Abstract
BACKGROUND: Patients with anaplastic thyroid cancer (ATC) have a dismal prognosis, despite systemic cytotoxic chemotherapy. The objective of this study was to investigate the efficacy and safety of targeted therapy in ATC patients when used outside of a clinical trial. METHODS: This is a retrospective review from April 2015 to May 2016 at a single academic institution where 16 ATC patients receiving targeted therapy outside of a clinical trial were studied. Ten patients (eight BRAF wild type and two BRAF(V600E) mutant tumors) were started on lenvatinib, and six with BRAF(V600E)-mutated tumors received a combination of dabrafenib plus trametinib. Best response evaluated by RECIST v1.1, progression-free survival, and overall survival were determined. Adverse events were evaluated for safety. RESULTS: The majority of patients (63%) were men, and all had distant metastases or radiation-resistant primary disease at the time of treatment. In the entire cohort, 6/16 (38%) had a partial response, 6/16 (38%) had stable disease, and 2/16 (12%) had progressive disease. Two (12%) patients died before restaging. Median follow-up time was 11.8 months. Median progression-free survival was 3.7 months [confidence interval 1.8-7.6] in the entire cohort, 2.7 months for lenvatinib, and 5.2 months for dabrafenib plus trametinib. Median OS was 6.3 months [confidence interval 1.8-7.6] for the entire cohort, 3.9 months for lenvatinib, and 9.3 months for dabrafenib plus trametinib. Adverse events were as expected and manageable. CONCLUSIONS: Targeted therapies, lenvatinib, and dabrafenib plus trametinib (for BRAF(V600E) mutants) may provide clinical benefit in ATC patients who are unable to participate in clinical trials, and toxicities are manageable.