A humanized, agonistic monoclonal antibody against P selectin glycoprotein ligand-1 (PSGL-1; SELPLG; CD162), with potential immunosuppressive activity. Upon administration, neihulizumab specifically targets and binds to CD162 expressed on activated T-lymphocytes. This induces apoptosis of activated T-cells and reduces T-cell-mediated immune responses. This may halt disease progression of T-cell-mediated autoimmune diseases and acute graft-versus-host disease (GvHD).