The purpose of this study is to determine how effective and safe a new investigational drug is in treating patients with relapsed or refractory multiple myeloma. The treatment involves daily dosing. A patient may continue to receive the treatment as long as they are benefiting from the treatment. Blood samples will be taken at specific times to measure the amount of drug in your body at specific times after the drug is given. Blood samples will also be taken for lab tests such as complete blood counts and clinical chemistries. Physical exams will be performed before each treatment. During the treatment phase, the patients will undergo regular assessments for safety and clinical response.