This is a multicenter, randomized, blinded, 2-arm phase IIb trial that will compare the efficacy and safety of Lenalidomide maintenance after Bortezomib/Melphalan/Prednison (VMP) induction to VMP without maintenance (Placebo). In addition the trial will assess the treatment of Revlimid/low dose Dexamethasone (Rd) as Salvage after VMP without sufficient response (less than PR) in an observational arm. Key eligibility criteria include patients with newly diagnosed multiple myeloma and who are 65 years of age or older or are not candidates for high-dose chemotherapy and autologous stem cell transplantation. Patients with poor performance status or serious coexistent medical conditions will be excluded from this study. After registration all patients receive 6 cycles VMP (modified according to Mateos et al.). Patients who receive at least a PR and completed VMP can be randomized to either Lenalidomide 10 mg/d continuously maintenance or to placebo. Randomization will be stratified according to the quality of response after VMP induction (PR vs. VGPR + stringent complete remission [sCR] + CR). Patients that are not able to complete VMP due to toxicity but reached at least a PR after a minimum of four cycles of therapy should immediately proceed to randomization. Blinded phase continues until progression or end of study. After unblinding, patients who received placebo should be treated with Rd.