Comparison of haploidentical and umbilical cord blood transplantation after myeloablative conditioning

Abstract

Haploidentical hematopoietic stem cell transplantation (haplo HSCT) has emerged as an important treatment modality. Most reports comparing haplo HSCT with post-transplant cyclophosphamide (PTCy) and other donor sources have focused on outcomes in older adults treated with reduced intensity conditioning. Therefore, in the current study, we evaluated outcomes in patients with hematological malignancy treated with myeloablative conditioning prior to haplo (n=375) or umbilical cord blood (UCB, n=333) HSCT. All haplo recipients received a 4 of 8 HLA matched graft while recipients of UCB were matched at 6-8/8 (n=145) or ≤5/8 (n=188) HLA antigens. Recipients of 6-8/8 UCB transplants were younger (14 years vs. 21 and 29 years) and more likely to have lower co-morbidity scores compared to recipients of ≤5/8 UCB and haplo HSCT (81% vs. 69% and 63%, respectively). UCB recipients were more likely to have acute lymphoblastic leukemia and transplanted in second complete remission (CR) whereas haplo HSCT recipients were more likely to have acute myeloid leukemia in first CR. Other characteristics, including cytogenetic risk were similar. Survival at 3 years was similar for the donor sources (66% haplo and 61% after ≤5/8 and 58% after 6-8/8 UCB). Notably, relapse at 3 years was lower in recipients of ≤5/8 UCB (21%, p=0.03) compared to haplo (36%) and 6-8/8 UCB (30%). However, non-relapse mortality was higher in ≤5/8 UCB (21%) compared to other groups (p<0.0001). These data suggest that haplo HSCT with PTCy after myeloablative conditioning provides an overall survival outcome comparable to that after UCB regardless HLA match group.

Haploidentical peripheral blood stem cell transplantation combined with unrelated cord blood in hematologic malignancy patients: A report of 80 cases

“…In the above study comparing the two ATG doses, the 3-year CIR was 17.6% and 15.3%, respectively, and the 3-year NRM was 20.2% and 24.4%, respectively (23). John et al (24) confirmed the lower relapse of cord blood transplantation than haploidentical transplantation by comparing the clinical outcomes of haploidentical transplantation and cord blood transplantation. The proportion of high-risk patients in our study was relatively high but not relapse was high, suggesting that haplo-cord-PBSCT may have a strong graft-versus-leukemia (GVL) effect; however, this finding needs to be substantiated with a large sample size in a paired randomized controlled trial.…”

Strategies for Success With Umbilical Cord Haematopoietic Stem Cell Transplantation in Children With Malignant and Non-Malignant Disease Indications

“…Barker reported rates of cGVHD that were less than 10%, even in the double cord setting, without serotherapy and where the median match was 5/8, and none were fully matched ( Barker et al, 2020 ). Wagner in his comparison of haplo-identical and cord blood transplants did not find any difference in rates of GVHD, even though the former is T-cell depleted and the latter are also significantly HLA-mismatched ( Wagner et al, 2021 ).…”

Umbilical cord blood: an undervalued and underutilized resource in allogeneic hematopoietic stem cell transplant and novel cell therapy applications

“…When HCT is being utilized as the curative approach for hematologic malignancies, HLA-mismatched UCB donor T-cells have characteristics that may lead to a reduced risk of relapse as compared to MSD [32], MUD [6 ▪▪ ], or haploidentical transplant [33], related to enhanced antitumor ability and cytotoxic CD8+ and CD4+ T-helper (Th1) profiles [34]. A higher CD8+ UCB content is associated with faster and higher myeloid and platelet engraftment, lower nonrelapse mortality (NRM), lower relapse, and increased overall survival (OS) [35].…”