Research Project 3: siRNA Therapy and Small Molecule Combination Treatment for Filoviruses

项目摘要-研究项目3 丝状病毒属埃博拉病毒和马尔堡病毒的成员是HHS一级A类优先病原体 在人类和非人类灵长类动物中引起严重且往往致命的出血热(HF)。确实有 目前还没有被批准的治疗埃博拉病毒或马尔堡病毒感染的药物，而且是广谱的 不存在对所有医学上相关的丝状病毒提供保护的暴露后治疗。Genevant 目前正在开发针对临床相关埃博拉病毒的RNA干扰(RNAi)疗法 马尔堡病毒。RNAi治疗方法的一个关键组成部分是需要递送技术来确保 摄取小干扰RNA(SiRNA)。Genevant‘s N-乙酰氨基半乳糖(GalNAc)结合物和脂质 纳米颗粒(LNP)平台稳定siRNA并确保有效地将其输送到疾病部位和靶细胞 是丝状病毒的主要感染部位。这项研究提案的目标是产生一个单一的广泛的 针对临床上最相关的埃博拉病毒和马尔堡病毒的光谱siRNA结合物。这 治疗将在一种联合治疗策略中使用，要么是完全人类抗丝状病毒 单抗或RNA聚合酶抑制剂GS-5734或法韦拉韦(T-705)。这个组合 策略旨在为丝状病毒感染提供有效和补充的治疗，即 比单独使用每种疗法都有效。为了产生抗丝状病毒siRNA结合物，在 两个部分将侧重于并行优化GalNAc配体和siRNA成分。以确保强有力 提供抗丝状病毒siRNA，新的GalNAc配体将被合成并评估结合亲和力和 根据它们调节RNA沉默的能力进行排名(目标1)。最有效的配体-偶联递送平台 然后将被选择用于与在AIM 2中选择的抗丝状病毒siRNAs接合。 已经被证实对EBOV、SUDV、BDBV、MARV和RAVV在我们的 目前的U19 CETR授权书。这些抗丝病毒亲本siRNA序列将经过化学修饰以 实现与配体共轭递送平台的兼容性。保持沉默的化学修饰siRNA 然后，针对每个临床相关丝状病毒的活性将与在 目的1在NHP丝状病毒感染模型中评估广谱疗效。不同的组合 在目标3中，siRNA结合物、单抗和直接作用的抗病毒小分子将在丝状病毒感染的NHP中进行测试，目的是确定这些组合方法中是否有任何一种将产生 在疾病晚期改善保护方面的好处。

PROJECT SUMMARY - Research Project 3 Members of the filovirus genera Ebolavirus and Marburgvirus are HHS Tier 1 Category A priority pathogens that cause severe and often fatal hemorrhagic fever (HF) in humans and nonhuman primates (NHPs). There are presently no approved therapeutics for ebolavirus or marburgvirus infections, and a broad spectrum postexposure treatment that confers protection across all medically relevant filoviruses does not exist. Genevant currently is developing RNA interference (RNAi) therapeutics targeting clinically relevant ebolaviruses and marburgviruses. A key component of a RNAi therapeutic approach is the need for delivery technologies to ensure uptake of the small interfering RNA (siRNA). Genevant’s N-acetylgalactosamine (GalNAc) conjugate and lipid nanoparticle (LNP) platforms stabilize siRNA and ensure effective delivery to disease sites and target cells that are the primary sites of infection for filoviruses. The goal of this research proposal is to generate a single broad spectrum siRNA-conjugate targeting the most clinically relevant ebolaviruses and marburgviruses. This therapeutic will then be used in a combinatorial treatment strategy with either fully human anti-filovirus monoclonal antibodies or the RNA polymerase inhibitors GS-5734 or favipiravir (T-705). This combinatorial strategy is intended to provide an effective and complementary treatment of filovirus infection that is more effective than each therapeutic alone. In order to generate anti-filoviral siRNA conjugates, work is proposed in two parts that will focus on optimizing the GalNAc ligand and siRNA components in parallel. To ensure potent delivery of anti-filoviral siRNAs, novel GalNAc ligands will be synthesized and assessed for binding avidity and ranked for their ability to mediate RNA silencing (Aim 1). The most effective ligand-conjugate delivery platform will then be selected for conjugation to anti-filoviral siRNAs selected in Aim 2. Lead siRNAs, delivered via LNP, have already been identified with demonstrated efficacy against EBOV, SUDV, BDBV, MARV, and RAVV in our current U19 CETR grant. These anti-filoviral parental siRNA sequences will undergo chemical modification to enable compatibility with a ligand conjugate delivery platform. Chemically modified siRNAs retaining silencing activity against each clinically relevant filovirus will then be combined with the most effective ligands identified in Aim 1 and assessed for broad spectrum efficacy in NHP models of filovirus infection. Different combinations of siRNA-conjugates, monoclonal antibodies, and direct acting antiviral small molecules will be tested in filovirus-infected NHPs in Aim 3, with the goal of determining whether any of these combinatorial approaches will yield benefit in improving protection during late stages of disease.