Racial differences in serious immune-related adverse events among cancer patients receiving immune checkpoint inhibitors.

1621 Background: Immune checkpoint inhibitors (ICIs) are associated with an increased risk of adverse events (irAEs). We aimed to evaluate disparities in serious irAEs among patients from different racial backgrounds. Methods: We performed a propensity score-matched study using the TriNetX Analytics Network database, which includes de-identified data from over 140 healthcare institutions. We included adult cancer patients treated with ICIs and grouped patients into White, Black, Asian, and Hispanic cohorts. The outcomes were incident composite irAEs, which included pneumonitis, colitis, thyroiditis, hypophysitis, adrenal insufficiency, Stevens-Johnson syndrome (SJS) / toxic epidermal necrolysis (TEN), and hepatitis within 12 months of ICI. Patients were matched using variables: age, sex, ICI type, cancer type, metastatic disease, and underlying comorbidities. Results: We identified 72,501 cancer patients who received ICIs, including 56,937 White, 7,027 Black, 5,623 Asian, and 2,914 Hispanic patients. Cohorts were adequately balanced across covariates after matching. White and Hispanic patients showed similar risks of irAEs, both having approximately 30% higher risk of developing serious irAEs compared with Black and Asian patients. Compared with Black patients, White and Hispanic patients had higher risks of colitis and adrenal insufficiency. Compared with Asian patients, White and Hispanic patients had higher risks of pneumonitis, colitis, and thyroiditis. Conclusions: White and Hispanic patients have the highest risks of developing serious irAEs. Further research is needed to explore the underlying causes and develop targeted interventions to mitigate these disparities. Hazard ratio for the effects of race on irAEs. White vs. Black White vs. Asian White vs. Hispanic Black vs. Asian Hispanic vs. Black Hispanic vs. Asian Outcomes n=7,207 each n=5,562 each n=3,314 each n=3,839 each n=2,680 each n=2,224 each Composite irAE 1.28 (1.16-1.41) 1.30 (1.16-1.45) 1.03 (0.91-1.18) 0.95 (0.82-1.10) 1.30 (1.11-1.52) 1.39 (1.16-1.67) Pneumonitis 1.55 (0.77-3.12) 1.93 (0.93-4.01) 1.01 (0.42-2.44) 0.68 (0.24-1.91) 2.86 (0.78-11.1) 4.35 (0.96-20.0) Colitis 1.44 (1.27-1.63) 1.72 (1.47-2.00) 1.04 (0.88-1.23) 1.12 (0.91-1.34) 1.22 (0.99-1.52) 1.69 (1.32-2.17) Thyroiditis 1.01 (0.81-1.25) 1.61 (1.19-2.17) 1.09 (0.81-1.47) 1.31 (0.91-1.89) 1.41 (0.98-2.04) 1.85 (1.19-2.86) Hypophysitis 0.34 (0.07-1.67) 0.50 (0.05-5.56) 0.68 (0.11-4.04) 2.00 (0.37-10.9) 0.65 (0.11-3.85) 1.47 (0.24-9.09) Adrenal insufficiency 1.70 (1.13-2.55) 1.18 (0.79-1.75) 1.10 (0.69-1.77) 0.64 (0.36-1.11) 2.50 (1.20-5.26) 0.89 (0.48-1.67) SJS/TEN 0.61 (0.15-2.54) 0.05 (0.01-0.40) 0.76 (0.17-3.40) 0.51 (0.15-1.68) 1.43 (0.24-8.33) 0.33 (0.07-1.61) Hepatitis 1.11 (0.88-1.40) 0.74 (0.59-0.93) 0.88 (0.67-1.16) 0.68 (0.50-0.91) 1.41 (0.99-2.00) 0.97 (0.69-1.37)