A Fc-modified monoclonal antibody directed against the human T-cell receptor cytotoxic T-lymphocyte-associated antigen 4 (CTLA4; CTLA-4), with potential immune checkpoint inhibitory and antineoplastic activities. Upon administration, anti-CTLA4 monoclonal antibody BMS-986218 targets and binds to CTLA4 expressed on T-cells and inhibits the CTLA4-mediated downregulation of T-cell activation. This leads to a cytotoxic T-lymphocyte (CTL)-mediated immune response against cancer cells. CTLA4, an inhibitory receptor and member of the immunoglobulin superfamily, plays a key role in the downregulation of the immune system. Removal of the fucose sugar units from the antibody's Fc region, enhances its activity and decreases the toxicity of BMS-986218.