Imatinib (Gleevec(Registered Trademark)) to Treat Chronic Myelomonocytic Leukemia and Atypical Chronic Myelogenous Leukemia

This study will evaluate the safety and effectiveness of imatinib (Gleevec(Registered Trademark)) in patients with chronic myelomonocytic leukemia (CMML) and atypical chronic myelogenous leukemia (CML). These conditions cause uncontrolled growth of malignant (cancerous) cells in the bone marrow that prevents the bone marrow from functioning normally in producing blood cells. The cancer cells also can spill over into the blood and invade other organs of the body. Imatinib has been approved by the Food and Drug Administration for treating chronic myelogenous leukemia, which has characteristics similar to atypical CML and to CMML, and data from other research suggests this drug may be able to produce a remission in forms of leukemia other than CML. Patients over 18 years of age with atypical CML or CMML may be eligible for this study. Candidates are screened with a medical history and physical examination, blood tests, electrocardiogram, chest x-ray, and bone marrow aspiration and biopsy (removal of a small piece of bone marrow tissue through a needle inserted into the hip bone). Participants take imatinib capsules once a day for 2 years. If at any time during the study the patient's blood counts begin to rise, disease symptoms develop, or the disease has progressed, the dose of imatinib is increased each week until the disease progression is stopped. Any patient whose disease does not response to treatment after 6 weeks of increased dosing and 30 days at the maximum daily dose of 800 mg is taken off the study and referred for different treatment. Patients are seen by their referring physician every week for the first 4 weeks of the study, every other week for the next 8 weeks, and then monthly until the study is completed. At each visit, blood is drawn to monitor for drug side effects and response to therapy. In addition, patients come to the NIH Clinical Center every 3 months for a complete history and physical examination and for a bone marrow aspiration and biop