Study of CX-4945 in Patients With Relapsed or Refractory Multiple Myeloma

Inclusion Criteria: * Males or females at least 18 years of age * Confirmed relapsed or refractory multiple myeloma after at least two prior lines of therapy. * Measureable disease. * Karnofsky Performance Status at least 60% * Adequate liver and renal function and hematology laboratory values * Female patients of child-bearing potential must have a negative pregnancy test. * Signed informed consent. Exclusion Criteria: * Treatment with systemic cancer therapy within 21 days before screening. * Major surgery within 4 weeks or minor surgery within 2 weeks of the start of study drug. * Grade 3 sensory neuropathy or motor neuropathy with pain * Concurrent severe or uncontrolled medical disease. * Active systemic fungal, bacterial, and/or viral infection. * Difficulty with swallowing, or an active malabsorption syndrome. * Gastrointestinal diseases including Crohn's disease or hemorrhagic coloproctitis. * History of gastric or small bowel surgery. * Pregnant or nursing females.