The EndRAD Trial: Eliminating Total Body Irradiation (TBI) for NGS-MRD Negative Children, Adolescents, and Young Adults With B-ALL

A Phase II pilot trial will estimate survival after a non-TBI based conditioning regimen in patients diagnosed with B-acute lymphoblastic leukemia (ALL) who are pre-allogeneic hematopoietic cell transplantation (HCT) next-generation-sequence (NGS) minimal residual disease (MRD) negative. The relationship of NGS-MRD status to survival in children, adolescents, and young adults with B-ALL undergoing any approach to allogeneic HCT will be explored in a larger cohort (treatment \[phase II\] and observational arms of the study). The primary objective is to estimate 2-year event free survival (EFS) in pre-HCT NGS-MRD negative patients with B-ALL undergoing a non-TBI based conditioning regimen through a multi-center prospective trial. The accrual period is 3 years. Patients that are NGS-MRD negative with B-ALL may be eligible for the Treatment Arm, which is myeloablative non-TBI conditioning with busulfan, fludarabine, and thiotepa followed -matched related, unrelated, and umbilical cord blood transplants. Patients that are NGS-MRD positive will be followed on the observational arm for outcome. Study sampling will include NGS-MRD bone marrow (BM) aspirate and peripheral blood (PB) samples collected \[same day when possible\] pre-HCT (within 4 weeks), and post-HCT on days 42 ± 14, 100 ± 20, and 365 ± 60; PB samples only will also be collected day 180± 60 and 270± 60; day +30, day +100, and 1-year post-HCT. NGS-MRD peripheral blood sample only at 6 months and 9 months post-HCT; (Blast specimen at time of diagnosis or relapse is required for NGS-MRD testing).