Tyrosine kinase inhibitors (TKI) have revolutionized the management and prognosis of chronic myeloid leukemia (CML). Daily treatment with TKI, which is necessary due to lack of cure, is frequently associated with moderate, chronic and sometimes severe adverse effects. The ability to permanently stop treatment with TKI has thus become a major goal in CML to prevent the occurrence of adverse events, improve quality of life and reduce the general cost of the treatment; we talk about Treatment Free Remission (TFR). It now remains to be demonstrated in a comparative prospective study that a strategy of de-escalation of the TKI treatment dose before treatment discontinuation optimizes TFR results. At the same time, it is possible to reduce adverse reactions and improve the quality of life of patients. In this context, the investigator propose to conduct a randomized clinical trial including CML patients, allowing to compare the results of TFR at 24 months between a sudden stop of treatment after a maintenance phase of dosage for 12 months and a de-escalation arm of dose (dosage reduced by 50%) for 12 months before stopping. A secondary immunological translational objective of this project will be to compare the quantitative and qualitative evolution of innate CD8 T cells between the 2 arms (abrupt cessation of ITK treatment versus progressive withdrawal) and look for a predictive innate CD8 T cells blood signature at the time of stopping treatment of a successful TFR in both arms.