Anti-eosinophil Gene Therapy for Eosinophilic Esophagitis

抽象的。嗜酸性食管炎（EoE）是一种慢性上消化道致残性疾病， 儿童和成人，其特征是嗜酸性粒细胞食管炎，进行性紊乱， 食管结构、食管功能障碍、吞咽困难和食物嵌塞。没有批准的 治疗EoE;标准治疗包括局部或全身糖皮质激素和饮食调整。 LEXEO Therapeutics是一家早期基因治疗公司，正在开发一种单一的管理基因， 用LXi 02（一种非人灵长类动物血清型rh.10腺相关病毒（AAVrh.10））治疗EoE的疗法 静脉内施用的载体，设计用于遗传修饰肝脏以表达和分泌 一种针对嗜酸性粒细胞的单克隆抗体，导致嗜酸性粒细胞从循环中清除 和纸巾。基因治疗相对于常规单克隆治疗的优势是持续稳定 单次静脉治疗后抗Eos单克隆抗体的水平。与水晶合作 实验室，Weill Cornell，建立了一种新的小鼠EoE模型，通过对花生的致敏诱导， 导致食管嗜酸性粒细胞积聚和伴随的食管上皮细胞紊乱， 架构单次静脉内施用编码抗Siglec-F的AAVrh. 10 mAnti-Eos， 抗鼠嗜酸性粒细胞唾液酸结合免疫球蛋白样凝集素的单克隆抗体 （Siglec-F），诱导小鼠嗜酸性粒细胞凋亡，清除血液高嗜酸性粒细胞，减少 食管结构紊乱时食管嗜酸性粒细胞积聚减少， 食物嵌塞作为将这种疗法转化为人类的下一步，我们产生了LXi 02 （AAVrh. 10 hAnti-Eos），与AAVrh. 10 mAnti-Eos相同，但具有抗Siglec-8的编码序列，一种 鼠Siglec-F的IgG 1人直系同源物。本阶段I STTR的重点是证明LXi 02 作为抗人嗜酸性粒细胞治疗有效。我们将静脉注射LXi 02 免疫缺陷小鼠，并评估随着时间的推移肝脏表达和血液中抗- Siglec-8，并且表达的抗Siglec-8将： 自然杀伤细胞抗体依赖性细胞毒性和人嗜酸性粒细胞凋亡;增强清除 免疫缺陷小鼠中的人嗜酸性粒细胞;并证明可以关闭LXi 02基因表达 如果需要的话。随着第一阶段STTR的成功，LEXEO将申请第二阶段STTR，目标是 将LXi 02转化为人类治疗EoE。目标1。为了证明LXi 02将介导 免疫缺陷小鼠抗Siglec-8的持续、稳态水平，其有效地发挥降低 人类嗜酸性粒细胞的水平。目标2.为了显示GalNAc缀合的siRNA的施用同源于 LXi 02中的序列将抑制由LXi 02编码的抗Siglec 8抗体的表达。

Abstract. Eosinophilic esophagitis (EoE), a chronic upper gastrointestinal disabling disorder affecting children and adults, is characterized by eosinophil esophageal inflammation, progressive disordering of esophageal architecture, esophageal dysfunction, dysphagia and food impaction. There are no approved therapies for EoE; standard of care includes topical or systemic glucocorticoids and diet modification. LEXEO Therapeutics, an early stage gene therapy company, is developing a single administration gene therapy to treat EoE with LXi02, a nonhuman primate serotype rh.10 adeno-associated virus (AAVrh.10) vector administered intravenously, designed to genetically modify the liver to express and secrete a monoclonal antibody directed against eosinophils, resulting in clearance of eosinophils from the circulation and tissues. The advantage of gene therapy over conventional monoclonal therapy is persistent stable levels of the anti-Eos monoclonal following single intravenous therapy. In collaboration with the Crystal laboratory, Weill Cornell, a novel murine EoE model was created, induced by sensitization to peanuts, resulting in esophageal eosinophil accumulation and concomitant derangement of esophageal architecture. A single intravenous administration of AAVrh.10mAnti-Eos coding for anti-Siglec-F, a monoclonal antibody directed against murine eosinophil sialic acid-binding immunoglobulin-like lectin (Siglec-F), induced murine eosinophil apoptosis, clearance of blood hyper eosinophilia, reduction in esophageal eosinophil accumulation reduction in esophageal architectural derangement and decrease in food impaction. As the next step in translating this therapy to humans, we generated LXi02 (AAVrh.10hAnti-Eos), identical to AAVrh.10mAnti-Eos, but with the coding sequence for anti-Siglec-8, an IgG1 human ortholog of murine Siglec-F. The focus of this phase I STTR, is to demonstrate that LXi02 is effective as an anti-human eosinophil therapy. We will administer LXi02 intravenously to immunodeficient mice at varying doses and assess over time liver expression and blood levels of anti- Siglec-8 and that the expressed anti-Siglec-8 will: bind to Siglec-8 and to human eosinophils; mediate natural killer cell antibody-dependent cytotoxicity and apoptosis of human eosinophils; enhance clearance of human eosinophils in immunodeficient mice; and demonstrate that LXi02 gene expression can be shut off if required. With success of this phase I STTR, LEXEO will apply for a phase 2 STTR, with the goal to translate LXi02 to human therapy for EoE. Aim 1. To demonstrate that LXi02 will mediate in immunodeficient mice persistent, steady state levels of anti-Siglec-8 that functions effectively to reduce levels of human eosinophils. Aim 2. To show that administration of GalNAc conjugated siRNA cognate to a sequence in LXi02 will suppress expression of the anti-Siglec8 antibody coded by LXi02.