Development of antibody drug conjugates as pan-filo antivirals

项目摘要 丝状病毒会引起严重的出血热，是最致命的人类病毒之一，未经批准 治疗或预防选择。周期性暴发，如最近的埃博拉病毒(EBOV)疫情 在西非，死亡率从50%到90%不等。它们被归类为A类优先生物武器 由疾病控制和预防中心提供的“代理商”。最先进的抗丝病毒候选者 利用RNA干扰(RNAi)、高剂量混合物对非人类灵长类动物(NHP)进行已被证实有效的治疗 抗流感病毒、疱疹病毒或丙型肝炎抑制药。尽管他们 代表着重要的进步，这些方法有严重的局限性，包括高治疗剂量。 所需(每个患者20-30克单抗)、有限的光谱(主要是扎伊尔埃博拉病毒)和/或治疗范围狭窄 窗口(小分子/RNAi)。 以最近的工作为基础，证明了丝状病毒之间内体相互作用的关键性质 糖蛋白(GP)和宿主胆固醇运输蛋白Niemann-Pick C1(NPC1)为丝状病毒进入，我们有 开发出抗体和小分子来破坏这一机制，以抑制病毒进入。这些措施包括 几种双特异性GP靶向泛埃博拉病毒广谱中和抗体(BNAbs)在多个 动物模型，根据NHP的疗效向下选择最终的鸡尾酒。与此同时，我们发现 苯基哌嗪类化合物MBX-5321抑制GP-NPC1相互作用阻断强毒感染 在体外，EBOV、SUDV和MAV在NM浓度下表现出良好的PK/PD特性，表现出 良好的小鼠耐受性，已在小鼠中确立疗效，目前正在针对靶向IND进行优化。 在这个方案中，我们将MBX-5321连接到双特异性的泛Flao bNAbs上，制成广谱抗体药物 结合物(ADC)，协同抑制病毒进入。 这项提议的目的是证明这些ADC将提供更好的效率和选择性 用于丝状病毒的单独治疗，提供高效的泛菲罗制剂，扩大了 治疗窗口和减轻药物储备的努力。我们将通过三个具体的途径来实现这一目标 目标：在目标1中，我们将合成并完成&gt；40个ADC的展示血清的物理表征 稳定性与高效的内吞体释出。在目标2中，我们将通过对泛丝病毒的体外分析来优先考虑adc。 抑制活性。在目标3中，我们优先考虑PK和毒性方面的ADC，并评估两种泛丝病毒ADC在体内的应用 在EBOV感染小鼠模型中的疗效。

Project Summary Filoviruses cause severe hemorrhagic fevers and are among the deadliest human viruses with no approved treatment or prophylactic options. Periodic outbreaks, such as the recent epidemic of Ebola virus (EBOV) in West Africa, exhibit mortality rates ranging from 50-90%. They are classified as “Category A priority bioweapon agents” by the Centers for Disease Control and Prevention. The most advanced candidates for anti-filovirus therapy with proven efficacy in non-human primates (NHPs) utilize RNA interference (RNAi), high dose mixtures of monoclonal antibodies (mAbs), or repurposed influenza, herpes or hepatitis C inhibitors. Although they represent important advances, these approaches have serious limitations including the high therapeutic doses required (20-30 g of mAb/patient), limited spectrum (primarily Zaire ebolavirus) and/or narrow therapeutic windows (small molecules/RNAi). Building on recent work demonstrating the critical nature of endosomal interactions between the filoviral glycoprotein (GP) and the host cholesterol transport protein Niemann-Pick C1 (NPC1) for filoviral entry, we have developed antibodies and small molecules that disrupt this mechanism to inhibit viral entry. These include several bispecific GP-targeting pan-ebolavirus broadly neutralizing antibodies (bNAbs) efficacious in multiple animal models, with down-selection to a final cocktail based on NHP efficacy underway. In parallel, we identified a phenylpiperazine compound MBX-5321, which inhibits the GP-NPC1 interaction to block infections of virulent EBOV, SUDV and MARV at nM concentrations in vitro, demonstrates excellent PK/PD properties, exhibits excellent murine tolerability, has established efficacy in mice, and is currently being optimized for a targeted IND. In this proposal we will tether MBX-5321 to bispecific pan-filo bNABs to make broad-spectrum antibody-drug conjugates (ADCs) that synergistically inhibit viral entry. The objective of this proposal is to demonstrate that these ADCs will provide improved efficacy and selectivity for filovirus treatment over either agent alone, providing highly efficacious pan-filo agents, broadening the therapeutic window and easing drug stockpiling efforts. We will accomplish this objective through three specific aims: In Aim 1 we will synthesize and complete physical characterization of >40 ADCs demonstrating serum stability with efficient endosomal release. In Aim 2 we will prioritize ADCs through in vitro analysis of pan-filovirus inhibitory activity. In Aim 3 we prioritize ADCs for PK and toxicity and evaluate two pan-filovirus ADCs for in vivo efficacy in a mouse model of EBOV infection.