A genetically engineered, fully humanized immunoglobulin G4 monoclonal antibody that binds to the PD-1 RECEPTOR, activating an immune response to tumor cells. It is used as monotherapy or in combination with IPILIMUMAB for the treatment of advanced malignant MELANOMA. It is also used in the treatment of advanced or recurring NON-SMALL CELL LUNG CANCER; RENAL CELL CARCINOMA; and HODGKIN'S LYMPHOMA.