Re-Engineering Blood-Borne Erythropoietin for Targeted Delivery

描述（由申请人提供）：促红细胞生成素（EPO）是一种治疗脑血管疾病（包括中风）的潜在新药。然而，EPO是一种大分子药物，不能穿过形成血脑屏障（BBB）的脑毛细血管内皮壁。目前的工作继续对一种重组形式的促红细胞生成素进行药物开发，其中促红细胞生成素作为IgG融合蛋白产生。IgG部分是针对人胰岛素受体（HIR）的基因工程单克隆抗体（MAb）。HIRMAb-EPO融合蛋白的HIRMAb部分作为分子特洛伊木马，通过内源性血脑屏障胰岛素受体介导的转运将融合的EPO运送过血脑屏障。本研究的pre-SBIR可行性阶段描述了HIRMAb-EPO融合蛋白的工程、表达、生化验证、在恒河猴体内的血浆药代动力学和血脑池转运。拟议的I期SBIR研究将制定生产HIRMAb-EPO融合蛋白的生产计划。该生产将被设计用于生产纯度、效力、安全性和杂质方面符合FDA规范的治疗产品，以便在未来用于临床试验的融合蛋白的GMP生产中可以重复生产。I期生产的融合蛋白随后将用于II期研究HIRMAb- EPO融合蛋白在恒河猴体内的活性和毒理学。II期的目标是产生一个功效/毒理学数据包，可以提交给FDA，用于设计这种新的IgG-EPO融合蛋白的未来GLP毒理学。

DESCRIPTION (provided by applicant): Erythropoietin (EPO) is a potential new pharmaceutical to treat vascular disease of the brain, including stroke. However, EPO is a large molecule pharmaceutical that does not cross the capillary endothelial wall in brain, which forms the blood-brain barrier (BBB). The present work continues the drug development of a re-engineered form of EPO, wherein the EPO is produced as an IgG fusion protein. The IgG part is a genetically engineered monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb part of the HIRMAb-EPO fusion protein acts as a molecular Trojan horse to ferry the fused EPO across the BBB via receptor-mediated transport on the endogenous BBB insulin receptor. The pre-SBIR feasibility stage of this research describes the engineering, expression, biochemical validation, and in vivo plasma pharmacokinetics and BBB transport in the Rhesus monkey of the HIRMAb-EPO fusion protein. The proposed phase I SBIR research will develop a manufacturing scheme for production of the HIRMAb-EPO fusion protein. This manufacturing will be designed to produce a therapeutic product that meets FDA specifications with regard to purity, potency, safety, and impurities, so that the manufacturing can be replicated in future GMP production of the fusion protein for clinical trials. The fusion protein produced in phase I will then be used in phase II for in vivo activity and toxicology of the HIRMAb- EPO fusion protein in Rhesus monkeys. The goal of phase II is to produce an efficacy/toxicology data package that can be presented to the FDA for design of future GLP toxicology of this new IgG-EPO fusion protein. PUBLIC HEALTH RELEVANCE: Erythropoietin (EPO) is a tissue-protective agent that could be developed as a new drug for the treatment of vascular disorders of the brain, including stroke. However, EPO cannot penetrate the brain following peripheral administration, because EPO does not cross the endothelial wall in brain, which forms the blood-brain barrier (BBB). This research will develop a new IgG-EPO fusion protein for the treatment of vascular disease of the brain including stroke.