Neoadjuvant immunotherapy for non-small cell lung cancer: State of the art

Lung cancer mortality has decreased over the past decade and can be partly attributed to advances in targeted therapy and immunotherapy. Immune checkpoint inhibitors (ICIs) have rapidly evolved from investigational drugs to standard of care for the treatment of metastatic non-small cell lung cancer (NSCLC). In particular, antibodies that block inhibitory immune checkpoints, such as programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1), have revolutionized the treatment of advanced NSCLC, when administered alone or in combination with chemotherapy. Immunotherapy is associated with higher response rates, improved overall survival (OS), and increased tolerability compared with conventional cytotoxic chemotherapy. These benefits may increase the utility of immunotherapy and its combinational use with chemotherapy in the neoadjuvant treatment of patients with NSCLC. Early findings from various ongoing clinical trials suggest that neoadjuvant ICIs alone or combined with chemotherapy may significantly reduce systemic recurrence and improve long-term OS or cure rates in resectable NSCLC. Here we further summarize the safety and efficacy of various neoadjuvant treatment regimens including immunotherapy from ongoing clinical trials and elaborate the role of neoadjuvant immunotherapy in patients with resectable NSCLC. In addition, we discuss several unresolved challenges, including the evaluations to assess neoadjuvant immunotherapy response, the role of adjuvant treatment after neoadjuvant immunotherapy, the efficacy of treatment for oncogenic-addicted tumors, and predictive biomarkers. We also provide our perspective on ways to overcome current obstacles and establish neoadjuvant immunotherapy as a standard of care.