Racial disparities in immune‑related adverse events with immune checkpoint inhibitors: A systematic review and meta‑analysis

Background: There is insufficient data on whether immune‑related adverse events (irAEs) from immune checkpoint inhibitors (ICIs) differ by race/ethnicity. The objective of our study was to systematically evaluate the incidence of irAEs by race to inform equitable treatment approaches. Methods: We searched PubMed/MEDLINE and Embase from inception through December 16, 2024 for randomized trials and cohort studies in adults receiving ICIs. Race‑specific incidence was pooled using a generalized linear mixed‑effects proportional meta‑analysis. Within‑study odds ratios (ORs) versus White were pooled with random‑effects inverse‑variance models; heterogeneity was summarized with I² and inspected with leave‑one‑out analyses. Subgroup analyses were conducted based on ICI class (PD‑1 monotherapy and dual PD-1/CTLA-4 therapy), tumor type (lung cancer), and study design (excluding organ-specific irAE reports and excluding registry-based database studies). Results: Of the 3,397 records screened, 510 full-text articles were assessed for eligibility, and 24 studies comprising 109,902 patients were included in the analysis. In the overall population, the pooled incidence of irAEs was 13.7% (95% CI, 2.7-47.5) in Asian, 20.6% (8.6-41.7) in Black, 16.0% (5.1-40.5) in Hispanic, and 20.5% (11.1-34.8) in White patients, with substantial heterogeneity (I²=85.7-99.8%). Pooled ORs versus White were not statistically significant: non‑White 1.28 (95% CI 0.82-1.98), Asian 1.67 (0.76-3.70), Black 1.37 (0.83-2.27), and Hispanic 0.89 (0.55-1.42); all p>0.05. Findings showed a consistent trend across the ICI-class subgroups, the lung-cancer subgroup, and the subgroup excluding registry-based studies. Conclusion: No significant differences in irAEs were observed among races. These findings support equitable access to ICI therapy and culturally competent toxicity monitoring. Pooled incidence of irAEs and odds ratios (ORs) by race. Abbreviation: NA, not applicable Overall population Sensitivity analysis, excluding studies reporting only organ-specific irAEs Race Incidence % (95% CI) I² (%) OR vs White (95% CI) p I² (%) Incidence % (95% CI) I² (%) OR vs White (95% CI) p I² (%) Asian (n=3516) 13.7 (2.7-47.5) 98.1 1.67 (0.76-3.70) 0.20 80.7 63.0 (57.6-68.3) 0.0 0.97 (0.40-2.37) 0.95 75.4 Black (n=8864) 20.6 (8.6-41.7) 98.3 1.37 (0.83-2.27) 0.45 94.8 43.4 (34.0-53.3) 94.0 1.37 (0.57-3.30) 0.47 94.8 Hispanic (n=638) 16.0 (5.1-40.5) 85.7 0.89 (0.55-1.42) 0.61 66.5 43.5 (39.1-47.9) 33.2 0.41 (0.18-0.93) 0.03 NA White (n=86676) 20.5 (11.1-34.8) 99.8 NA NA NA 40.0 (29.8-51.2) 98.7 NA NA NA Non-White (n=14565) NA NA 1.28 (0.82-1.98) 0.27 94.6 NA NA 1.15 (0.66-2.01) 0.62 93.1