The marked activity of thalidomide (thal) and dexamethasone (dex) in relapsed and refractory multiple myeloma (MM) provided the basis for this phase 2 clinical study aimed at investigating the efficacy and toxicity of thal-dex incorporated into melphalan-based double autologous stem cell transplantation (ASCT)for patients less than 65 years old with newly diagnosed symptomatic MM. Thal-dex was given as primary induction therapy and was then continued throughout the subsequent treatment phases until the day before the second autotransplantation. Primary study endpoints,as evaluated on an intention to treat basis, are response rates to the different treatment phases (induction, first and second ASCT), best response whenever achieved, duration of response (DOR), time to progression (TTP), progression free survival (PFS)and toxicity profile of thal-dex. Secondary endpoints, as evaluated on an intention to treat basis, are overall survival (OS) and clinical outcomes (DOR, TTP, PFS and OS)according to prognostic factors, including cytogenetic abnormalities and imaging features, as detected by 18F-FDG PET/CT.