Related Experiment Video
Updated: Sep 27, 2025
A Syngeneic Mouse B-Cell Lymphoma Model for Pre-Clinical Evaluation of CD19 CAR T Cells
Published on: October 16, 2018
Humanized CD19 CAR-T cells in relapsed/refractory B-ALL patients who relapsed after or failed murine CD19 CAR-T
Lihong An1, Yuehui Lin1, Biping Deng2
1Department of Hematology, Beijing Boren Hospital, No.6 South Zhengwangfen, Fengtai District, Beijing, 100070, China.
Background:
For CD19-positive relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL) after treatment with murine CD19 (mCD19) CAR-T, the reinfusion of mCD19 CAR-T cells may be ineffective due to anti-mouse single-chain variable fragment (scFv) antibody caused by mCD19 CAR. To overcome this immunogenicity, we applied humanized CD19 (hCD19) CAR-T cells to treat r/r B-ALL patients with prior mCD19 CAR-T therapy.
Methods:
Nineteen pediatric and adult patients were included, 16 relapsed after and 3 were primarily resistant to mCD19 CAR-T. All patients presented with more than 5% blasts in bone marrow and/or extramedullary disease, and still showed CD19 antigen expression. Humanized CD19-CARs were lentiviral vectors carrying a second generation CAR with 4-1-BB co-stimulatory and CD3ζ signaling domains. Patient-derived cells were collected for producing CAR-T cells, the median dose of infused hCD19 CAR-T cells was 2.4 × 105/kg (range, 1.0-18.0 × 105/kg).
Results:
hCD19 CAR-T resulted in a complete remission (CR) rate of 68% (13/19). Among 13 remission patients, 11 underwent allogeneic hematopoietic cell transplantation (allo-HCT) (3 were second HCT) and 10 remained in CR; the event-free survival rates at 12-18 months were 91% in 11 patients received following allo-HCT and 69% in all CR patients. Six cases had no response to hCD19 CAR-T, 3 died of disease progression; another 3 received salvage second transplantation, of them, 2 relapsed again (one died). Cytokine release syndrome (CRS) occurred in 95% (18/19) of patients, most CRS events were grade 1 and grade 2 (n = 17), there was only one grade 4 CRS. Two cases experienced grade 1 neurotoxicity.
Conclusions:
Humanized CD19 CAR-T cell therapy could be a treatment option for CD19-positive B-ALL patients who relapsed after or resisted prior murine CD19 CAR-T, hCD19 CAR-T followed by allo-HCT provided a longer remission in CR patients. Nevertheless, the prognosis of non-responders to hCD19 CAR-T remained dismal.
Trial Registration:
Chinese Clinical Trial Registry/WHO International Clinical Trial Registry ( ChiCTR1900024456 , URL: www.chictr.org.cn ); registered on July 12, 2019.
![Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F62334.jpg&w=3840&q=50)