Clark RE, et al. - Given the abrupt discontinuation of tyrosine kinase inhibitor (TKI) treatment in all studies of treatment-free remission (TFR) in patients with chronic myeloid leukemia with a focus on patients with stable MR4 (BCR-ABL to ABL ratio ≤0·01%), researches investigated the influence of gradual treatment withdrawal and the feasibility of TFR for patients with less deep but stable remission. In the De-Escalation and Stopping Treatment with Imatinib, Nilotinib, or sprYcel (DESTINY) study undertaken at 20 UK hospitals, researchers included patients (aged ≥18 years) with chronic myeloid leukaemia in first chronic phase, who had received TKI therapy for 3 years or more, with three or more BCR-ABL quantitative PCR transcript measurements ( BCR-ABL to ABL1 ratio) less than 0·1% (major molecular response [MMR]) in the 12 months before entry. De-escalation of The MR4 group comprised patients with all PCR measurements of less than 0·01%. TKI treatment to half the standard dose was done for 12 months, then it was stopped for a further 24 months, with frequent PCR monitoring. Outcomes support the possibility of achieving improvement in the success of TFR protocols via initial de-escalation before discontinuation, although the mechanism of its benefit is not yet clear. The findings support further study of TFR in patients with stable MMR.