Haploidentical/Mismatched Hematopoietic Stem Cell Transplantation for Nonresponders to Immunosuppressive Therapy Compared with First-Line Rabbit Antithymocyte Immunoglobulin Treatment Against Acquired Severe Aplastic Anemia

Abstract

We treated 86 patients with SAA, 31 patients who failed to respond to previous therapy underwent haploidentical hematopoietic SCT (haplo-HSCT, n=26) or mismatched unrelated donor HSCT (MMUD-HSCT, n=5). The other 55 patients were treated with immunosuppressive therapy (IST). At 6 months post-treatment, the treatment failure rates of HSCT and IST groups were 19.35% and 29.09% (P =0.320). Hematopoietic recovery time was shorter in the HSCT group than IST group (P > 0.05). The estimated OS at 3 years was 79.2% ± 7.7% in HSCT group and 89.7% ± 4.4% in the IST group (P =0.058). The estimated failure-free survival (FFS) at 3 years was 79.2% ± 7.7% in the HSCT group and 62.9% ± 8.0% in the IST group (P =0.391). The estimated FFS at 3 years in SAA that had progressed from non-SAA (NSAA) of HSCT was 71.6% ± 14.0% and 16.7% ± 13.6% of IST (P =0.021). Within the HSCT group, 38.71% of the patients developed grade II-IV acute GVHD, and 18.52% of the patients experienced moderate-severe chronic GVHD. These results suggest that haplo-HSCT/MMUD-HSCT and IST have similar treatment failure rate, OS and FFS. haplo-HSCT/MMUD-HSCT might provide a better chance of FFS than IST for SAA that had progressed from NSAA. DisclosuresNo relevant conflicts of interest to declare.