Definition

An Fc-enhanced immunoglobulin G1 (IgG1) monoclonal antibody directed against the costimulatory receptor CD137 (4-1BB; tumor necrosis factor receptor superfamily member 9; TNFRSF9) covalently linked to a peptide mask, with potential immunostimulating and antineoplastic activities. Upon administration, anti-CD137 agonistic monoclonal antibody ADG206 is selectively activated in the tumor microenvironment (TME), and targets, binds to, and activates CD137 expressed on a variety of leukocyte subsets including activated T lymphocytes and natural killer (NK) cells. This enhances CD137-mediated signaling, induces cytokine production and promotes T-cell mediated anti-tumor immuneresponses. CD137, a surface glycoprotein of the tumor necrosis factor receptor superfamily, is an inducible costimulatory receptor that plays a key role in T-cell proliferation, survival and cytolytic activity.