Antithymocyte globulin before allogeneic stem cell transplantation for progressive myelodysplastic syndrome: a study from the French Society of Bone Marrow Transplantation and Cellular Therapy.

We investigated the impact of rabbit antithymocyte globulins (ATG) on patient outcomes after allogeneic stem cell transplantation (allo-SCT) for progressive myelodysplastic syndrome (MDS). Of the 242 consecutive patients who underwent allo-SCT for progressive MDS between October 1999 and December 2009, 93 received ATG (ATG group) at the median dose of 5 mg/kg, whereas 149 patients did not (no-ATG group). Donors were sibling (n = 153) or HLA-matched unrelated (n = 89). Patients received blood (n = 90) or marrow (n = 152) grafts after either myeloablative (n = 109) or reduced-intensity (n = 133) conditioning. Three-year overall and event-free survival, nonrelapse mortality, relapse, and chronic graft-versus-host disease (GVHD) development were not significantly different between the 2 groups. In contrast, acute grade II to IV GVHD occurred more often in the no-ATG group (55% of the patients) than in the ATG group (27%, P < .0001). Similar results were observed with acute grade III to IV GVHD (28% and 14% in the no-ATG group and ATG group, respectively; P = .009). In multivariate analysis, after adjustment with propensity score, the absence of ATG was the strongest parameter associated with an increased risk of acute grade II to IV GVHD (hazard ratio, 2.13; 95% confidence interval, 1.35 to 3.37; P = .001]. ATG had no impact on overall and event-free survival or cumulative incidence of the relapse. In conclusion, the addition of ATG to allo-SCT conditioning did not increase the incidence of relapse of patients with progressive MDS. The incidence of acute GVHD was decreased without compromising outcomes.