PDCD1 and melanoma: Since the approval of pembrolizumab, (brand name: Keytruda, also known as MK-3475 or lambrolizumab) a humanized IgG4 kappa anti-PD-1 antibody with a high affinity for the treatment of advanced melanoma, the clinical development of PD-1 and PD-L1 inhibitors as anticancer agents has expanded.