Safety of KN057 Prophylaxis in Patients With Haemophilia A or B

The purposes of this open-label, multicenter III clinical trial are to evaluate the safety and efficacy of long-term preventive treatment with KN057 in Haemophilia A or B patients with or without inhibitors, and to assess the pharmacokinetic characteristics of the new and old processes KN057. The participants in Part PK will be randomly assigned to Old process Group or New process Group in a 1:1 ratio. The participants in Old process Group will receive old process KN057 prophylaxis for the first 26 weeks and new process KN057 prophylaxis for the following 26 weeks. The participants in New process Group will receive new process KN057 prophylaxis for both the first 26 weeks and the last 26 weeks. The participants in Part non-PK will be non-randomized and treated with new process KN057 for 52 weeks prophylaxis after enrollment. Priority screening and enrollment of participants who have participated in the KN057-A-301 or KN057-A-302 study.