Investigational treatments for multiple myeloma.

Multiple myeloma remains a fatal neoplasm and new treatments are urgently needed. In recent years, advances in understanding the molecular pathophysiology of myeloma and the mechanisms of drug resistance led to the development of several novel agents. The drugs with the most available clinical data are thalidomide, bortezomib and lenalidomide. Impressive results obtained with these agents - both in relapsed disease and in newly diagnosed patients - have significantly improved the outcome of myeloma patients. Several other new targeted agents are presently under investigation. These include monoclonal antibodies, agents that target mammalian target of rapamycin, histone acetylation, heat-shock proteins, growth factor signalling cascades, oncogenes, signal transducer and activators of the transcription pathway, Akt pathway and MAPK pathway. Their mechanisms of action, the available knowledge on their efficacy, safety and possible future clinical application are reviewed.