High throughput camelid antibody screening as a drug discovery platform

 描述（由申请人提供）：单克隆抗体用于治疗从癌症到感染性疾病的广泛疾病。然而，具有高亲和力和特异性的抗体的开发仍然是耗时的、劳动密集型的和不可预测的，特别是对于低免疫原性或毒性靶标。急需一种新的方法来快速开发针对各种疾病，特别是针对新兴疾病的抗体。Abzyme Therapeutics LLC正在积极开发无动物抗体发现平台，以加速诊断和治疗抗体的生成。第一阶段的目标已经顺利完成。具体地，我们已经创建了所谓的酵母表面展示骆驼科动物自我多样化VHH抗体文库或SDALib，作为在体外提供多样化抗体阵列的单克隆抗体产生系统，而不使用体内免疫。该系统的主要特点是能够通过在抗体编码基因中的超突变诱导而自我产生具有多样化抗体的文库。作为原理验证，我们已经成功地使用该平台分离了一组针对来自H5 N1流感病毒的N1神经氨酸酶（NA）的单域抗体。已显示所获得的VHH抗体在细菌系统中有效表达，从而提供了用于治疗应用的抗体生产的加速放大的机会。已经在体外测定中纯化和表征了抗NA VHH抗体。作为原理的证明，与H5 N1和H1N1流感病毒的N1 NA反应的几种抗NA VHH抗体中的一种（Flu 27 -8）已经被人源化，保留了亲本分子的全部抗NA活性。在细菌系统中作为线性融合物产生的二价抗NA抗体在体外测定中显示抗体活性的显著增加。II期的后续工作包括三个将同时进行的具体目标：（i）通过证明抗H5 N1和H1N1流感病毒的体外和体内活性，将I期中分离的N1抗NA抗体推向临床应用;（ii）扩大该平台的应用范围，以开发针对其他流感病毒亚型的血凝素和NA的抗体，例如H3 N2和H7N9，其具有不寻常的人畜共患病潜力，并且旨在获得与几种不同的神经氨酸酶（H5 N1、H1N1、H3 N2和H7N9）交叉反应的抗体;（iii）利用抗体发现平台来开发针对一组癌症靶标的VHH抗体，随后产生新的基于IgG样VHH的双特异性人源化抗体。第二阶段的努力是进一步扩大该技术的应用，以快速开发新的抗体的治疗目标，并推进人源化的抗流感抗体在第一阶段分离到临床研究。

 DESCRIPTION (provided by applicant): Monoclonal antibodies are used for treatment of a wide range of diseases from cancer to infectious diseases. However, development of antibodies with high affinity and specificity is still time- consuming, labor-intensive and unpredictable, especially to low immunogenic or toxic targets. A new approach for rapid development of antibodies against a variety of diseases, especially against emerging diseases is much needed. Abzyme Therapeutics LLC is actively developing animal-free antibody discovery platforms to accelerate generation of diagnostic and therapeutic antibodies. Phase I objectives have been successfully completed. Specifically, we have created a so-called yeast surface display camelid Self-Diversifying VHH Antibody Library or SDALib as a monoclonal antibody generating system providing a diverse array of antibodies in vitro, without using in vivo immunization. The main feature of the system is the ability to self-generate a library with diversified antibodies by mean of hypermutation induction in antibody encoding genes. As proof-of-principle, we have successfully used the platform to isolate a set of single-domain antibodies against N1 neuraminidase (NA) derived from influenza H5N1 virus. Obtained VHH antibodies have been shown to express efficiently in a bacterial system providing an opportunity for accelerated scale-up of antibody production for therapeutic application. Anti-NA VHH antibodies have been purified and characterized in in vitro assays. As proof of principle one (Flu27-8) out of several anti-NA VHH antibodies, that is reactive with N1 NAs of both H5N1 and H1N1 influenza viruses, has been humanized preserving the full anti-NA activity of the parental molecule. Bi- valent anti-NA antibodies that have been produced in a bacterial system as linear fusions showed a significant increase in antibody activity in in vitro assays. Subsequent efforts of Phase II consis of three specific aims that will be performed simultaneously: (i) advance the N1 anti-NA antibodies isolated in Phase I toward clinical application by demonstrating both in vitro and in vivo activity against H5N1 and H1N1 influenza viruses; (ii) expand the application of the platform for developing antibodies targeting both hemagglutinin and NAs of other influenza virus subtypes, e.g. H3N2 and H7N9 which have unusual zoonotic potential and aiming for antibodies cross-reacting with several different neuraminidases (H5N1, H1N1, H3N2 and H7N9); (iii) utilize the antibody discovery platform for developing VHH antibodies against a set of cancer targets followed by production of novel IgG-like VHH-based bispecific humanized antibodies. Phase II efforts are to further extend the application of the technology for rapid development of novel antibodies to therapeutic targets and to advance humanized anti-influenza antibodies isolated in phase I into clinical studies.