You are here
FDA Approves Obizur (Antihemophilic Factor) for Acquired Hemophilia A
The FDA has given the nod to Obizur (antihemophilic factor [recombinant], porcine sequence, Baxter International) for the treatment of bleeding episodes in adults with acquired hemophilia A (AHA), a rare and potentially life-threatening acute bleeding disorder.
Obizur was granted “orphan drug” status by the FDA, and its review was prioritized based on the classification of AHA as a rare disease and on the potential for the treatment to address an important unmet medical need.
Obizur is the first recombinant porcine FVIII therapy approved for AHA that allows physicians to manage the treatment’s efficacy and safety by measuring factor VIII activity levels in addition to clinical assessments. Obizur replaces the inhibited human factor VIII with a recombinant porcine sequence factor VIII based on the rationale that it is less susceptible to inactivation by circulating human factor VIII antibodies.
The FDA’s approval was based on results from a global, prospective, controlled, phase II/III open-label trial that examined the efficacy of Obizur in the treatment of serious bleeding episodes in adults with AHA. Twenty-nine patients were evaluated for safety, and 28 were evaluated for efficacy.
All of the patients treated with Obizur (28/28) showed a positive response (i.e., an effective or partially effective response with bleeding stopped or reduced and clinical improvement) at 24 hours after the initial infusion. Of these 28 patients, 24 (86%) had successful treatment of the initial bleeding episode. The overall treatment success was determined by the investigator based on the ability to discontinue or reduce the dose and/or dosing frequency of Obizur. The most common adverse reaction observed among the 29 patients in this study was the development of inhibitors to porcine FVIII.
The safety and efficacy of Obizur have not been established in patients with baseline anti-porcine factor VIII inhibitor titers greater than 20 BU. The treatment is not indicated for patients with congenital hemophilia A or von Willebrand disease.
Unlike congenital hemophilia, acquired hemophilia typically affects older adults and occurs in both males and females. In acquired disease, individuals typically experience subcutaneous, soft-tissue, and post-surgical bleeding. The co-morbidities in this typically elderly population also pose a challenge in treating serious bleeding episodes.
Source: Baxter; October 24, 2014.