Kinetics and genomic characteristics of MRD. (A) Serial PB MRD assessments of all participants. (B) Time from initiation of iFCR until MRD conversion (left), and MRD growth kinetics without intervention in 13 patients with MRD conversion (right). Each patient’s study identification number is shown at the end of each line. Serial PB MRD data during retreatment are shown separately in panel E. (C) Status of TP53 and NOTCH1 mutations at pretreatment and at the time of MRD conversion. (D) Status of BTK, PLCG2, and CLL driver gene mutations at MRD conversion. (E) MRD kinetics during ibrutinib retreatment. Asterisks indicate clinical CLL progression. C3, cycle 3 of iFCR; del, deletion; dMRD, detectable MRD (≥10^-4); EoCT, end of combination therapy with iFCR; mut, mutated; NA, not assessed; NE, not evaluable; pre, before initiation of iFCR; Rx, patient who received retreatment with ibrutinib; uMRD4, undetectable MRD (<10⁻⁴); VAF, variant allele frequency; Y, years after iFCR.