducting clinical trials to study the drug’s potential for solid tumors and blood diseases either as a single agent or in combination therapy.
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