The aim of this study is to verify the feasibility of rabbit ATG (Thymoglobulin(R)) (5 mg/kg) in combination with 600 cGy fractionated total body irradiation (fTBI; 200cGy, 3 times) and fludarabine (Flu, 150 mg/m(2)) as a conditioning regimen for haploidentical stem cell transplantation from a related mismatched donor (Haplo-SCT) in adult patients with severe aplastic anemia (SAA). We analyzed 47
consecutive patients who underwent Haplo-SCT, including 24 patients from our previous pilot report. The median age was 36.0 years (17-61) and 25 (53%) patients had very SAA (VSAA) at transplantation. All patients achieved primary engraftment. The cumulative incidence of acute GVHD (grade ≥2) and chronic GVHD (≥ moderate) was 27.7% at 100 days and 13.5% at 3 years, respectively. With a median follow-up of 32.3 months, the 3-year probability of overall survival and failure-free survival was 91.0% and 88.6%, respectively. The 3-year GVHD- and failure-free survival (GFFS) was 71.6%. Offspring donor and lower comorbidity index were independent factors correlated with higher GFFS in multivariate analysis. In conclusion, the outcomes of Haplo-SCT with fTBI 600 cGy/Flu/ATG-5 indicate that Haplo-SCT can be an effective alternative option when fully matched donors are not available, or for patients with VSAA who need an urgent transplant.