Long‐term FEIBA prophylaxis does not prevent progression of existing joint disease

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Abstract
Summary. Activated prothrombin complex concentrates have been used to treat bleeding episodes for patients who have developed an inhibitor to factor VIII (FVIII). FEIBA‐Vh® (FVIII bypassing activity, FEIBA) has been used since 1970 for this purpose and with FVIII for immune tolerance programmes. Studies have not been presented to show the safety and efficacy of FEIBA when given over a long period of time to prevent haemophilic arthropathy with bleeding into the joints of these patients. This study was undertaken to ascertain the outcome of haemophilic arthropathy with FEIBA prophylaxis. Data were collected on seven patients with known long‐standing high‐titre FVIII inhibitors given FEIBA prophylaxis for 3–6½ years. Patients were given 50–100 units of FEIBA three to four times weekly. A functional joint evaluation revealed some degree of arthropathy already present in all patients at time of prophylaxis initiation. Safety was measured by medical status, evidence of thrombosis, life‐threatening bleeding and inhibitor titre. Efficacy was measured for joint outcome by a functional physical therapeutic scale. At the conclusion of the study, efficacy was mixed as all of the joints for which the patients were placed on prophylaxis had progressed and developed synovitis. Two patients had a functional improvement in their arthropathy, and all were functional enough to attend regular school. The product was deemed safe for long‐term use, as there were no complications of therapy with no thrombosis, no life‐threatening bleeding episodes and no anamnesis caused by FEIBA alone. Inhibitor titres fell in all patients over the course of the study. Total product usage ranged from approximately 9373–15 571 U kg−1 year−1. FEIBA is safe for long‐term prophylaxis when given in the recommended dosage for an extended period of time. Efficacy to prevent arthropathy could not be seen as all patients had some degree of arthropathy at time of prophylaxis initiation. An additional study needs to be performed using FEIBA before arthropathy has developed.