Objective: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment for acquired aplastic anemia (acquired AA) in young patients. The objective of the study was to compare patient outcomes after Cyclophosphamide and horse antithymocyte globulin (Cy-hATG) versus Fludarabine-cyclophosphamide and rabbit ATG (Flu-Cy-rATG) as part of conditioning regimen in allo-HSCT for acquired AA.
Methods: Descriptive retrospective study conducted on patients with acquired AA who received allo-HSCT from HLA-matched sibling donors between January 2008 and August 2022 after conditioning regimen with Cy-hATG or Flu-Cy-rATG.
Results: A total of 121 patients were enrolled. Cumulative incidence of graft failure was 11.2% in Cy-hATG and 5.3% Flu-Cy-rATG group (p=0.4). There were no significant differences between the two groups in terms of grade II-IV acute GVHD, chronic GVHD and transplant related mortality. Flu-Cy-rATG group was associated with significantly higher CMV and EBV reactivation(s) compared to Cy-hATG group. After a median follow-up of 58 months (range, 5 days-165 months), estimated overall survival, event-free survival and graft rejection-free survival were not statistically different between the two groups.
Conclusion: In high-risk population, Flu-Cy-rATG is associated with comparable outcomes to Cy-hATG in allo-HSCT from MSD. However, it seems to be associated with significant risk of viral infections.