FDA Approves Tazemetostat for Treatment of Adults with Epithelioid Sarcoma

Officials with the FDA have granted accelerated approval to tazemetostat (Tazverik, Epizyme Inc) for the treatment of adults and pediatric patients age 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection.

Epithelioid sarcoma is a rare sub-type of soft tissue sarcoma that often occurs in young adults. Tazemetostat blocks any activity of the EZH2 methyltransferase, which may help keep the cancer cells from further growth.

Surgical removal has been the main source of treatment when the cancer is localized to 1 area of the body. Chemotherapy or radiation may also be given; however, there is a high likelihood for local, and regional spread of the disease, even with treatment.

The approval of tazemetostat was based on the results of a clinical trial that included 62 patients with metastatic or locally advanced epithelioid sarcoma. During the trial, patients received 800 milligrams of tazemetostat twice a day until the disease progressed or the patient reached an unacceptable level of toxicity.

Every 8 weeks, tumor response assessments were performed to measure how many patients experienced complete or partial shrinkage of their tumors during treatment. The overall response rate was 15%, with 1.6% of patients having a complete response and 13% having a partial response. Out of the 9 patients that had a response, 6 patients had a response lasting 6 months or longer.

The most common adverse effects reported in patients taking tazemetostat were pain, fatigue, nausea, decreased appetite, vomiting, and constipation. Patients treated with tazemetostat are at an increased risk of developing secondary malignancies including T-cell lymphoblastic lymphoma, myelodysplastic syndrome, and acute myeloid leukemia.

REFERENCE

FDA approves first treatment option specifically for patients with epithelioid sarcoma, a rare soft tissue cancer [news release]. Silver Springs, MD; FDA: January 23, 2020. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-option-specifically-patients-epithelioid-sarcoma-rare-soft-tissue?utm_campaign=012320_PR_FDA%20approves%20first%20treatment%20option%20for%20epithelioid%20sarcoma&utm_medium=email&utm_source=Eloqua. Accessed January 24, 2020.