Development and functional characterization of novel fully human anti-CD19 chimeric antigen receptors for T-cell therapy.

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.

Dai Z ，Hu X ，Jia X ，Liu J ，Yang Y ，Niu P ，Hu G ，Tan T ，Zhou J ... -  《-》

Identification of Potent CD19 scFv for CAR T Cells through scFv Screening with NK/T-Cell Line.

Kang CH ，Kim Y ，Lee HK ，Lee SM ，Jeong HG ，Choi SU ，Park CH ... -  《-》

Efficacy and safety of CD19 CAR T constructed with a new anti-CD19 chimeric antigen receptor in relapsed or refractory acute lymphoblastic leukemia.

Gu R ，Liu F ，Zou D ，Xu Y ，Lu Y ，Liu B ，Liu W ，Chen X ，Liu K ，Guo Y ，Gong X ，Lv R ，Chen X ，Zhou C ，Zhong M ，Wang H ，Wei H ，Mi Y ，Qiu L ，Lv L ，Wang M ，Wang Y ，Zhu X ，Wang J ... -  《Journal of Hematology & Oncology》

Development of novel humanized CD19/BAFFR bicistronic chimeric antigen receptor T cells with potent antitumor activity against B-cell lineage neoplasms.

Chimeric antigen receptor T cell (CAR-T) therapy has shown remarkable efficacy in treating advanced B-cell malignancies by targeting CD19, but antigen-negative relapses and immune responses triggered by murine-derived antibodies remain significant challenges, necessitating the development of novel humanized multitarget CAR-T therapies. Here, we engineered a second-generation 4-1BB-CD3ζ-based CAR construct incorporating humanized CD19 single-chain variable fragments (scFvs) and BAFFR single-variable domains on heavy chains (VHHs), also known as nanobodies. The resultant CAR-T cells, with different constructs, were functionally compared both in vitro and in vivo. We found that the optimal tandem and bicistronic (BI) structures retained respective antigen-binding abilities, and both demonstrated specific activation when stimulated with target cells. At the same time, BI CAR-T cells (BI CARs) exhibited stronger tumour-killing ability and better secretion of interleukin-2 and tumour necrosis factor-alpha than single-target CAR-T cells. Additionally, BI CARs showed less exhaustion phenotype upon repeated antigen stimulation and demonstrated more potent and persistent antitumor effects in mouse xenograft models. Overall, we developed a novel humanized CD19/BAFFR bicistronic CAR (BI CAR) based on a combination of scFv and VHH, which showed potent and sustained antitumor ability both in vitro and in vivo, including against tumours with CD19 or BAFFR deficiencies.

Wu S ，Luo Q ，Li F ，Zhang S ，Zhang C ，Liu J ，Shao B ，Hong Y ，Tan T ，Dong X ，Chen B ... -  《-》

A tetravalent bispecific TandAb (CD19/CD3), AFM11, efficiently recruits T cells for the potent lysis of CD19(+) tumor cells.

Reusch U ，Duell J ，Ellwanger K ，Herbrecht C ，Knackmuss SH ，Fucek I ，Eser M ，McAleese F ，Molkenthin V ，Gall FL ，Topp M ，Little M ，Zhukovsky EA ... -  《-》