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型分子成像方法基因和细胞治疗在再生医学和肿瘤学领域开创了一个新的机遇时代。然而，有效开发和评估细胞疗法的一个关键障碍是无法跟踪治疗患者的治疗基因和细胞的命运和功能。我们建议利用正电子发射断层扫描（PET）技术开发特异性识别和跟踪体内治疗基因和细胞的技术，这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。该应用解决了当前报告基因策略的一个关键限制，其中治疗载体和细胞经过基因修饰以产生PET可检测的信号。代替常用的高免疫原性病毒蛋白，我们将基于全人类蛋白产生新的PET报告基因，以克服临床实施的挑战。这个项目依靠多年的资助和基础研究成果，现在已经准备好进入商业领域。我们建议通过三年的努力，将最近的进展转化为最终用户可用的PET报告基因（PRG）递送试剂盒和PET报告探针（PRP）的实际结果，从而实现全身药代动力学和治疗结果信息。该应用程序还将提供新PET报告探针生物分布和剂量测定的首次人体0期小型试验的初步信息。我们的提案利用了加州大学洛杉矶分校（Ahmanson转化成像部门的实验室和Harvey Herschman的实验室）和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）之间建立的合作伙伴关系。加州大学洛杉矶分校与cst的合作关系建立在加州大学洛杉矶分校研究人员和顾问之间过去广泛的互动基础上，如本申请所述。我们将实现四个具体目标。目的1包括体外、细胞培养和动物研究，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PRG是人胸苷激酶2 （tk2）基因的点突变体（N44D）。L-[18F]FMAU和L-[18F] FEAU是两种hTK2-N44D底物。在Aim 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，并提出一种消除这种可能性的策略。在Aim 2中，我们提出对新的PRG-PRP系统进行严格的临床前评估，使用基于基因和细胞的治疗动物模型来治疗两种类型的癌症：结直肠癌的肝转移和黑色素瘤。目标3提出了一项战略，开发、验证和商业化用于将PRG输送到小鼠和人类治疗细胞中的试剂盒，并计划将这种新能力传播给更广泛的最终用户群体。在Aim 4中，我们将完成一份终末研究报告（eIND）的提交，以进行新的PET报告探针L-FMAU和L-FEAU的生物分布和剂量学的首次人体研究。这些“首次人体”研究将为后续研究奠定基础，其中加州大学洛杉矶分校和CST将向FDA提交完整的IND申请，以启动新的PRG-PRP系统在癌症患者中的临床试验。加州大学洛杉矶分校和CST研究人员共同开发的一套新的PET成像技术可能会立即在癌症的实验性基因和细胞治疗中找到临床应用，并可能广泛适用于具有重大公共卫生影响的疾病的治疗，包括先天性和获得性疾病（如艾滋病）的造血干细胞移植、1型糖尿病的胰岛细胞移植、帕金森病的es来源神经干细胞移植。以及心肌功能障碍中的干细胞。

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.