Impact of race/ethnicity and the presence of immune-related adverse events on outcomes for non-small cell lung cancer patients treated with immune checkpoint inhibitors

Background: Immune checkpoint inhibitors (ICIs) have changed the treatment landscape for non-small cell lung cancer, but the role of race/ethnicity is not well understood. Design: This is a retrospective study of non-small cell lung cancer (NSCLC) patients receiving ICI. Objective: We evaluated the role of race/ethnicity in ICI response and immune-related adverse events (irAEs) in NSCLC patients. Methods: NSCLC patients treated with ICIs from 2014 to 2022 at Los Angeles General Medical Center and Norris Comprehensive Cancer Center were included. Primary endpoints were irAE incidence, time on ICI treatment (TOT), overall survival (OS), and progression-free survival (PFS). TOT, OS, and PFS were evaluated using the Kaplan–Meier method. Landmark analysis was performed of patients receiving >6 month ICIs. Fisher’s exact test was performed for analysis of variables between groups. Results: In total, 211 NSCLC patients receiving ICIs were analyzed, including 86 (40.8%) Asian American/Pacific Islander (AAPI), 65 (30.8%) non-Hispanic White/Caucasian (NHW), 37 (17.5%) Hispanic/Latino (HIS), and 23 (10.9%) African American/Black (AA). Among stage IV patients, median OS for AAPI was 23.2 months (95% confidence interval (CI) 16.0–not reached (NR)), 23.6 months (95% CI 6.9–38.8) for NHW, 12.7 months for AA (95% CI 2.2–37.0), and 11.0 months (95% CI 4.8–14.8) for HIS ( p = 0.008). Median TOT and PFS were similar among race/ethnicities. 48.3% of AAPI developed irAE versus 27.3% for AA, 27.0% for HIS, and 39.4% for NHW. Landmark analysis showed that AAPI had longer median OS 60.6 months (95% CI 20.6–NR), while HIS had shorter median OS 15.4 months (95% CI 8.9–NR; p < 0.01). Among patients who experienced irAEs, median OS for AAPI was 60.6 months (95% CI 20.6–NR), compared to NHW at 48.4 months (95% CI 20.5–NR), AA at 35.7 months (95% CI 2.2–NR), and HIS at 15.2 months (95% CI 6.3–31.0; p = 0.0211). There was no difference in median OS among patients who did not experience irAEs. Multivariate analysis for OS in stage IV patients showed that HIS versus AAPI (hazard ratio: 2.27; 95% CI 1.30–3.95) was a significant variable. Conclusion: Our study demonstrates that AAPIs and NHW had higher irAE incidence and longer OS. Validation studies evaluating the role of race/ethnicity in ICI response and toxicity are merited.