Haploidentical BMT and post-transplant Cy for severe aplastic anemia: a multicenter retrospective study

Area of Science:

• Hematology
• Transplantation Immunology
• Oncohematology

Background:

• Refractory severe aplastic anemia (SAA) patients often lack suitable donors for hematopoietic stem cell transplantation (HSCT).
• Traditional HSCT with mismatched or haploidentical donors carries significant risks of graft-versus-host disease (GVHD) and mortality.
• Post-transplant cyclophosphamide (Cy) is emerging as a strategy to mitigate GVHD in haploidentical HSCT, primarily studied in hematologic malignancies.

Purpose of the Study:

• To evaluate the efficacy and safety of haploidentical HSCT using a reduced-intensity conditioning regimen with post-transplant cyclophosphamide in patients with refractory SAA.
• To assess engraftment rates, GVHD incidence, and overall survival in this patient population.

Main Methods:

• Retrospective analysis of 16 patients with refractory SAA undergoing haploidentical HSCT.
• Reduced-intensity conditioning regimen followed by post-transplant cyclophosphamide administration.
• Stem cell sources included bone marrow (BM) or peripheral blood stem cells (PBSCs).

Main Results:

• High rates of neutrophil (94%) and platelet (75%) engraftment were observed.
• Low incidence of acute GVHD (grades 2-4 in two patients); two patients experienced secondary graft failure but were salvaged.
• One-year overall survival (OS) was 67.1%.

Conclusions:

• Reduced-intensity conditioning with post-transplant cyclophosphamide in haploidentical HSCT is a viable approach for refractory SAA patients.
• This strategy demonstrates encouraging engraftment rates and a reduced risk of GVHD in this challenging patient group.
• Further investigation is warranted to optimize outcomes for SAA patients undergoing haploidentical transplantation.