FeAsiBility of a Treatment Free Interval in Newly Diagnosed MM Patients Treated With Daratumumab-lenalidomide-dexamethasone (HOVON174MM)

Inclusion Criteria: * Patient was diagnosed with MM, based on the IMWG criteria, and measurable disease at the time of diagnosis (appendix A). * Age ≥ 18 years. * Patient was treated with 12 cycles (13 cycles is accepted) of Dara-Rd and will continue treatment with Dara-Rd. Reduced dosing of lenalidomide, but not to less than 5 mg, and previous discontinuation or dose reduction of dexamethasone is allowed. * Partial response or better after treatment with 12 cycles of Dara-Rd, without signs of biochemical progression. * ANC ≥ 1.0x109/L and platelets ≥ 75x109/L. * Patient is capable of giving informed consent. * Written informed consent. Exclusion Criteria: * Patient with non-secretory MM at diagnosis of the disease, i.e., before the start of treatment with Dara-Rd. * Patient in whom a plasmacytoma was the only measurable parameter at diagnosis of the disease, i.e., before the start of treatment with Dara-Rd. * Patient in whom urine M-protein was the only measurable parameter at diagnosis of the disease, i.e., before the start of treatment with Dara-Rd. * Patient in whom treatment with daratumumab, lenalidomide or both has been discontinued for whatever reason (patients may only have discontinued dexamethasone). * Patient in whom continuation of treatment with Dara-Rd is deemed not feasible because of medical reasons. * Any psychological, familial, sociological and geographical condition potentially hampering compliance with the study protocol and follow-up schedule.