Inclusion Criteria:  Age ≥ 18 years; Diagnosis of CML-CP with Ph+; ECOG 0, 1, or 2; Patients with imatinib-related Low-grade Adverse Events for more than 12 months and AE lasting for at least 2 months, or relapsed at least 3 times in the past 12 months; Ability to provide written informed consent prior to any study related screening procedures being done  Exclusion Criteria:  Previously documented T315I mutation; Previous treatment with any other tyrosine kinase inhibitor except for imatinib; Prior accelerated phase or blast phase CML; Loss of CHR or cytogenetic response