Bispecific antibodies targeting immunomodulatory checkpoints for cancer therapy

Advances in antibody engineering have led to the generation of more innovative antibody drugs,such as bispecific antibodies(bs Abs).Following the success associated with blinatumomab,bs Abs have attracted enormous interest in the field of cancer immunotherapy.By specifically targeting two different antigens,bs Abs reduce the distance between tumor and immune cells,thereby enhancing tumor killing directly.There are several mechanisms of action upon which bs Abs have been exploited.Accumulating experience on checkpoint-based therapy has promoted the clinical transformation of bs Abs targeting immunomodulatory checkpoints.Cadonilimab(PD-1×CTLA-4)is the first approved bs Ab targeting dual inhibitory checkpoints,which confirms the feasibility of bs Abs in immunotherapy.In this review we analyzed the mechanisms by which bs Abs targeting immunomodulatory checkpoints and their emerging applications in cancer immunotherapy.