The FDA has approved dabrafenib (Tafinlar) and trametinib (Mekinist), administered together, for the treatment of anaplastic thyroid cancer (ATC) that cannot be removed by surgery or has spread to other parts of the body (metastatic), and is BRAF V600E mutation-positive. Both drugs are Novartis products.
“This is the first FDA-approved treatment for patients with this aggressive form of thyroid cancer, and the third cancer with this specific gene mutation that this drug combination has been approved to treat,” said Richard Pazdur, MD, Director of the FDA’s Oncology Center of Excellence and Acting Director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “This approval demonstrates that targeting the same molecular pathway in diverse diseases is an effective way to expedite the development of treatments that may help more patients.”
Thyroid cancer is a disease in which cancer cells form in the tissues of the thyroid gland. Anaplastic thyroid cancer is a rare, aggressive type of thyroid cancer. The National Institutes of Health estimates there will be 53,990 new cases of thyroid cancer and an estimated 2,060 deaths from the disease in the United States in 2018. Anaplastic thyroid cancer accounts for about 1% to 2% of all thyroid cancers.
Both dabrafenib and trametinib are also approved for use, alone or in combination, to treat BRAF V600 mutation-positive metastatic melanoma. In addition, dabrafenib and trametinib are approved for use, in combination, to treat BRAF V600E mutation-positive, metastatic non-small cell lung cancer.
The efficacy of dabrafenib and trametinib in treating ATC was shown in an open-label clinical trial of patients with rare cancers with the BRAF V600E mutation. Data from trials in BRAF V600E mutation-positive, metastatic melanoma or lung cancer and results in other BRAF V600E mutation-positive rare cancers provided confidence in the results seen in patients with ATC. The trial measured the percent of patients with a complete or partial reduction in tumor size (overall response rate). Of 23 evaluable patients, 57% experienced a partial response and 4% experienced a complete response; in nine (64%) of the 14 patients with responses, there were no significant tumor growths for six months or longer.
The FDA granted priority review and breakthrough therapy designation for this indication. Orphan drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases, was also granted for this indication.
Source: FDA; May 4, 2018.