Reduced dose cyclophosphamide, fludarabine and antithymocyte globulin for sibling and unrelated transplant of children with severe and very severe aplastic anemia.

We evaluated the results of a novel conditioning regimen of reduced dose cyclophosphamide (Cy, 25 mg/kg for four days), fludarabine (Flu, 30 mg/m(2) for four days), and rabbit ATG (2.5 mg/kg for three days) for allogeneic transplant of children with SAA, implemented since January 2009. Overall, 23 patients were treated with this regimen (16 male, seven female), including 10 diagnosed with VSAA. Donors included eight-MSD and 15 UD (five-matched UD, and 10 mismatched UD). All patients showed neutrophil and platelet engraftment. Cumulative incidence of acute (grade 2 or above) and chronic GVHD was 26.1% and 8.7%, respectively. Estimated two-yr FFS and OS for the entire cohort was 90.3 ± 6.5%. Rates of TRM and graft failure were 5.3% and 4.3%, respectively. No difference in OS was found according to disease severity (SAA vs. VSAA, p = 0.184), or according to donor type (MSD vs. UD, p = 0.699). Excellent outcomes of patients with VSAA underscore the efficacy of allogeneic transplant as a means of expediting hematopoietic recovery. Improved survival of UD transplant reaffirms its role as a valid therapeutic alternative in the absence of MSD.