HB-1275

HB-1275 is an orally bioavailable, small molecule antagonist of V-domain Ig suppressor of T cell activation (VISTA), an immune checkpoint protein that plays a critical role in maintaining an immunosuppressive tumor microenvironment. VISTA is predominantly expressed on myeloid-derived suppressor cells (MDSCs) and regulatory T cells, where it functions to inhibit T cell activation and proliferation. By blocking VISTA signaling, HB-1275 aims to reprogram the immune landscape within tumors, promoting the activation and infiltration of effector T cells. Developed by HiberCell, HB-1275 is currently being investigated in Phase 1/2 clinical trials for the treatment of advanced solid tumors, both as a monotherapy and in combination with other immunotherapies such as PD-1 inhibitors, to address mechanisms of resistance in cold or poorly responsive tumors.