QLF3108

QLF3108 is a bispecific antibody targeting Programmed Death-Ligand 1 (PD-L1) and 4-1BB (CD137), developed by Qilu Pharmaceutical. It is designed to simultaneously block the PD-1/PD-L1 inhibitory pathway and provide localized 4-1BB agonistic signaling within the tumor microenvironment. By binding to PD-L1 on tumor cells, QLF3108 facilitates the clustering and activation of 4-1BB on tumor-infiltrating lymphocytes, thereby enhancing anti-tumor immune responses while potentially minimizing systemic toxicities associated with traditional 4-1BB agonists. It is currently being evaluated in Phase 1 clinical trials for patients with advanced solid tumors.