Used in the treatment and prevention of bleeding episodes in patients with hemophilia B, especially those with factor IX deficiency or inhibitors to factor IX. It functions as a bispecific monoclonal antibody that bridges activated factor IX and factor X, mimicking the role of factor VIII in the coagulation cascade. This helps restore hemostasis in patients who cannot effectively use traditional factor replacement therapy. Emicizumab is administered prophylactically to reduce the frequency of bleeding episodes and can be used across various age groups, including infants. Its subcutaneous route of administration offers a more convenient and less invasive option compared to intravenous infusions of clotting factors.