Recent progress in relapsed multiple myeloma therapy: implications for treatment decisions.

The availability of novel therapies for the treatment of multiple myeloma has had a dramatic impact on the depth of response that can be expected on initial treatment. Despite these advances, disease relapse remains inevitable in most patients and brings with it a different set of priorities for therapy. The most recent wave of novel agents may have a particular impact in the relapsed setting. In this review, we examine the evidence currently available from clinical trials for the use of novel agents, particularly in the formation of triplet therapy. We consider data supporting the addition of the proteasome inhibitors carfilzomib and ixazomib, or the monoclonal antibodies elotuzumab or daratumumab, to a treatment backbone of lenalidomide and dexamethasone. The clinical data set is less well developed for the addition of a third agent to the combination of bortezomib and dexamethasone; nonetheless, data are presented supporting the addition of the histone deacetylase inhibitor panobinostat, or elotuzumab or daratumumab. While acknowledging the lack of head-to-head data on which to base comparisons between the numerous regimens, we collate the latest data in order to provide a basis on which to make clinical decisions in this rapidly advancing field.