Geptanolimab (Anti-PDCD1 / PD-1 / CD279) is an immunoglobulin G4 (IgG4) humanized monoclonal antibody directed against the negative immunoregulatory human cell surface receptor programmed cell death 1 (PD-1, PD1, PDCD1, CD279) with potential immune checkpoint inhibitory and antineoplastic activities. MW: 144.4 KD.