This pilot phase 2 study evaluates the effectiveness and safety of the Rechallenge concept in patients with BRAF-positive anaplastic thyroid cancer after progression on anti-BRAF therapy. Patients with BRAF-positive anaplastic thyroid cancer who were previously treated with dabrafenib and trametinib (with a clinical or objective response at the start of treatment) and later with tumor progression during anti-BRAF therapy and subsequent lines of chemotherapy are scheduled to undergo targeted therapy (repeated administration of dabrafenib and trametinib in standard doses) and evaluate the outcomes according to the primary and secondary endpoints.
immunohistochemically verified anaplastic thyroid cancer;
presence of a mutation in the BRAF V600 gene;
documented progression during targeted therapy with dabrafenib + trametinib;
documented progression during at least one line of chemotherapy (use of taxane-containing chemotherapy is mandatory);
primary resistance (absence of initial clinical and radiological response to therapy with dabrafenib and trametinib (response criteria - primary objective response according to RECIST 1.1 criteria and duration of response of at least 3 months);
absence of taxane-containing chemotherapy as second or third line;
contraindication to taking any of the study drugs (including severe toxicity that occurred during a previous dose, which led to discontinuation of treatment);
patients with unsatisfactory functional status (ECOG 3-4);