Toripalimab, a recombinant, humanized programmed death receptor-1 (PD-1) 
monoclonal antibody that binds to PD-1 and prevents binding of PD-1 with 
programmed death ligands 1 (PD-L1) and 2 (PD-L2), is being developed by Shanghai 
Junshi Bioscience Co., Ltd in China for the treatment of various cancers. In 
December 2018, based on positive efficacy results of a phase 2 trial and safety 
data from several clinical studies, toripalimab received conditional approval in 
China for the treatment of unresectable or metastatic melanoma that has failed 
previous systemic therapy. This article summarizes the milestones in the 
development of toripalimab leading to this first global approval for the 
treatment of unresectable or metastatic melanoma.