Patients are enrolled to screening (Reg Step 1) prior to or after ASCT but prior to Reg Step 2. Patients are followed until they will begin Maintenance and then registered to Reg Step 2 (first randomization). Patients are randomized between Lenalidomide for 2 years and Lenalidomide + Daratumumab/rHuPH20. After 2 years of Maintenance, MRD is assessed to guide further therapy. MRD-positive patients will continue with the assigned treatment. MRD-negative patients will be further randomized (Reg Step 3) to either continue or discontinue the assigned treatment. Patients are treated for up to 7 years from Step 2 reg and followed for up to 15 years.