FDA Approves Treatment for Patients with Hemophilia with Inhibitors

The US Food and Drug Administration (FDA) today approved coagulation factor VIIa (recombinant)-jncw (Sevenfact) to treat and control bleeding in patients with hemophilia A or B with inhibitors.

The treatment is the first product for hemophilia treatment that contains an active ingredient from rabbits genetically engineered to produce a protein needed for blood coagulation, Peter Marks, MD, PhD, said.

An initial study aimed to evaluate the safety and pharmacokinetics of 3 escalating doses of the treatment in 15 patients with severe hemophilia A or B with or without inhibitors, and the results were used to select the 2 doses that were evaluated.

The agency tested the safety and efficacy of the treatment doses using data from a clinical study of 27 patients with hemophilia A or B with inhibitors. The study included treatment of 465 mild or moderate and 3 severe bleeding episodes.

Investigators assessed the efficacy of treatment 12 hours after the initial dosing.

For both mild and moderate bleeding episodes, the proportion treated successfully with the lower dose of 75 mcg/kg and higher dose of 225 mcg/kg of the treatment was approximately 86%. The patients required no further treatment for the bleeding.

The 3 severe cases were successfully treated with the higher dose of the treatment.

The congenital bleeding disorder is caused by a dysfunction or deficiency of Coagulation Factor VII or IX. Patients with hemophilia bleed for a longer time than others after sustaining an injury or undergoing surgery.

If a patient has inhibitors, they may not respond to factor replacement therapy.

Bleeding can be managed by on-demand treatment or prophylaxis using products containing FVIII or FIX, but once inhibitors to them develop, treatment with the products are no longer effective.

The active ingredient of the treatment can help bypass the FVIII and FIX reactions to promote clot formation and control bleeding. The active ingredient is a recombinant analog of human FVII, which is expressed in genetically engineered rabbits and secreted into the rabbits’ milk.

“This approval is an example of our efforts to advance safe biotechnology innovations to support patient health,” Marks, the director of the FDA’s Center for Biologics Evaluation and Research, said in a statement.