Long-acting Low Dose Ropeginterferon for Chronic Myeloid Leukemia Treated With Bosutinib From Diagnosis

Bosutinib, provided by Pfizer, starting dose of 200mg QD and stepwise dose escalation (\> 300 mg/d \> 400 mg/d) during the first three months. A pharmacological study will be performed in the French cohort (BOSUSTEP Substudy). BOS residual plasma concentration (Cmin) will be checked after initiation, before each dose step in the French cohort, and at M3 also for Nordic patients in ancillary studies.

Ro-Peg-Interferon α2b will be supplied by AOP Orphan to be administered by subcutaneous injections from prefilled injection pens. RoPegIFN will be given in an open-label fashion. Patients assigned to RoPegIFN will start with 50 μg injected subcutaneously every 14 days, in combination with Bosutinib.