Clinical trials investigating immune checkpoint inhibitors in non-small-cell lung cancer

Introduction: Non-Small Cell Lung Cancer (NSCLC) is an aggressive malignancy with poor overall survival that accounts for up to 85% of lung cancer diagnoses. The use of immunotherapy in the form of checkpoint inhibition, to enhance the immune system’s ability to attack malignant cells, has been a promising addition to treatment options in advanced NSCLC. Results: Such therapeutic agents aimed at the Programmed Death 1 (PD-1) receptor or Programmed Death Ligand 1 (PD-L1) have revealed promising results against many types of cancer including NSCLC. Examples of these agents include nivolumab, pembrolizumab, BMS-936559, atezolizumab, and MEDI4736, of which the first two are approved by US FDA in the second line treatment of advanced NSCLC. Discussion: Impressive improvements in objective responses from PD-1 blockade were found in both first line therapy as well as treatment after progression on platinum based therapy. In addition, the safety profile is favorable with significantly lower grade 3-4 adverse events compared to standard of care. The optimal selection criteria and factors that show an increased response to therapy are still being determined.