Antithymocyte globulin for patients with myelodysplastic syndrome


Dr Jeffrey J. Molldrem University of Texas M. D. Anderson Cancer Center, Department of Hematology, Section of Blood and Marrow Transplantation, Box 24, 1515 Holcombe Boulevard, Houston, TX 77030, U.S.A.


Twenty-five transfusion-dependent myelodysplastic syndrome (MDS) patients (with < 20% blasts) were treated in a phase II study with antithymocyte globulin (ATG) at 40 mg/kg/d for four doses and then followed with blood counts every 2 weeks and clinic visits every 3 months, for a median of 14 months (range 1–38 months). 11 (44%) patients responded and became transfusion-independent after ATG, including three complete responses, six partial responses, and two minimal responses. Responses were observed in 9/14 patients (64%) with refractory anaemia (RA) and 2/6 patients (33%) with refractory anaemia with excess blasts (RAEB). Median response duration was 10 months (range 3–38 months). The Kaplan-Meier estimate of overall survival was 84% at 38 months, with one early death due to pneumonia and two deaths from disease progression to leukaemia. Side-effects consisted mainly of mild serum sickness in all patients. A single course of ATG restored haemopoiesis in some patients with MDS and was well tolerated.