May 4, 2018—Today, the U.S. Food and Drug Administration (FDA) approved the use of dabrafenib (a BRAF inhibitor) in combination with trametinib (a MEK inhibitor) for the treatment of unresectable or metastatic anaplastic thyroid cancer (ATC) harboring a BRAF V600E mutation. This follows the approval of the BRAF/MEK inhibitor combination for adjuvant melanoma earlier this week.
 
“This is the first FDA-approved treatment for patients with this aggressive form of thyroid cancer, said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence, in a press release.
 
The targeted combination is also approved for patients with BRAF-mutated metastatic melanoma and non-small cell lung cancer (NSCLC). “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,” said Pazdur.
 
Today’s approval was based on results from the non-randomized phase II BRF117019 trial (NCT02034110) in which patients with multiple rare cancer types harboring a BRAF V600E mutation were divided into multiple cohorts. For patients with locally advanced, unresectable, or metastatic ATC the overall response rate (ORR) was 61% (N=14/23). The complete and partial response rates were 4% (N=1) and 57% (N=13), respectively. Response duration was reported to be at least 6 months in 64% of responding patients (N=9/14).
 
Adverse events (AEs) reported with dabrafenib/trametinib were consistent with those seen in previous trials and other cancers. Common AEs can include pyrexia, rash, chills, headache, joint pain, cough, fatigue, nausea, vomiting, diarrhea, muscle pain, dry skin, decreased appetite, edema, hemorrhage, hypertension, and difficulty breathing. Serious AEs have included the development of new cancers, including in patients with BRAF wild-type tumors, increased bleeding, skin toxicity, anemia, and complication in the heart, lungs, and eyes.
 
Updated prescribing information for dabrafenib can be found here. Updated prescribing information for trametinib can be found here.
 
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Jonathan A. Bell
Published Online: Friday, May 04, 2018