Bioengineering of a New Antibody Drug Delivery Technology

描述（由申请人提供）：单克隆抗体（MAb）是许多脑部疾病的潜在新疗法，包括阿尔茨海默病（AD）、帕金森病、疯牛病、西尼罗河脑炎、神经艾滋病、脑损伤、脑癌或多发性硬化症。在几乎所有情况下，给药到血液中的单克隆抗体必须能够到达大脑内的目标部位。然而，MAb是大分子药物，不能穿过血脑屏障（BBB）。血脑屏障问题阻碍了抗体药物的开发。该研究将开发出一种新的抗体药物输送到大脑的技术，这种技术也可以用于其他器官，并将应用于阿尔茨海默病。这项工作是基于由两种抗体组成的融合蛋白的基因工程。一种抗体是针对阿尔茨海默病的β淀粉样肽的治疗性抗体，另一种抗体是针对人血脑屏障上的内源性转运体的药物递送系统。I期研究完成了以下工作：(1)表达异四聚体融合蛋白的串联载体的基因工程；(2)克隆永久转染的宿主细胞系，在无血清培养基中表达高水平的融合抗体；(3)融合抗体的生化和功能表征；(4)测定融合蛋白在成年恒河猴体内的血浆药代动力学（PK）和脑摄取。II期研究将完成以下工作：(1)宿主细胞系在50L生物反应器中生长，然后进行可在GMP实验室复制的3柱下游处理；(2)融合蛋白生化分析，超过15项分析试验；(3)恒河猴剂量测定PK及毒性研究。这些研究将使该新型AD融合蛋白的人体试验能够在未来提交IND。

DESCRIPTION (provided by applicant): Monoclonal antibodies (MAb) are potential new therapeutics for many brain diseases, including Alzheimer's disease (AD), Parkinson's disease, mad cow disease, West Nile encephalitis, neuro- AIDS, brain injury, brain cancer, or multiple sclerosis. In almost all cases, it is necessary that the MAb therapeutic that is administered into the blood be able to access target sites within the brain. However, MAb's are large molecule drugs that do not cross the blood-brain barrier (BBB). The BBB problem prevents the brain drug development of antibody drugs. The proposed research will develop a new technology for antibody drug delivery to brain, which could also be used for other organs, and the new technology will be applied to AD. This work is based on the genetic engineering of a fusion protein comprised of 2 antibodies. One antibody is the therapeutic antibody against the Abeta amyloid peptide of AD, and the other antibody is a drug delivery system, which is directed at an endogenous transporter on the human BBB. The Phase I studies accomplished the following: (1) genetic engineering of a tandem vector expressing the hetero-tetrameric fusion protein, (2) cloning of a permanently transfected host cell line that expresses high levels of the fusion antibody in serum free medium, (3) biochemical and functional characterizion of the fusion antibody, and (4) determination of the plasma pharmacokinetics (PK) and brain uptake of the fusion protein in the adult Rhesus monkey. The phase II studies will accomplish the following: (1) growth of the host cell line in a 50L bioreactor, followed by 3-column downstream processing that can be replicated in a GMP lab; (2) biochemical analysis of the fusion protein with over 15 analytical tests; (3) dose finding PK and toxicity study in Rhesus monkeys. These studies will enable future submission of an IND for human testing of this new fusion protein for AD. PUBLIC HEALTH RELEVANCE: Monoclonal antibodies are powerful new therapeutic products of biotechnology. Antibody drugs could be applied to many serious brain disorders, such as Alzheimer's disease (AD), Parkinson's disease, mad cow disease, West Nile encephalitis, neuro-AIDS, brain injury, brain cancer, or multiple sclerosis. However, antibody drugs cannot be developed for these disorders, because the antibody drugs do not cross the blood-brain barrier (BBB). The present research will develop a new technology for the drug delivery of antibody drugs for the brain, which could be applied to diseases such as AD.