Combination Therapy of Severe Aplastic Anemia

This study will test the safety and effectiveness of a combination of three drugs in treating severe aplastic anemia and preventing its recurrence. Two drugs used in this trial ATG and cyclosporine are standard combination therapy for aplastic anemia. This study will try to improve this therapy in three ways: 1) by altering the drug regimen to allow the drugs to work better; 2) by reducing the risk of kidney damage; and 3) by adding a third drug mycophenolate mofetil to try to prevent disease relapse. Patients with severe aplastic anemia who do not have a suitable bone marrow donor or who decline bone marrow transplantation may participate in this study. Patients will have a skin test for ATG allergy, chest X-ray, blood test, and bone marrow aspiration before treatment begins. ATG will then be started, infused through a vein continuously for 4 days. Ten days after ATG is stopped, cyclosporine treatment will begin, taken twice a day by mouth in either liquid or capsule form and will continue for 6 months. Also, in the first 2 weeks of treatment, patients will be given a full dose of corticosteroid (prednisone) to prevent serum sickness that could develop as a side effect of ATG therapy. The dosage will be decreased after that. Mycophenolate will be started at the same time as ATG, in two daily doses by mouth, and will continue for 18 months. Patients will be hospitalized at the beginning of the study. During this time, blood will be drawn at 3-week intervals and a bone marrow examination will be repeated 3 months after treatment has begun. Additional tests, including X-rays may be required. After hospital discharge, patients will be followed on an outpatient basis at 3-month intervals. The patients own physician will perform blood tests weekly and kidney and liver function tests every 2 weeks during cyclosporine therapy. Transfusions may be required initially.