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

Inclusion Criteria: Inclusion Criteria - all subjects must: 1. Be at least 18 years of age 2. Subjects must have a documented diagnosis of MM and have either refractory or relapsed and refractory after first line treatment disease defined as: * Primary refractory * Refractory * Relapsed and Refractory 3. Subjects must have undergone prior treatment with one treatment line of anti-myeloma therapy. Induction therapy followed by ASCT and consolidation/maintenance will be considered as one line.Have a confirmed diagnosis of MM 4. Have received lenalidomide after one prior treatment for MM and have reached at least a partial response (PR), according to IMWG criteria, including two consolidating cycles. Subjects have experienced a response at least PR after starting treatment with lenalidomide and cortisone cycles. 5. Have personally signed and dated a legally effective written informed consent form prior to admission to the study. 6. Must be willing and able to understand and comply with the study requirements. 7. Females of childbearing potential must agree to ongoing pregnancy testing and to practice contraception. 8. Male must agree to practice contraception Exclusion Criteria: 1. Any of the following laboratory abnormalities: * Absolute neutrophil count (ANC) \< 1,000/µL * Platelet count \< 75,000/ µL * Creatinine Clearance \< 45 mL/min according to Cockcroft-Gault formula * Serum SGOT/AST or SGPT/ALT \> 3.0 x upper limit of normal (ULN) * Serum total bilirubin \> 2.0 mg/dL 2. ECOG performance status \<4. 3. Individuals who have had a stem-cell transplant as a 2nd line treatment for MM 4. Individuals who have taken any experimental drugs or participated in a clinical trial within 30 days prior to screening. 5. Individuals with significant psychiatric illness or a clinically significant acute/chronic uncontrolled medical condition that might affect their experience of myeloma symptoms or their ability to describe them. 6. Pregnant or lactating females. 7. Any other clinically significant medical disease or condition that, in the Investigator´s opinion, may interfere with protocol adherence or a subject´s ability to give informed consent.