Phase II trial of co-administration of CD19- and CD20-targeted chimeric antigen receptor T cells for relapsed and refractory diffuse large B cell lymphoma

Abstract

Purpose: Anti-CD19 chimeric antigen receptor T (CAR-T) cell therapy has demonstrated remarkable efficacy for refractory and relapsed diffuse large B cell lymphoma (R/R DLBCL). However, this therapy failed in nearly 25% patients mainly due to antigen loss. The authors performed a phase Ⅱ trial by coadministration of anti-CD19 and anti-CD20 CAR-T cells treatment for R/R DLBCL and evaluated its efficacy and toxicity.

Methods: Totally 21 patients with DLBCL were enrolled in this study. The patients were conditioned with fludarabine and cyclophosphamide before the infusion of anti-CD19 and anti-CD20 CAR-T cells. Treatment response, toxicity, and persistence were monitored continuously.

Results: Of the 21 patients received the treatment, the objective response rate (ORR) is 81.0% (95% confidence interval [CI], 58.1%-94.6%) with four cases of bulk (4/5) and one case of testis involvement; 52.4% (95% CI, 29.8%-74.3%) had a complete response (CR). Peak levels of anti-CD19 and anti-CD20 CAR cells were associated with response (P = .007 and .002). Grade 3-4 cytokine release syndrome (CRS) and neurologic events occurred in 28.5% and 9.5% patients, respectively. Median overall survival (OS) and progression-free survival (PFS) were 8.1 and 5.0 months, respectively. The maximum standard uptake value (SUVmax) of CD4/CD8 ratio before and after infusion were associated with responses, and the total lesion glycolysis (TLG) before infusion correlates with cytokines level.

Conclusions: Coadministration of anti-CD19 and CD20 CAR-T cells therapy for DLBCL is feasible with manageable toxicity. Cytokine markers are related to toxicity and SUVmax could predict efficacy. This trial was registered at www.clinicaltrials.gov as NCT03207178.

Keywords: CAR-T; CD19; CD20; DLBCL; clinical trial.

FIGURE 1

Design of chimeric antigen receptor (CAR) targeting CD19 and CD20. (A) Schematic of anti‐CD19 CAR and anti‐CD20 CAR. Single‐chain (sc) Fv region recognizes CD19 or CD20, CAR contained 4‐1BB costimulatory domain and CD3‐ζ T cell activation domain. (B) Fludarabine combined with cyclophosphamide was used as the pretreatment regimen. Cells were ready for infusion on day 0

FIGURE 2

Function of anti‐CD19 and anti‐CD20 CAR‐T cells in R/R DLBCL. (A, B) The median PFS and OS of 21 patients are shown. (C) The response duration and non‐relapse mortality (NRM) (D) of 17 patients with response are shown. The survival fractions were calculated by the Kaplan‐Meier method, and the (green) lines indicate censored patients. (E) The clinical responds and survival condition of anti‐CD19 combined with anti‐CD20 CAR‐T cells therapy

FIGURE 3

Changes of serum biomarkers and CD4/CD8 ratio after CAR‐T cell infusion. (A‐D) IL‐6, IFN‐γ, ferritin, and CRP were associated only with CRS. The peak value is defined as the maximum level of the cytokine after baseline within a month of cell infusion. The peak factor is the value in patients with CRS of grade 3‐4 vs those with events of grade 1‐2. The horizontal line within each box represents the median, the lower and upper borders of each box represent the 25th and the 75th percentiles, respectively, and the I bars represent the minimum and maximum range. The Mann‐Whitney U test or t test was used for statistical analysis. (E) Dynamic changes of CD4/CD8 ratio in patients after CAR‐T cell infusion. P6, 9, 10, and 11 were CR patients, P12, 14, and 15 were PR patients, P18 was SD patient, and P19 was PD patient. (F) Dynamic changes of CD4/CD8 ratio in 17 patients with response. (G) Dynamic changes of CD4/CD8 ratio in 9/17 patients with relapse after CAR‐T cell infusion. (H) Dynamic changes of CD4/CD8 ratio in patients with response duration. The Wilcoxon rank‐sum test or t test were used for statistical analysis

FIGURE 4

Expansion and persistence of anti‐CD19 and anti‐CD20 CAR‐T cells in vivo. (A, B) Peak CAR DNA copies of anti‐CD19 and anti‐CD20 CAR‐T cells in the groups with response and without response. (C) Peak CAR DNA copies of anti‐CD19 CAR‐T cell and anti‐CD20 CAR‐T cell in patients of CR. (D, E) CAR DNA copies of anti‐CD19 CAR‐T cell at serial time points after infusion in patients who developed grade 1‐2 CRS and those who developed grade 3‐4 CRS. (F) Peak CAR DNA copies of anti‐CD19 CAR‐T cell in the groups with grade 1‐2 and grade 3‐4 CRS. (G, H) CAR DNA copies of anti‐CD20 CAR‐T cell at serial time points after infusion in patients who developed grade 1‐2 CRS and those who developed grade 3‐4 CRS. (I) Peak CAR DNA copies of anti‐CD20 CAR‐T cell in the groups with grade 1‐2 and grade 3‐4 CRS. The horizontal line at 100 copies per microgram of DNA represents the lower limit of quantification of this assay. The Mann‐Whitney U test was used for statistical analysis

FIGURE 5

The values of SUVmax and TLG in response, CRS and CAR‐T cells expansion. (A, B) The vaule of SUVmax and TLG in the groups with and without response. (C, D) The vaule of SUVmax and TLG in grade 1‐2 and grade 3‐4 CRS. (E‐H) Peak CAR DNA copies of anti‐CD19 and anti‐CD20 in below and above the median SUVmax/TLG groups. (I‐P) The peak value of serum biomarkers (IL‐6, IFN‐γ, ferritin, and CRP) in below and above the median SUVmax/TLG groups. The peak value is defined as the maximum level of the cytokine after baseline within a month. The data represent the means ± SD. The Mann‐Whitney U test or t test were used for statistical analysis