Photo courtesy of
Baxter International Inc.
The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has recommended approval for Obizur, a recombinant porcine
factor VIII (FVIII) product, to treat bleeding episodes in adults with acquired hemophilia A.
If the European Commission approves Obizur, it will be the first recombinant porcine FVIII treatment available in the European Union (EU) for this patient population. Obizur already has orphan designation in the EU.
The European Commission is expected to make a decision on Obizur later this year. The decision will be applicable to all 28 EU member states plus Iceland, Norway, and Liechtenstein.
About Obizur
Acquired hemophilia A is caused by the formation of antibodies directed against the body’s own FVIII. The underlying cause of this may be pregnancy, cancer, or the use of certain medications, but the cause is often unknown.
Obizur replaces inhibited human FVIII with a recombinant porcine sequence FVIII based on the rationale that porcine FVIII is less susceptible to inactivation by circulating human FVIII antibodies. Physicians can monitor patients’ response to Obizur by measuring FVIII activity levels.
The CHMP’s positive opinion of Obizur is based on a phase 2/3 trial in which patients with acquired hemophilia A received the drug as treatment for serious bleeding episodes.
Twenty-nine patients were enrolled and evaluated for safety. Researchers determined that one of the patients did not actually have acquired hemophilia A, so this patient could not be evaluated for efficacy.
At 24 hours after the initial infusion, all 28 patients in the efficacy analysis had a positive response to Obizur. This meant that bleeding stopped or decreased, the patients experienced clinical stabilization or improvement, and FVIII levels were 20% or higher.
Eighty-six percent of patients (24/28) had successful treatment of their 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 adverse event most frequently reported in the 29 patients in the safety analysis was the development of inhibitors to porcine FVIII.
Nineteen patients were negative for anti-porcine FVIII antibodies at baseline, and 5 of these patients (26%) developed anti-porcine FVIII antibodies following exposure to Obizur.
Of the 10 patients with detectable anti-porcine FVIII antibodies at baseline, 2 (20%) experienced an increase in titer, and 8 (80%) decreased to a non-detectable titer.
Obizur is under development by Baxalta Incorporated. The product is already approved in the US and is under regulatory review in Canada, Switzerland, Australia, and Colombia.
