ATG as part of the conditioning regimen reduces transplant-related mortality (TRM) and improves overall survival after unrelated stem cell transplantation in patients with chronic myelogenous leukemia (CML).

Abstract

Matched unrelated donor transplants have an increased risk of severe graft-versus-host disease and transplant-related mortality (TRM). ATG has been introduced to decrease GvHD and to facilitate engraftment. We conducted a retrospective analysis of 333 patients with chronic myelogenous leukemia, who were treated with Fresenius ATG (n=145, average=90 mg/kg bw, range 40-90 mg/kg bw) or standard immunosuppression without ATG (n=188). Both groups were comparable regarding distribution of age, sex, HLA-matched vs mismatched donors. ATG Fresenius led to a faster leukocyte engraftment, decreased the incidence of acute GvHD and TRM (P=0.01 and P=0.03) and led to a significant better overall survival (70 vs 57%, P=0.03). We concluded that a prospective randomized study is needed to evaluate the definite role of ATG in hemopoietic stem cell transplantation.