Post-transplant Cyclophosphamide for HLA-haploidentical Transplantation in Wiskott-Aldrich Syndrome

Patients were enrolled in CIP-2015 Protocol at the Capital Institute of Pediatrics (Beijing). The conditioning regimen consisted of fludarabine (40 mg/m2) from days -6 to -3, and Busulfan was administered intravenously for 4 days, from days -5 to -2，using dose targeting based on therapeutic drug monitoring. Thymoglobulin (Sanofi, Cambridge, MA) 7.5 to 10 mg/kg (cumulative dose over 4 days) was administered over 4 days, from days -5 to -2. Bone marrow (BM) and PBSC were infused on day 0, followed by post-transplant CY (50 mg/kg/day, on days +3 and +4). To protect against hemorrhagic cystitis, MESNA (2-mercaptoethane sodium sulfonate) was administered at 150% of the CY dose. Post grafting immunosuppression with mycophenolate mofetil and tacrolimus commenced on day +5 and extended until days +28 and +84, respectively. Tacrolimus was tapered off by day +90 if there was no GVHD.