Allogeneic HSCT in children with hypodiploid or BCR::ABL1 B-ALL
Buechner J, Poetschger U, Bader P, et al. Outcome of Children With B-Cell Acute Lymphoblastic Leukemia With Hypodiploidy or BCR::ABL1 Fusion Undergoing Allogeneic HSCT. Blood. 2025; (doi: 10.1182/blood.2025030951).
The results of a prospective study favor the use of a standardized protocol for allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients with a particular type of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The FORUM clinical trial examined post-HSCT outcomes in 741 children with BCP-ALL with and without hypodiploidy (Hypo) or BCR::ABL1fusion, two genetic disease characteristics known to elevate the risk of relapse. Each participant underwent HSCT from HLA-matched donors. At 3-year follow-up, survival rates among the children with BCR-ABL+ disease or Hypo were no worse than those of children outside of those subgroups. Overall survival (OS) at 3 years was 0.86 for BCR-ABL+, 0.79 for Hypo, and 0.79 for children without either one of these high-risk genetic features. Event-free survival (EFS) was 0.71, 0.73, and 0.67, respectively. While outcomes were similar overall across all three subpopulations, Hypo patients in second complete remission had lower OS and EFS and higher non-relapse mortality, while BCR-ABL+ patients in second complete remission registered 3-year OS of 96%.