Project 1: Transgenic TCR-mediated tumor therapy

项目一：转基因TCR介导的肿瘤治疗

• 批准号: 10629190
• 负责人: PHILIP D GREENBERG
• 金额: $ 57.96万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-04 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629190
• 关键词: Address; Adoptive Transfer; Affect; Affinity; Alleles; Antigens; Antitumor Response; Autoimmune; Autologous; Avidity; Biopsy; Blood; Blood donor; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; CD8B1 gene; Cell Cycle; Cell physiology; Cells; Characteristics; Clinical; Clinical Trials; Cytolysis; Data; Disease; Disease Progression; Disease remission; Dose; Down-Regulation; Ensure; Epitope spreading; Epitopes; Exhibits; Failure; Functional disorder; Funding; Future; Genome; HLA A*0201 antigen; HLA-A gene; Immune; Immune checkpoint inhibitor; Immune system; Immunobiology; Immunohistochemistry; Immunotherapy; In Vitro; Individual; Infusion procedures; Laboratory Study; Ligation; Link; Low Dose Radiation; MHC Class I Genes; Macrophage; Malignant Epithelial Cell; Malignant Neoplasms; Measurable; Mediating; Merkel Cells; Merkel cell carcinoma; Neurosecretory Systems; Oncoproteins; PD-1 blockade; PDL1 inhibitors; Partial Remission; Patients; Persons; Phase I/II Trial; Polyomavirus; Predisposition; Progressive Disease; Proliferating; Refractory; Resistance; Risk; Safety; Sampling; Simian virus 40; Site; Skin; Skin Cancer; Specificity; T cell therapy; T-Cell Activation; T-Cell Development; T-Cell Receptor; T-Lymphocyte; Therapeutic; Thymus Gland; Time; Transgenic Organisms; Translating; Treatment Efficacy; Treatment Failure; Treatment outcome; Tumor Tissue; United States National Institutes of Health; Up-Regulation; Viral; Viral Proteins; Viral Tumor Antigens; Virus; anti-PD-L1; anti-tumor immune response; antigen-specific T cells; cancer diagnosis; cell mediated immune response; cellular transduction; clinical efficacy; clinical translation; design; epidemiologic data; immune checkpoint blockade; immunogenic; improved; insight; model development; mortality; neoplastic cell; next generation; pressure; programmed cell death ligand 1; programmed cell death protein 1; receptor binding; response; single fraction radiation; single-cell RNA sequencing; success; tool; treatment response; treatment strategy; tumor; tumor microenvironment

Summary – Project 1 Merkel cell carcinoma (MCC) is a highly aggressive skin cancer diagnosed in >2,500 persons per year in the US. ~80% of MCCs are caused by the Merkel cell polyomavirus (MCPyV), and these tumors rely on persistently-expressed cell cycle promoting oncoproteins (T-Antigens). These viral T antigens are ideal targets for immunotherapies: they are highly expressed, not readily lost, exclusive to tumor tissue, non-human in sequence (reducing off-target risk), and highly immunogenic. Recent studies have shown that reducing dysfunction of endogenous T cells in MCC is effective, as half of patients have durable responses to PD-1 axis blockade. However, many patients do not respond, representing an unmet clinical need. We hypothesize that patients whose tumors do not respond to PD-1 blockade have insufficient or poorly avid MCPyV-responsive T cells, and that therapeutic efficacy can be improved with a combination of approaches. In an R01-funded trial, we have used “Triple Therapy” to treat MCC patients with metastatic disease, where we combined single-fraction radiation to reverse MCC-specific downregulation of MHC class I, infusion of autologous ex vivo-expanded MCPyV specific CD8+ T cells to supplement the lack of effective MCPyV-specific T cells and avelumab (a PD-L1 checkpoint inhibitor) to boost antigen-specific responses. These treatments have been well tolerated, encouragingly effective (with 3 of 6 patients achieving complete remission, 2 durable at >2 years), and we have demonstrated persistence, function, and tumor localization of infused T cells. However, this strategy was limited by the rarity and low avidity of the endogenous MCPyV-specific T cells in most patients, and the 2-3 months required to generate T cell products in the face of rapidly progressive disease. To circumvent the challenges encountered, we now propose a transgenic T cell therapy approach. We will 1) use a newly developed high-throughput strategy to identify safe, high-affinity HLA-restricted T cell receptors (TCRs) to ensure all patients can receive highly avid, effective MCPyV-specific T cells. We have successfully used this approach to identify an MCPyV-specific HLA A*0201-restricted TCR (TCRA2-MCC1) and will now employ these strategies to identify TCRs of 3 additional specificities. 2) in a Phase I/II trial for patients with PD- 1 blockade-refractory metastatic MCC, evaluate the safety and efficacy of autologous CD8+ T cells transduced to express the validated TCRA2-MCC1 combined with MHC upregulation and PD-1 axis blockade, and 3) use a suite of cutting-edge tools on patient samples to characterize infused T cells, MCC cells and other features of the tumor microenvironment, identify parameters associated with treatment responses and/or failures. We believe the proposed studies will provide critical insights into the design of next-generation T cell therapies for MCC patients, with implications for other immunogenic malignancies.

摘要 – 项目 1 默克尔细胞癌 (MCC) 是一种高度侵袭性的皮肤癌，每年有超过 2,500 人被诊断出 美国。约 80% 的 MCC 是由默克尔细胞多瘤病毒 (MCPyV) 引起的，这些肿瘤依赖于 持续表达的细胞周期促进癌蛋白（T 抗原）。这些病毒 T 抗原是理想的靶标 用于免疫疗法：它们高度表达，不易丢失，仅在肿瘤组织中存在，非人类 序列（减少脱靶风险），并且具有高度免疫原性。最近的研究表明，减少 MCC 中内源性 T 细胞功能障碍是有效的，因为一半患者对 PD-1 轴有持久反应 封锁。然而，许多患者没有反应，代表临床需求未得到满足。我们假设 肿瘤对 PD-1 阻断没有反应的患者的 MCPyV 反应性 T 不足或较差 细胞，并且可以通过组合方法来提高治疗效果。 在一项R01资助的试验中，我们使用“三联疗法”来治疗患有转移性疾病的MCC患者，其中 我们结合单次放疗来逆转 MCC 特异性 MHC I 类下调，输注 自体体外扩增的 MCPyV 特异性 CD8+ T 细胞，以补充有效的 MCPyV 特异性的缺乏 T 细胞和 avelumab（一种 PD-L1 检查点抑制剂）可增强抗原特异性反应。这些治疗 耐受性良好，效果令人鼓舞（6 名患者中有 3 名达到完全缓解，2 名患者达到持久缓解） > 2 年），我们已经证明了输注 T 细胞的持久性、功能和肿瘤定位。 然而，该策略受到内源性 MCPyV 特异性 T 细胞的稀有性和低亲合力的限制。 大多数患者，面对快速进展的情况，需要 2-3 个月来生成 T 细胞产品 疾病。 为了规避所遇到的挑战，我们现在提出了一种转基因 T 细胞治疗方法。我们将 1) 使用新开发的高通量策略来鉴定安全、高亲和力的 HLA 限制性 T 细胞受体 (TCR)，以确保所有患者都能接受高度活跃、有效的 MCPyV 特异性 T 细胞。我们已经成功 使用这种方法来识别 MCPyV 特异性 HLA A*0201 限制性 TCR (TCRA2-MCC1)，现在将 使用这些策略来识别 3 个额外特异性的 TCR。 2) 在针对 PD 患者的 I/II 期试验中 1 封锁难治性转移性 MCC，评估自体 CD8+ T 细胞转导的安全性和有效性 表达经过验证的 TCRA2-MCC1 与 MHC 上调和 PD-1 轴阻断相结合，以及 3) 使用 针对患者样本的一套尖端工具，用于表征输注的 T 细胞、MCC 细胞和其他特征 肿瘤微环境，识别与治疗反应和/或失败相关的参数。我们 相信拟议的研究将为下一代 T 细胞疗法的设计提供重要见解 MCC 患者，对其他免疫原性恶性肿瘤有影响。