Distinct outcomes in Hispanic/Latinx and non-Hispanic/Latinx patients with metastatic renal cell carcinoma (mRCC) treated with first-line ipilimumab plus nivolumab (ipi/nivo).

4554 Background: Subgroup analyses have reported differences in clinical outcomes by ethnicity in patients (pts) receiving immune checkpoint inhibitors (Cheng et al Ann Oncol 2019; Peravali et al World J Clin Oncol 2021). We sought to compare real-world outcomes between Hispanic/Latinx and non-Hispanic/Latinx mRCC pts treated with first-line ipi/nivo within a safety-net healthcare system and at a tertiary care center in Southern California. Methods: We performed a retrospective analysis of mRCC pts who received ipi/nivo within the Los Angeles County Department of Health Services (a safety-net healthcare system) and the City of Hope Comprehensive Cancer Center (a tertiary oncology center) between Jan 1, 2015 and Dec 31, 2021. Pts were identified using institutional databases and clinical data were compiled from electronic health records. Pts with pathologic diagnosis of stage IV mRCC, age > 18 years and receipt of ipi/nivo as first-line therapy were included. Progression-free survival (PFS) was analyzed using the Kaplan-Meier method and covariates were adjusted using multivariate Cox proportional hazards regression. Results: Of 96 pts, 67 (70%) were male, 90 (94%) had clear-cell histology, and 89 (93%) had intermediate/poor IMDC risk. Forty-two pts (44%) were Hispanic/Latinx while the remainder were non-Hispanic/Latinx (44 pts [46%] White, 7 pts [7%] Asian, and 3 pts [3%] Other). Fifty (52%) and 46 (48%) pts received their care at a tertiary care center and within a safety-net healthcare system, respectively. Median age, IMDC risk classification, BMI, and number of comorbidities were similar between both groups. Pooled analysis by ethnicity revealed significantly shorter PFS in Hispanic/Latinx vs non-Hispanic/Latinx pts (HR 1.60, 95% CI 1.04-2.48, p = 0.03). At 12 months, 19% of Hispanic/Latinx pts (95% CI, 9-32) and 35% of non-Hispanic/Latinx pts (95% CI, 23-48) were alive and progression-free. There was no difference in PFS between pts at the safety-net hospital system vs tertiary care center (HR 1.32, 95% CI 0.87-2.02, p = 0.19). Conclusions: Our real-world analysis of mRCC pts demonstrated poorer outcomes with ipi/nivo in Hispanic/Latinx pts. We are currently interrogating multiple social determinants of health that may contribute to these concerning disparities.