Randomized Trial Comparing Lenalidomide With Low Dose Dexamethasone Versus Lenalidomide in Second Line Multiple Myeloma

This is: * A prospective, randomized, open, phase II, multi-centre, interventional study. Patients who are in at least PR and have received lenalidomide as 2nd line treatment for MM will be recruited. * The patients will be randomized into two groups. Group R will receive lenalidomide 25 mg/day p.o. continuously for 21 days and group Rb will receive a similar dose of lenalidomide with the addition of 40 mg of dexamethasone p.o. on days 1, 8, 15 and 22 of every 28 day treatment cycle. Study includes a maximum of 24 cycles including two consolidating cycles per patients.