January 23, 2020
The U.S. FDA has granted accelerated approval to Tazverik™ (tazemetostat), manufactured by Epizyme, to treat patients who are at least 16 years old and have metastatic or locally advanced epithelioid sarcoma and who are not eligible for complete resection. Tazverik is the first treatment approved specifically for epithelioid sarcoma, and the first FDA-approved EZH2 inhibitor.
Epithelioid sarcoma is a rare soft tissue cancer that accounts for less than 1% of all soft tissue sarcomas. It is a slow-growing cancer often seen in young adults and teenagers, and in most cases begins as a small, firm, painless lump under the skin. Because it shares characteristics with other, non-cancerous conditions, epithelioid sarcoma can be difficult to properly diagnose. Current standards of care include surgical removal of tumors and treatment with radiation therapy and chemotherapy. Tazverik may help slow or halt tumor growth by blocking EZH2 methyltransferase, a compound overexpressed by cancer cells and suspected to play a role in tumor growth.
In a clinical trial, Tazverik produced an overall response rate of 15%, with 1.6% of patients experiencing a complete response (absence of tumors) and 13% having a partial response (shrinkage of tumors). Of the patients who responded to treatment, 67% had a duration of response lasting at least six months. Because Tazverik was granted accelerated approval, continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials. Recommended dosing is 800mg taken orally twice a day until disease progression or unacceptable toxicity.
Tazverik will be available at a list price of $15,500 per month when launched, but Epizyme has not yet announced a launch date.