Evolving transplant options for multiple myeloma: autologous and nonmyeloablative allogenic.

High-dose chemotherapy supported by a single autologous hemopoietic stem cell transplant is considered by many to be the "standard of care" for suitable newly diagnosed patients with multiple myeloma. The majority of myeloma patients, however, still die from their disease. Approaches to improve response and overall survival rates include tandem autologous transplants, nonmyeloablative allogenic transplants, and posttransplant maintenance and immunotherapy strategies. Support for tandem autologous transplantation comes from single-center studies as well as the recently reported large IMF94 trial that demonstrated a statistically significant increase in both event-free and overall survival for the double transplant arm. A number of subsequent, but as yet less mature, studies have been presented recently. Although there is some support for the conclusions of the IMF94 trial, the exact place of this therapy is yet to be resolved. Reduced intensity allogeneic transplantation has been proposed as an alternative to conventional allogenic transplantation as a means of reducing the high transplant-related morbidity and mortality of the latter procedure while still retaining the advantages of the allogeneic graft. Preliminary reports suggest a reduction of acute transplant-related complications, although graft-versus-host disease remains a significant issue. Finally, a variety of posttransplant strategies and novel therapeutic agents are in active development.