Sequential BCR::ABL1 evaluation during dose de-escalation in peripheral blood is more predictive of TFR success than single assessment at dose de-escalation in either peripheral blood or bone marrow

Continuous tyrosine kinase inhibitor (TKI) treatment provides rapid disease control in almost all patients with chronic phase (CP) chronic myeloid leukemia (CML), leading to near-normal survival [ 1 , 2 ]. However, most patients report poorer quality-of-life due to TKI-related side-effects [ 3 , 4 , 5 , 6 ]. Some of the CP-CML patients achieving deep molecular responses (DMR; BCR::ABL1 IS \(\,≤\) 0.01%) can stop their TKI, often after many years of therapy, and successfully maintain major molecular response (MMR; BCR::ABL1 IS \(≤\) 0.1%), termed “treatment-free remission” (TFR) [ 7 ]. Longer durations of TKI treatment and DMR are associated with improved rates of successful TFR; however, a reliable prediction of individual TFR success is not possible.