This is a multicenter, Phase 3, randomized, open-label study comparing daratumumab, pomalidomide and low-dose dexamethasone (DaraPomDex) with pomalidomide and low-dose dexamethasone (PomDex) in subjects with relapsed or refractory Multiple Myeloma who have received at least 1 prior treatment regimen with both lenalidomide and a proteasome inhibitor and have demonstrated disease progression. Subjects will be randomized in a 1:1 ratio to receive either DaraPomDex or PomDex. The original design of this study was to treat subjects with daratumumab for intravenous (IV) infusion (Dara IV); however, as of Amendment 1, all new subjects will be dosed subcutaneously with daratumumab co-formulated with recombinant human hyaluronidase rHuPH20 (hereafter referred to as Dara SC). Subjects who already began treatment with Dara IV (ie, prior to Amendment 1) will have the option to switch to Dara SC on Day 1 of any cycle starting with Cycle 3 or later for the remainder of their participation in the study, and they will be counted toward the total of 302 subjects. Subjects will receive treatment until disease progression or unacceptable toxicity. Drug administration and follow-up visits will occur more frequently for early cycles (e.g., weekly or bi-weekly). Disease evaluations will occur every cycle and consist mainly of measurements of myeloma proteins. Subject safety will be assessed throughout the study. The primary endpoint will be progression-free survival (PFS). Study end is anticipated at approximately 5 years after the last subject is randomized.