Evolution of FLT3-ITD mutations between diagnosis and R/R disease. (A) FLT3-ITD status at R/R disease assessed by HTS, according to the treatment group and the type of progression. Left panel: only patients harboring FLT3-ITD macroclones at diagnosis are displayed. Only macroclones are taken into account to determine FLT3-ITD status at R/R disease. Right panel: patients harboring FLT3-ITD microclones and/or macroclones at diagnosis are displayed. Both macroclones and microclones are taken into account to determine FLT3-ITD status at R/R disease. (B) Patterns of evolution of FLT3-ITD microclones and macroclones between diagnosis and R/R disease, according to the number of FLT3-ITD clones detected at diagnosis (either a single clone or multiple clones) and the treatment group. Each square represents 1 patient. Patterns of evolution (from diagnosis to R/R disease) were assessed by HTS and defined as follows. Identical: clone A → clone A. Loss: clone A + clone B → clone A. Gain: clone A → clone A + clone B. Switch: clone A → clone B. Complex changes: clone A + clone B → clone B + clone C. Eradication: clone A → ⦰. ∗, <.05; ∗∗, <.01. Pts, patients.