• The FABT-based regimen achieved 100% NE engraftment, a 91.7% 2-year OS rate, and no primary graft failure. • The incidence of grade II–IV aGVHD was 8.3%; cGVHD was limited to the skin in 11.1% of patients. CMV reactivation occurred in 11.1% with no CMV disease observed. • Patients under 40 years of age achieved 100% 2-year OS, with rapid hematopoietic recovery and manageable toxicity. Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) serves as an alternative treatment for severe aplastic anemia (SAA) patients lacking a suitable HLA-identical sibling donor. However, its development has been hindered by graft failure and severe graft-versus-host disease (GVHD). We conducted a prospective study to evaluate the efficacy of FABT regimen for AA in Haplo-HSCT. This regimen introduced thiotepa into the protocol for the first time, combined with low-dose ATG (2 mg/kg/day) and the PTCy regimen to prevent GVHD. From April 2022 to June 2024, 36 eligible AA patients were recruited for the study, with a median follow-up duration of 21 (2∼30) months. None of the 36 patients experienced primary graft failure, and the engraftment rates for NE and PLT were 100% and 91.7%, respectively. The median time to PLT and NE engraftment was 13 (8∼27) and 14 (8∼21) days, respectively. The 2-year cumulative incidence of CMV reactivation was only 11.1% and no CMV disease was observed. The incidence of aGVHD and grade II-IV aGVHD was 27.8% and 8.3%, respectively. Additionally, the incidence of cGVHD was 11.1%, all of which were mild cutaneous rejection. The 2-year OS and 2-year GRFS were both 91.7%. Surprisingly, patients under 40 years old have a 2-year OS of 100%. Compared to the traditional Baltimore regimen, this approach reduced the incidence of aGVHD, cGVHD, and CMV reactivation, while improving OS and GRFS, which may offer a new option for Haplo-HSCT in AA patients.
Liu et al. (Sun,) studied this question.