Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA.
Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX 77030, USA; Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
Mol Ther. 2023 Jan 4;31(1):24-34. doi: 10.1016/j.ymthe.2022.09.003. Epub 2022 Sep 9.
Chimeric antigen receptor (CAR)-mediated targeting of T lineage antigens for the therapy of blood malignancies is frequently complicated by self-targeting of CAR T cells or their excessive differentiation driven by constant CAR signaling. Expression of CARs targeting CD7, a pan-T cell antigen highly expressed in T cell malignancies and some myeloid leukemias, produces robust fratricide and often requires additional mitigation strategies, such as CD7 gene editing. In this study, we show fratricide of CD7 CAR T cells can be fully prevented using ibrutinib and dasatinib, the pharmacologic inhibitors of key CAR/CD3ζ signaling kinases. Supplementation with ibrutinib and dasatinib rescued the ex vivo expansion of unedited CD7 CAR T cells and allowed regaining full CAR-mediated cytotoxicity in vitro and in vivo on withdrawal of the inhibitors. The unedited CD7 CAR T cells persisted long term and mediated sustained anti-leukemic activity in two mouse xenograft models of human T cell acute lymphoblastic leukemia (T-ALL) by self-selecting for CD7, fratricide-resistant CD7 CAR T cells that were transcriptionally similar to control CD7-edited CD7 CAR T cells. Finally, we showed feasibility of cGMP manufacturing of unedited autologous CD7 CAR T cells for patients with CD7 malignancies and initiated a phase I clinical trial (ClinicalTrials.gov: NCT03690011) using this approach. These results indicate pharmacologic inhibition of CAR signaling enables generating functional CD7 CAR T cells without additional engineering.
嵌合抗原受体 (CAR) 介导的 T 系抗原靶向治疗血液恶性肿瘤，常因 CAR T 细胞的自我靶向或其持续的 CAR 信号驱动的过度分化而变得复杂。靶向 CD7 的 CAR 的表达，CD7 是一种在 T 细胞恶性肿瘤和一些髓样白血病中高度表达的泛 T 细胞抗原，可产生强烈的同型杀伤作用，通常需要额外的缓解策略，如 CD7 基因编辑。在这项研究中，我们表明使用伊布替尼和达沙替尼，即关键的 CAR/CD3ζ 信号激酶的药理学抑制剂，可以完全防止 CD7 CAR T 细胞的同型杀伤。伊布替尼和达沙替尼的补充挽救了未经编辑的 CD7 CAR T 细胞的体外扩增，并允许在停用抑制剂后恢复完全的 CAR 介导的细胞毒性。未经编辑的 CD7 CAR T 细胞长期存在，并通过自我选择 CD7、对同型杀伤有抗性的 CD7 CAR T 细胞，在两种人类 T 细胞急性淋巴细胞白血病 (T-ALL) 的小鼠异种移植模型中发挥持久的抗白血病活性，这些 CD7 CAR T 细胞在转录上与对照 CD7 编辑的 CD7 CAR T 细胞相似。最后，我们证明了使用这种方法为 CD7 恶性肿瘤患者制造未经编辑的自体 CD7 CAR T 细胞的 cGMP 生产的可行性，并启动了一项 I 期临床试验（ClinicalTrials.gov：NCT03690011）。这些结果表明，CAR 信号的药理学抑制可以在不进行额外工程的情况下产生功能性的 CD7 CAR T 细胞。
