152P A phase I study of HBM4003, an anti-CTLA-4 heavy chain only monoclonal antibody, in combination with toripalimab in advanced melanoma

HBM4003 is a fully human heavy chain only monoclonal antibody targeting CTLA-4. In addition to blocking the CTLA-4 pathway, HBM4003 is also engineered to deplete Treg cells by enhanced antibody-dependent cellular cytotoxicity (ADCC) activity that was clinically validated. Here we reported updated results of a phase I study that evaluated HBM4003 plus toripalimab (anti-PD-1 antibody) in advanced melanoma.