Sequential Transplantation of Haploidentical Stem Cell and Unrelated Cord Blood With Using ATG/PTCY Increases Survival of Relapsed/Refractory Hematologic Malignancies.

Allogeneic haploidentical HSCT (haplo-HSCT) and unrelated umbilical cord blood transplantation(UCBT)are used in patients lacking HLA-identical sibling or unrelated donors. With myeloablative condition and GVHD prophylaxis of using low-dose ATG and post-transplantation cyclophosphamide (PTCY), we conducted a prospective clinical trial. Of eligible 122 patients from February 2015 to December 2019 in the study, 113 patients were involved. Forty-eight patients were in the group of sequential haplo-cord transplantation (haplo-cord HSCT), and 65 patients were in the group of single UCBT. The primary endpoint of 2-year disease-free survival (DFS) was no statistical difference between groups (64.1 56.5%), >0.05. The analysis of subgroup patients with relapsed/refractory showed haplo-cord HSCT was associated with better OS (HR 0.348, 95% CI, 0.175-0.691; =0.0025), DFS (HR 0.402, 95% CI, 0.208-0.779; =0.0069), and GRFS (HR 0.235, 95% CI, 0.120-0.457, <0.0001) compared to the single cord group. The 2-year's probability in OS, DFS, and GRFS was 64.9 31.6%, 64.5 31.6%, and 60.8 15.0% in the haplo-cord group and single cord group, respectively. III-IV acute GVHD 8.3 6.2%, chronic GVHD 25.8 13.7%, and extensive chronic GVHD 5.3 1.8% were shown in corresponding group, >0.05. The patients engrafted persistently with UCB showed better survival outcomes. Our sequential Haplo-cord HSCT with ATG/PTCY improved the survival of patients and might be an alternative transplantation approach for patients with relapsed/refractory hematologic malignancies.