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.