Earlier this week, the combination therapy received approval for adjuvant use in BRAF V600-mutant melanoma following complete surgical resection. Dabrafenib plus trametinib are also approved to treat BRAF V600-mutation-positive, metastatic non-small cell lung 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. Rare and aggressive, ATC accounts for about 1% to 2% of all thyroid cancers.
“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,” 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, said in a press release. “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.”
The approval is based on a clinical trial demonstrating the combination therapy’s efficacy in treating ATC among patients with rare cancers with the BRAF V600E mutation. Of 23 evaluable patients in the trial, 57% experienced a partial response and 4% experienced a complete response to the treatment. In 9 of 14 patients with responses, there were no significant tumor growths for 6 months or longer.
Adverse effects associated with the therapy in patients with ATC were shown to be consistent with those seen in other cancers. Common adverse events include fever, rash, chills, headache, joint pain, cough, fatigue, nausea, vomiting, diarrhea, myalgia, dry skin, decreased appetite, edema, hemorrhage, high blood pressure, and difficulty breathing.
Severe adverse effects of dabrafenib include the development of new cancers, growth of tumors in patients with BRAF wild-type tumors, serious bleeding problems, heart problems, severe eye problems, fever that may be severe, serious skin reactions, high blood sugar or worsening diabetes, and serious anemia.
Severe adverse effects of trametinib include the development of new cancers; serious bleeding problems; inflammation of intestines, and perforation of the intestines; blood clots in the arms, legs or lungs; heart problems; severe eye problems; lung or breathing problems; fever that may be severe; serious skin reactions; and high blood sugar or worsening diabetes.
In addition, both drugs can cause harm to a developing fetus. Women should be advised of the potential risk to the fetus and to use effective contraception.
FDA approves new uses for two drugs administered together for the treatment of BRAF-positive anaplastic thyroid cancer [news release]. FDA’s website. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm606686.htm?utm_campaign=05042018_PR_FDA%20approves%20new%20uses%20for%202%20drugs%20for%20BRAF%20positive%20patients&utm_medium=email&utm_source=Eloqua. Accessed May 7, 2018.