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

项目总结 脑瘤是儿童癌症相关死亡的主要原因；其中弥漫性固有脑桥。 胶质瘤(DIPG)和其他组蛋白-3 K27M(H3K27M)突变的弥漫性中线胶质瘤(DMG)最多 攻击性强，在目前的标准疗法中普遍是致命的。尽管经过几十年的调查 试验测试了数十种治疗方法，DIPG的中位总生存期为11个月。嵌合抗原 受体(CAR)表达的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，最近 临床前和早期临床结果表明，在中枢神经系统恶性肿瘤中受益。我们发现了同质的，高的 GD2神经节苷脂在H3K27M DMGs上的高效表达及其抗肿瘤作用 GD2-CAR T细胞(GD2-CART、MOUNT、NAT)处理H3K27M突变型DIPG的异种移植模型 Med 2018)。GD2靶向CAR T细胞的重要临床经验，主要来自于 神经母细胞瘤，表现出安全性和抗肿瘤活性的一些早期信号。安全有效的翻译 对于患有DMGs的儿童来说，这些发现将改变这种普遍致命的儿科大脑的面貌 肿瘤。这个从床到床到板凳的项目将利用最近启动的一项 GD2.BB.z.iCasp9-CAR T细胞的单一机构I期试验 H3K27M DMGs儿童和年轻人的淋巴去除准备方案。第一个目标集中在 在安全性方面，将我们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。第二个目标集中在疗效上，评估临床活动 DMG的GD2-CART，并确定与反应相关的生物标志物和临床特征。我们进一步 使用一种新型机器解决这些浸润性肿瘤的标准放射成像的局限性 学习辅助MRI放射组学方法量化肿瘤内的纹理变化并评估这种变化 变化与临床结果相关，我们评估GD2-CART是否引起脑脊液游离细胞的变化 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， 重点是提高对GD2-CART后髓系细胞激活相关生物学的理解 DMGs的治疗，我们在临床前模型中观察到，我们在第一个治疗的患者中观察到。在这里我们 对患者GD2-CART后出现的脑脊液髓系细胞进行全面的单细胞分析 登记参加这项研究和临床前模型，并使用小鼠模型测试床边到工作台的翻译 GD2-CART诱导中枢神经系统髓系细胞扩增/激活的假说限制了GD2-CART的疗效。 是由皮质类固醇疗法调节的，这一障碍可以通过改造CD47来克服 在GD2-Cart中过度表达。

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.