Dock and Lock: novel protein engineering

对接和锁定：新型蛋白质工程

• 批准号: 7157248
• 负责人: Chien Hsing K. Chang
• 金额: $ 13.43万
• 依托单位: IMMUNOMEDICS, INC.
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-29 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7157248
• 关键词: antibody; antigens; lead; neoplasm /cancer; neoplasm /cancer therapy; peptides; protein engineering; proteins; radionuclides

DESCRIPTION (provided by applicant): Project Summary: The objective of this research is to develop a new generation of fusion proteins that can be used for improved imaging and therapy of cancer and other diseases by the method of pretargeting, which separates antibody localization from the delivery of diagnostic or therapeutic radionuclides. This application describes a novel technology for the facile and quantitative assembly of trivalent, bispecific, binding structures from 2 distinct fusion proteins, and proposes to advance prototype molecules composed of three Fab fragments that are stably linked and retain the binding affinity of the parental antibodies. These novel constructs were purified to homogeneity and shown to be useful for pretargeted delivery of radio-labeled tracers to human colonic tumor xenografts in nude mice, achieving exceptional tumor-to-nontumor ratios. For example, at 1h post-injection of a 99mTc-labeled tracer, the tumor to blood ratio was as high as 66+5, with tumor uptake exceeding 30% injected dose per gram. The primary aim of this application is to further characterize 1 such construct both in vitro and in vivo, so that the feasibility of its future clinical development for pretargeted therapy can be defined. Another key aim is to show that this new construct can be prepared more efficiently and with higher productivity than previously-generated recombinant bispecific antibodies from this group. Upon meeting these milestones, we should be in a position to submit a Phase II application directed toward additional development of this agent for initial clinical testing as pretargeted radioimmunotherapy of CEA-positive cancers, such as colonic cancer. Project Narrative: This innovative research will produce multivalent, multifunctional, structures in general, and trivalent bispecific Fab-based binding proteins in particular, that can be useful for the detection, imaging, and therapy of various human diseases which have antigen targets, including cancers, cardiovascular diseases, autoimmune diseases, and infectious diseases.

描述（由申请人提供）： 项目摘要：本研究的目的是开发新一代融合蛋白，可用于通过预靶向方法改善癌症和其他疾病的成像和治疗，该方法将抗体定位与诊断或治疗放射性核素的递送分开。该申请描述了一种新技术，用于从两种不同的融合蛋白中轻松定量地组装三价、双特异性结合结构，并提出改进由三个稳定连接并保留亲本抗体的结合亲和力的 Fab 片段组成的原型分子。这些新颖的构建体被纯化至同质性，并被证明可用于将放射性标记的示踪剂预先靶向递送至裸鼠中的人结肠肿瘤异种移植物，从而实现特殊的肿瘤与非肿瘤比率。例如，注射99mTc标记示踪剂后1小时，肿瘤与血液的比率高达66+5，肿瘤摄取超过每克注射剂量的30%。本申请的主要目的是在体外和体内进一步表征这种构建体，以便确定其未来临床开发用于预靶向治疗的可行性。另一个关键目标是表明，与之前从该组中生成的重组双特异性抗体相比，可以更有效地制备这种新构建体，并具有更高的生产率。达到这些里程碑后，我们应该能够提交 II 期申请，旨在进一步开发该药物，用于初步临床测试，作为 CEA 阳性癌症（如结肠癌）的预靶向放射免疫疗法。项目简介：这项创新研究将产生多价、多功能的一般结构，特别是三价双特异性 Fab 结合蛋白，可用于检测、成像和治疗具有抗原靶点的各种人类疾病，包括癌症、心血管疾病、自身免疫性疾病和传染病。