GSK3903371

GSK3903371 is an investigational monoclonal antibody that targets interleukin-1 receptor accessory protein (IL1RAP), a co-receptor for IL-1 family cytokine signaling that is overexpressed on certain tumor cells and tumor-associated stroma and is implicated in tumor growth and immunosuppression. By binding IL1RAP and inhibiting its function, GSK3903371 is designed to block IL-1–mediated pro‑tumor inflammatory signaling within the tumor microenvironment, thereby reducing tumor proliferation and potentially enhancing anti-tumor immune responses. The antibody was originally developed by GSK and has been out-licensed to Boston Pharmaceuticals (asset name BOS-371) for further development in oncology indications, particularly solid tumors where IL1RAP is a tumor-associated antigen driving disease biology.[1][3][5][9][11][12]