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

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. 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. 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. 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.