BSI-507

BSI-507 is a first-in-class bispecific antibody developed by Biosion that targets both PD-1 (Programmed cell death protein 1) and PVRIG (Poliovirus receptor-related immunoglobulin domain-containing, also known as CD112R). The drug is designed to block both the PD-1 and PVRIG immune checkpoint pathways, thereby enhancing the reversal of T cell inhibition in cancer immunotherapy. By simultaneously inhibiting these two pathways, BSI-507 aims to improve anti-tumor immune responses beyond what can be achieved with single-target agents. The molecule was discovered using Biosion’s H³ antibody discovery platform and has demonstrated favorable biophysical and functional characteristics in preclinical studies, supporting its progression toward manufacturing and IND-enabling activities[3][5][6].