Haploidentical hematopoietic cell transplantation with or without an unrelated cord blood unit for adult acute myeloid leukemia:a multicenter,randomized,open-label,phase 3 trial

Coinfusion of unrelated cord blood(UCB)units in haploidentical hematopoietic cell transplantation(haplo-HCT)(haplo-cord HCT)for hematopoietic malignancies showed promising results in previous reports,but the efficiency of haplo-cord HCT in acute myeloid leukemia(AML)still lacks sufficient evidence.This multicenter,randomized,phase 3 trial(ClinicalTrials.gov NCT03719534)aimed to assess the efficacy and safety of haplo-cord HCT in AML patients.A total of 268 eligible patients aged 18-60 years,diagnosed with measurable residual disease in AML(excluding acute promyelocytic leukemia),with available haploidentical donors and suitable for allotransplantation,were randomly allocated(1:1)to receive haplo-cord HCT(n=134)or haplo-HCT(n=134).The 3-year overall survival(OS)was the primary endpoint in this study.Overall median follow-up was 36.50 months(IQR 24.75-46.50).The 3-year OS of Haplo-cord HCT group was better than haplo-HCT group(80.5%,95%confidence interval[CI]:73.7-87.9 vs.67.8%95%CI 60.0-76.5,p=0.013).Favorable progression-free survival(70.3%,95%CI 62.6-78.8 vs.57.6%,95%CI 49.6-67.0,p=0.012)and cumulative incidence of relapse(12.1%,95%CI 12.0-12.2 vs.30.3%,95%CI 30.1-30.4,p=0.024)were observed in haplo-cord HCT group.Grade 3-4 adverse events(AEs)within two years posttransplantation in the two groups were similar.Haplo-cord HCT patients exhibited a faster cumulative incidence of neutrophil recovery(p=0.026)and increased T-cell reconstitution in the early period posttransplantation.Haplo-cord HCT can improve OS in AML patients without excessive AEs,which may exert additional benefits for recipients of haplo-HCT.