Background：Toripalimab is an anti-PD-1 monoclonal antibody developed for its ability to block PD-1 interactions with its ligands, PD-L1 and PD-L2, and for enhanced receptor endocytosis function. PD-L1 and PD-L2 are tumor checkpoint proteins which recognize the PD-1 receptor on T cells and exhaust their anti-tumor activity. Blocking PD-1 interactions with PD-L1 and PD-L2 is thought to recharge the immune system’s ability to attack and kill tumor cells.
