Factors affecting response and survival in patients with myelodysplasia treated with immunosuppressive therapy

Purpose Marrow failure in some patients with myelodysplastic syndrome (MDS) responds to immunosuppressive treatment (IST), but long-term outcome after IST has not been described. We evaluated patients with MDS treated with IST at our institution to determine their clinical course compared with a comparable supportive care only group. Patients and Methods One hundred twenty-nine patients with MDS received IST with a median follow-up of 3.0 years (range, 0.03 to 11.3 years), using antithymocyte globulin (ATG) or cyclosporine (CsA) in combination or singly. Variables affecting response and survival were studied and outcomes were compared with those of 816 patients with MDS reported to the International Myelodysplasia Risk Analysis Workshop (IMRAW) who received only supportive care. Results Thirty-nine (30%) of 129 patients receiving IST responded either completely or partially: 18 (24%) of 74 patients responded to ATG, 20 (48%) of 42 patients responded to ATG plus CsA, and one (8%) of 13 patients responded to CsA. Thirty-one percent (12 of 39) of the responses were complete, resulting in transfusion independence and near-normal blood counts. In multivariate analysis, younger age was the most significant factor favoring response to therapy. Other favorable factors affecting response were HLA-DR15 positivity and combination ATG plus CsA treatment (P = .001 and P = .048, respectively). In multivariate analysis of the combined IMRAW and IST cohorts, younger age, treatment with IST, and intermediate or low International Prognostic Scoring System score significantly favored survival. Conclusion IST produced significant improvement in the pancytopenia of a substantial proportion of patients with MDS and was associated with improved overall and progression-free survival, especially in younger individuals with lower-risk disease.