Study design, dose and mode of administration, and duration of treatment: Multicenter, open-label, single arm, two-stage, Phase II study of dasatinib in combination with melphalan and prednisone (D-MP) in advanced, refractory MM patients. The three drugs will be concurrently administered through 6 cycles; each cycle will be 28 days long (1 cycle = 4 weeks), for a total of 24 weeks of treatment. The treatment schedule will be the following: