Advances in multiple myeloma therapy during two past decades

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by aberrant expansion of plasma cells within bone marrow and extramedullary sites. It is one of the most common haematological malignancies; it accounts for 1.4% of all tumours and is responsible for 2% of cancer-related mortality. Over the last decades, the paradigm of MM therapy has changed dramatically - from the conventional combination of oral melphatan + prednisone, high-dose chemotherapy with stem cell (ASCT) support for younger patients to the present paradigm with the use of one (or more) of 3 major new targeted agents - the first-in class proteasome inhibitor bortezomib, the immunomodulatory drug thalidomide, and its more potent derivative lenalidomide. Their use as a part of initial therapy is associated with high overall response rates as well as high rates of complete response (CR), both for elderly patients unable to undergo ASCT and for younger patients treated prior to ASCT. Altogether, the advent of novel agents has resulted in a 50% improvement in median survival. Moreover, the development of new drug classes based on preclinical rationale and the introduction of next-generation agents are likely to further expand treatment options and improve outcomes for especially relapsed MM. This review highlights important historic landmarks as well as more recent events that have played an important role in the evolution of myeloma targeted therapy.