Novel therapeutic targets for multiple myeloma.

The past decade has witnessed a dramatic improvement in the therapeutic options in multiple myeloma (MM). Several novel biologically targeted agents are in clinical use and have resulted in improved outcomes. However, the disease remains incurable, underscoring the need for continued efforts towards understanding MM biology, better risk stratification and exploitation of novel therapeutic approaches. Novel agents that target tumor and stromal compartments can be categorized as those that target protein dynamics (e.g., heat shock protein 90 and the ubiquitin-proteasome system), intracellular signaling kinases (e.g., JAK/STAT, PI3k/Akt/mTOR and MAPK pathways), cell cycle molecular machinery (e.g., cyclin-dependent kinase inhibitor and Aurora kinase inhibitors), membrane-bound receptors (e.g., IGF-1, VEGF and CD40), epigenetic modulators (e.g., DNA methyltransferase and histone deacetylase), tumor vasculature and microenvironment (e.g., angiogenesis and integrins) and agents modulating anti-MM immune responses. This article focuses on a series of new therapeutic targets that have shown promising preclinical results and early evidence of anti-MM activity in clinical studies, either alone or in combination with other conventional or novel anti-MM treatments.