Discontinuation Study

Inclusion Criteria: 1. 18 years of age or over 2. Patient with diagnosis of multiple myeloma as per IMWC in first line of treatment (induction, consolidation, ASCT, maintenance is considered single line therapy for the purpose of this study, also discontinuation of 1 maintenance regimen due to toxicity and start of another is considered single line therapy for the purpose of this study). 3. Received at least 2 years of maintenance therapy, defined as any anti-myeloma therapy to prevent disease recurrence and prolong time in remission 4. Patients who have discontinued maintenance therapy earlier than 2 years due to side effects but also achieved sustained MRD negative CR might be also included 5. Patients must be able to understand and be willing to sign a voluntary informed consent form and agree to compliance with the protocol schedule, with the knowledge that they may withdraw consent at any time without impact on future medical care. Exclusion Criteria: 1. Patients who have received more than one line of therapy (induction, consolidation, ASCT, maintenance is considered single line therapy for the purpose of this study, also discontinuation of 1 maintenance regimen due to toxicity and start of another is considered single line therapy for the purpose of this study) or patients who have not completer two years of maintenance therapy, unless maintenance was discontinued voluntarily and the patient has achieved sustainable MRD negative remission.. 2. Patients with plasma cell disorders other than MM: lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia, AL amyloidosis, POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, and Skin changes), etc… 3. Prior organ transplant or condition requiring immunosuppressive therapy. 4. Prior allogenic haematopoietic cell transplant 5. Treatment with any investigational therapy that does not include maintenance as a part of the treatment strategy. 6. Unable to sign an informed consent form.