Novel molecular imaging approaches to monitor gene and cell-based therapies

描述(由申请人提供)：监测基因和细胞治疗的新分子成像方法基因和细胞治疗在再生医学和肿瘤学中开创了一个充满机遇的新时代。然而，在细胞疗法的有效开发和评估中的一个关键障碍是无法跟踪治疗患者中治疗基因和细胞的命运和功能。我们建议开发使用正电子发射断层扫描(PET)在体内特定识别和跟踪治疗基因和细胞的技术，正电子发射断层扫描是一种适用于临床前和临床环境的定量、非侵入性分子成像方法。这项应用解决了当前报告基因策略的一个关键限制，即对治疗载体和细胞进行基因改造，以产生可由PET检测的信号。我们将在完全基于人类蛋白质的基础上产生新的PET报告基因，而不是常用的高免疫原性病毒蛋白，以克服这一临床实施的挑战。这个项目依赖于多年的赠款和基础研究成果，现在这些成果已经准备好进入商业领域。我们建议进行三年的努力，将最新的进展转化为实际成果，作为最终用户就绪的PET报告基因(PRG)传递试剂盒和PET报告探针(PRP)，将使全身药代动力学和治疗结果信息成为可能。该应用程序还将提供首次人类0期小规模试验的初步信息，该试验是一项新的PET报告探测器的生物分布和剂量测定。我们的提案充分利用了加州大学洛杉矶分校(Ahmanson Translational Imagation Department)的实验室和Harvey Herschman的实验室与CellSight Technologies(CST，一家总部位于加利福尼亚州旧金山的生物技术公司)之间的合作伙伴关系。加州大学洛杉矶分校-CST合作伙伴关系建立在过去加州大学洛杉矶分校调查人员和顾问之间广泛互动的基础上，如本申请中所述。我们将落实四个具体目标。目的1包括体外、细胞培养和动物实验，以评估和优化新的PET报告基因-PET报告探针(PRG-PRP)系统。我们目前正在开发的新的PRG是人胸苷激酶2(TK2)基因的一个点突变(N44D)。L-[18F]FMAU和L-[18F]FEAU这两个hTK2-N44D底物是我们新的PRPS。在目标1中，我们还将确定基于TK2的PRG是否可以在人类中引发免疫反应，我们提出了一种消除这种可能性的策略。在目标2中，我们建议对新的PRG-PRP系统进行严格的临床前评估，使用基于基因和细胞治疗的动物模型来治疗两种类型的癌症：结直肠癌肝转移和黑色素瘤。AIM 3提出了一项战略，以开发、验证和商业化将PRG输送到小鼠和人类治疗细胞的试剂盒，并计划向更广泛的最终用户社区传播这一新能力。在目标4中，我们将完成EED提交，以实现对新的PET记者探针L-FMAU和L-FEAU的生物分布和剂量学的首次人体研究。这些“人类首例”研究将为后续研究奠定基础，届时加州大学洛杉矶分校和CST将向FDA提交一份完整的IND申请，以启动新的PRG-PRP系统在癌症患者中的临床测试。加州大学洛杉矶分校和CST研究人员共同开发的这套新的PET成像技术可能会立即在癌症的实验性基因和细胞疗法中找到临床应用，并可能广泛适用于对公共健康有重大影响的疾病的治疗，包括针对先天性和后天疾病的造血干细胞移植，如艾滋病的造血干细胞移植，1型糖尿病的胰岛细胞移植，帕金森氏病的胚胎干细胞衍生神经干细胞，以及心肌功能障碍的干细胞移植。 与公共卫生相关：基于细胞的疗法的最大希望之一是，医生将找到一种方法来分离和修改患者的干细胞或T淋巴细胞，以便将它们重新注射到患者体内治疗他们的疾病。然而，一个关键的挑战是能够在给药后监测这些细胞，看看它们是否存活和移植，它们是否是病区的家园，以及它们是否能够重建对抗疾病所需的活动。我们正在开发新的工具来跟踪移植细胞的命运和功能，这种工具基于一种名为PET扫描仪的强大医学相机。PET成像，或正电子发射断层扫描，使医生能够可视化包括患者在内的活体细胞的生物学。开发新的工具和技术最终将使PET能够用于肿瘤学和再生医学中基于细胞的治疗的临床监测，这是一项复杂的努力，超出了典型的学术团体的能力，并为初创生物技术公司带来了巨大的风险。在我们看来，解决方案是一种综合的方法，其中学术和行业合作伙伴从项目开始就在发现和产品开发阶段进行合作。这项工作的科学成果可能会导致癌症治疗方法的改进，从而显著影响公众健康。

DESCRIPTION (provided by applicant): Novel molecular imaging approaches to monitor gene and cell-based therapies Gene and cell-based therapies have ushered in a new era of opportunities in regenerative medicine and oncology. However, a critical roadblock in the effective development and evaluation of cellular therapeutics is the inability to follow the fate and function of the therapeutic genes and cells in treated patients. We propose to develop technologies for specific identification and tracking of therapeutic genes and cells in vivo using positron emission tomography (PET), a quantitative, non-invasive molecular imaging approach applicable to both preclinical and clinical settings. This application addresses a key limitation of current reporter gene strategies, in which therapeutic vectors and cells are genetically modified to produce a signal detectable by PET. Instead of commonly used, highly immunogenic viral proteins, we will generate novel PET reporter genes based on fully human proteins, to overcome this challenge to clinical implementation. This project relies on many years of grants and basic research results that are now ready to advance to the commercial domain. We propose a three year effort to turn recent advances into practical outcomes delivered as end-user-ready PET Reporter Gene (PRG) delivery kits and PET Reporter Probes (PRP) that will enable whole body pharmacokinetic and therapeutic outcomes information. This application will also deliver preliminary information from a first-in-human Phase 0 small trial of new PET reporter probe biodistribution and dosimetry. Our proposal leverages an established partnership between UCLA (the laboratories of the Ahmanson Translational Imaging Division and the laboratory of Harvey Herschman) and CellSight Technologies (CST, a biotech company based in San Francisco, CA). The UCLA-CST partnership builds on past extensive interactions at UCLA between investigators and consultants, as described in this application. We will carry out four Specific Aims. Aim 1 consists of in vitro, cell culture and animal studies to evaluate and optimize new PET Reporter Gene-PET Reporter Probe (PRG-PRP) systems. Our new current PRG being developed is a point mutant (N44D) of the human thymidine kinase 2 (tk2) gene. L-[18F]FMAU and L- [18F]FEAU, two hTK2-N44D substrates, are our new PRPs. In Aim 1 we will also determine whether the TK2- based PRG can elicit an immune response in humans and we propose a strategy to eliminate this possibility. In Aim 2 we propose a stringent preclinical evaluation of the new PRG-PRP systems, using animal models of gene and cell-based therapies against two types of cancer: hepatic metastases of colorectal cancer and melanoma. Aim 3 proposes a strategy to develop, validate, and commercialize kits for PRG delivery into murine and human therapeutic cells and a plan to disseminate this new capability to wider communities of end- users. In Aim 4 we will complete an eIND submission to enable first-in-human studies of the biodistribution and dosimetry of the new PET reporter probes L-FMAU and L-FEAU. These "first-in-human" studies will set the stage for a follow-up study in which UCLA and CST will submit a full IND application to the FDA to initiate clinical testing of the new PRG-PRP systems in cancer patients. The set of new PET imaging technologies co-developed by UCLA and CST investigators may find immediate clinical applications in experimental gene and cell-based therapies in cancer and may be broadly applicable to therapies for diseases with significant public health impact, including transplantation of hematopoietic stem cells in congenital and acquired disorders such as AIDS, islet cells in type 1 diabetes, ES-derived neural stem cells in Parkinson's disease, and stem cells in myocardial dysfunction. PUBLIC HEALTH RELEVANCE: One of the great promises of cell-based therapies is that physicians will find a way to isolate and modify patient's stem cells or T lymphocytes so that they can be re-injected into patients to treat their disease. However, a key challenge is to be able to monitor the cells after they have been administered and see if they survive and engraft, whether they home to areas of disease, and whether they are able to reestablish the activity needed to counteract disease. We are developing novel tools to follow the fate and function of transplanted cells, based on a powerful medical camera called the PET scanner. PET imaging, or positron emission tomography, allows doctors to visualize the biology of cells in living organisms, including patients. The development of novel tools and technologies that will ultimately enable the routine use of PET for clinical monitoring of cell-based therapies in oncology and regenerative medicine represents a complex endeavor that exceeds the capabilities of a typical academic group and carries substantial risks for start-up biotech companies. In our opinion, the solution is an integrated approach in which academic and industry partners work together from the inception of the project, on both discovery and product development phases. The scientific yield from this work may lead to improved therapies for cancer, significantly impacting public health.