Longitudinal follow-up of PB MRD in the I-FCG arm, based on the IGHV mutational status. (A) IGHV-mutated status. (B) IGHV-unmutated status. MRD is expressed as percentage of evaluable patients, with MRD+ ≥0.01%, low-level positive MRD+ <0.01%, or undetectable MRD subdivided into mutually exclusive (not cumulative) categories depending on the LOD. Undetectable MRD was subdivided as follows: MRD4 for 10^-4 ≥ LOD >10^-5, MRD5 for 10^-5 ≥ LOD >10^-6, and MRD6 for LOD ≤10^-6. PB MRD was assessed until month 64. N above each bar represents the number of evaluable patients at that timepoint.