How I use bypassing therapy for prophylaxis in patients with hemophilia A and inhibitors.

Inhibitor development poses a significant challenge in the management of hemophilia because once an inhibitor is present, bleeding episodes can no longer be treated with standard clotting factor replacement therapy. Consequently, patients with inhibitors are at increased risk for difficult-to-control bleeding and complications, particularly arthropathy and physical disability. Three clinical trials in patients with inhibitors have demonstrated that prophylaxis with a bypassing agent reduces joint and other types of bleeding and improves health-related quality of life compared with on-demand bypassing therapy. In hemophilia patients without inhibitors, the initiation of prophylaxis with factor (F) VIII or FIX prior to the onset of recurrent hemarthroses can prevent the development of joint disease. Whether this is also true for bypassing agent prophylaxis remains to be determined.