Photo courtesy of
Baxter International Inc.
Health Canada has approved a recombinant porcine factor VIII (FVIII) product (Obizur) to treat bleeding episodes in patients with acquired hemophilia A caused by autoantibodies to FVIII.
Obizur is the first recombinant porcine treatment to be made available for acquired hemophilia A in Canada.
It is specifically designed so physicians can monitor treatment response by measuring FVIII activity levels in addition to making clinical assessments.
Health Canada’s approval is based on a phase 2/3 trial in which patients with acquired hemophilia A received Obizur as treatment for serious bleeding episodes.
Twenty-nine patients were enrolled in this trial 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 drug is currently approved for use in the US and is under regulatory review in the European Union, Switzerland, Australia, and Colombia.
