Compare Lenalidomide and Subcutaneous Daratumumab vs Lenalidomide and Dexamethasone in Frail Subjects With Previously Untreated Multiple Myeloma Who Are Ineligible for High Dose Therapy

Inclusion Criteria: 1. Subject must be at least 65 years of age. 2. Subject must have documented multiple myeloma satisfying the CRAB criteria and measurable disease. 3. Newly diagnosed and not considered candidate for high-dose chemotherapy with SCT. 4. Subject must have a Frailty Score ≥ 2 5. Subject must have within 5 days prior to first drug intake (C1D1) pretreatment clinical laboratory values meeting the following criteria during the Screening Phase: * hemoglobin ≥7.5 g/dL * absolute neutrophil count ≥1.0 x 109/L * platelet count ≥70 x 109/L * aspartate aminotransferase (AST) ≤2.5 x upper limit of normal (ULN) * alanine aminotransferase (ALT) ≤2.5 x ULN * total bilirubin ≤2.0 x ULN * creatinine clearance≥30mL/min 6. Measurable ISS with β2-microglobulin and albumin values for randomization 7. A man who is sexually active with a woman of childbearing potential must agree to use a latex or synthetic condom, even if they had a successful vasectomy. All men must also not donate sperm during the study, for 4 weeks after the last dose of lenalidomide, and for 4 months after the last dose of daratumumab. Women participating in this study must be postmenopausal. 8. Each subject must sign an informed consent form (ICF) indicating that he or she understands the purpose of and procedures required for the study and are willing to participate in the study. Subject must be willing and able to adhere to the prohibitions and restrictions specified in this protocol, as referenced in the ICF. 9. Subjects affiliated with an appropriate social security system. Exclusion Criteria: 1. Subject has a diagnosis of primary amyloidosis, monoclonal gammopathy of undetermined significance, or smoldering multiple myeloma. 2. Subject has a diagnosis of Waldenström's disease, or other conditions in which IgM M-protein is present in the absence of a clonal plasma cell infiltration with lytic bone lesions. 3. Subject has prior or current systemic therapy or SCT for multiple myeloma 4. Subject has a history of malignancy (other than multiple myeloma) within 5 years before the date of randomization 5. Subject has had radiation therapy within 14 days of randomization. 6. Subject has had plasmapheresis within 28 days of randomization. 7. Subject is exhibiting clinical signs of meningeal involvement of multiple myeloma. 8. Subject has known chronic obstructive pulmonary disease (COPD) (defined as a forced expiratory volume \[FEV\] in 1 second \<60% of predicted normal), persistent asthma, or a history of asthma within the last 2 years (intermittent asthma is allowed). 9. Subject is known to be seropositive for history of human immunodeficiency virus (HIV) 10. Seropositive for hepatitis B. 11. (Known to be) seropositive for hepatitis C 12. Subject has any concurrent medical or psychiatric condition or disease that is likely to interfere with the study procedures or results, or that in the opinion of the investigator, would constitute a hazard for participating in this study. 13. Subject has clinically significant cardiac disease, including: * myocardial infarction within 1 year before randomization, or an unstable or uncontrolled disease/condition related to or affecting cardiac function * uncontrolled cardiac arrhythmia or clinically significant ECG abnormalities * screening 12-lead ECG showing a baseline QT interval as corrected by Fridericia's formula (QTcF) \>470 msec 14. Subject has known allergies, hypersensitivity, or intolerance to corticosteroids, monoclonal antibodies or human proteins, or their excipients 15. Subject has plasma cell leukemia or POEMS syndrome 16. Subject is known or suspected of not being able to comply with the study protocol. Subject has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the subject or that could prevent, limit, or confound the protocol-specified assessments. 17. Subject has had major surgery within 2 weeks before randomization or has not fully recovered from surgery. 18. Subject has received an investigational drug (including investigational vaccines) or used an invasive investigational medical device within 4 weeks before randomization or is currently enrolled in an interventional investigational study. 19. Refusal to consent or protected by legal regime ( guardianship, trusteeship) 20. Subject has contraindications to required prophylaxis for deep vein thrombosis and pulmonary embolism 21. Incidence of gastrointestinal disease that may significantly alter the absorption of oral drugs.