Antithymocyte globulin for patients with myelodysplastic syndrome

TLDR

Twenty‑five transfusion‑dependent MDS patients received a phase II ATG regimen of 40 mg/kg/day for four doses, followed by biweekly blood counts and quarterly clinic visits over a median 14‑month period. ATG induced transfusion independence in 44 % of patients (11/25), including 3 complete, 6 partial, and 2 minimal responses, with a median response duration of 10 months, an 84 % overall survival at 38 months, and only mild serum sickness as adverse events.

Abstract

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.