Anti-thymocyte Globulin and Cyclosporine as First-Line Therapy in Treating Patients With Severe Aplastic Anemia

PRIMARY OBJECTIVES: To determine the response rate of r-ATG and CsA in the first line setting. SECONDARY OBJECTIVES: To determine the level of IS as assessed by Immuknow assay in responders and compare it to non-responders. OUTLINE:Patients receive anti-thymocyte globulin IV over 4-24 hours daily on days 1-5. Beginning on day 6, patients receive oral cyclosporine twice daily for 6 months followed by a taper. Treatment continues in the absence of disease progression or unacceptable toxicity.