Comparison of CAR T–cell persistence between NHL1 and NHL2 T-cell therapy. gDNA was extracted from frozen aliquots of whole blood and tested for the WPRE copy number by TaqMan qPCR. Average copy numbers are presented if ≥2 of 3 replicates generated a cycle threshold (Ct) value. In the time points where only 1 of 3 was detectible, actual value (not average) was plotted. Starting on day 1, participants were measured for WPRE every 7 days (±3 days) during the first 28 days on study and then monthly thereafter. (A) WPRE copy numbers from 1 mL blood collected from day 1 up to day 158 after T-cell infusion in the NHL1 trial, except patient NHL1-3 (who only had PBMC sample), are plotted (whole blood, N = 7). After day 28, there was no detectable WPRE for any patient. (B) WPRE copy numbers from 1 mL blood collected from day 1 up to day 157 after T-cell infusion in the NHL2 trial are plotted (whole blood, N = 8). After day 27, there was no detectable WPRE for any patient. (C) WPRE copy numbers from blood collected from day 1 through day 28 after T-cell infusion in the NHL1 trial are plotted as a function of log10 copies/µg of gDNA (whole blood, N = 7; PBMCs, N = 1; UPN043). Gray area at bottom of graph is below the lower limit of quantification for the assay. (D) WPRE copy numbers from blood collected from day 1 through day 28 after T-cell infusion in the NHL2 trial are plotted as a function of log10 copies/µg of gDNA (whole blood, N = 8). Gray area at bottom of graph is below the lower limit of quantification for the assay. (E) The figure provides box and whisker plots of CAR copy number over time (AUC) by trial and dose level, with the individual patient AUCs shown in black. Box and whisker plots graphically present the median (heavy gray line), the mean (dashed line), low and upper quartiles (ends of the box), and minimum and maximum values. Outlier values are in red. The AUCs were calculated on the log10 WPRE values from day 1 through day 25 after T-cell infusion (see D-E). If a 25-day WPRE was not available, one was interpolated. Measurements that were considered below the limit of quantification were set to 4 copies/μg of gDNA. WPRE data were available from 8 participants (whole blood, N = 7; PBMCs, N = 1) from NHL1 and all 8 participants from NHL2 (whole blood, N = 8). Each participant had 5 to 8 measurements. The mean AUC for NHL2 was 40.2 copies × days/μg and the mean AUC for NHL1 was 25.4 copies × days/μg, giving a mean difference of 14.8 (95% CI: 7.4-22.3), with a P value for the Welch 2-sample 2-tail Student t test of <.001. (F) Mean peak expansion is the peak WPRE value measured in log10 CAR copies/µg of gDNA. Mean peak expansion for NHL1 was 1.6 copies/μg and for NHL2 was 2.79 copies/μg, giving a mean difference of 1.19 (95% CI: 0.54-1.83), yielding a P value of .002 using a t test. (G) Maximum persistence is the day associated with the last value above the lower limit of detection followed by 2 measurement that were below the limit of detection. Mean maximum persistence for NHL1 was 18.25 days and for NHL2 was 20.5 days, giving a mean difference of 2.25 (95% CI: −8.56 to 13.1), yielding a P value of >.5 using a t test.
