A phase II pilot trial to estimate survival after a non-total body irradiation (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

Pediatric Blood Cancer
Hisham Abdel-Azim, MD, MS
Children's Hospital Los Angeles


Total body irradiation (TBI) in hematopoietic stem cell transplant (HSCT) has been a key element in the treatment of acute lymphoblastic leukemia (ALL) and is associated with improved outcomes. However, there are long-term adverse effects of TBI, therefore, there is a strong need to define patients who could be candidates for non-TBI approaches. This phase II pilot trial will determine if deescalating therapy (use of a non-TBI conditioning regimen in place of a TBI conditioning regimen) in B-ALL patients with low risk of relapse (defined by NGS MRD negative) will result in similar outcomes to those who receive a TBI conditioning regimen. An arm consisting of patients with B-ALL NGS-MRD positive undergoing TBI-based condition therapy will be utilized as a direct comparator.

Trial Registration: ClinicalTrials.gov Identifier: NCT03509961