[Emicizumab: a paradigm shift in hemophilia treatment]

Regular prophylaxis using clotting factor (F) VIII products to prevent hemorrhage in patients with hemophilia A results in considerable suppression in chronic arthropathy development and greatly improves their quality of life. However, there have been some concerns regarding hemostatic treatment for these patients, such as frequent intravenous infusion of FVIII and the development of FVIII inhibitors. A humanized recombinant anti-FIXa/FX bispecific antibody and FVIIIa cofactor function-mimetic (emicizumab) was developed. Several clinical trials have demonstrated that emicizumab remarkably decreases bleeding events by simple subcutaneous infusion and it is currently available as a regular infusion to prevent hemorrhage in congenital hemophilia A patients with or without FVIII inhibitors. There is now a paradigm shift in hemophilia treatment with emicizumab, which is a non-factor product. However, there are some concerns with emicizumab that require clinical attention, such as thromboembolism in cases of concomitant treatment with a bypassing agent, hemostasis monitoring, perioperative hemostatic management, and preventative effects in patients with a proactive lifestyle.