ADVANCES IN HEMATOPOIETIC CELL TRANSPLANTATION Conditioning regimens for hematopoietic cell transplantation: one size does not fi t all

Anessentialcomponentofallogeneicand autologous hematopoietic cell transplantation (HCT) is the conditioning regimen administered before the hematopoietic cellinfusion.Earlyregimensreliedondose intensity,assumingthathigh-dosechemo-radiotherapy would eliminate malignant disease and reinfusion of the graft would then restore hematopoiesis. However, as the contribution of graft-versus-tumor effects to the success of allogeneic HCT was recognized over time, in an effort to exploit these, many investigators lowered the dose of radiation and chemotherapeutic agents in thepreparativeregimen. This resulted in a major paradigm shift, and consequently, thepool of eligiblepatients underwent a remarkable expansion. In this article, we provide a review of the de-finition of high-dose, reduced-intensity, and nonmyeloablative conditioning regimens, the most commonly used agents and combinations, and the evolution of some early regimens. We also provide a brief review of the toxicities associated with these regimens. ( Blood . 2014;124(3): 344-353)