Neoadjuvant Immunotherapy for Non-Small Cell Lung Cancer

Immune checkpoint blockade (ICB) has improved outcomes for patients with advanced non-small cell lung carcinoma (NSCLC). Building off of this, it has been hypothesized that the utilization of ICB early during the disease course may be advantageous, particularly in the neoadjuvant setting prior to definitive surgical resection. Preclinical studies have suggested that a more potent immune response may be induced by neoadjuvant ICB in the presence of a higher antigen burden and intact tumor draining lymph nodes. Recent clinical trials evaluating neoadjuvant ICB with or without chemotherapy combinations in patients with resectable NSCLC led to improved pathological responses and longer event-free survival when neoadjuvant ICB was added to chemotherapy. Surgical outcomes were also supportive of this approach, with encouraging rates of pathological downstaging. Additionally, the availability of pre-treatment biopsy samples and post-treatment surgical resection tissues facilitates the conducting of correlative studies that continue to improve our understanding of the mechanisms of response and resistance to ICB. As long-term survival outcomes from ongoing clinical trials are awaited, several important questions require further investigation, including the optimal duration of neoadjuvant therapy, the clinical endpoints most predictive of long-term outcomes, and translational studies that should be investigated in future trial designs. Additionally, the optimal clinical management of patients with residual disease at the time of surgical resection and those who experience recurrence remains to be determined. In this review, we will (1) discuss the rationale behind neoadjuvant ICB-based therapy in NSCLC, (2) summarize the clinical data available thus far, and (3) highlight unanswered questions that need to be addressed in future studies to maximize the clinical benefits of this approach.