BACKGROUND: Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a key treatment for hematologic malignancies, but donor selection impacts outcomes.

RESULTS: In a cohort of 152 patients undergoing allo-SCT from 2012 to 2023, haploidentical donors with post-transplant cyclophosphamide (PTCy) showed superior survival compared to 9/10 mismatched unrelated donors (MMUD). Cox regression analysis revealed that patients not in complete remission (CR) before transplantation particularly benefited from haplo donors, while those with 9/10 MMUD and lacking CR had worse outcomes.

CONCLUSION: These results highlight the importance of donor selection, suggesting that haplo donors with PTCy may be preferable for patients not in CR, necessitating alternative approaches for others.

CLINICAL TRIAL REGISTRATION: The authors have confirmed clinical trial registration is not needed for this submission.