BCR-ABL1^IS level monitored during dose reduction is predictive for individual CML recurrence after TKI cessation. (A) BCR-ABL1^IS dynamics of 2 patients upon dose reduction. The left example corresponds to a patient with a low positive slope of the BCR-ABL1^IS values during the dose reduction period (green line indicates the slope) that remains in TFR after therapy stop. The right example illustrates a patient who is characterized by a high slope during the 12-month dose reduction period (red line) and presents with a recurrence after TKI stop (red dots). (B) Histogram for patient-specific estimates of the individual BCR-ABL1^IS slope during the 12-month dose reduction period (n = 171). The 95%-quantile (red dashed line) of the normal distribution fitted to patients with negative/low slope (green curve) is taken as a cutoff parameter (at 0.068 log[BCR-ABL1^IS] per month) to separate patients with high slopes (red curve). (C) Logistic regression curve for patient-specific estimates of the individual BCR-ABL1^IS slope during the 12-month dose reduction period (n = 171) with corresponding OR and 95% CI per 0.01 log-increase per month. Patients are separated into cohorts with negative/low slopes (green area) and patients with high slopes (red area) by applying the cutoff parameter announced in panel B. (D) Fraction of patients with and without recurrence in the cohorts with negative/low and high slopes during dose reduction (n = 171) and corresponding OR with 95% CI.