Discontinuation of therapy and treatment-free remission in CML

Tyrosine kinase inhibitor (TKI) treatment of chronic myeloid leukaemia (CML) has resulted in a life expectancy comparable to that of the general population for many individuals. This has led patients and clinicians to question whether, after a sustained period of deep molecular response, it might one day be possible to discontinue the TKI. A sustained molecular response without the need for ongoing treatment is referred to as a treatment-free remission (TFR). TFR has many potential advantages: patients in TFR may be free of chronic TKI toxicities that affect quality of life, and they may avoid the potential for late emerging toxicities (e.g. vascular events with nilotinib, pulmonary complications with dasatinib). It is imperative that young women with CML stop TKI prior to pregnancy due to the risk of teratogenesis. This can be achieved most safely for the mother and the baby if TFR has already been established. TFR reduces the considerable economic burden of long-term drug provision and improves the cost-effectiveness of the treatment. In this chapter, we review the clinical and biological data relevant to the topic of treatment discontinuation.