-Author name in bold denotes the presenting author
-Asterisk * with author name denotes a Non-ASH member
Clinically Relevant Abstract denotes an abstract that is clinically relevant.

PhD Trainee denotes that this is a recommended PHD Trainee Session.

Ticketed Session denotes that this is a ticketed session.

1041 Haploidentical Hematopoietic Cell Transplantation Combined with an Unrelated Cord Blood Unit for Adult Acute Myeloid Leukemia Results in Improved Survival Compared to Haploidentical Hematopoietic Cell Transplantation: Results of a Multicenter, Randomized, Phase III Trial

Program: Oral and Poster Abstracts
Type: Oral
Session: 721. Allogeneic Transplantation: Conditioning Regimens, Engraftment and Acute Toxicities: Expanding the Donor Pool
Hematology Disease Topics & Pathways:
Research, clinical trials, Acute Myeloid Malignancies, AML, adult, Clinical Research, Diseases, Therapies, Myeloid Malignancies, Study Population, Human
Monday, December 11, 2023: 5:00 PM

Biqi Zhou, M.D.1,2*, Jia Chen, M.D.1,2*, Tianhui Liu, PhD1,2*, Yanming Zhang, M.D.3*, Yishan Ye, MD4*, Yiyang Ding, M.D.1*, Mingqing Zhu1*, Xiao Ma, M.D.1,5*, Xiaoli Li, M.D.5*, Zhihong Lin, M.D.6*, He Huang, M.D.4*, Yang Xu, M.D.1,2* and Depei Wu, M.D.1,2

1National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
2Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
3Department of Hematology, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'An, China
4Bone Marrow Transplantation Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
5Soochow Hopes Hematology Hospital, Suzhou, China
6Hygeia Suzhou Yongding Hospital, Department of Affiliated Renji Hospital of Shanghai Jiao Tong University of Medicine, Suzhou, China


Haploidentical hematopoietic cell transplantation (haplo-HCT) is a potent treatment to improve the prognosis of acute myeloid leukemia (AML), but relapse and graft-versus-host disease (GVHD) related to dysregulation of alloreactivity are still the main causes of death posttransplantation. Cord blood graft usually has a promising graft-versus-leukemia effect with a lower cumulative incidence of GVHD. To improve the transplantation strategy, haplo-cord HCT combining haploidentical and unrelated cord blood (UCB) grafts (haplo-cord HCT) has been attempted. Previous studies showed significant improvement in prognosis in B-cell acute lymphoblastic leukemia or refractory acute leukemia patients with haplo-cord HCT compared to haplo-HCT. However, outcomes of haplo-cord HCT for AML patients are not yet clear. This is the first multicentric randomized trial designed specifically for the efficacy and safety of haplo-cord HCT for AML.


This is a multicenter, randomized, open-label, phase III study conducted in 5 centers in China (NCT03719534). Patients aged 18-60 years, diagnosed with AML (except for acute promyelocytic leukemia) with measurable residual disease, had an available haploidentical donor and were suitable for allotransplantation were enrolled. Patients were randomized 1:1 to receive UCB and haploidentical grafts infusion after Bu/Cy-based regimen or haploidentical graft infusion only after Bu/Cy-based regimen. The UCB unit, which had at least 3/6 matched HLA loci to the recipient and more than 1×104 CD34+ cells/kg of recipient weight, was infused immediately after resuscitation and eight hours before the haploidentical graft infusion. The primary endpoint was 3-year overall survival (OS) and secondary endpoints included progression-free survival (PFS), cumulative incidence of relapse (CIR), and non-relapse mortality (NRM).


From June 1, 2017, to June 30, 2021, 268 patients were enrolled (Table 1). With a median follow-up of 36.00 months, the 3-year OS was 80.5% (95% CI 73.7-87.9) in the haplo-cord HCT group and 67.8% (95% CI 60.0-76.5) in the haplo-HCT group, respectively (p=0.013, figure 1A). Haplo-cord HCT group showed favorable 3-year PFS and CIR than haplo-HCT group (PFS: 70.3%, 95% CI 62.6-78.8 vs. 57.6%, 95% CI 49.6-67.0, p=0.012; CIR: 12.1%, 95% CI 12.0-12.2 vs. 30.3%, 95% CI 30.1-30.4, p=0.024, figure 1B,C). The 3-year NRM was similar in the two groups (figure 1D).

Within two years posttransplantation, the most common grade 3-4 adverse events (AEs) in the haplo-cord HCT and haplo-HCT groups were infections (33.8% and 29.1%), acute GVHD (20.3% and 12.7%) and chronic GVHD (12.0% and 16.4%). AEs leading to death occurred in 8.3% of haplo-cord HCT and 14.9% haplo HCT patients.

Post- hoc analysis showed similar median levels of haploidentical chimerism in bone marrow (BM) between the two groups. However, UCB microchimerism was detected in the haplo-cord HCT patients by SNP-NGS in +1m posttransplantation (BM: 0.3%, IQR 0.04-1.6; peripheral blood: 0.06%, IQR 0.03-0.4) and its chimerism percentage decreased with time (figure 1E). Compared to haplo-HCT group, haplo-cord HCT group showed a faster cumulative incidence of neutrophil recovery (p=0.026, figure 1F) and a similar cumulative incidence of platelet recovery. Monitor of immune reconstitution showed a more rapidly increasing rate of T cells in the early period after transplantation in the haplo-cord HCT group (figure 1G). Improved recovery of Th2 (p=0.042), Th17 (p=0.047), Treg (p=0.045), and Tc2 (p=0.045) cells was observed in haplo-HCT group.


Coinfusion of a UCB unit in haplo-HCT can improve OS in AML patients without excessive AEs, and affect T-cell reconstitution pattern posttransplantation. Haplo-cord HCT could serve as a suitable therapeutic option for this patient population.

Disclosures: No relevant conflicts of interest to declare.

*signifies non-member of ASH