NCIt definition : A monoclonal antibody directed against the negative immunoregulatory human cell receptor
programmed cell death protein 1 (PD-1; PDCD1; CD279), with potential immune checkpoint
inhibitory and antineoplastic activities. Upon administration, anti-PD-1 monoclonal
antibody SHR-1901 targets, binds to and inhibits PD-1 and its downstream signaling
pathways. This may restore immune function through the activation of T-cells and T-cell-mediated
immune responses against tumor cells. PD-1, a transmembrane protein in the immunoglobulin
superfamily (IgSF) expressed on T-cells, functions as an immune checkpoint that negatively
regulates T-cell activation and effector function when activated by its ligands, programmed
cell death-1 ligand 1 (PD-L1; B7-H1; CD274) and 2 (PD-L2). PD-1 plays an important
role in tumor evasion from host immunity.;