Reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation in myelodysplastic syndromes and acute myelogenous leukemia

Abstract

The aim of this article is to summarize the outcome in recent studies of patients with acute myelogenous leukemia/myelodysplastic syndromes after reduced intensity conditioning for allogeneic stem cell transplantation. Reduced intensity conditioning has demonstrated the capability to achieve engraftment and to decrease early nonrelapse mortality in older and unfit patients. Most large retrospective studies have demonstrated that reduced intensity conditioning regimens lead to a reduction of nonrelapse mortality in patients with acute myelogenous leukemia and myelodysplastic syndromes, but disease relapse is higher than with standard myeloablative conditioning regimens. Chronic graft-versus-host disease has emerged as one of the more powerful variables reducing relapses and improving overall and disease-free survival. The use of in-vivo T-cell depletion with alemtuzumab or antithymocyte globulin reduces acute graft-versus-host disease but appears to have no impact on survival. Hopefully, a new second generation of reduced intensity conditioning will study new strategies for reducing disease relapse with low nonrelapse mortality. Allogeneic stem cell transplantation with reduced intensity conditioning allows many patients considered ineligible for standard myeloablative conditioning to benefit from this therapy. Research must now focus on designing new strategies for reducing the increased risk of disease relapse.