Combined BRAF and MEK inhibition for the treatment of BRAF-mutated metastatic melanoma.

Combined BRAF and MEK inhibition out-performed BRAF inhibitor monotherapy in 3 randomized Phase 3 studies for BRAF-mutated metastatic melanoma patients and the combination of BRAF inhibitor dabrafenib with MEK inhibitor trametinib is now an FDA-approved treatment in this setting. Nevertheless, the majority of patients face progressive disease even when treated with the combination. Mechanisms of resistance to BRAF inhibition have been extensively investigated, whilst less is known about the specific mechanisms of resistance to combined therapy. The aim of this paper is to review the efficacy and safety of the combination of BRAF plus MEK inhibitors compared with BRAF inhibitor monotherapy and immunotherapy, as well as to discuss the existing evidence for the mechanisms of resistance to combined therapy and assess future treatment strategies to improve outcome based on data provided by clinical and translational research studies.