BRAF and melanoma: Based on their similar mechanism of action and efficacy, nivolumab and pembrolizumab are considered interchangeable.9, 10, 11, 12 TTs have a different mechanism of action,13 as the selective BRAF inhibitors (e.g. dabrafenib) and MEK inhibitors (e.g. trametinib) block cancer cell proliferation in melanomas driven by a mutated BRAF gene (BRAF-mt), which is present in 40%-60% of melanomas.14