Frontline CP-CML Treatment Selection: Treatment-free Remission Eligibility and Retreatment After Relapse

In clinical practice, only a subset of patients become eligible for treatment discontinuation after meeting the required clinical milestones. Typically, this group represents about 20–30% of patients, though this can vary depending on the population and practice setting. Eligibility requires sustained deep molecular response (DMR), usually MR4 or MR4.5 for at least two years, along with adherence to monitoring guidelines. Even among eligible patients, not all choose to stop therapy—some prefer to continue due to anxiety about relapse or comfort with their current regimen.

Among those who attempt treatment-free remission, the majority maintain molecular response initially, but a notable portion do experience molecular relapse. Approximately 40–60% of patients remain in TFR at the 2-year mark, depending on the TKI used and the depth and duration of prior response. The highest risk of relapse typically occurs within the first 6 months of stopping therapy. Regular molecular monitoring (e.g., monthly PCR) is critical during this period to detect early loss of response.

The good news is that most patients who relapse after a TFR attempt respond well to re-initiation of their previous TKI. Molecular responses are usually regained quickly, often within a few months, and without significant new toxicities or resistance. This makes TFR a safe and feasible goal for a well-selected and well-monitored group of patients. However, it remains essential to individualize the decision, considering the patient’s clinical stability, preferences, and access to reliable follow-up.