高通量双特异抗体合成筛选及抗肿瘤双抗的发现与研究

快速筛选出临床有效的双特异抗体已经成为抗肿瘤及其他疾病创新药物开发的迫切任务。 本项目是应用前期建立的"蛋白质反式剪接双抗合成平台（BAPTS)"平台，开拓其高效合成筛选功能，建立包含上千种不同组合的双特异抗体库，可从不同的靶点、同一靶点不同表位、不同疾病的靶点靶位等抗体序列，进行组合筛选出具有突出生物学活性的双特异抗体，完成建立高通量筛选不同的双抗组合的筛选设计及程序建立。本课题以抗肿瘤双抗为例，在用BAPTS技术平台制备出创新的抗肿瘤抗体（CD3和PRLR双特异性抗体），证明这项研究课题的可行性。按照本课题的研究路线及方法，将会筛选获得若干个具有抗肿瘤或其他生物学活性的双抗，然后进行靶位分析，分子作用机理的研究，体外抗肿瘤活性、工程化生产可行性以及体内包括药代动力学、肿瘤抑制等成药性研究。本课题具有快速筛选获得原始创新双特异抗体药物先进性和创新性。

Rapid generating clinical effective bispecific antibodies for treatment of cancer and other diseases has been highly desirable. Based on previous accomplishments of the researches supported by the National Science Foundation of China, the applicants have established the innovative platform called BAPTS，to synthesize “Bispecific Antibody by Protein Trans-Splicing”. Having optimized the platform currently on-going in the lab, we would like to propose establishment of a quick procedure of assemble bispecific antibodies from different combinations of two fragments that cover over 1000 possible bispecific sequences. After initial small scale around 10-20 paring, we will synthesize over 70~100 antibody fragments that are significant in cancer and other diseases. These fragments could contains different versions of CD3, popular drug targets such as HER2, PRLR, Mesothelin, EGFRvⅢ, Tissue Factor, CD22, CD171, CD174, EpCAM, BCMA, Siglec 15, GPC-3 and LRRC-15. Through possible paring them to generate over 1000 bispecific antibodies, some of them will be further characterized in vivo and in vitro. Compared with existing methods published, this would be the only method that can be so efficient to assemble many antibodies to different targets such as cancer cell surface antigens, cytokines, and others, as well as different epitopes within one antigen target. Many bispecific antibodies with outstanding biologic functions such as anti-tumor and/or other activities will be achieved by this approach within relative short period of time. A couple of bispecific antibodies by initial feasibility testing have been illustrated as examples to demonstrate the feasibility of the approach. Two to three bispecific antibodies by this method will be intensively characterized through in vitro evaluations including physic-chemistry, properties, cell-based bioactivity assay, as well as in vivo pharmacokinetics, and anti-cancer activity in an animals. All the results will be evaluated to demonstrate if this approach is an innovative, high efficient, reliable and huge beneficial to biopharmaceutical industry to speed up development of bispecific antibody.