NCIt definition : A monoclonal antibody directed against the negative immunoregulatory human cell surface
receptor programmed cell death 1 (PD-1, PCD-1; PDCD1), with potential immune checkpoint
inhibitory and antineoplastic activities. Upon administration, anti-PD-1 monoclonal
antibody ABBV-181 targets and binds to PD-1, thereby blocking its binding to the PD-1
ligand, programmed cell death-1 ligand 1 (PD-L1), and preventing the activation of
PD-1/PD-L1 downstream signaling pathways. This may restore immune function through
the activation of cytotoxic T-lymphocytes (CTLs). PD-1, a transmembrane protein in
the immunoglobulin superfamily expressed on activated T-cells, negatively regulates
T-cell activation and effector function when activated by its ligand; it plays an
important role in tumor evasion from host immunity.;