Real-world use and survival outcomes of immune checkpoint inhibitors in older adults with non–small cell lung cancer

Background: Limited data exist regarding the characteristics and survival outcomes of older adults with non–small cell lung cancer (NSCLC) who receive immune checkpoint inhibitors in routine oncology practice. Methods: Using the Surveillance, Epidemiology, and End Results–Medicare linked database, we identified 1256 patients aged ≥65 years who were diagnosed with pathologically confirmed stage I to stage IV NSCLC between 2002 and 2015 and initiated nivolumab or pembrolizumab in 2016. We examined patient characteristics and overall survival from the time of immune checkpoint inhibitor initiation through December 31, 2017. Results: The median patient age at the time of immune checkpoint inhibitor initiatiton was 75.3 years (interquartile range, 8.5). A substantial percentage of patients were initially diagnosed with stage IV disease (42.6%) and had ≥2 comorbid conditions (48.7%). Using a claims-based proxy, 11.5% of patients had poor performance status and 12.6% had a history of autoimmune conditions. The median overall survival after initiation of immune checkpoint inhibitor was 9.3 months (95% CI, 8.5-10.5 months). The 1-year survival rate was 43.0% (95% CI, 40.2-45.7%). In multivariable analyses, multiple comorbid conditions, squamous histology, a history of nonplatinum doublet systemic therapy, recent radiotherapy, and a shorter time from initial diagnosis to treatment initiation were found to be statistically significantly associated with an increased hazard of death. Demographics, poor performance status, and prior autoimmune conditions were not significantly associated with the hazard of death. Conclusions: Many older adults with NSCLC who initiated immune checkpoint inhibitors had multiple comorbidities, a history of autoimmune disease, or poor performance status. Factors associated with poor prognosis among patients with advanced NSCLC were also associated with worse survival in older adults treated with immune checkpoint inhibitors.