Allogeneic transplantation following nonmyeloablative conditioning for aggressive lymphoma.

Allogeneic hematopoietic SCT following myeloablative conditioning is associated with a high nonrelapse mortality and usually reserved for young, medically fit patients. The use of allogeneic stem cells is associated with a less risk of relapse, but is also associated with the risk of GVHD. The increased antitumor activity is due to graft-vs-tumor immune responses. The newer use of nonmyeloablative or reduced-intensity conditioning has decreased the toxicity of this approach and allows the treatment of older patients or those with medical comorbidities that preclude the use of a myeloablative regimen. A nonmyeloablative regimen using fludarabine and 2 Gy TBI was developed in Seattle that reliably allows allogeneic engraftment from either matched related or unrelated donor stem cell sources. Here we describe our results using this regimen in multicenter studies for the treatment of aggressive non-Hodgkin's lymphoma (NHL) and mantle cell NHL.