CDC-501 Therapy in Relapsed or Refractory Multiple Myeloma

* Subject must be diagnosed with multiple myeloma (with measurable M-Protein in serum and/or urine), and be considered to have disease progression after at least two cycles of treatment or have relapsed after treatment. * Subject must understand and voluntarily sign an informed consent document. * Subject must not have received corticosteroids, other chemotherapy, thalidomide, or other investigational agents, within 21 days of baseline * ECOG (Zubrod) performance status of 0 to 2. * Subject must be able to adhere to the study visit schedule and other protocol requirements. * Women of childbearing potential (WCBP ) must have a negative serum or urine pregnancy test within 7 days of baseline. In addition, sexually active WCBP must agree to use adequate contraceptive methods (oral, injectable, or implantable hormonal contraceptive; tubal ligation; intra-uterine device; barrier contraceptive with spermicide; or vasectomized partner) while on study drug.