Phase 1 Safety and Tolerability of MEDI4736 in Combination With Dabrafenib and Trametinib or With Trametinib Alone

Inclusion Criteria: * Adults \>= 18 years old * Histologically confirmed cutaneous melanoma that is either Stage IIIc (unresectable) or Stage IV (metastatic) and determined to be BRAF V600E or V600K mutation-positive (cohort A) or mutation-negative (cohorts B and C) * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Measurable disease by radiographic or physical examination * Adequate organ and marrow function * Willingness to provide consent for biopsies positive or BRAF WT measurable disease and adequate organ and marrow function Exclusion Criteria: * Prior treatment with a BRAF inhibitor or MEK inhibitor * Any prior Grade \>= 3 immune-related adverse event while receiving immunotherapy * Active or prior documented autoimmune disease within the past 2 years * History of or current risk for retinal vein occlusion (RVO) or central serous retinopathy (CSR) * History of or current cardiovascular risk including myocardial infarction, \>= Class II congestive heart failure, uncontrolled arrhythmias, or refractory hypertension * Active, untreated central nervous system (CNS) metastases * Women who are pregnant or lactating