Developing Safe and Effective GD2-CAR T Cell Therapy for Diffuse Midline Gliomas

项目摘要 脑肿瘤是儿童癌症相关死亡的主要原因;其中，弥漫性内在脑桥 神经胶质瘤（DIPG）和其他组蛋白-3 K27 M（H3 K27 M）突变的弥漫性中线神经胶质瘤（DMG）是最常见的肿瘤。 具有侵袭性，并且对于目前的标准疗法是普遍致命的。尽管经过几十年的研究 试验测试了几十种治疗方法，DIPG的中位总生存期为11个月。嵌合抗原 表达CAR受体的T细胞在B细胞恶性肿瘤中介导了令人印象深刻的临床活性， 临床前和早期临床结果表明在CNS恶性肿瘤中获益。我们发现了同质的， GD 2神经节苷脂在H3 K27 M DMG上的过表达，并在H3 K27 M DMG中表现出令人印象深刻的抗肿瘤作用。 在用GD 2-CAR T细胞（GD 2-CART，Mount，Nat. Med 2018）。GD 2靶向CAR T细胞的重要临床经验，主要来自以下研究： 神经母细胞瘤，证明了安全性和抗肿瘤活性的一些早期信号。安全有效的翻译 如果将这些发现应用于患有DMG的儿童， 肿瘤这个从实验台到床边到实验台的项目将利用最近推出的 GD2.BB.z.iCasp9-CAR T细胞的单机构I期试验， 在患有H3 K27 M DMG的儿童和年轻成人中使用淋巴细胞清除准备方案。第一个目标聚焦于 在安全性方面，将我们在临床前模型中收集的见解整合到试验设计中，以降低肿瘤风险 炎症相关神经毒性（TIAN），以建立最佳实践，并制定改进的分级和 这种新型毒性的治疗算法。第二个目标侧重于疗效，评估 DMG中的GD 2-CART和鉴定与应答相关的生物标志物和临床特征。我们进一步 使用一种新的机器解决标准放射成像在这些浸润性肿瘤中的局限性 学习辅助MRI放射组学方法来量化肿瘤内的纹理变化，并评估这种变化是否 这些变化与临床结果相关，我们评估了GD 2-CART是否诱导了CSF细胞游离的变化， DNA可以提供抗肿瘤反应的快速定量评估。我们的第三个目标是发现目标， 专注于提高对GD 2-CART后骨髓细胞活化相关生物学的理解 我们在临床前模型中观察到，并且我们在第一个接受治疗的患者中观察到。这里我们 对患者中GD 2-CART后出现的CSF髓样细胞进行全面的单细胞分析 入组研究和临床前模型，并使用鼠模型进行床边到实验室转换，以测试 GD 2-CART诱导CNS骨髓细胞扩增/活化的假设限制了GD 2-CART的功效， 通过皮质类固醇治疗来调节，并且这种障碍可以通过工程化CD 47来克服。 在GD 2-CART中的过度表达。

PROJECT SUMMARY Brain tumors are the leading cause of cancer related death in children; among these, diffuse intrinsic pontine glioma (DIPG) and other histone-3 K27M (H3K27M) mutated diffuse midline gliomas (DMGs) are the most aggressive and are universally fatal with current standard therapies. Despite several decades of investigational trials testing dozens of therapeutic approaches, median overall survival for DIPG is 11 months. Chimeric antigen receptor (CAR)-expressing T-cells have mediated impressive clinical activity in B-cell malignancies, and recent preclinical and early clinical results suggest benefit in CNS malignancies. We discovered homogenous, high overexpression of the GD2 ganglioside on H3K27M DMGs and demonstrated impressive antitumor effects in xenograft models of H3K27M-mutant DIPG following treatment with GD2-CAR T cells (GD2-CART, Mount, Nat Med 2018). Significant clinical experience with GD2 targeting CAR T cells, available mostly from studies in neuroblastoma, demonstrate safety and some early signals of antitumor activity. Safe and effective translation of these findings to children with DMGs would transform the landscape for this universally lethal pediatric brain tumor. This bench-to-bedside-to-bench project will conduct three aims in parallel leveraging a recently launched single institution Phase I trial of GD2.BB.z.iCasp9-CAR T cells administered intravenously following a lymphodepleting preparative regimen in children and young adults with H3K27M DMGs. The first aim focuses on safety, integrating insights gleaned in our preclinical models into trial design to diminish the risk of tumor inflammation associated neurotoxicity (TIAN), to establish best practices and to develop improved grading and treatment algorithms for this novel toxicity. The second aim focuses on efficacy, assessing clinical activity of GD2-CART in DMG and identifying biomarkers and clinical features associated with response. We further address the limitations of standard radiographic imaging in these infiltrative tumors using a novel machine learning aided MRI radiomics approach to quantify textural changes within the tumor and assess whether such changes correlate with clinical outcome, and we assess whether GD2-CART induced changes in CSF cell free DNA can provide a rapid quantitative assessment of antitumor response. Our third aim is a discovery aim, focused on improving understanding of the biology associated with myeloid cell activation following GD2-CART therapy for DMGs, which we observe in preclinical models and we observed in the first patient treated. Here we undertake comprehensive single cell profiling of CSF myeloid cells emerging post-GD2-CART in patients enrolled on the study and in preclinical models, and bedside-to-bench translation using murine models to test the hypotheses that GD2-CART induced CNS myeloid cell expansion/activation limit the efficacy of GD2-CART, are modulated by corticosteroid therapy and that this obstacle can be overcome by engineering CD47 overexpression in the GD2-CART.