Hemophilia A or B With Inhibitors
As many as 20% to 30% of patients with hemophilia develop inhibitors to their factor-replacement therapy at some time in their lives. Inhibitors usually develop in patients with the severe form of the disorder.51
- About 15% to 35% of all patients with hemophilia A (Factor VIII deficiency)
develop inhibitors to Factor VIII.51
- Inhibitors are much less common in hemophilia B (Factor IX deficiency) at less than 5%.51
Patients with hemophilia A or B with inhibitors are diagnosed with inhibitors after a Bethesda Inhibitor Assay confirms antibody resistance to either FVIII or FIX replacement therapy. Based on Bethesda titers, patients are classified in two categories:
- Low titer—Patients with inhibitor levels below 5 BU are considered low titer or low responding and can most likely be treated with higher doses of factor to neutralize the inhibitor titer and achieve hemostasis.
- High titer—Patients with levels at 5 BU or higher are considered high titer or high responding and will need an alternative therapy because of how strongly their inhibitors react to factor replacement.
Bypassing agents such as NovoSeven® RT are used to treat bleeding episodes in patients with inhibitors. Bypassing agents work with platelets and other clotting factors (skipping some of the normal steps where Factor VIII and Factor IX are needed) to make a blood clot and stop the bleeding, even when there isn’t enough Factor VIII or Factor IX in the blood.50 Recombinant Factor VIIa (NovoSeven® RT)
bypasses Factor VIII and Factor IX in the coagulation process.
Get information about Efficacy in hemophilia A or B with inhibitors.
Get information about Dosing and Administration for NovoSeven® RT for hemophilia A or B with inhibitors.