CAR T cells targeting mesothelin and secreting bispecific antibodies targeting fibroblasts in pancreatic cancer

项目总结 实体肿瘤的CAR T细胞治疗因缺乏肿瘤特异性抗原而受到阻碍，这些抗原是安全的靶向和 在整个肿瘤中均匀表达，由于致密的肿瘤间质而难以渗透到肿瘤中，以及 肿瘤微环境(TME)对CAR T细胞功能的抑制我们计划解决这些问题 使用新型Meso-FAP CAR-Team细胞同时靶向间皮蛋白，一种固体肿瘤抗原，具有 已经被证明是针对患者的安全靶向，以及抑制T细胞的癌症相关成纤维细胞(CAF) 并抑制T细胞在TME中的功能。CAF以结合T细胞的抗体为靶点 分子(组)由CAR T细胞分泌，与CD3和成纤维细胞激活蛋白(FAP)结合，后者 在CAF上高度表达。该研究小组允许肿瘤中的CAR和非CAR T细胞消除CAF。 我们已经证明了Meso-FAP CAR-Team细胞在体外杀死胰腺癌细胞和CAF， 在体内和在患者衍生的体外模型中，与Meso-CAR T相比具有更优越的抗肿瘤功能 单独的细胞。对于这个项目的UG3阶段，我们将通过以下方式进一步优化Meso-FAP CAR-Team Cell 确定要使用的最佳中间蛋白粘合剂(SS1与我们实验室开发的一种新型粘合剂)，最佳路线 针对胰腺肿瘤的注射(IV与IP)，以及针对CAR T细胞的药物组合的基本原理 实体瘤的局限性。我们将使用ADAM17抑制剂(INCB7839)来提高抗原密度，以防止 使用伊布鲁替尼从胰腺癌细胞中切割间充质蛋白，优化CAR T细胞杀伤和持续时间 将Meso-FAP CAR T细胞极化为Th1/Th17表型，进一步防止肿瘤的抑制 使用PD1抑制剂(Pembrolizumab)的微环境。这些药物将单独与Meso-FAP联合使用 CAR-Team Cells以确定在我们的临床前模型中哪一种最能提高疗效。总而言之，这些结果 将为晚期胰腺癌患者的I期临床试验的设计提供信息。在.期间 UH3期，我们将确定Meso-FAP车队电池的安全性和耐受性。我们已经选择了 胰腺癌作为我们的第一个实体肿瘤靶点，由于疾病预后不佳，所占比例很高 以及CAF在促进肿瘤生长方面的已知作用。而当 我们的主要目标将是确定安全性，我们还将监测患者的结果(进展和生存) 同时进行相关研究以确定CAR T细胞的表型和功能。我们还将监测 肿瘤和肿瘤微环境的反应或耐药机制，如抗原的变化 表达和免疫抑制细胞。总体而言，该项目将开发一种新的汽车团队设计，以达到目标 一个实体肿瘤及其微环境，同时通过严格的临床前测试优化试验设计。如果 成功制备的Meso-FAP CAR T细胞产物可直接应用于其他表达间充质蛋白的固体 肿瘤和从UG3阶段获得的知识将提供CAR T细胞功能的关键方面的信息 在启动临床试验之前进行优化。

PROJECT SUMMARY CAR T cell therapy for solid tumors is hindered by a lack of tumor-specific antigens that are safe to target and homogenously expressed throughout the tumor, difficulty infiltrating the tumor due to dense tumor stroma, and suppression of CAR T cell function by the tumor microenvironment (TME). We plan to address these issues using novel meso-FAP CAR-TEAM cells that simultaneously target mesothelin, a solid tumor antigen that has already been proven safe to target in patients, and cancer-associated fibroblasts (CAFs), which inhibit T cell infiltration and suppress T cell function in the TME. The CAFs are targeted with T cell-engaging antibody molecules (TEAMs) secreted from the CAR T cells that bind to CD3 and fibroblast activation protein (FAP), which is highly expressed on CAFs. The TEAM allows for CAF elimination by CAR and non-CAR T cells in the tumor. We have already demonstrated that meso-FAP CAR-TEAM cells kill pancreatic cancer cells and CAFs in vitro, in vivo, and in patient-derived ex vivo models and have superior anti-tumor function compared to meso-CAR T cells alone. For the UG3 phase of this project, we will further optimize meso-FAP CAR-TEAM cells by determining the best mesothelin binder to use (SS1 vs. a novel binder developed by our lab), optimal route of injection (IV vs. IP) for targeting pancreatic tumors, and rationale drug combinations that address CAR T cell limitations in solid tumors. We will improve antigen density using an ADAM17 inhibitor (INCB7839) to prevent mesothelin cleavage from pancreatic cancer cells, optimize CAR T cell killing and persistence using ibrutinib to polarize meso-FAP CAR T cells to a Th1/Th17 phenotype, and further prevent suppression by the tumor microenvironment using a PD1 inhibitor (pembrolizumab). These drugs will be singly combined with meso-FAP CAR-TEAM cells to determine which best promotes efficacy in our preclinical models. Collectively, these results will inform the design of a phase I clinical trial for pancreatic cancer patients with advanced disease. During the UH3 phase, we will determine the safety and tolerability of meso-FAP CAR-TEAM cells. We have chosen pancreatic cancer as our first solid tumor target due to the dismal prognosis of the disease, the high percentage of patients with mesothelin-expressing tumors, and the known role of CAFs in promoting tumor growth. While our primary objective will be to determine safety, we will also monitor patient outcomes (progression and survival) while performing correlative studies to determine CAR T cell phenotype and function. We will also monitor the tumor and tumor microenvironment for mechanisms of response or resistance, such as changes in antigen expression and immunosuppressive cells. Overall, this project will develop a novel CAR-TEAM design to target a solid tumor and its microenvironment while optimizing the trial design through rigorous preclinical testing. If successful, the meso-FAP CAR T cell product could be directly applied to other mesothelin-expressing solid tumors and the knowledge gained from the UG3 phase will inform on the critical aspects of CAR T cell function to optimize prior to initiating a clinical trial.