Survival outcomes with immune checkpoint inhibitors among patients with cancer from minoritized racial and ethnic groups: A systematic review and meta-analysis.

Abstract

1648 Background: Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape across multiple malignancies; however, minoritized racial/ethnic groups remain underrepresented in pivotal trials, limiting the generalizability of efficacy estimates. Whether treatment outcomes with ICIs differ across these groups remains incompletely characterized. Thus, we conducted a systematic review and meta-analysis of published randomized controlled trials (RCTs) to evaluate differences in overall survival (OS) and progression-free survival (PFS) among these groups treated with ICIs. Methods: We systematically searched MEDLINE, Embase, Cochrane CENTRAL, and ClinicalTrials.gov for RCTs published through December 31, 2024, that evaluated ICIs in adult patients with cancer and reported OS or PFS by race/ethnicity. Risk of bias was independently assessed using the Cochrane Risk of Bias tool for randomized trials (RoB 2). Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. Between-study heterogeneity was quantified using I². Random-effects meta-analyses were performed using Review Manager (RevMan) and stratified by: non-White and White patients; Asian, Black, and White patients; Asian and non-Asian patients; and Hispanic and non-Hispanic patients. Publication bias was evaluated using funnel plots. This review followed Cochrane methodology and PRISMA guidelines and was registered in PROSPERO (CRD420251027941). Results: A total of 97 trials comprising 59,949 patients were included. For OS, ICIs were associated with significant benefit in both non-White (HR 0.70, 95% CI 0.63–0.77; p<0.001) and White patients (HR 0.75, 95% CI 0.67–0.84; p<0.001). Significant OS benefit was also observed in analyses stratified by Asian (HR 0.81, 95% CI 0.76–0.86; p<0.001) and White patients (HR 0.86, 95% CI 0.82–0.91; p<0.001), and by Asian (HR 0.83, 95% CI 0.76–0.91; p<0.001) and non-Asian patients (HR 0.79, 95% CI 0.73–0.86; p<0.001). Similar patterns were observed for PFS. Estimates for Black and Hispanic patients were not statistically significant, reflecting limited sample sizes. Heterogeneity ranged from low to substantial (I² 0–87%), with higher heterogeneity observed in PFS analyses. Only one trial reported race-specific survival outcomes for American Indian/Alaska Native (AI/AN) patients, and none reported outcomes for Native Hawaiian/Pacific Islander (NH/PI) patients, precluding analyses for these groups. Conclusions: ICIs were associated with improved OS and PFS across racial/ethnic groups, with no consistent evidence of differential treatment effects. However, the persistent underrepresentation of minoritized populations, particularly AI/AN, Black, Hispanic, and NH/PI patients, limits definitive conclusions and highlights the need for more equitable representation in oncology trials.