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To address antigen escape and loss of T-cell functionality, we report a phase I clinical trial (NCT04007029) evaluating autologous naive and memory T (TN/MEM) cells engineered to express a bispecific anti-CD19/CD20 chimeric antigen receptor (CAR; CART19/20) for patients with relapsed/refractory non-Hodgkin lymphoma (NHL), with safety as the primary endpoint. Ten patients were treated with 36 × 106 to 165 × 106 CART19/20 cells. No patient experienced neurotoxicity of any grade or over grade 1 cytokine release syndrome. One case of dose-limiting toxicity (persistent cytopenia) was observed. Nine of 10 patients achieved objective response [90% overall response rate (ORR)], with seven achieving complete remission [70% complete responses (CR) rate]. One patient relapsed after 18 months in CR but returned to CR after receiving a second dose of CART19/20 cells. Median progression-free survival was 18 months and median overall survival was not reached with a 17-month median follow-up. In conclusion, CART19/20 TN/MEM cells are safe and effective in patients with relapsed/refractory NHL, with durable responses achieved at low dosage levels.Significance:Autologous CD19/CD20 bispecific CAR-T cell therapy generated from TN/MEM cells for patients with NHL is safe (no neurotoxicity, maximum grade 1 cytokine release syndrome) and demonstrates strong efficacy (90% ORR, 70% CR rate) in a first-in-human, phase I dose-escalation trial.This article is highlighted in the In This Issue feature, p. 517

Representativeness of study participants

CART19/20 cell product characteristics. (A) % CD4+ among total T cells and CAR-expressing T cells. (B) Comparison of T-cell subtype frequency among CD4+ vs. CD8+ T cells in cryopreserved CART19/20 cell products. Te/exh: effector/exhausted T cells, CD45RA+/CD45RO–/CD62L–; Tem: effector-memory T cells, CD45RA–/CD45RO+/CD62L–; Tcm: central-memory T cells: CD45RA–/CD45RO+/CD62L+; naïve: CD45RA+/CD45RO–/CD62L+. (C) Phenotype of leukopak content prior to cell isolation. (D) Phenotype of cells obtained after isolation. (E) CD14 and CD25 expression patterns among CD62L+ cells in patient leukopak content prior to cell isolation.

T cell populations become CD8-dominant post CART19/20 cell infusion. % CD8+ among (A) CAR-expressing T cells and (B) all CD3+ T cells was quantified by flow cytometry. Data are shown for CAR-T cells only up to day 90 post infusion as values post day 90 become unreliable due to low CAR+ cell count detected by flow. FP: final product (i.e., cryopreserved CART19/20 cells).

PET scans taken for all patients treated with CART19/20 cell therapy.

CD14/CD20 depletion did not significantly alter regulatory T (Treg) cell content in CART19/20 cell product and in patient peripheral blood post infusion. Intracellular staining of starting (unactivated) TN/MEM population, CART19/20 final product, and patient PBMC collected 14 days post CART19/20 infusion. FOXP3+ frequency is shown as a percentage of CD3+CD4+ T cells.

Flow-cytometry analysis of post-infusion peripheral blood samples. (A) Gating strategy for T-cell analysis in CART19/20 cell products and post-infusion patient peripheral mononuclear blood cells (PBMCs). Two viable gates were set based on side scatter (SSC-A) vs. forward scatter (FSC-A). The more restrictive “Viable” gate includes only viable lymphocytes, to enable more precise identification of T cells. The “Viable (inclusive)” gate includes all viable PBMCs, to enable calculation of CAR-T cells as a fraction of PBMCs. Truncated epidermal growth factor receptor (EGFRt) is co-expressed with the CAR, and EGFRt staining is used for CAR expression detection. Percent CAR+ T cells among viable singlets as shown in main-text Fig. 4b is the EGFRt+ population as a % of grandparent in the viable PBMC branch.Percent CAR expression among T cells as shown in main-text Fig. 4c is the EGFRt+ population as a % of parent in the viable lymphocyte branch. (B) Examples of post-infusion patient sample analysis.

Patient 009 exhibited elevated cytokine, C-reactive protein, and ferritin levels prior to and after CART19/20 cell infusion. (A) Serum levels of various cytokines measured by Luminex multiplex assay. (B) C-reactive protein (CRP) levels for Patient 009 (left-most) and all patients (second from left). Peak and median CRP levels are shown in box-and-whisker plots. (C) Ferritin levels for Patient 009 (left-most) and all patients (second from left). Peak and median ferritin levels are shown in box-and-whisker plots.

Comparison of CART19/20 cell therapy results with reported data from trials evaluating other CD19/CD20 bispecific CAR-T cell therapies and commercially available CD19 CAR-T cell therapies.

To address antigen escape and loss of T-cell functionality, we report a phase I clinical trial (NCT04007029) evaluating autologous naive and memory T (TN/MEM) cells engineered to express a bispecific anti-CD19/CD20 chimeric antigen receptor (CAR; CART19/20) for patients with relapsed/refractory non-Hodgkin lymphoma (NHL), with safety as the primary endpoint. Ten patients were treated with 36 × 106 to 165 × 106 CART19/20 cells. No patient experienced neurotoxicity of any grade or over grade 1 cytokine release syndrome. One case of dose-limiting toxicity (persistent cytopenia) was observed. Nine of 10 patients achieved objective response [90% overall response rate (ORR)], with seven achieving complete remission [70% complete responses (CR) rate]. One patient relapsed after 18 months in CR but returned to CR after receiving a second dose of CART19/20 cells. Median progression-free survival was 18 months and median overall survival was not reached with a 17-month median follow-up. In conclusion, CART19/20 TN/MEM cells are safe and effective in patients with relapsed/refractory NHL, with durable responses achieved at low dosage levels.Significance:Autologous CD19/CD20 bispecific CAR-T cell therapy generated from TN/MEM cells for patients with NHL is safe (no neurotoxicity, maximum grade 1 cytokine release syndrome) and demonstrates strong efficacy (90% ORR, 70% CR rate) in a first-in-human, phase I dose-escalation trial.This article is highlighted in the In This Issue feature, p. 517

To address antigen escape and loss of T-cell functionality, we report a phase-1 clinical trial (NCT04007029) evaluating autologous naïve and memory T (TN/MEM) cells engineered to express a bispecific anti-CD19/CD20 CAR (CART19/20) for patients with relapsed/refractory NHL, with safety as the primary end point. Ten patients were treated with 36–165 × 106 CART19/20 cells. No patient experienced neurotoxicity of any grade, or over grade-1 cytokine release syndrome. One case of dose-limiting toxicity (persistent cytopenia) was observed. Nine of ten patients achieved objective response (90% ORR), with seven achieving complete remission (70% CR rate). One patient relapsed after 18 months in CR, but returned to CR after receiving a second dose of CART19/20 cells. Median progression-free survival and overall survival were not reached with a 17-month median follow-up. In conclusion, CART19/20 TN/MEM cells are safe and effective in patients with relapsed/refractory NHL, with durable responses achieved at low dosage levels.