Superior Graft-Versus-Leukemia Effect in Haploidentical Transplantation Compared with HLA-Matched Sibling Transplantation for High-Risk Acute Myeloid Leukemia in First Complete Remission: A Prospective Multicentre Cohort Study

This study aimed to investigate graft-versus-leukemia (GVL) of haploidentical donor (HID) compared with HLA-matched sibling donor (MSD) for high-risk acute myeloid leukemia (H-AML) in first complete remission (CR1). One hundred and eighty-nine patients with H-AML in CR1 were enrolled in this multicentre prospective cohort study. Patients were assigned to groups transplanted with HID (n=83) or MSD (n=106) based on donor availability (biological randomization). The primary endpoint was the incidence of MRD positivity post-transplantation (post-MRD+). All post-MRD+ patients received preemptive interventions. The cumulative incidences of post-MRD+ were 18% and 42% in HID and MSD groups, respectively, (p<.001). Fifty-two patients received preemptive DLI, including 13 (16%) in HID and 39 cases (37%) in MSD groups (p=.001). Among HID and MSD groups, the 3-year cumulative incidence of relapse were 14% and 24% (p=0.101); the 3-year cumulative incidence of treatment-related mortality were 15% and 10% (p=0.368); the 3-year overall survival rates were 72% and 68% (p=0.687); the 3-year disease-free-survival were 71% and 66% (p=0.579); the 3-year graft-versus-host disease and relapse free survival were 63% and 43% (p=0.035), respectively. HID has a stronger GVL than MSD in H-AML patients. HID transplantation as post-remission therapy should be recommended as one of the optimal choices for H-AML in CR1.