Comparison of outcomes of BuCy versus BuCyMel as preparation for allogeneic HSCT in infants with acute myeloid leukemia in first complete remission: a multicenter study from the EBMT PDWP.

This international registry-based study by the EBMT evaluated conditioning regimens in children under 2 years undergoing allogeneic HSCT for first complete remission (CR1) of high-risk pediatric AML.

Among 335 patients treated between 2000 and 2022, those receiving the BuCyMel regimen (Busulfan, Cyclophosphamide, Melphalan) showed significantly improved outcomes compared to BuCy (Busulfan, Cyclophosphamide) alone:

• 4-year leukemia-free survival: 74.8% vs 58.8%
• Overall survival: 77.9% vs 66.2%
• Lower relapse incidence: 18.1% vs 31.5%

BuCyMel was not associated with an increase in non-relapse mortality.

These findings support BuCyMel as the superior conditioning regimen in this young pediatric AML population undergoing HSCT in CR1.