Current roles for allogeneic hematopoietic cell transplantation following nonmyeloablative or reduced-intensity conditioning.

Nonmyeloablative and reduced-intensity conditioning regimens followed by allogeneic hematopoietic cell transplantation (HCT) have been evaluated in patients with hematologic malignancies who were not considered candidates for conventional HCT because of age or medical comorbidities and in selected patients with metastatic renal cell carcinoma. The regimens have relied more on graft-versus-tumor effects than on chemoradiation therapy to facilitate engraftment and eradicate malignant cells. While nonmyeloablative HCT has been associated with reduced regimen-related toxicities and has been curative for a number of patients with hematologic malignancies, challenges have remained in regard to graft-versus-host disease, infections, and disease progression. In this article, we review data from a number of published phase I and II studies that describe the results of allogeneic HCT after nonmyeloablative conditioning.