Treatment-Free Remission: the New Goal in CML Therapy.

Multiple studies have demonstrated that attempting a treatment-free remission is safe and effective in a select group of patients. More recent data suggested that undetectable BCR-ABL1 by digital PCR prior to discontinuation is highly predictive of successful TFR. However, some patients have a successful TFR with no evidence of clinical disease despite persistent detectable BCR-ABL1. Some recent studies have shed some more light on possible mechanisms for this phenomena. Some possible mechanisms include immune mechanism, BCR-ABL1 detected in the lymphoid component only, or stem cell exhaustion. TFR should be discussed with patients with CML. Patients who achieve a sustained deep molecular response may be eligible to attempt TFR, however, setting expectations that overall only 20% of patients with newly diagnosed CML will achieve a successful TFR. The importance of compliance to treatment early on cannot be overemphasized. Further studies using other drugs to get patients to a deeper remission in order to be eligible for TFR attempt, or attempting a second TFR in patients who had disease recurrence after first TFR attempt, are currently underway.