Research progress in immune checkpoint inhibitors for lung cancer in China

Immune checkpoint inhibitors (ICIs) have come to play an increasingly prominent role in the treatment of lung cancer, and some are recommended as a first-line treatment for late-stage non-small-cell lung cancer, either as a monotherapy or in combination with chemotherapy. Accordingly, the indications of Food and Drug Administration-approved ICIs have increased. In this background, China has implemented various policies to encourage and accelerate the marketing of domestic and imported innovative antitumor drugs. Eight ICIs have been approved in China. Among these, four imported programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors have received approval for six indications, and one domestic PD-1 inhibitor has received approval for one indication for lung cancer in 2018. Numerous clinical trials of ICIs for lung cancer are underway in China. This review aims to summarize the recent advances and future directions of ICIs, including PD-1 inhibitors, PD-L1 inhibitors, cytotoxic T lymphocyte-associated antigen-4 inhibitors, bi-specific antibodies, and a novel inhibitor of T-cell immune-receptor with Ig and immunoreceptor tyrosine-based inhibitory motif domains in immunotherapies for lung cancer in China.