Kinetics of response and CAR T-cell expansion. (A) Shows the depth of MRD estimated from deep sequencing of the immunoglobulin loci (left y-axis) and T-cell expansion and persistence quantified by qPCR of the CAR transgene (right y-axis) for individual patients over a 42 month follow-up period. The time of ibrutinib discontinuation, where applicable, is indicated by an arrow. (B) quantifies the presence of CD19+ CD20+ B cells in the blood of individual patients over time as an indicator of CAR-T cell functional persistence. MRD, measurable residual disease; VCN, vector copy numbers per microgram of DNA.