Outcomes of Hispanic and non-Hispanic white pediatric and young adult patients with B-cell acute lymphoblastic leukemia after commercial tisagenlecleucel.

Abstract

10016 Background: Population-level data show significantly inferior outcomes for Hispanic children, adolescents, and young adults (CAYA) diagnosed with B-cell acute lymphoblastic leukemia (B-ALL) relative to non-Hispanic whites (NHW). Here, we compare outcomes between Hispanic and NHW CAYA patients with relapsed and/or refractory (RR) B-ALL receiving tisagenlecleucel, a CD19-specific chimeric antigen receptor (CAR) T cell therapy. Methods: We used data from the Pediatric Real World CAR Consortium retrospective cohort of 200 patients who underwent cell shipment for standard-of-care tisagenlecleucel between August 2017 and March 2020 (N=15 US institutions). Race/ethnicity was identified by medical record review. Patients reported as belonging to more than one racial/ethnic group were classified as multiracial and excluded from analysis. Baseline factors, outcomes, and safety post-infusion were characterized for Hispanic vs. NHW infused patients. Outcomes included complete response (CR) rate, overall survival (OS), duration of response (DOR), and duration of B-cell aplasia (DBA). A multivariate Cox model for OS was constructed, including all baseline factors. Results: Among 185 infused patients, 90 (48.6%) were NHW and 70 (37.8%) were Hispanic. Among 15 non-infused patients, 3 (20.0%) were NHW and 5 (33.3%) were Hispanic. Hispanic patients were significantly older at diagnosis (mean: 10.7 vs. 8.3 years, p=0.02) and had significantly shorter time from diagnosis to infusion (mean: 34.4 vs. 46.4 months, p=0.04). Hispanic and NHW patients did not significantly differ across sex, leukemia type, number of prior lines of therapy, receipt of prior CD19-directed therapy, level of disease burden pre-infusion, and number of relapses pre-infusion. Hispanic and NHW patients did not significantly differ across 1-month CR, 6-month OS, 1-year OS, 18-month OS, 6-month DOR, 1-year DOR, 6-month DBA, and 1-year DBA (Table). On multivariate analysis including the above covariates, OS did not significantly differ for Hispanic patients (HR=1.04, p=0.92). Hispanic and NHW patients did not significantly differ across grade ≥ 3 cytokine release syndrome, grade ≥ 3 neurotoxicity, grade 4 neutropenia, tumor lysis syndrome, or number of infections post-infusion. Conclusions: Outcomes were similar between Hispanic and NHW CAYA RR B-ALL patients receiving tisagenlecleucel in the real-world setting. Increasing access to CAR therapy among Hispanic CAYA B-ALL patients could help mitigate population-level disparities in outcomes observed after receipt of conventional therapies. [Table: see text]