Long Acting VEGF Binding Proteins for Treating Rheumatoid Arthritis

描述(申请人提供)：类风湿性关节炎(RA)是一种慢性炎症性疾病，会导致进行性关节破坏、畸形和残疾。类风湿关节炎最早的观察特征之一是在滑膜内形成新的血管网络，允许细胞和营养物质输送到侵袭的血管膜。这种新血管的形成(也称为血管生成)是一个在宿主微环境和一些分泌介质的影响下高度调控的过程。RA中表达多种促血管生成介质。其中，血管内皮生长因子(VEGF)在关节滑膜中内皮细胞的分化和血管系统的发育中起着关键作用，因此是RA患者治疗干预的合理靶点。我们的总体目标是创造一种长效的血管内皮生长因子抑制剂，并在类风湿关节炎动物模型中测试其疗效。在第一阶段，我们利用已发表的可溶性血管内皮生长因子受体I(也称为sFlt-1)的结构信息，使用半胱氨酸反应性挂钩合理地设计了聚乙二醇(PEG)-sFlt-1结合物。我们引入了一种新的“游离”半胱氨酸，在sFlt-1被认为不是生物活性必需的区域进行了定点突变。“游离的”半胱氨酸残基是利用具有硫醇反应的聚乙二醇对蛋白质进行共价修饰的部位。这项技术允许创建新的、完全活性的、具有特定结构的聚乙二醇半胱氨酸-sflt-1类似物，并克服了使用标准的胺反应挂钩修饰蛋白质时生物活性降低和异质性降低的问题。在第一阶段，我们确定了sFlt-1中可以在不影响蛋白质体外生物活性的情况下进行修饰的位点。我们还进行了药代动力学研究，以证实聚乙二醇化延长了sFlt-1的循环半衰期。在第二阶段，我们将开发一种具有成本效益的制造工艺，并生产足够数量的聚乙二醇化重组sFlt-1，用于RA动物疾病模型的测试。类风湿关节炎(RA)是一种慢性炎症性疾病，会导致进行性关节破坏、畸形和残疾。血管内皮生长因子(VEGF)似乎在这一炎症过程中发挥了关键作用，因此是RA患者治疗干预的合理靶点。血管内皮生长因子抑制剂已经在人类身上进行了测试，并被证明可以延缓疾病的进展。我们的总体目标是创造一种长效的血管内皮生长因子抑制剂，可以每周一次或每两周一次。

DESCRIPTION (provided by applicant): Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes progressive joint destruction, deformities and disability. One of the earliest observed features of RA is the development of a new vascular network within the synovium that allows for the delivery of cells and nutrients to the invading pannus. This formation of new blood vessels (also known as angiogenesis) is a highly regulated process under the influence of the host microenvironment and a number of secreted mediators. Many proangiogeneic mediators are expressed in RA. One of these mediators in particular, vascular endothelial growth factor (VEGF) appears to play a critical role in the differentiation of endothelial cells and the development of the vascular system in the synovial lining of the joints and therefore, is a reasonable target for therapeutic intervention in RA patients. Our overall goals are to create a long acting VEGF inhibitor and test its efficacy in animal models of RA. During Phase I, we used the published structural information for soluble VEGF Receptor I (also known as sFlt-1) to rationally design polyethylene glycol (PEG)-sFlt-1 conjugates using cysteine-reactive PEGs. We introduced a new "free" cysteine using site-directed mutagenesis in regions of sFlt-1 that were believed to be non-essential for biological activity. The "free" cysteine residue served as the site for the covalent modification of the protein using a thiol-reactive PEG. This technology allows for the creation of novel, fully active PEG-Cys-sFlt-1 analogues of defined structure and overcomes the problems of reduced bioactivity and heterogeneity when proteins are modified using standard amine-reactive PEGs. During Phase I we identified sites in sFlt-1 that can be modified without affecting the protein's in vitro bioactivity. We also performed a pharmacokinetic study to verify that PEGylation extends the circulating half-life of sFlt-1. During Phase II, we will develop a cost effective manufacturing process and produce sufficient quantities of PEGylated recombinant sFlt-1 for testing in animal disease models of RA. Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes progressive joint destruction, deformities and disability. Vascular endothelial growth factor (VEGF) appears to play a critical role in this inflammatory process and therefore, is a reasonable target for therapeutic intervention in RA patients. VEGF inhibitors have been tested in humans and have been shown to delay the progression of the disease. Our overall goal is to create a long acting VEGF inhibitor that can be dosed once a week or once every two weeks.