 When the study was unblinded, subjects still on protocol therapy had completed the Double-Blind Induction, and were on monotherapy in Double-Blind Maintenance. Subjects in arm MPRR continued their monotherapy on lenalidomide. Subjects in arms MPRp and MPpp discontinued their placebo monotherapy and went into an observation period in which no antimyeloma therapy was taken. If disease progressed for any subject, the investigator had the option of entering the subject in Open Label Extension Phase to receive lenalidomide therapy up to 25 mg daily or the Follow-up Phase. All subjects were to be followed for at least 5 years from the start of the study. 