This study tests if adding **Ruxolitinib** (a medicine) to a **Tyrosine Kinase Inhibitor (TKI)** helps people with chronic myeloid leukemia (CML) stay in remission longer after stopping TKI. CML is a blood cancer where the bone marrow makes too many white blood cells. Participants must have tried to stop TKI before but had to restart it. The study lasts about 48 months. For 12 months, participants take both Ruxolitinib and TKI. Then, for up to 36 months, participants will be monitored without taking TKI. Tests like central polymerase chain reaction (PCR) will check their health for the first 24 months of this phase.

• Study Length: Approximately 48 months
• Visits and Tests: Regular PCR testing for the first 24 months of treatment-free phase
• Eligibility: Must have CML, previously stopped a TKI, and meet other health criteria

Participants must be able to follow the study's guidelines and attend all appointments. They should not have other health issues that interfere with the study, be pregnant, or have had certain treatments before.