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

PURPOSE OF REVIEW: Treatment-free remission (TFR) is considered one of the main goals of therapy in patients with CML. Our goal in this paper is to review the current data on TFR, and discuss future directions.

RECENT FINDINGS: 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.