A Population-based Study of Immunotherapy-related Toxicities in Lung Cancer.

BACKGROUND: Population-level data regarding incidences of immune-related adverse events (irAEs) are lacking. This study evaluated the frequencies of irAEs among patients with non-small-cell lung cancer (NSCLC) who received immune checkpoint inhibitors. PATIENTS AND METHODS: Administrative claims data from a large United States commercial insurance database (OptumLabs Data Warehouse) were used to retrospectively identify patients with NSCLC between January 1, 2015 and December 31, 2017 who received a programmed death-ligand 1/programmed cell death protein-1 (PD(L)-1) inhibitor. Cumulative risks for irAEs were estimated at 1, 3, 6, 9, and 12 months after initiation of a PD-(L)1 inhibitor. Additionally, associations between patient characteristics and frequency of irAEs were investigated utilizing multivariate logistic modeling.
RESULTS: The risk of developing any irAE was 52.5% (95% confidence interval, 49.9%-55.2%) after 12 months in 3164 patients with NSCLC who initiated a PD-(L)1 inhibitor (median age, 69.0 years; 1763 [55.7%] males; 1401 [44.3%] females). Cumulative risks of irAEs increased over time: pneumonitis was recorded in 2.5% of patients 1 month after initiation of treatment, and increased to 14.3% after 9 months. Risks of hypophysitis and pericarditis were 3.6% and 1.7% at 9 months, respectively. Patients who received PD-(L)1 inhibitors in the first line had lower frequencies of irAEs (hazard ratio, 0.77; 95% confidence interval, 0.67-0.87).
CONCLUSION: Our findings suggest that the frequencies of some irAEs may be higher than the rates reported in the pivotal trials that led to United States Food and Drug Administration approvals for PD-(L)1 inhibitors. These real-world data refine provider and patient expectations for outcomes in a broader population beyond what is observed in clinical trials.