A Pan-Dengue Virus Immunotherapeutic for Prevention and Treatment

描述（由申请人提供）：本项目的最终目标是开发一种许可的免疫制剂，以预防和治疗登革热病毒（DV）感染引起的发热性疾病。本文提出的工作将导致验证具有体内有效性的候选产品，开发生产工艺并完成所有IND使能研究，从而显著推进该候选产品的临床应用。第二次感染DV的个体通常会经历更严重的疾病，这是由于初次感染的中和抗体较差，通过Fc？？受体。我们提出的免疫系统将被设计为消除Fc？R结合，并因此ADE，同时保持长血清半衰期和结合补体的能力，增强治疗活性。工作将围绕四个具体目标展开。(1)设计一种有效的、长半衰期的免疫鸡尾酒，中和所有四种DV血清型，最大限度地减少对逃逸突变体的选择，同时防止感染的抗体依赖性增强（ADE）。现有的有效血清型特异性MAb将用作构建多价、多特异性抗体样分子（IgDART）的基础，所述多价、多特异性抗体样分子具有抗体的许多期望的治疗性质并且易于表达和纯化。对于具有多个靶标的疾病，IgDARTs允许产生比使用MAb更简单的鸡尾酒，其组分更少。在DV的情况下，4种血清型将被两种IgDART分子中和。交叉反应性MAb也将被工程化以用作药物鸡尾酒的重要最终组分，以控制逃逸突变体的出现。活动将包括人源化、亲和力成熟以增加效力、去免疫化和IgDART的产生。(2)在小鼠中进行体内研究，以建立预防、治疗和药代动力学活性的参数，以及测量控制逃逸突变体出现的能力。(3)产品开发和制造。将为每种分子（2种IgDART和1种MAb）建立优化的表达、纯化和配制条件。将建立细胞库，用于生产在cGMP条件下生产的适用于人用的材料。(4)完成IND赋能研究。将在非人灵长类动物模型中评价疗效、毒理学和药代动力学。将进行人和非人灵长类动物组织交叉反应性研究。所需研究将在GLP条件下进行。该项目旨在将DV中和单克隆抗体的集合推进到一个简洁的定义明确的免疫原中，以启动临床研究。

DESCRIPTION (provided by applicant): The ultimate goal of this project is to develop a licensed immunotherapeutic to prevent and treat the spectrum of febrile illnesses caused by Dengue virus (DV) infection. The work proposed here will result in the validation of product candidates with proven efficacy in vivo, development of manufacturing process and completion of all IND-enabling studies, significantly advancing this product candidate toward clinical use. Individuals infected a second time by DV generally experience more severe disease resulting from poorly neutralizing antibodies from the primary infection leading to an antibody-dependent enhancement (ADE) of infection by recruiting DV particles to monocytes, their primary cellular targets of infection, via Fc??receptors. The immunotherapeutic that we propose will be engineered to eliminate Fc?R binding, and therefore ADE, while maintaining long serum half-life and the ability to bind complement that enhances therapeutic activity. The work will progress through 4 Specific Aims. (1) Engineer a potent, long half-life immunotherapeutic cocktail that neutralizes all four DV serotypes and minimizes selection for escape mutants, while preventing antibody dependent enhancement (ADE) of infection. Existing potent serotype specific MAbs will be used as the basis to build multivalent, multispecific antibody like molecules (IgDARTs) that have many of the desirable therapeutic properties of antibodies and are easily expressed and purified. For diseases with multiple targets, IgDARTs allow generation of simpler cocktails with fewer components than if MAbs were employed. In the case of DV, 4 serotypes will be neutralized by two IgDART molecules. A cross- reactive MAb will also be engineered to serve as an important final component of the drug cocktail to control emergence of escape mutants. Activities will include humanization, affinity maturation to increase potency, de-immunization, and generation of IgDARTs. (2) Perform in vivo studies in mice to establish parameters of prophylactic, therapeutic, and pharmacokinetic activity, as well as measuring the ability to control emergence of escape mutants. (3) Product development and manufacturing. Optimized expression, purification, and formulation conditions will be established for each molecule (2 IgDARTs and 1 MAb). Cell banks will be established for the generation of material suitable for human use that will be manufactured under cGMP conditions. (4) Complete IND-enabling studies. Efficacy, toxicology, and pharmacokinetics will be evaluated in non-human primate models. Human and non-human primate tissue cross-reactivity studies will be performed. Required studies will be performed under GLP conditions. This project aims to advance a collection of DV-neutralizing MAbs into a concise well-defined immunotherapeutic validated for initiation of clinical studies.