Improving the efficacy of reduced intensity allogeneic transplantation for lymphoma using radioimmunotherapy.

Nonmyeloablative allogeneic transplantation provides a valuable therapeutic option for patients with relapsed non-Hodgkin lymphomas, particularly those that have recurred after autologous transplantation. However, the absence of an intensive conditioning regimen renders this approach less effective for patients with aggressive or bulky lymphoma because rapid tumor growth may outpace the evolution of the graft-versus-lymphoma effect. Radioimmunotherapy provides an attractive, minimally toxic modality to safely prevent early progression of B-cell lymphomas and induce remissions without incurring the risks of traditional intensive therapy. This approach provides a time window during which a robust graft-versus-lymphoma effect may be established before tumor progression, thereby providing more effective long-term disease control. The rationale for incorporation of radioimmunotherapy into reduced intensity allogeneic transplantation regimens for non-Hodgkin lymphoma is discussed, as are current study designs, preliminary results, and future directions.