Dabrafenib and Trametinib Therapy for Advanced Anaplastic Thyroid Cancer- Real-World Outcomes From UK Centres

Aims: Anaplastic thyroid cancer (ATC) is a rare but aggressive form of thyroid cancer with a median survival of 4 months. Recent advances in molecular profiling have shown that up to half of ATCs harbour the BRAF-V600E mutation. The aim of this study was to provide real-world data and experience on the use of combination therapy dabrafenib and trametinib in patients with BRAF-V60 0E-mutated advanced ATC.Materials and methods: We retrospectively evaluated patients with confirmed BRAF-V60 0E-mutated ATC, defined as patients with locally advanced or met-astatic ATC with no locoregional, radical treatment options. Outcomes measured were overall survival, progression-free survival, response rate, discontinuation rate, dose reduction rate and toxicity data.Results: Seventeen patients were evaluated and the mean age was 68 years. Ten patients died by the time of censoring. The median duration of follow-up was 12 months (3-43 months). The estimated median overall survival was 6.9 months (95% confidence interval 2.46 months -upper confidence interval not reached) and the median progression-free survival was 4.7 months (95% confidence interval 1.4-7.8 months). Dose interruptions and/or reductions were common, but none of the patients had to permanently discontinue treatment because of toxicities. Severe toxicities (grades 3 and 4) were uncommon.Conclusions: This study supports the indication of dabrafenib and trametinib in BRAF-V60 0E-mutated ATC as an effective and well-tolerated treatment in an historically difficult to treat cancer.(c) 2022 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.