Excellent Outcomes of Hematopoietic Stem Cell Transplant for Pediatric High Risk and Relapsed Acute Myeloid Leukemia–A Decade Long Experience From Developing Nation

Aim: Hematopoietic stem cell transplant (HSCT) remains the cornerstone of treatment in patients with high-risk and relapsed acute myeloid leukemia (AML). In the absence of a fully matched donor, haploidentical HSCT is a feasible option. The aim of this study is to analyze the outcomes of pediatric AML patients, who underwent HSCT at our center. Methods: This was a retrospective analysis of 48 pediatric patients who underwent 50 transplants at our center from January 2014 to December 2024. Results: Median age at transplant was 8.5 years, and the male-to-female ratio was 1.9:1. Out of 48 children, 46 patients had de novo AML, and 2 had secondary AML. Twenty-nine patients underwent matched sibling donor (MSD), 3 underwent matched related donor (MRD) and the remaining 18 received haploidentical HSCT. All patients received Fludarabine-based conditioning regimens and engrafted. Incidence of acute graft versus host disease (GVHD) in matched donor and haploidentical HSCT was 21.8% and 44.4%, respectively ( P =0.09). Incidence of chronic GVHD was 3.1% in matched donor and 5.5% in haploidentical HSCT ( P =0.72). Cumulative incidence of relapse was 16%. Viral reactivations were seen in 17 patients, cytomegalovirus (CMV) being the commonest. At a median follow-up of 40.9 months, EFS and OS of the overall cohort were 78% and 86%, respectively. Nonrelapse mortality (NRM) was 6%. EFS in matched donor and haploidentical HSCT was 78.1% versus 77.8% ( P =0.78). OS in matched donor and haploidentical HSCT was 84.4% versus 88.9% ( P =0.83). GVHD-free relapse-free survival (GRFS) was 58%. Among the factors analyzed, only pretransplant minimal residual disease (MRD) positivity was found to be associated with significantly poor outcome. Conclusion: HSCT for children with AML from the developing world shows promising outcomes with high survival rates even in the absence of matched donors. Having expertise in multiple specialties, such as a molecular hematologist, infectious disease (ID), and intensive care specialist, can significantly enhance the outcomes for transplant patients.