Overcoming tumor heterogeneity in glioblastoma with multi-targeted CAR T cells secreting bispecific antibodies

利用分泌双特异性抗体的多靶点 CAR T 细胞克服胶质母细胞瘤的肿瘤异质性

• 批准号: 10021622
• 负责人: Marcela Valderrama Maus
• 金额: $ 55.64万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-20 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10021622
• 关键词: Address; Adoptive Immunotherapy; Antibodies; Antigen Presentation; Antigen Targeting; Antigens; B lymphoid malignancy; B-Lymphocytes; Biological Assay; Bispecific Antibodies; Bite; Blood - brain barrier anatomy; Brain; Brain Neoplasms; Bulky Disease; Bypass; CD19 gene; CTLA4 gene; Cells; Clinical; Clinical Trials; Data; Disease; Disease Progression; Drug Kinetics; Engineering; Epidermal Growth Factor Receptor; Epitope spreading; FDA approved; Genetic Engineering; Glioblastoma; Glioma; Goals; Heterogeneity; Human; Immune; Immunosuppression; Immunotherapy; Infusion procedures; Intracranial Neoplasms; Intravenous; Intravenous infusion procedures; Investigational New Drug Application; Lead; Lung; Malignant - descriptor; Malignant Neoplasms; Mediating; Membrane Proteins; Modeling; Mutation; Normal tissue morphology; Oncogenic; PD-1/PD-L1; PDL1 pathway; Patients; Penetration; Peripheral; Pharmaceutical Preparations; Phase I Clinical Trials; Primary Brain Neoplasms; Recurrence; Regulatory T-Lymphocyte; Role; Route; Sampling; Site; Skin; Solid Neoplasm; Surface Antigens; T-Lymphocyte; T-cell receptor repertoire; Testing; Toxic effect; Toxicity Tests; Tumor Escape; Work; Xenograft Model; base; bi-specific T cell engager; chimeric antigen receptor; chimeric antigen receptor T cells; clinical development; clinical efficacy; cytotoxic; design; effector T cell; engineered T cells; epidermal growth factor receptor VIII; first-in-human; high dimensionality; immune checkpoint blockade; immunoengineering; leukemia/lymphoma; model design; mouse model; neoplastic cell; novel; personalized immunotherapy; pre-clinical; preclinical study; receptor; response; side effect; trafficking; tumor; tumor heterogeneity; tumor microenvironment; tumor progression

PROJECT SUMMARY Glioblastoma (GBM) is uniformly lethal and is the most common malignant primary brain tumor. Immunotherapy promises a precise approach, and the hope of durability. One way to deliver precision immunotherapy is with genetically-engineered T cells designed to express a target-specific chimeric antigen receptor, or CAR. In 2017, CAR T cells targeting CD19 were approved by the FDA for B cell malignancies, and several CARs targeting GBM have been described recently. We have developed CARs that target the EGFRvIII tumor mutation, and demonstrated their activity in preclinical studies and in a first-in-human clinical trial. We found that peripheral infusion of CART-EGFRvIII cells was safe and led to elimination of EGFRvIII-expressing glioma cells in patients. However, despite CART-EGFRvIII trafficking to intracranial tumors and targeting of EGFRvIII, the patients ultimately had outgrowth of EGFRvIII-negative disease and tumor progression. Thus, while the CAR T cell platform certainly holds great promise, a critical barrier to clinical impact for brain tumors is targeting a single antigen in an inherently heterogeneous disease. In addition, our study also demonstrated an adaptive increase in immunosuppression within the tumor microenvironment; specifically, the endogenous T cell infiltrate increased in the tumor, but consisted largely of immune-suppressive regulatory T cells (TRegs), rather than effector T cells reflective of antitumor epitope spreading. To simultaneously address antigenic heterogeneity and promote local antitumor activity in GBM, we have now modified CART-EGFRvIII to secrete bispecific antibodies known as bispecific T cell engagers (BiTEs) against wild-type EGFR, which is not expressed in the normal brain but is nearly always expressed in GBM. Delivering BiTES to the brain using T cells as carriers is also attractive because antibodies do not effectively cross the blood-brain barrier. The overall goal of this work is to develop a safe and effective immunotherapy for patients with GBM. We test the hypothesis that anti- EGFRvIII CAR T cells designed to secrete anti-EGFR BiTEs (CAR-BiTE) will lead to potent and durable responses in models of heterogeneous GBM. We will test their mechanism of action by quantifying secretion of BiTEs and systematically testing the role of bystander T cells (Aim 1). Next, we will determine the optimal route of administration of CAR-BiTE products, and the pharmacokinetics and biostribution of these two-in-one active "drugs” (Aim 2). These data are expected to lead to an Investigational New Drug (IND) application and Phase I clinical trial of CART-vIII/BiTE-EGFR in patients with recurrent glioblastoma. Finally, CAR-BiTEs represent a platform that can target multiple combinations of antigens. In Aim 3 we will identify targetable antigens in primary glioma samples and test CAR-BiTEs targeting three or more antigens.

项目概要 胶质母细胞瘤（GBM）均具有致命性，是最常见的恶性原发性脑肿瘤。 免疫疗法有望提供精确的方法以及持久的希望。提供精度的一种方法 免疫疗法是利用基因工程 T 细胞来表达特定靶点的嵌合抗原 受体，或 CAR。 2017年，靶向CD19的CAR T细胞被FDA批准用于治疗B细胞恶性肿瘤， 最近描述了几种针对 GBM 的 CAR。我们开发了针对 EGFRvIII 的 CAR 肿瘤突变，并在临床前研究和首次人体临床试验中证明了它们的活性。我们 发现外周输注 CART-EGFRvIII 细胞是安全的，并且可以消除表达 EGFRvIII 的细胞 患者体内的神经胶质瘤细胞。然而，尽管 CART-EGFRvIII 转运至颅内肿瘤并靶向 EGFRvIII，患者最终出现 EGFRvIII 阴性疾病和肿瘤进展。因此， 虽然 CAR T 细胞平台无疑前景广阔，但影响脑肿瘤临床影响的一个关键障碍是 针对固有异质性疾病中的单一抗原。此外，我们的研究还表明 肿瘤微环境中免疫抑制的适应性增强；具体来说，内源性T细胞 肿瘤中的浸润增加，但主要由免疫抑制性调节性 T 细胞 (TReg) 组成，而不是 比效应 T 细胞更能反映抗肿瘤表位的扩散。同时解决抗原异质性 并促进 GBM 的局部抗肿瘤活性，我们现在已经修改了 CART-EGFRvIII 以分泌双特异性 抗野生型 EGFR 的双特异性 T 细胞接合器 (BiTE) 抗体，该抗体在 正常大脑，但几乎总是在 GBM 中表达。使用 T 细胞作为载体将 BiTES 递送至大脑是 也很有吸引力，因为抗体不能有效穿过血脑屏障。本次工作的总体目标 旨在为 GBM 患者开发安全有效的免疫疗法。我们检验以下假设：反 旨在分泌抗 EGFR BiTE (CAR-BiTE) 的 EGFRvIII CAR T 细胞将带来有效且持久的治疗 异质 GBM 模型中的反应。我们将通过量化分泌物来测试其作用机制 BiTE 并系统地测试旁观者 T 细胞的作用（目标 1）。接下来，我们将确定最佳路线 CAR-BiTE 产品的给药方式，以及这些二合一活性物质的药代动力学和生物分布 “毒品”（目标 2）。这些数据预计将导致新药研究 (IND) 申请和 I 期临床试验 CART-vIII/BiTE-EGFR 在复发性胶质母细胞瘤患者中的临床试验。最后，CAR-BiTE 代表了 可以针对多种抗原组合的平台。在目标 3 中，我们将鉴定原代细胞中的可靶向抗原 神经胶质瘤样本并测试针对三种或更多抗原的 CAR-BiTE。