Arroyo-Ródenas Javier, Falgas Aida, Díez-Alonso Laura, Martinez-Moreno Alba, Roca-Ho Heleia, Gil-Etayo Francisco J, Pérez-Pons Alba, Aguilar-Sopeña Óscar, Velasco-Sidro Miriam, Gómez-Rosel Marina, Jiménez-Matías Beatriz, Muñoz-Sánchez Guillermo, Pacheco Yedra, Bravo-Martín Clara, Ramírez-Fernández Ángel, Jiménez-Reinoso Anaïs, González-Navarro Europa Azucena, Juan Manel, Orfao Alberto, Blanco Belén, Roda-Navarro Pedro, Bueno Clara, Menéndez Pablo, Álvarez-Vallina Luis
Cancer Immunotherapy Unit (UNICA), Department of Immunology, Hospital Universitario 12 de Octubre, Madrid, Spain.
Immuno-Oncology and Immunotherapy Group, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, Spain.
J Immunother Cancer. 2025 Apr 30;13(4):e009048. doi: 10.1136/jitc-2024-009048.
CD19-directed cancer immunotherapies, based on engineered T cells bearing chimeric antigen receptors (CARs, CAR-T cells) or the systemic administration of bispecific T cell-engaging (TCE) antibodies, have shown impressive clinical responses in relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, more than half of patients relapse after CAR-T or TCE therapy, with antigen escape or lineage switching accounting for one-third of disease recurrences. To minimize tumor escape, dual-targeting CAR-T cell therapies simultaneously targeting CD19 and CD22 have been developed and validated both preclinically and clinically.
We have generated the first dual-targeting strategy for B-cell malignancies based on CD22 CAR-T cells secreting an anti-CD19 TCE antibody (CAR-STAb-T) and conducted a comprehensive preclinical characterization comparing its therapeutic potential in B-ALL with that of previously validated dual-targeting CD19/CD22 tandem CAR cells (TanCAR-T cells) and co-administration of two single-targeting CD19 and CD22 CAR-T cells (pooled CAR-T cells).
We demonstrate that CAR-STAb-T cells efficiently redirect bystander T cells, resulting in higher cytotoxicity of B-ALL cells than dual-targeting CAR-T cells at limiting effector:target ratios. Furthermore, when antigen loss was replicated in a heterogeneous B-ALL cell model, CAR-STAb T cells induced more potent and effective cytotoxic responses than dual-targeting CAR-T cells in both short- and long-term co-culture assays, reducing the risk of CD19-positive leukemia escape. In vivo, CAR-STAb-T cells also controlled leukemia progression more efficiently than dual-targeting CAR-T cells in patient-derived xenograft mouse models under T cell-limiting conditions.
CD22 CAR-T cells secreting CD19 T-cell engagers show an enhanced control of B-ALL progression compared with CD19/CD22 dual CAR-based therapies, supporting their potential for clinical testing.
基于携带嵌合抗原受体（CARs，CAR-T细胞）的工程化T细胞或双特异性T细胞衔接（TCE）抗体的全身给药的CD19导向癌症免疫疗法，在复发/难治性B细胞急性淋巴细胞白血病（B-ALL）中已显示出令人印象深刻的临床反应。然而，超过一半的患者在接受CAR-T或TCE治疗后复发，其中抗原逃逸或谱系转换占疾病复发的三分之一。为了尽量减少肿瘤逃逸，已开发出同时靶向CD19和CD22的双靶点CAR-T细胞疗法，并在临床前和临床中得到验证。
我们基于分泌抗CD19 TCE抗体的CD22 CAR-T细胞（CAR-STAb-T），生成了针对B细胞恶性肿瘤的首个双靶点策略，并进行了全面的临床前表征，将其在B-ALL中的治疗潜力与先前验证的双靶点CD19/CD22串联CAR细胞（TanCAR-T细胞）以及两种单靶点CD19和CD22 CAR-T细胞的联合给药（混合CAR-T细胞）进行比较。
我们证明，CAR-STAb-T细胞能有效重定向旁观者T细胞，在效应细胞与靶细胞比例有限的情况下，导致B-ALL细胞的细胞毒性高于双靶点CAR-T细胞。此外，当在异质性B-ALL细胞模型中复制抗原丢失时，在短期和长期共培养试验中，CAR-STAb T细胞比双靶点CAR-T细胞诱导出更有效和更强的细胞毒性反应，降低了CD19阳性白血病逃逸的风险。在体内，在T细胞受限条件下的患者来源异种移植小鼠模型中，CAR-STAb-T细胞也比双靶点CAR-T细胞更有效地控制白血病进展。
与基于CD19/CD22双CAR的疗法相比，分泌CD19 T细胞衔接分子的CD22 CAR-T细胞对B-ALL进展的控制增强，支持其进行临床试验的潜力。
