The Relapse from MRD Negativity As Indication for Treatment (REMNANT) Study

391 patients with newly diagnosed multiple myeloma eligible for high dose therapy with autologous stem cell support will be included in the phase II part of the study and receive standard of care first line treatment according to Norwegian national guidelines; bortezomib- lenalidomide - dexamethasone for 4 pre-transplant induction and 4 post-transplant consolidation cycles (all 21-d cycles). After induction patients will undergo tandem or single ASCT, depending on toxicity and response to first ASCT. The primary endpoint of the phase 2 part of the study is the number of patients who achieve MRD negative (Euroflow NGF 10 -5 ) complete response 30-45 days post consolidation. Patients (176) achieving MRD negative complete response will be randomly assigned in a 1:1 ratio to receive second line treatment at MRD reappearance (arm A) or at progressive disease as defined by the IMWG criteria (arm B). Randomization will be stratified by R-ISS stage at diagnosis and single vs tandem ASCT. Patients in arm A will be followed with MRD assessment every 4 month and start second line treatment at loss of MRD negative CR. Patients in arm B will be followed up by standard criteria and start second line treatment at progressive disease. Both arms will receive the same 2.L treatment; carfilzomib - dexamethasone - daratumumab. (all 28-d cycles) Second line treatment will continue until disease progression, unacceptable AEs or patient withdrawal. In arm A MRD Euroflow will be assessed after 6 and 18 months of 2L therapy. In arm B MRD Euroflow will be assessed if >CR is achieved but not before 6 months of 2 L therapy, and again after 12 consecutive months.