From November 2014 to May 2017, 332 patients homogeneously treated with VRD induction, ASCT and VRD consolidation were randomized to receive maintenance therapy with RD (161 patients) vs IRD (171 patients). RD consisted of lenalidomide 15 mg/d from days 1-21 plus dexamethasone 20 mg/d on days 1-4 and 9-12 at 4-weeks intervals while in the IRD arm oral ixazomib at a dose of 4 mg on days 1,8, and 15 was added. MRD negative patients after 24 cycles were discontinued while those who were …