A Study of Imatinib and Valproic Acid in Patients With Chronic Myelogenous Leukemia (CML)

Inclusion Criteria: * All patients, 18 years of age or older, with a diagnosis of CML. * Patients must have a life expectancy of at least 12 weeks. * Patients must have an ECOG performance status of 0-2. * Patients must sign an informed consent. * Patients should have adequate hepatic function with a total bilirubin \< 2 mg/dl and SGOT or SGPT \< two times the upper limit of normal, and adequate renal function as defined by a serum creatinine \< 1.5 x upper limit of normal. * Patients with CML in chronic phase on imatinib as first line therapy who fulfill the following criteria: * The patient has at least two tests for quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for bcr-abl (peripheral blood or bone marrow aspirate). The results of these tests should demonstrate a relative plateau in the effect of imatinib on the detected level of the transcript (i.e. there should less than a ½ log difference between the last two values). Note: Patients will be eligible if the more recent study is greater than the previous study by any value. * The last two quantitative RT-PCR studies should be at least 3 months apart. * The patient should have received at least 9 months of imatinib since the diagnosis of CML. * The patient is tolerating imatinib without any grade 3 or greater toxicity. Exclusion Criteria: * Pregnant women or nursing mothers are not eligible for this trial. Patients of child bearing potential must use adequate contraception. * Patients may receive no other concurrent chemotherapy or radiation therapy during this trial. * Patients with severe medical problems such as uncontrolled diabetes mellitus or cardiovascular disease or active infections are not eligible for this trial. * Patients who have a hypersensitivity to valproic acid, derivatives, or any component of the formulation. Patients with hepatic disease or significant impairment, or urea cycle disorders