One course versus two courses of antithymocyte globulin for the treatment of severe aplastic anemia in children

Purpose: The aim of the therapeutic trials was to optimize the treatment of severe aplastic anemia (SAA) and moderate aplastic anemia in children who lack a suitable bone marrow donor, using immunosuppressive therapy in the most effective combination and dose. Patients and Methods: Two sequential therapeutic trials for the treatment of severe and moderate aplastic anemia in children were conducted by 10 institutions. The treatment protocols included antithymocyte globulin (ATG), prednisone, and cyclosporine A (CSA); patients entered on the first protocol, 0190 (ATG × 2), were given two courses of ATG, and those enrolled on the second protocol, 0190B (ATG × 1), were given only one course of ATG. Ten patients were evaluable on ATG × 2. All patients had SAA; three had hepatitis-induced severe aplastic anemia (HI-SAA). Twelve patients were evaluable on ATG × 1; all had SAA, one of whom had HI-SAA. Results: Seven of 10 patients on ATG × 2 responded, and eight of 12 patients treated on ATG × 1 responded. Conclusion: Treatment with immunosuppressive therapy using ATG, CSA, and prednisone was very well tolerated. The response rates in both protocols were similar, and results compare favorably with those of previous therapeutic trials, suggesting that a second course of ATG is not necessary.