Treatment-free remission after stopping second-line dasatinib.

Treatment-free remission after treatment with a tyrosine-kinase inhibitor (TKI) for chronic myeloid leukaemia is gaining increasing importance, as it offers patients freedom from treatment-related toxic effects and reduces long-term treatment costs. Several studies of imatinib discontinuation have been reported, but the Japanese Dasatinib Discontinuation (DADI) trial reported by Jun Imagawa and colleagues in The Lancet Haematology prospectively assessed discontinuation of second-line or subsequent dasatinib.1 63 patients with chronic myeloid leukaemia who had achieved and maintained molecular response 4·0 (BCR-ABL1 0·01% or less standardised to the International Scale [IS]) for at least 1 year while taking dasatinib were enrolled. The estimated proportion of patients with treatment-free remission 6 months after treatment cessation, the primary endpoint, was 49% (95% CI 36–61). High counts of natural-killer (NK) cells and low counts of γδ+ and CD4+ regulatory T cells (CD25+ CD127low) before discontinuation were significantly correlated with treatment-free remission.