FDA Approves New Treatment for Hemophilia A, B with Inhibitors

The U.S. Food and Drug Administration approved Sevenfact (coagulation factor VIIa [recombinant]-jncw) for the treatment of adults and adolescents (12 years and older) with hemophilia A and B with inhibitors.

The active ingredient in coagulation factor VIIa (recombinant)-jncw is a recombinant analog of human FVII, which is expressed in the mammary gland of genetically engineered rabbits and secreted into the rabbits’ milk. During purification and processing of the milk, FVII is converted into activated FVII.

The safety and efficacy of this treatment were assessed in a clinical trial that included 27 patients with hemophilia A or B with inhibitors. In this cohort, there were 465 mild or moderate and three severe bleeding episodes requiring treatment. The study assessed the efficacy of treatment 12 hours after the initial dose was given; there were two doses studied: low, 75 mcg/kg; and high, 225 mcg/kg. A previous study evaluated the safety and pharmacokinetics of three escalating doses of coagulation factor VIIa (recombinant)-jncw in 15 patients with severe hemophilia A or B with or without inhibitors and found the two doses, 75mcg/kg and 225 mcg/kg, to be acceptable.

Bleeding episodes successfully treated

The proportion of mild or moderate bleeding episodes successfully controlled (defined as requiring no further treatment for the bleeding episode, no administration of blood products, and no increase in pain beyond 12 hours from initial dose) with both doses was approximately 86%. The three severe bleeding episodes were treated successfully with the higher dose.

The most common adverse events associated with coagulation factor VIIa (recombinant)-jncw are headache, dizziness, infusion site discomfort, infusion-related reaction, infusion site hematoma, and fever. Patients with hemophilia A or B with inhibitors who have other risk factors for thrombosis may be at increased risk of serious arterial and venous thrombotic events. This product is contraindicated in patients with a known allergy or hypersensitivity to rabbits or rabbit proteins.