Phase II study of thymoglobulin, cyclosporine and G-CSF for initial treatment of aplastic anemia and low risk myelodysplastic syndrome

7093 Background: Aplastic anemia (AA) is commonly treated with equine anti-thymocyte globulin (ATG) and cyclosporine with response rates up to 65%. Thymoglobulin has been used successfully in relapsed/refractory AA, reducing the risk associated with re- administration of equine preparations. Immunosuppressive therapy is also effective in some patients (pts) with myelodysplastic syndrome (MDS). Methods: In this single-arm, phase II study, we investigated efficacy (primary endpoint) and safety (secondary endpoint) of combined thymoglobulin, cyclosporine and G-CSF as a first-line therapy for pts with AA (goal: 30 pts) or low-risk MDS (goal: 30 pts, low or intermediate-1 International Prognostic Scoring System). Thymoglobulin 3.5 mg/kg (or 2.5mg/kg/d for pts ≥55 years) was given for 4 days in the first 10 pts and for 5 days in the remaining pts. Methylprednisone (1 mg/kg/d) was given for 5 days, followed by a tapering dose of oral prednisone. Cyclosporine (5 mg/kg), and G-CSF (5 μg/kg) were also given daily a...