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Updated: Nov 21, 2025
In Vitro Tumor Cell Rechallenge For Predictive Evaluation of Chimeric Antigen Receptor T Cell Antitumor Function
Published on: February 27, 2019
Development and functional characterization of novel fully human anti-CD19 chimeric antigen receptors for T-cell
Zhenyu Dai1, Xuelian Hu1, Xiangyin Jia2
1Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Abstract:
Impressive outcomes have been achieved by chimeric antigen receptor (CAR)-T cell therapy using murine-derived single-chain variable fragment (scFv) FMC63 specific for CD19 in patients with B cell malignancies. However, evidence suggests that human anti-mouse immune responses might be responsible for poor persistence and dysfunction of CAR-T cells, leading to poor outcomes or early tumor recurrence. Substituting a fully human scFv for murine-derived scFv may address this clinically relevant concern. In this study, we discovered two human anti-CD19 scFv candidates through an optimized protein/cell alternative panning strategy and evaluated their function in CAR-T cells and CD19/CD3 bispecific antibody formats. The two clones exhibited excellent cytotoxicity in CAR-T cells and bispecific antibodies in vitro compared with the benchmarks FMC63 CAR-T cells and blinatumomab. Furthermore, Clone 78-BBz CAR-T cells exhibited similar in vivo antitumor activity to FMC63-BBz CAR-T cells. Our results indicate that Clone 78-BBz CAR has excellent efficacy and safety profile and is a good candidate for clinical development.
Insights
Human anti-CD19 scFv CAR-T cells offer improved persistence and efficacy in B cell malignancies. This study identified a promising human scFv (Clone 78-BBz) for enhanced CAR-T cell therapy, showing excellent safety and antitumor activity.
Area of Science:
- Immunology
- Oncology
- Biotechnology
Background:
- Chimeric antigen receptor (CAR)-T cell therapy shows promise for B cell malignancies.
- Murine-derived single-chain variable fragments (scFv) in CAR-T cells can elicit anti-mouse immune responses, limiting efficacy.
- Human anti-mouse immune responses may cause CAR-T cell dysfunction and poor patient outcomes.
Purpose of the Study:
- To discover and evaluate fully human anti-CD19 scFv candidates for CAR-T cell therapy.
- To address the clinical concern of anti-mouse immune responses in CAR-T cell therapy.
- To assess the efficacy and safety of novel human anti-CD19 scFv in CAR-T cells and bispecific antibodies.
Main Methods:
- An optimized protein/cell alternative panning strategy was used to discover human anti-CD19 scFv candidates.
- The identified scFv candidates were incorporated into CAR-T cells and CD19/CD3 bispecific antibody formats.
- In vitro cytotoxicity assays and in vivo antitumor activity studies were performed to evaluate CAR-T cell function.
Main Results:
- Two human anti-CD19 scFv candidates demonstrated excellent in vitro cytotoxicity compared to benchmark FMC63 CAR-T cells and blinatumomab.
- Clone 78-BBz CAR-T cells exhibited comparable in vivo antitumor activity to FMC63-BBz CAR-T cells.
- Clone 78-BBz CAR-T cells showed a promising safety profile.
Conclusions:
- Fully human anti-CD19 scFv, such as Clone 78-BBz, can overcome limitations associated with murine-derived scFv in CAR-T cell therapy.
- Clone 78-BBz CAR-T cells demonstrate potent efficacy and a favorable safety profile.
- Clone 78-BBz represents a promising candidate for clinical development in B cell malignancies.
