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.

项目总结 胶质母细胞瘤(GBM)是最常见的恶性原发脑肿瘤，具有致死性。 免疫疗法承诺了一种精确的方法，并有望持久。提供精确度的一种方法 免疫疗法是利用基因工程T细胞来表达靶标特异性嵌合抗原 接收器，或CAR。2017年，针对CD19的CAR T细胞被FDA批准用于B细胞恶性肿瘤，以及 最近描述了几款针对GBM的汽车。我们已经开发了针对EGFRvIII的汽车 肿瘤突变，并在临床前研究和首次人类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，并导致EGFRvIII表达的消除 患者体内的胶质瘤细胞。然而，尽管CART-EGFRvIII贩运到颅内肿瘤，并以 EGFRvIII，患者最终出现EGFRvIII阴性的疾病和肿瘤进展。因此， 虽然CAR T细胞平台前景看好，但影响脑瘤临床效果的一个关键障碍是 在一种天生的异质性疾病中以单一抗原为靶点。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加；具体地说，内源性T细胞 浸润物在肿瘤中增加，但主要由免疫抑制调节性T细胞(Tregs)组成，而不是 比效应性T细胞能反映抗肿瘤表位的扩散。同时解决抗原异质性问题 和促进GBM的局部抗肿瘤活性，我们现在已经修饰了CART-EGFRvIII来分泌双特异性 针对野生型EGFR的抗体称为双特异性T细胞结合蛋白(BITE)，这种抗体在 大脑正常，但几乎总是在GBM中表达。使用T细胞作为载体将叮咬物输送到大脑是 另一个吸引人的原因是抗体不能有效地穿过血脑屏障。这项工作的总体目标是 是为GBM患者开发一种安全有效的免疫疗法。我们检验了这样的假设：反- EGFRvIII CAR T细胞被设计成分泌抗EGFR咬伤(CAR咬伤)将导致强大和持久的 异质GBM模型中的响应。我们将通过量化分泌的方式来测试它们的作用机制 咬人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 卡铂制剂的给药情况，以及这两种二合一活性药物的药代动力学和生物分布 “药物”(AIM 2)。这些数据预计将导致研究性新药(IND)申请和第一阶段 CART-VIII/BIT-EGFR治疗复发性胶质母细胞瘤的临床研究最后，汽车咬伤代表着一种 可针对多种抗原组合的平台。在目标3中，我们将识别初级的靶向抗原 胶质瘤样本和针对三种或三种以上抗原的测试咬伤。