PRIMARY OBJECTIVES:~I. To evaluate the efficacy of the combination of hATG (horse anti-thymocyte globulin), methylprednisolone, cyclosporine, and GCSF (filgrastim) in achieving response (complete response [CR], partial response [PR], or hematologic improvement [HI]) in patients with aplastic anemia, or myelodysplastic syndromes (MDS).~SECONDARY OBJECTIVES:~I. To assess the safety, tolerability, and toxicities of the combination of hATG, methylprednisolone, cyclosporine, and GCSF in patients with aplastic anemia, or MDS. II. To assess time to response, response duration, and overall survival of patients with aplastic anemia, or MDS being treated with the combination of hATG, methylprednisolone, cyclosporine, and GCSF.~OUTLINE:~Patients receive methylprednisolone intravenously (IV) over 10 minutes on days 1-4 and IV or orally (PO) with taper over days 5-30. Patients also receive horse anti-thymocyte globulin IV over 8 hours daily on days 1-4, cyclosporine PO twice daily (BID) on days 1-180, and pegfilgrastim or pegfilgrastim biosimilar subcutaneously (SC) on day 5 and/or filgrastim SC beginning on day 5 and continuing until absolute neutrophil count recovers. Treatment continues for up to 6 months in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up every 6-12 months.
This phase II trial studies methylprednisolone, horse anti-thymocyte globulin, cyclosporine, filgrastim, and/or pegfilgrastim or pegfilgrastim biosimilar in treating patients with aplastic anemia or low or intermediate-risk myelodysplastic syndrome. Horse anti-thymocyte globulin is made from horse blood and targets immune cells known as T-lymphocytes. Since T-lymphocytes are believed to be involved in causing low blood counts in aplastic anemia and in some cases of myelodysplastic syndromes, killing these cells may help treat the disease. Methylprednisolone and cyclosporine work to suppress immune cells called lymphocytes. This may help to improve low blood counts in aplastic anemia and myelodysplastic syndromes. Filgrastim and pegfilgrastim are designed to cause white blood cells to grow. This may help to fight infections and help improve the white blood cell count. Giving methylprednisolone and horse anti-thymocyte globulin together with cyclosporine, filgrastim, and/or pegfilgrastim may be an effective treatment for patients with aplastic anemia or myelodysplastic syndrome.