Human Coagulation Factor IX (Yuanda Shuyang)

Primary objective: To evaluate the pharmacokinetic characteristics of a single dose of human coagulation factor IX in children (<12 years old) with moderate and severe hemophilia B. Secondary objective: To evaluate the safety of a single dose of human coagulation factor IX in children (<12 years old) with moderate and severe hemophilia B. To assess the safety and efficacy of human coagulation factor IX in the on-demand treatment of bleeding events in children (<12 years old) with moderate and severe hemophilia B.