Dabrafenib plus trametinib first regimen to produce clinical activity in BRAF V600E-mutated anaplastic thyroid cancer
Dabrafenib plus trametinib produced significant clinical activity among patients with BRAF V600E-mutated anaplastic thyroid cancer, marking an advancement in treating the disease, study data showed.
“Anaplastic thyroid carcinomas (ATCs) are rare, highly aggressive, undifferentiated tumors and patients diagnosed with ATCs have a median survival of 5 to 12 months and a 1-year overall survival of 20% to 40%,” Bhumsuk Keam, MD, PhD, professor in the department of internal medicine at Seoul National University Hospital, Korea, and colleagues wrote. “Despite multimodality therapy, including surgery, external beam radiation and systemic chemotherapy, response rates to standard systemic therapies are [less than] 15% and long-term outcomes remain dismal, with no curative options for patients who have exhausted locoregional therapies.”
The researchers performed a phase 2, open-label trial of 16 patients with BRAF V600E-mutated cancers. All patients received 150 mg of dabrafenib twice daily and 2 mg of trametinib once daily until death, disease progression or unacceptable toxicity. The main outcome was overall response rate, and secondary endpoints were OS, PFS, duration of response and safety.
Median follow-up was 47 weeks (range, 4-120 weeks). All patients had previously undergone treatment in the form of radiation and/or surgery. Six patients had previously received systemic therapy.
Eleven patients responded to therapy (69%; 95% CI, 41-89), seven of which were ongoing. Due to the patients’ ongoing responses and subsequent lack of progression or deaths, secondary endpoints such as OS, PFS and duration of response were not met; however, the 12-month estimate for OS was 80%, PFS was 79% and duration of response was 90%. The safety population (n = 100) included seven rare tumor histologies. Fatigue was the most common adverse event (38%), followed by pyrexia (37%) and nausea (35%).
“Dabrafenib plus trametinib is a highly promising new combination targeted therapy for patients with BRAF V600E-mutated ATC, demonstrating a high OS, prolonged duration of response and prolonged survival with manageable toxicity,” the researchers wrote. “This is the first regimen to demonstrate robust clinical activity in BRAF V600E-mutated ATC.” – by Andy Polhamus
Disclosures: Keam reports no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.