A multicenter phase III study evaluating the efficacy of an imatinib mesylate dose-tuning strategy on molecular response in patients with chronic myeloid leukemia in chronic phase treated with imatinib mesylate 400 mg/day for at least two years, and in complete cytogenetic response for at least one year. - MIM

PRIMARY OUTCOME: Main Objective: To compare the efficacy of an imatinib mesylate dose-tuning strategy (based on trough plasma concentration of IM) to the efficacy of a standard strategy (fixed-dose IM of 400 mg/day). Primary endpoint(s): BCR-ABL transcript levels will be analyzed by RT-PCR at baseline, and at 3, 6, 9, and 12 months. Treatment is considered effective at 12 months if: for patients with a baseline transcript level less than 0.1%: transcript level less than or equal to 0.001% or undetectable. • For patients with a baseline transcript level greater than 0.1%: transcript level less than 0.1% Secondary Objective: • Evaluate the rate and time to achieve a complete molecular response at 6, 9 and 12 months; • Evaluate the rate and time to achieve a major molecular response at 6, 9 and 12 months; • Evaluate the rate and time to achieve a first undetectable BCR-ABL transcript level at 6, 9 and 12 months; • Evaluate overall survival and progression-free survival at 12 months; • Evaluate the tolerance of IM. INCLUSION CRITERIA: 1. Patients with CML-PC treated for at least two years with Imatinib Mesylate 400 mg/day, 2. Patients in complete cytogenetic response for at least one year, 3. Patients with detectable minimal residual disease by quantitative RT-PCR, 4. ECOG performance status ≥ 2, 5. Age ≥ 18 years, 6. Signed informed consent, 7. Treatment compliance, 8. Social security coverage. Are the trial subjects under 18? No. Number of subjects for this age range: F.1.2 Adults (18–64 years) Yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (≥ 65 years) Yes F.1.3.1 Number of subjects for this age range