Flow cytometry analysis of longitudinal patient samples. (A) Flow cytometry (FC) analysis over time of total B cells in Rs (red) vs NRs (light blue). Time from last anti-CD20 directed therapy (in months) indicated by lines. P values by Wilcox. (B) Percent PFS for FC patients with higher baseline circulating B cells (red) compared with the remaining patients with lower baseline circulating B cells (blue). (C) FC analysis of T cells (left), NK cells (middle), and lymphocytes (right) before and after infusion; box plot of Rs vs NRs cell type proportions at day –28 (baseline; inset). (D) Percent of monocytes by FC in Rs vs NRs before and after infusion. (E) Ratio of ALC/AMC in Rs (red) vs NRs (blue) at day –28 measured by FC. (F) ALC/AMC at day –28 in all patients treated with commercial axi-cel at DFCI between 2018 and 2022, measured by clinical CBC with differential; Rs (pink; n = 128); NRs (turquoise; n = 102). (G) Percent PFS for ZUMA-1 patients with baseline circulating B cells ≥0.5% (pink) compared with patients with baseline circulating B cells <0.5% (light blue). (H) Percent PFS for ZUMA-1 patients predicted to respond based on baseline circulating B cells ≥0.5% or ALC/AMC ≥ 1.2 (pink) compared with patients predicted to not respond (ie, baseline circulating B cells <0.5% and ALC/AMC <1.2; light blue). NK cell, natural killer cell.