A Study to Evaluate 3 Dose Schedules of Daratumumab in Participants With Smoldering Multiple Myeloma

This is a randomized, open-label (identity of assigned treatment will be known to participants and study staff), 3-arm (3 treatment groups), multicenter study of daratumumab in participants diagnosed with intermediate or high-risk Smoldering Multiple Myeloma (SMM \[ie, early disease without any symptoms\]). Participants will be randomized (assigned by chance) to one of 3 treatment groups (arm A \[long intense\], arm B \[intermediate\] and arm C \[short intense\]) to receive daratumumab. Each treatment group will investigate 1 of 3 dosing schedules of daratumumab. The study will include a 28-Day Screening Phase, a Treatment Phase of 1 to 20 treatment cycles (each cycle is 8 weeks in duration for total period of 8 to 160 weeks), and a Follow up Phase of 4-weeks from the last dose of study drug. For participants in Arm A (long intense) and Arm B (intermediate), there is a possibility to extend treatment with IV daratumumab (Q8W) after the end of Cycle 20 if, as per investigator discretion, there is a positive benefit/risk ratio, absence of Grade \>=3 treatment related toxicity, and at least stable disease has been achieved. For participants participating in treatment extension, the duration of infusion may be shortened to a 90-minute infusion or can switch to daratumumab 1800mg subcutaneous (Q8w). The Follow-up Phase will continue until death, lost to follow up, consent withdrawal, or study end, whichever occurs first. The end of the study will occur approximately 7 years after the last participant enrolled receives a first dose of study drug. 'Disease assessment will be performed locally per Standard of Care.