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.