Immunotherapy in previously treated non-small cell lung cancer (NSCLC).

Treatment with immunotherapy has made a significant impact in the outcomes for those individuals diagnosed with metastatic non-small cell lung cancer (NSCLC) and its use is currently an established treatment modality. In light of recent advances in immunotherapy, improved survival, particularly for patients with stage IV NSCLC, has been reported with durable and prolonged responses in a subset of patients. Immune check point inhibitors, which include nivolumab, pembrolizumab, and atezolizumab, are standard treatment options in the salvage setting. Nivolumab and atezolizumab are approved for patients regardless of programmed death-ligand 1 (PD-L1) expression, whereas pembrolizumab requires tumor PD-L1 expression at the cut-off ≥1%. In this review, we will outline the clinical development of immunotherapy in previously treated NSCLC, current challenges and discuss novel treatment strategies.