Preliminary, Updated Outcomes Of The Modified, Pediatric-Based Usc All Frontline Regimen In Hispanics And Non-Hispanics

Context: In 2014, USC reported use of multiple doses of pegaspargase (PEG) for newly diagnosed ALL patients (7-year overall survival [OS] 51%). This is currently part of the NCCN Guidelines for frontline ALL treatment. Since then, the regimen consisting of 2 induction phases (IP) was modified, with fractionated doses of cytarabine changed to a single dose and consolidations increased to six cycles (six doses of PEG total). Objective: Outcomes since modification of the USC ALL induction regimen, with immunotherapies given when appropriate, in Hispanics versus non-Hispanics. Design: Retrospective chart review. Setting: Single institution, academic center/county hospital. Patients or Other Participants: Male/female patients (18–99 years) with any type of ALL diagnosed by bone-marrow/tissue biopsies during 1/2016–12/2020, treated at our institution. Patients who did not receive the modified USC ALL induction regimen with/without PEG were excluded. Interventions: Ninety-four ALL patient chart reviews. Main Outcomes Measures: OS, event-free survival (EFS) at 5 years, CR/CRi, minimal residual disease (MRD) flow; 2-sided p-value ≤0.05 was considered significant. Results: Among 63 Hispanics and 31 non-Hispanics, 67 achieved CR/CRi, 39 had MRD flow negativity after IP1; 50 CR/CRi, and 29 had MRD flow negativity after IP2. PEG was given in 59% Hispanics and 60% non-Hispanics. Salvage BiTE was given to 30 patients (Hispanic, 63%). Median follow-up for Hispanics was 17 (0.5–60) months and 21 (0.1–53) months for non-Hispanics. Median OS not-reached (NR) in both groups. Estimated OS for Hispanics at 5 years was 80% and 51% for non-Hispanics (p=0.020). Median EFS for Hispanics was 46 months and 34 months for non-Hispanics (p=0.306). Conclusions: CR/CRi and MRD flow negativity were appreciable with the median OS NR. Interestingly, a significant improvement in Hispanic OS versus non-Hispanics was noted. An explanation could be on how more Hispanics received salvage BiTE (63.3% of 30 patients). Also, 40% of Hispanics were able to receive stem cell transplant versus 33% of non-Hispanics. No significant difference in median EFS between Hispanics and non-Hispanics was noted.