BI 770371

BI 770371 is a next-generation human IgG1 monoclonal antibody that acts as an antagonist of signal-regulatory protein alpha (SIRPα), targeting both the V1 and V2 allelic variants. SIRPα interacts with CD47 on tumor cells to deliver a "don't eat me" signal that inhibits macrophage-mediated phagocytosis and allows cancer cells to evade the innate immune system. By blocking this interaction, BI 770371 enhances innate immunity and restores myeloid cell function in the tumor microenvironment. The drug is being developed primarily for solid tumors—including head and neck squamous cell carcinoma—and metabolic dysfunction-associated steatohepatitis (MASH), liver cirrhosis, fibrosis, and other cardiovascular-renal-metabolic diseases. It has been evaluated as monotherapy and in combination with PD-1 inhibitors such as ezabenlimab or pembrolizumab[2][5][6][9].