Efficacy of extended half-life products for the treatment of hemophilia

Abstract

Hemophilia is a bleeding disorder characterized by frequent spontaneous joint and muscle bleeding and superficial bleeding occurring from infancy. Induction of prophylactic replacement of Factor VIII and IX products at a young age resulted in decreased bleeding frequency, leading to improved quality of life (QOL). However, patients and their families have suffered from frequent venipuncture for prophylaxis, especially during childhood. In Japan, extended half-life (EHL) products have been available since 2014. We report the efficacy of these products in nine and seven patients with hemophilia A and B, respectively, who used them for >1 year. The administration of EHL products resulted in reduced intravenous injection frequency and annual bleeding rate in patients with hemophilia A and B. Furthermore, increased Factor VIII or IX trough levels were observed in patients and higher factor levels were obtained with EHL products than with standard half-life (SHL) products using the same frequency of administration in patients actively performing sports. Our data showed that 70% of patients with hemophilia A and all patients with hemophilia B used EHL products as a prophylactic replacement for SHL products. Patients’ satisfaction and QOL were further improved. The development of a nonfactor product, emicizumab, will lead to more choices for personalized prophylaxis according to the lifestyle of each patient.