Hemophilia A is a congenital disorder caused by deficiency or malfunction of coagulation factor (F) VIII. While exogenously provided FVIII effectively reduces bleeding complications in many hemophilia A patients, multiple efforts are underway to develop new drugs to meet the needs that conventional FVIII agents do not. We have been long engaged in creating and clinically developing a humanized anti-FIXa/FX asymmetric bispecific IgG antibody with a FVIIIa-cofactor activity. Since this project was born from a creative and unique idea, our group recognized from the first that it would face many difficulties in the course of research including establishment of industrial manufacturability of an asymmetric bispecific IgG antibody. The group actually faced various challenges, but addressed all of them during about 10 years of research, and successfully created the potent humanized bispecific antibody, emicizumab. Emicizumab has showed clinical benefits in the human trials among which the first one was started in 2012, and has been currently approved in US, EU, Japan, and some other countries. It is now expected to improve the quality of life of patients and their families. In this article, we review the course of the research and clinical development of emicizumab, and describe its molecular characteristics.

中文翻译：

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Emicizumab，抗凝血因子IXa和X的人源化双特异性抗体，具有因子VIIIa-辅因子活性

A型血友病是由凝血因子（F）VIII缺乏或功能异常引起的先天性疾病。尽管外源提供的FVIII有效地减少了许多A型血友病患者的出血并发症，但正在努力开发新药，以满足常规FVIII药物不能满足的需求。我们一直致力于创建和临床开发具有FVIIIa辅因子活性的人源化抗FIXa / FX不对称双特异性IgG抗体。由于该项目源于一个独特的创意，我们团队从一开始就认识到它将在研究过程中面临许多困难，包括建立不对称双特异性IgG抗体的工业可制造性。该小组实际上面临着各种挑战，但是在大约10年的研究中解决了所有这些挑战，并成功创建了有效的人源化双特异性抗体艾米珠单抗。Emicizumab在人体试验中显示出临床益处，其中第一项试验始于2012年，目前已在美国，欧盟，日本和其他一些国家获得批准。现在有望改善患者及其家人的生活质量。在本文中，我们回顾了艾米珠单抗的研究和临床发展过程，并描述了其分子特征。