Haplo-Cord HCT Versus Haplo-Identical HCT for Acute Leukemia Patients Not in Remission: A Multicenter Study

Accumulating evidences indicated the effectiveness of HCT using a haplo-identical donor graft and an unrelated cord blood unit (haplo-cord HCT) for patients with acute leukemia (AL), including reduced incidence of relapse and transplant-related mortality. However, few study has been reported for those who failed to achieve remission. This multicenter study was conducted to compare the clinical outcomes of haplo-cord HCT with haplo-identical donor HCT (haplo HCT) in AL patients not in remission (NR). A total of 104 patients who underwent haplo-cord HSCT and 45 patients who underwent haplo-HCT at NR status between 2014 and 2018 were retrospectively included in this study. The median follow-up of survivals was 43.8 months. The complete remission rates post transplantation (90.4% and 88.9%), 3-year overall survival (OS) (38.6% vs. 35.1%, P>0.05) and progression-free survival (PFS) (27.8% vs. 26.2%, P>0.05) were similar between haplo-cord HCT and haplo HCT groups. Nevertheless, when compared the subgroup of patients whose OS or PFS over 12 months by landmark analysis, haplo-cord HCT led to superior 3-year OS (77.1% vs. 56.0%，P=0.020) and PFS (79.2% vs. 50%，P=0.033). Multivariate analysis for the whole cohort revealed that the myeloid linage of leukemic cells was an independent parameter associated with 3-year PFS of NR AL patients (HR=0.601, P=0.011). In addition, bone marrow blasts≧20% pre-HSCT and acute graft-versus-host disease independently predicted unfavorable 3-year OS and PFS. In conclusion, the co-infusion of an unrelated cord blood unit in haplo HCT may potentially exert a late-effect for an improved survival.

Keywords: acute leukemia; not in remission; haploidentical donor; cord blood

No relevant conflicts of interest to declare.