Oncologists may soon have another weapon at their disposal in the fight against advanced follicular lymphoma, a type of cancer in need of new treatment options. The Food and Drug Administration has accepted Epizyme's (NASDAQ:EPZM) application to review tazemetostat for use by patients with that form of cancer.
Tazemetostat is an epigenetic therapy that targets EZH2-activating mutations by inhibiting chromatin-modifying proteins, or CMPs, that regulate chromatin, a complex comprising DNA and histone proteins responsible for gene expression. In January, the FDA approved it for use in advanced epithelioid sarcoma patients under the brand name Tazverik following a unanimous vote of support from the agency's advisory committee.
In mid-stage trials, 77% of follicular lymphoma patients with the EZH2 mutation and 34% with wild-type EZH2 responded to Tazverik. Including patients with stable disease, the disease control rate was 100% and 68% for the two cohorts. Only 8% of patients in the trials stopped taking the drug because of treatment-emergent adverse events.
The FDA is reviewing Tazverik under an accelerated timeline, with a prescription drug user fee act (PDUFA) target action date set for June 18. If approved, Tazverik could be used in patients with or without mutation who have seen their disease advance after trying two prior lines of therapy. Approximately 25,000 cases of follicular lymphoma are diagnosed in the U.S. and five largest European countries annually, and roughly 20% of these patients are EZH2 mutation positive.
The need for new late-line treatment options is significant. About 80% of first-line patients progress to a second-line therapy, and 75% of second-line patients progress to a third-line therapy. Unfortunately, the median survival from diagnosis in this indication is just 10 years.
The biotech company is also pursuing other avenues to expand Tazverik's potential market. Trials are underway to evaluate the drug alongside Rituxan in earlier lines of treatment, as well as in other indications, including prostate cancer and diffuse large B-cell lymphoma.