Efficacy and safety of immune checkpoint inhibitor monotherapy in pretreated elderly patients with non-small cell lung cancer.

Purpose: Immune checkpoint inhibitors (ICIs) are an effective subsequent-line treatment for patients with advanced non-small cell lung cancer (NSCLC). However, it remains unclear whether the efficacy and safety of subsequent-line ICI monotherapy in elderly patients (aged ≥ 75 years) are similar to that in non-elderly patients. Therefore, we aimed to investigate the efficacy and safety of ICI monotherapy in pretreated elderly patients with NSCLC.

Methods: Between January 2016 and February 2018, 131 elderly patients with advanced NSCLC who received subsequent-line ICI monotherapy at 13 Japanese institutions were enrolled in this study. Baseline characteristics, the efficacy of ICI treatment, and adverse events were evaluated.

Results: Ninety-eight men and 33 women (median age 77 [range 75-87] years) were enrolled. Among those who received subsequent-line ICI monotherapy, the overall response, disease control rates, median progression-free survival (PFS), and overall survival (OS) were 27.4%, 61.8%, 4.5 months, and 16.0 months, respectively. Adverse events such as anorexia, fatigue, pneumonitis, and hypothyroidism were observed. There were two treatment-related deaths due to pneumonitis and thrombocytopenia. Subsequent-line ICI monotherapy in patients with good performance status (PS), receiving steroids for immune-related adverse events (irAEs), and exhibiting partial response (PR) was associated with improved PFS, as well as OS in patients with good PS and PR.

Conclusions: Subsequent-line ICI monotherapy in elderly patients, with previously treated NSCLC, was effective, safe and showed outcomes equivalent to those in non-elderly patients. Immunotherapy provides a survival benefit for elderly patients, who exhibit its efficacy and a favorable general condition.