1. Patient is 65 years of age or younger.
2. Patient has a diagnosis of Severe Aplastic Anemia.
3. Patient has a suitable, unrelated donor. (The donor cannot be a family member.)
4. Patient may be either female or male.
Other eligibility criteria may apply.
1. Clonal cytogenetic abnormalities associated with MDS or AML on marrow examination.
2. Diagnosis of Fanconi anemia.
3. Diagnosis of other ?congenital? marrow failure states (such as Diamond-Blackfan, Shwachmann-Diamond, congenital amegakaryocytosis).
4. Symptomatic or uncontrolled heart failure or coronary artery disease.
5. Uncontrolled infection.
6. Blood test results show presence of HIV infection.
7. Pregnancy or breastfeeding.
8. Known allergy to ATG, cyclosporine or tacrolimus.
9. Patient is also enrolled in another phase I study.
10. Patient has had a prior allogeneic marrow or stem cell transplant.
11. Patient has had a prior malignancy, except resected basal cell carcinoma or treated carcinoma in-situ.
Other exclusion criteria may apply.