Therapy of aplastic anemia with sequential antithymocyte globulin and cyclosporin.

Five consecutive patients with severe aplastic anemia were treated with antithymocyte globulin followed by cyclosporin A. All received antithymocyte globulin initially, and because of lack of response within a 4 week period, cyclosporin was administered subsequently. Hematologic improvement occurred within four months of initiation of cyclosporin. Four patients no longer require blood product support, while one remains transfusion-dependent. In two patients, thrombocytopenia developed when the cyclosporin was tapered but re-institution of the drug resulted in a prompt improvement of counts. These observations indicate that the sequential use of antithymocyte globulin and cyclosporin may be an effective therapeutic approach in the treatment of severe aplastic anemia.