Recent advances of immunotherapy in lung cancer: anti-programmed cell death-1/programmed death ligand-1 antibodies

Encouraging data from the clinical trials of inhibiting programmed cell death-1 (PD-1)/programmed death-ligand (PD-L) pathway in recent years suggests improvement in the efficiency of immunotherapy in lung cancer. The interaction between PD-1 and its ligands, PD-L1 and PD-L2 as the second signal of the activation of T cells leads to the downregulation of T-cell responses and inhibit cytokine production. Blocking the PD-1/PD-L pathway can enhance antitumor immunity. Phase I clinical trials of anti-PD-1 or PD-L1 monoclonal antibodies showed promising safety and durable clinical activity in non-small-cell lung cancer. Currently, a lot of clinical trials of anti-PD-1/PD-L pathway monotherapy or combination therapy are ongoing. This review will focus on the mechanism of action of PD-1/PD-L pathway in antitumor immunity, in addition to the clinical activity and toxicity of anti-PD-1/PD-L1 monoclonal antibodies.