Optimizing Blinatumomab Access for Low- and Middle-Income Countries: Feasibility of a Shortened, Vial-Sharing, Outpatient Approach for Pediatric ALL.

Abstract

This study aims to evaluate the safety, feasibility, effectiveness, and cost-saving potential of a shortened, vial-sharing outpatient blinatumomab regimen for treating relapsed or refractory (R/R) ALL in children. We conducted a retrospective study of pediatric patients with R/R B-cell ALL (B-ALL) treated with a shortened outpatient blinatumomab regimen (<21 days), aiming to achieve a negative measurable residual disease (MRD) remission before hematopoietic stem-cell transplantation (HSCT). Twelve patients were included: three (25%) with primary refractory disease and nine (75%) with relapse. The median follow-up time was 33 months (range, 10-76 months). Blinatumomab was administered for a median of 19 days (range, 11-21), with 75% (9 of 12) of patients completing treatment entirely on an outpatient basis. Five patients (62%) achieved CR with undetectable MRD, and all four patients who initiated treatment because of persistent MRD achieved MRD clearance (100%). Ten patients (83%) proceeded to haploidentical HSCT. The estimated 3-year overall survival (OS) was 54%, and the relapse-free survival (RFS) was 44%. These optimization measures resulted in a 43% reduction in drug-related expenditures. Reduced-duration outpatient blinatumomab shows promise as a context-adapted strategy for heavily pretreated pediatric patients with ALL. Given the small retrospective cohort, these findings should be interpreted with caution.