PD-L1 trap

**PD-L1 trap** is a recombinant fusion protein designed to block PD-L1 (Programmed death-ligand 1) in the tumor microenvironment, thereby enhancing antitumor immune responses. The molecule consists of the extracellular domain of PD-1 fused to a trimerization domain, achieving high affinity for PD-L1. Unlike monoclonal antibodies, the PD-L1 trap is transiently and locally expressed via delivery of its coding plasmid in a lipid-protamine-DNA nanoparticle system, favoring targeted action within tumors and reducing systemic immune-related adverse effects. Its primary indication is for cancer immunotherapy, particularly in combination with chemotherapy such as oxaliplatin[1].