Maintenance and continuous therapy for multiple myeloma

Introduction: In multiple myeloma (MM), maintenance therapy is a longer, less intensive treatment course than initial therapy that is administered postinduction to delay disease progression. Maintenance and continuous therapy have been shown to suppress minimal residual disease and deepen and prolong responses, with the goal of improving progression-free survival and overall survival. Areas covered: In this review, we have summarized current clinical trial data on maintenance and continuous therapy in newly diagnosed MM and relapsed/refractory MM (RRMM), focusing on lenalidomide and bortezomib. We have also analyzed the potential uses of newer agents, including carfilzomib, daratumumab, elotuzumab, pomalidomide, and ixazomib. Expert commentary: Although lenalidomide- and bortezomib-containing regimens have demonstrated safety and efficacy, only lenalidomide is approved for maintenance; it is the preferred agent in the National Comprehensive Cancer Network and European Society for Medical Oncology guidelines. Furthermore, results from the FIRST trial support lenalidomide plus low-dose dexamethasone (Rd) as a standard of care for continuous therapy. In RRMM, newer agents have been successfully added to Rd and data from additional trials are awaited. The vital roles of maintenance and continuous therapy and their benefits are now more clearly understood, but important questions remain regarding optimal duration of therapy and regimens.