The emerging role of consolidation and maintenance therapy for transplant-eligible multiple myeloma patients.

Multiple myeloma (MM) is an incurable malignant cancer of plasma cell origin. It is highly treatable with glucocorticoids, alkylating drugs, and novel agents including the proteasome inhibitors (bortezomib and carfilzomib) and the immunomodulatory drugs (IMiDs) thalidomide, lenalidomide and pomalidomide. Induction regimens incorporating the newer agents have resulted in deeper responses that have translated into prolonged response and survival for transplant eligible and transplant-ineligible MM patients. For the transplant-eligible patient, the current approach to those patients requiring therapy is induction, hematopoietic stem cell (HSC) collection, autologous HSC transplant (AHSCT) which may be followed by consolidation. Maintenance therapies with bortezomib or lenalidomide prolong response and appear to improve overall survival. For very high risk patients, allogeneic (alloHSCT) is an alternative therapy that may improve survival for selected patients. Incorporation of new therapies in combination with existing agents should lead increased response and improved survival of the MM patient with the ultimate goal of development of curative approaches for this disease.