2nd or 3rd TKI-stop After 2 Years Nilotinib Pre-treatment in CML-patients

Inclusion Criteria: * Age ≥ 18 years * Patients with Ph chromosome and/or the BCR-ABL (either b3a2 and /or b2a2) fusion gene positive CML * CML in CP having failed a prior attempt to stop imatinib or other TKIs therapy either within EURO-SKI or not * Pretreatment at least one year with any TKI after 1st stop * Written informed consent Exclusion Criteria: * Previous hematological relapse after first stop of TKI. * Failure to any TKI at any time during CML treatment according to current ELN criteria * Previous planned or performed allo SCT * Previous AP/BC at any time in the history of the disease * High cardiac risk according to ESC score (≥ 10 Points) * Impaired cardiac function including any of the following: * Use of a ventricular paced pacemaker; congenital long QT syndrome or family history of; history or presence of significant ventricular or atrial tachyarrhythmias; clinically significant resting bradycardia (\<50 bpm); QTcF \>450 msec at baseline, myocardial infarction before baseline; other clinically significant heart disease (e.g., unstable angina, congestive heart failure, or uncontrolled hypertension). * Treatment with inhibitors of CYP3A4 or medications that have been well documented to prolong the QT interval is contraindicated. * History of acute pancreatitis within one year of study entry or medical history of chronic pancreatitis. * Positive hepatitis B virus serology test or HBV infection * Any other malignancy except if neither clinically significant nor requires active intervention. * Severe or uncontrolled medical conditions (i.e., uncontrolled diabetes, acute or chronic liver disease, pancreatic, or severe renal disease unrelated to tumor, active or uncontrolled infection). * Women who are pregnant, breast feeding, or of childbearing potential without a negative serum pregnancy test at baseline. Male or female patients of childbearing potential unwilling to use an effective barrier contraceptive method