Therapeutic choices for patients with hemophilia and high-titer inhibitors

Effective treatment of bleeding episodes in hemophilia with high titer inhi bitors (HTI) remains a challenge, despite the fact that the therapeutic arm amentarium has expanded considerably over the past few years. Treatment saf ety has improved with the availability of porcine factor VIII (FVIII) and b ypassing products such as recombinant factor VIIa (rFVIIa), and plasma-deri ved activated Prothrombin Complex Concentrates (aPCCs) that are virally ina ctivated. The major drawbacks of rFVIIa and aPCCs are their unpredictable h emostatic effect, lack of laboratory assays to monitor efficacy and dosing frequency, and the risk of thrombosis. The proceedings of a one-day worksho p of physicians who specialized In treating patients with hemophilia held i n Vienna on May 13, 2000 have been summarized. In making a decision regardi ng the choice of product, physicians often consider the type of bleeding ep isode (life or limb threatening), age of the patient, volume of the reconst ituted product, previous exposure to plasma derived products, cost, efficac y, and safety. For plasma naive patients, to achieve rapid hemostasis a maj ority of the panelists used porcine FVIII (for patients who lack porcine in hibitory antibodies) or rFVIIa, For patients previously treated with plasma derived factors, in addition to the above concentrates, aPCCs were recomme nded. Although no data exists regarding safety and efficacy, switching prod ucts was routinely practiced either because of availability or cost. Furthe rmore, the panelists were uncertain about the efficacy of bypassing agents in the prevention of joint disease in inhibitor patients. The workshop part icipants felt that future research offers the best solution to resolve some of the dilemmas faced by clinicians and may help individualise treatment i n a hemophilia patient with a high titer inhibitor. (C) 2001 Wiley-Liss. In c.