Armocibart

The purpose of this study is to show that KN057 can prevent bleeds in patients with haemophilia A or B without inhibitors and is safe to use. Participants receiving on-demand treatment prior to screening will be randomly assigned to Experimental group or Control group at a ratio of 2:1 in Part A. Participants receiving prophylaxis prior to screening will be nonrandomly assigned to Prophylaxis group in Part B. Participants in Experimental group will receive KN057 prophylaxis for 52 weeks upon enrollment. Participants in Control group will first receive on-demand treatment for 26 weeks, then switch to KN057 prophylaxis for 26 weeks. Participants in Prophylaxis group will first receive prophylaxis with coagulation factor for 26 weeks, then switch to KN057 prophylaxis for 26 weeks.

The purpose of this study is to show that KN057 can prevent bleeds in patients with haemophilia A or B with inhibitors and is safe to use. Successfully screened participants will be randomly assigned to KN057 Prophylaxis (Arm 1) versus No Prophylaxis (Arm 2) at a ratio of 2:1. Participants in KN057 Prophylaxis will receive KN057 prophylaxis for 52 weeks upon enrollment. Participants in No Prophylaxis will first receive on-demand treatment for 26 weeks, then switch to KN057 prophylaxis for 26 weeks.The trial period is 59 weeks, including a 3-week screening period, a 26-week main trial, a 26-week extension period, and a 4-week follow-up period after the last administration.