HLA-haploidentical blood and bone marrow transplantation with anti-thymocyte globulin: long-term comparison with HLA-identical sibling transplantation.

We present an update of our results regarding related HLA-haploidentical and HLA-identical sibling hematopoietic stem cell transplantation (HSCT) in patients with leukemia. We compared the outcomes of 107 patients with leukemia undergoing HLA-identical sibling (n=51) or related HLA-haploidentical (n=56) HSCT performed during the same time period. Patients received BU-CY/CY-TBI in HLA-identical sibling HSCT or TBI+Ara-C+CY+ATG/CCNU+Ara-C+Bu+CY+ATG in haploidentical HSCT as conditioning regimens, followed by unmanipulated marrow and/or peripheral blood (PB) transplantation. All patients achieved full engraftment. The cumulative incidence of grades II through IV acute graft-versus-host disease (aGvHD) in the matched and haploidentical cohorts was 13.7% and 26.8% (P<0.05), respectively. The risk of developing cGvHD was not different between HLA-matched and haploidentical patients (P>0.05). The two-year incidence of treatment-related mortality for matched and haploidentical patients was 7.8% and 12.5%, respectively, with P>0.05, and the incidence of relapse was 17% and 22%, respectively, with P>0.05. The two-year adjusted leukemia-free survival for matched versus haploidentical patients was 76% and 68%, respectively, with P>0.05, and the overall survival for matched versus haploidentical patients was 80% and 70%, respectively, with P>0.05. Multivariate analyses showed that only advanced disease stage and a diagnosis of acute leukemia were related to increased risk of relapse, treatment failure, and overall mortality. In summary, HSCT performed with related HLA-haploidentical donors is a feasible approach with acceptable outcomes.