Epizyme (EPZM) secured an accelerated approval from the Food and Drug Administration for its sarcoma drug Tazverik. The drug was approved specifically for patients with metastatic or locally advanced epithelioid sarcoma who aren't eligible for surgery to completely remove the tumor.
Tazverik is the first FDA-approved drug for epithelioid sarcoma. It's also the first FDA-approved drug that targets enhancer of zeste homolog 2 (EZH2), a protein involved in modifying DNA, which leads to the suppression of expression of certain genes, including tumor suppressor genes. By inhibiting EZH2, Tazverik reduces the DNA modification, thereby increasing the expression of tumor suppressors that can slow or stop growth of cancerous cells.
In the phase 2 clinical trial used as a basis for the approval, 15% of patients responded to the drug, including 1.6% of patients who had a complete response. While a 15% response rate is rather low, most of the patients had a prior surgery and/or chemotherapy before entering the clinical trial, so their options were limited -- as noted, there aren't any approved therapies for this type of cancer.
Since Epizyme received an accelerated approval based on a mid-stage trial, the biotech will need to verify the results with a confirmatory study. Epizyme has already started the study that's comparing Tazverik plus the chemotherapy doxorubicin to doxorubicin alone in epithelioid sarcoma patients who were previously untreated. In addition to securing full approval, the confirmatory trial could be used as the basis for an additional approval in the first-line treatment, expanding the potential market for Tazverik.
Epizyme expects Tazverik to be available to patients within 10 business days.