Introduction: Among racial and socioeconomic minorities not appropriately represented by trial populations, rates of immune-related adverse events (irAEs) are unclear.

Objective: We sought to characterise factors associated with irAEs in adult cancer patients at Boston Medical Center, a safety-net hospital serving a diverse patient population, including racial and ethnic minorities.

Methods: We performed a retrospective study on all adult cancer patients at Boston Medical Center treated with first-line immune checkpoint inhibitors (ICIs) between 7/1/15 and 6/30/22. Baseline demographic (including socioeconomic) and oncologic variables were collected.

Results: From the overall cohort (n = 469), 34 patients (n = 34, 7%) on first-line ICI without prior chemotherapy developed at least one ICI toxicity. Toxicity was experienced in 10% of White patients, 5% of Black patients, 7% of Hispanic patients, 7% of non-Hispanic patients, 9% of public insurance recipients and 7% of private insurance recipients. When comparing those who sustained irAEs (n = 34) relative to their counterparts (n = 435), Fisher’s exact test did not indicate any significant association between incidence of irAEs and gender (p = 0.853), race (p = 0.352), ethnicity (p = 1.00), language (p = 0.827), insurance (p = 1.00), education (p = 0.267) or smoking (p = 0.695).

Conclusion: We did not identify disproportionate rates of toxicity among patients of racial and ethnic minorities or with public insurance. These findings suggest that management decisions and toxicity risk assessment should not be based solely on race or socioeconomic status. Future studies featuring diverse patient populations must be conducted to formulate clinical algorithms for irAE management.