Haploidentical hematopoietic cell transplantation for adult acute myeloid leukemia: a position statement from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Abstract

Allogeneic blood or marrow hematopoietic cell transplantation continues to be the most potent anti-leukemic treatment for adult patients with standard, high-risk, or chemo-refractory acute myeloid leukemia. Until recently, this procedure was generally limited to those recipients who had an available matched-sibling donor or matched-unrelated donor. Technical advances in graft cell processing and manipulation, control of bidirectional T cell alloreactivity, graft-versus-host disease prophylaxis, and other supportive measures in haploidentical transplantation now enable nearly all patients with acute myeloid leukemia to benefit from the graft-versus-leukemia effect with substantial reduction in procedure-related mortality. Over recent years, haploidentical donors have been increasingly adopted as a valid donor source in allogeneic hematopoietic cell transplantation for acute myeloid leukemia in the absence of an HLA-matched donor. Among centers of the European Society for Blood and Marrow Transplantation, the use of haploidentical related donor transplantation has increased by 250% since 2010, and 291% since 2005. On behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarize recent utilization trends in haploidentical transplantation for acute myeloid leukemia and describe the transformative changes in haploidentical hematopoietic cell transplantation techniques over the past decade, which have led to the current widespread use of this procedure. Furthermore, we review the efficacy of haploidentical hematopoietic cell transplantation for acute myeloid leukemia from available studies, including preliminary comparative studies, and bring attention to remaining unanswered questions and directions for future research. We conclude this report with our recommendations for the role of haploidentical hematopoietic cell transplantation in acute myeloid leukemia.

Impact of Donor Type in Patients with AML Given Allogeneic Hematopoietic Cell Transplantation After Low-Dose TBI-Based Regimen

“…Recent progress in haplo-HCT has changed the algorithm of donor selection in many transplantation centers (34,35). Consequently, haplo-HCT is increasingly used in Europe while the use of CBT is declining (36).…”

A prospective observational study of immune reconstitution following transplantation with post‐transplant reduced‐dose cyclophosphamide from HLA ‐haploidentical donors

“…Allogeneic hematopoietic cell transplantation (HCT) is still the most effective strategy for cure of refractory hematopoietic malignancies or those with a poor prognosis. In recent years, HLA‐haploidentical donors have been increasingly used as an alternative stem cell source in the absence of available HLA‐matched donors, especially after the development of HLA‐haploidentical hematopoietic cell transplantation using post‐transplantation high‐dose cyclophosphamide (PT/Cy‐haplo) due to its simplicity and favorable regulation of graft‐versus‐host disease (GVHD) . PT/Cy administered within a narrow window shortly after transplantation can selectively eliminate host–donor alloreactive T cells, resulting in bi‐directional T‐cell tolerance and, thus, low incidences of GVHD.…”

Haploidentical transplantation for acute myeloid leukemia patients with minimal/measurable residual disease at transplantation

“…Haploidentical SCT (haplo‐SCT) is being increasingly used as an alternative donor source in AML, with several observational studies have proven its efficacy similar to an HLA‐matched transplants . There have been conflicting results regarding the impact of MRD status on haplo‐SCT outcomes .…”