Hemophilia A bleeding drops with Pfizer gene therapy in advanced trial

Pfizer's gene therapy for hemophilia A significantly cut the number of annual bleeding episodes in patients with the rare disorder in a late-stage study and performed better than the current standard treatment, the company said on Wednesday.

The data takes Pfizer one step closer to securing US regulatory approval for a second gene therapy to treat hemophilia.

Pfizer had received the Food and Drug Administration's nod for Beqvez as a one-time gene therapy for hemophilia B, a less common type of the disorder, in April.

If approved, Pfizer's hemophilia A gene therapy will compete with BioMarin Pharmaceutical's one-time treatment Roctavian, which was approved in the U.S. last year and is priced at $2.9 million.

Currently, the standard-of-care treatment for hemophilia A patients is to undergo routine replacement of the clotting protein called Factor VIII.

Pfizer said its gene therapy for hemophilia A not only met the main goal of showing non-inferiority compared to the Factor VIII replacement therapy in reducing the annual bleeding rate in patients, but also showed superiority to the current standard treatment.

Data from the 75-patient pool also showed that 84% of patients who were given Pfizer's gene therapy had Factor VIII levels above 5% at 15 months post-infusion, the company said.

The company will present additional data at upcoming medical meetings, it added. Pfizer is co-developing the hemophilia A gene therapy from with Sangamo Therapeutics, from whom it had licensed the therapy.

People with hemophilia have a fault in a gene that regulates production of proteins called clotting factors, leading to spontaneous as well as severe bleeding following injuries or surgery.

Hemophilia A affects about 25 in every 100,000 male births worldwide, according to data cited by Pfizer, with majority of them having a moderate to severe form of the disease for which the gene therapy was tested.