CC-5013-MM020/IFM 07-01 is a Phase III, multicenter, randomized, open-label, 3-arm study that will compare the efficacy and safety of two Lenalidomide plus low-dose dexamethasone regimens given for two different durations of time (i.e., until progressive disease [PD] or for up to a maximum of 18 four-week cycles) to that of MPT given for a maximum of 12 six-week cycles.