sitrelimab

Sitrelimab (HMPL-309) is a humanized IgG1 monoclonal antibody that targets programmed death-ligand 1 (PD-L1). Developed by HUTCHMED, it is designed to block the interaction between PD-L1 and its receptors, programmed cell death protein 1 (PD-1) and B7.1 (CD80). By inhibiting this checkpoint pathway, sitrelimab aims to restore and enhance T-cell-mediated anti-tumor immune responses, which are often suppressed in the tumor microenvironment. The drug has been investigated in Phase 1 clinical trials, specifically in China, for the treatment of patients with advanced malignant solid tumors to evaluate its safety, pharmacokinetics, and preliminary efficacy.