Pomalidomide- and dexamethasone-based regimens in the treatment of refractory/relapsed multiple myeloma

Pomalidomide is a potent immunomodulatory agent that is currently a standard of care backbone for the treatment of multiple myeloma (MM) patients in the relapsed/refractory setting after exposure to lenalidomide and a proteasome inhibitor. The present review addresses current knowledge regarding the clinical use of pomalidomide in relapsed myeloma patients. Pomalidomide has direct myeloma cell tumoricidal effects by activating proteasomal degradation of Ikaros and Aiolos transcription factors and also indirect effects by modulation of immune responses, interaction with bone marrow stromal cells, and inhibition of angiogenesis. It is approved by regulatory authorities as doublet combination with dexamethasone but four more triplets are also approved for this setting. Many ongoing trials are evaluating the pomalidomide-dexamethasone backbone with newer anti-myeloma class agents or in quadruplet combinations. Pomalidomide-dexamethasone is currently one of the powerful tools available for use in the relapsed/refractory MM setting. Insights into the synergistic immunomodulatory effects of pomalidomide and other anti-myeloma agents and the mechanisms that overcome clonal resistance will potentially allow targeted use of triplet combinations at each relapse.