AUTHOR=Seber Adriana , Arcuri Leonardo Javier , Colturato Vergilio Rensi , Souza Mair Pedro , Zogbi Yana Augusta Novis , Funke Vaneuza , Lerner Decio , Macedo Maria Cristina , Daudt Liane , Kerbauy Mariana Nassif , Zecchin Victor Gottardello , Duarte Fernando Barroso , Rabello Chiattone Ricardo , Soares Rodolfo Daniel de Almeida , Bettarello Gustavo , Vaz de Macedo Antonio , Paton Eduardo , Monteiro Tatiana Dias Marconi , Schmidt Filho Jayr , Astigarraga Claudia Caceres , Scheinberg Phillip , Vigorito Afonso Celso , Vergueiro Carmen Silvia Vieitas , Simione Anderson , Hashmi Shahrukh , Saber Wael , Patel Jinalben , Bonfim Carmem Maria Sales , Pasquini Marcelo , Flowers Mary Evelyn , Hamerschlak Nelson 

TITLE=Haploidentical, matched-related, and matched-unrelated hematopoietic cell transplant for acute leukemias in the early years of haploidentical transplant implementation in a developing country with a large unrelated donor registry

JOURNAL=Frontiers in Oncology

VOLUME=Volume 15 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1584631

DOI=10.3389/fonc.2025.1584631

ISSN=2234-943X

ABSTRACT=IntroductionOver the last decades, the donor network for hematopoietic cell transplantation (HCT) has grown exponentially, including unrelated and haploidentical (Haplo) donors. This study aimed to describe HCT outcomes with MSD, Haplo, and matched unrelated donors (MUD) in an early period of Haplo with posttransplant cyclophosphamide in a developing country with a large unrelated donor registry.MethodsThis study was conducted in collaboration with the CIBMTR. We included patients with acute leukemias undergoing HCT between 2014-2018.ResultsWith 595 patients, 2-year overall survival (OS) was 69% for the MSD, 65% for the Haplo, and 71% for MUD (p=0.24) in CR1, confirmed in multivariable analysis. Relapse rate was lower for MUD (HR=0.35, p=0.0005) than MSD in patients with CR2+, leading to higher OS. Relapse was also higher with Haplo compared with MUD (HR=2.06, p=0.03).DiscussionOnly survival bias can explain these findings in CR2+, suggesting some high-risk MUD patients, in which HCT timing is crucial, may not achieve HCT. Alternative donors were associated with higher non-relapse mortality, while PTCy-based Haplo offered the best protection against chronic graft-versus-host disease. Our study suggests Haplo and MUD are acceptable options for patients lacking MSD in developing countries like ours.