Patients that do not reach PR after induction with VMP or are progressive during treatment with VMP should not be randomized, but switched to the observation arm and treated with Rd immediately. The study treatment ends with the confirmed progression on maintenance treatment (Lenalidomide or placebo) for patients that reached PR with induction treatment, or with the confirmed progression on second-line therapy with Revlimid® and Dexamethasone for patients that did not reach PR on induction treatment. All patients will be followed up every 3 months after end of study treatment, until end of study. The study ends two years after Last Patient In (i.e. randomization for maintenance) if sufficient events for the primary endpoint were received, but not later than 8 years after trial initiation (whatever comes first).