The goal of this clinical research study is to see if imatinib mesylate (Gleevec, STI571) can improve CML in chronic phase.

Objectives:

Primary Objective:

To increase the proportion of patients achieving a complete cytogenetic response in patients with Ph-positive early chronic phase CML using initial Gleevec therapy.

Secondary Objective:

To evaluate the duration of cytogenetic response, duration of hematologic response and survival.

Before treatment starts, patients will have a physical exam including medical history and documentation of disease, blood tests, and a bone marrow study. The bone marrow will be removed with a large needle.

Patients on this study will take 400 mg of imatinib daily (morning or evening). If you have side effects, the dose may be lowered. If the response is not good, the dose of imatinib mesylate will be increased to 800 mg daily (400 mg in the morning and 400 mg in the evening) or may be decreased to 300 mg daily based on how the drug is tolerated. Imatinib mesylate should be taken with a large glass of water. Bottles containing the tablets will be given to the patient every 6 months. Unused supplies must be returned at the end of the study.

After completing 3 to 12 months of therapy, response to imatinib mesylate will be evaluated. If the response is good, treatment with imatinib mesylate alone will be continued. Treatment may be continued for up to 20 years, or as long as it is judged best to control the leukemia.

Update: June 2010:

Blood tests are recommended 2 times per year. Your doctor will discuss with you how often you should have blood tests. Bone marrow will be done if your doctor thinks it is necessary to check your disease. You must return to MD Anderson at least once every year. You may not need a bone marrow test every visit, but you will have blood drawn to measure the amount of disease you have. If the leukemia cannot be found for 2 years or longer on the blood test called PCR which is done to measure the amount of disease you have, your doctor may talk to you about stopping treatment with imatinib. If you and your doctor decide to stop your therapy, you will have a blood test for PCR done every 3 to 6 months. You do not need to return to MD Anderson to have this blood test done. You may have the blood taken by your local doctor and mailed to MD Anderson. If the leukemia is found again by the PCR blood test, your doctor may recommend that you restart treatment with imatinib. You may decide to stay on treatment with imatinib even if your PCR blood test does not show any sign of leukemia for 2 years or longer.

This is an investigational study. Imatinib mesylate has been approved in CML. A total of 50 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Diagnosis of Philadelphia chromosome (Ph)- positive or breakpoint cluster region (bcr)-positive CML in early chronic (diagnosis < 12 months).
2. Age 15 years or above
3. Adequate renal, hepatic, cardiac and performance status (ECOG 0-2) - no psychiatric disability (psychosis)
4. Signed informed consent

Exclusion Criteria:

1. Grade 3-4 cardiac
2. Psychiatric problem
3. Pregnant or lactating