Repeated immunosuppressive rabbit antithymocyte globulin therapy for adult patients with relapsed or refractory aplastic anemia

Objectives Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporin A is the standard treatment for aplastic anemia (AA). However, the efficacy of repeated IST with rabbit ATG (rATG) as salvage therapy remains unclear in patients with relapsed or refractory AA. Methods We retrospectively evaluated the efficacy and safety of IST2 with rATG (IST2‐rATG) in 19 consecutive patients with relapsed or refractory AA who received first‐line IST with rATG in two centers between 2009 and 2020. Results The overall 6‐month response rate of the patients was 58%. The response rates were similar between patients with relapsed and refractory AA. The presence of glycophosphatidylinositol‐deficient blood cells was associated with a better response to IST2‐rATG. Despite retreatment with the same rATG, serum disease and severe allergic reactions were not observed. Conclusion IST2‐rATG is effective and safe for the treatment of adult patients with relapsed and refractory AA after receiving first‐line IST with rATG.