A Systematic Review on Second Treatment-Free Remission (TFR) Attempt in Chronic Myeloid Leukemia (CML): Can it be Applied in Clinical Practice?

The prognosis and life expectancy of chronic myeloid leukemia (CML) patients have improved significantly with the launch of first tyrosine kinase inhibitor (TKI), imatinib. Maintaining at least one major molecular response in CML patients without the use of TKI is known as treatment-free remission (TFR). The safety of the first TFR (TFR1) effort has been reported by numerous studies. However, some patients relapse during TFR1. A second TFR (TFR2) can be tried again in those patients. This systematic review aims to evaluate individual patient characteristics for a TFR2, factors predicting successful TFR2, monitoring, consequences of the cessation of TKI, and studies about TFR2. We identified 5 studies related TFR2. The results showed that the first failed TKI discontinuation attempt is not an indicator of a second TKI discontinuation failure. TKIs could safely and successfully be discontinued for a second time in chronic phase CML patients despite a TFR1 failure. The most important factors for estimating TFR2 success are the speed of molecular relapse and the TKI-free duration after the first TKI discontinuation attempt. New trends in the management of CML patients are reducing the side effects of treatment, lessening the financial burden, and improving the quality of life of patients as CML has developed into a manageable chronic disease rather than an aggressive cancer. Although there are many studies and guidelines on TFR1, there are few studies on TFR2 and predictive factors. More data is still needed regarding TFR2 attempt in patients with CML.