Comparing Imatinib Standard Dose With Imatinib High Dose Induction in Pretreated Chronic Myeloid Leukemia (CML) Patients in Chronic Phase

Inclusion Criteria: 1. Patients \> 18 years of age 2. BCR-ABL positive CML patients in chronic phase, confirmed by karyotype (Ph+) or RT-PCR. 3. Patients pretreated with any drug that is known to control the disease of CML in chronic phase except imatinib (Glivec®). 4. Patients without a major cytogenetic response at study entry (\> 35% Ph+ metaphases in bone marrow cytogenetic analysis performed \< 3 months before study entry). 5. Patients either intolerant to interferon-alpha (non-hematologic toxicity grade 3-4 for more than 2 weeks) or having received pretreatment for CML at least 12 months before study entry. 6. World Health Organization (WHO) status 0-2 7. Adequate end organ function, defined as the following: * total bilirubin \< 1.5 x upper limit of normal (ULN) * SGOT and SGPT \< 2.5 x ULN * creatinine \< 1.5 x ULN * absolute neutrophil count (ANC) \> 1.5 x 10 \^ 9/L * platelets \> 100 x 10 \^ 9/L 8. Female patients of childbearing potential must have negative pregnancy test within 7 days before initiation of study drug dosing. Postmenopausal women must be amenorrheic for at least 12 months to be considered of non-childbearing potential. Male and female patients of reproductive potential must agree to employ an effective barrier method of birth control throughout the study and for up to 3 months following discontinuation of study drug. 9. Written voluntary informed consent. Exclusion Criteria: 1. Patients eligible for allogeneic bone marrow transplantation. 2. Patients in accelerated phase or blast crisis. 3. Known tuberculosis or other uncontrolled infection. 4. Other primary tumor of a different histological origin than the study indication (unless the relapse-free interval is \> 5 years, and with the exception of cervical carcinoma in situ \[CIS\], basal cell epithelioma, or squamous cell carcinoma of the skin). 5. Major surgery within the last 14 days. 6. Known to be HIV positive. 7. Unstable medical disorder (except for indication) that excludes the patient in the opinion of the investigator. 8. Patient has received any other investigational agents within 28 days of first day of study drug dosing. 9. Patients with a WHO performance status score \> 3 10. Patients with Grade III/IV cardiac problems as defined by the New York Heart Association criteria (i.e., congestive heart failure, myocardial infarction within 6 months of study). 11. Female patients who are pregnant or breast-feeding. 12. Refusal by female patients of childbearing age to use a safe contraceptive. 13. Patients with known chronic liver disease (i.e., chronic active hepatitis, and cirrhosis). 14. Patients with any significant history of non-compliance to medical regimens or an inability to grant reliable informed consent.