Phase II Study of Allogeneic Hematopoietic Stem Cell Transplantation for Children with High-Risk Neuroblastoma Using a Reduced-Intensity Conditioning Regimen: Results from the AIEOP Trial

Despite aggressive multimodal treatment, the outcomes of pediatric patients with highrisk (HR) neuroblastoma (NB) remain poor. The rationale for allogeneic hematopoietic stem cell transplantation (allo-HCT) to treat NB was based on the possible graft -versustumor effect; however, toxicity limits its efficacy. We sought to prospectively assess the feasibility and efficacy of allo-HCT using a reduced -intensity conditioning regimen in pediatric patients with HR NB in a multicenter phase II trial. Primary endpoints were the rate of neutrophil and platelet engraftment, 5 -year transplantation -related mortality (TRM), and disease -free survival (DFS). Secondary endpoint measures included the incidence of acute graft -versus -host disease (aGVHD) and chronic GVHD. Fifty-one patients were enrolled in the study. The 5 -year cumulative incidence (CuI) of TRM was 29.4 +/- 6.4%, and that of DFS was 11.8 +/- 4.5%. Patients undergoing allo-HCT within 1 year of diagnosis or with bone marrow as their stem cell source had a higher DFS probability. The CuI of neutrophil engraftment, platelet engraftment, and grade II -IV aGVHD was 97.9 +/- 2.1%, 93.8 +/- 3.5%, and 47.1 +/- 7.0%, respectively. The development of new therapeutic strategies could further improve disease control. (c) 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. This is an open access article under the CC BY -NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)