The U.S. Food and Drug Administration (FDA) announced Thursday an accelerated approval of Tazverik (tazemetostat) for the treatment of metastatic and locally advanced epithelioid sarcoma, a rare soft tissue cancer. It has been approved for adult and pediatric patients aged 16 and above.
Epithelioid sarcoma is a rare soft tissue sarcoma, which occurs in younger adults.
Dr. Richard Pazdur said, “Epithelioid sarcoma accounts for less than one percent of all soft tissue sarcomas.”
Dr. Pazdur is the director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research.
“Until today, there were no treatment options specifically for patients with epithelioid sarcoma. The approval of Tazverik provides a treatment option that specifically targets this disease,” added. Dr. Pazdur. “When we brought Tazverik’s application to the Oncologic Drugs Advisory Committee last month, the committee voted unanimously that the benefits of the drug outweighed the risks.”
Developed by Epizyme Inc., Tazverik inhibits the enzyme called “EZH2 methyltransferase,” keeping the cancer cells from growing. In most cases, epithelioid sarcoma begins in the soft tissues under the skin of an extremity; however, it may occur in other parts of the body.
The condition is treated by surgically removing the tumor; however, it can be treated with chemotherapy or radiotherapy. Unfortunately, 50 percent of the cases are diagnosed when the tumor has metastasized, which could be life-threatening.
The FDA approved Tazverik after considering the results of a clinical trial that enrolled 62 patients with metastatic or locally advanced epithelioid sarcoma. The patients were given Tazverik 800 mg twice a day.
The overall drug response rate was 15 percent, 1.6 percent of patients had a complete response and 13 percent had a partial response. Six patients had a complete response lasting for more than six months.
The FDA said the common side effects associated with Tazverik were pain, nausea, vomiting, fatigue, decreased appetite, and constipation.
The health agency said patients treated with Tazverik are at risk of developing secondary malignancies such as T-cell lymphoblastic lymphoma, myelodysplastic syndrome, and acute myeloid leukemia.
Medical professionals are advised to inform female patients of reproductive potential to use effective contraception while undergoing treatment with Tazverik. The FDA said that further clinical trials are required to verify and describe the clinical benefits of Tazverik.