BRAF and melanoma: In 2014, pembrolizumab, a humanized IgG4 anti-PD-1 antibody, and nivolumab, a fully human IgG4 anti-PD-1 monoclonal antibody (mAb), were approved in the United States for second- or third-line treatment of patients with AM that was refractory to ipilimumab (BRAF wild-type melanoma) or to ipilimumab and BRAF inhibitors (BRAF V600-mutated melanoma).