Stage 1: To select the optimal dose of naporafenib + trametinib to be studied in Stage 2. Stage 2: To compare progression free survival (PFS) and overall survival (OS) for patients with NRAS-mutant (NRASm) melanoma who are randomized to receive the combination of naporafenib + trametinib to that of patients who are randomized to physician's choice of therapy (dacarbazine, temozolomide, or trametinib monotherapy).