Dabrafenib and Trametinib Combination as a Neoadjuvant Strategy in BRAF-positive Anaplastic Thyroid Cancer

The aim of the study was to evaluate the effectiveness of combination therapy with dabrafenib and trametinib (anti-BRAF and anti-MEK inhibitors) in the neoadjuvant treatment of BRAF-positive anaplastic thyroid cancer. The prognosis in patients with ATC is poor due to the rapid and invasive tumor growth and the rapid development of metastases. Dabrafenib is an antineoplastic agent, a selective RAF kinase inhibitor that competes with ATP. Oncogenic substitutions of the amino acid valine at position 600 (V600) BRAF lead to constitutive activation of the RAS / RAF / MEK / ERK pathway and stimulation of tumor cell growth. Trametinib is a reversible, highly selective, allosteric inhibitor of the activation of mitogen-activated, extracellular signal-regulated kinases 1 (MEK1) and 2 (MEK2). Dabrafenib and trametinib inhibit two kinases in the signaling pathway, BRAF, and MEK. The combination of the two drugs provides effective inhibition of proliferative signal conduction. The investigators hypothesize that the combination treatment with these two drugs - dabrafenib and trametinib - can improve the response rate in the neoadjuvant mode in ATC without significant regimen-limiting toxicity and with better follow-up locoregional control.