The goal of this clinical trial is to evaluate the safety and efficacy of KN057 in adult patients with severe Hemophilia A (coagulation factor FVIII activity \<1%) or moderate-to-severe Hemophilia B (FIX activity ≤2%). Participants will be administered subcutaneously with KN057 once a week for 20 weeks. KN057 works differently than factor replacement products and will work in the presence of inhibitors. The potential for once weekly subcutaneous administration provides better convenience and compliance.