FDA approves first once-weekly drug treatment regimen for hemophilia

Oct. 11 (UPI) -- Patients suffering from hemophilia received a "meaningful" advancement on Friday when federal regulators approved the first once-weekly treatment for the disease.

Hympavzi, made by Pfizer, is the first antitissue-factor pathway inhibitor to be approved for the blood-clotting disorder, as well as the first hemophilia drug to offer a once-weekly treatment regimen. Now it has been given the nod by the Food and Drug Administration , the agency announced .

Pfizer's new drug is aimed at adult and pediatric patients 12 years of age and older with hemophilia A without factor VIII inhibitors or hemophilia B without factor IX inhibitors (neutralizing antibodies). It is administered via a pre-filled, auto-injector pen.

Its approval was hailed a major breakthrough in the treatment of the disease, whose victims until recently were required to undergo intravenous infusions multiple times per week, severely affecting their quality of life and limiting their ability to participate in a variety of jobs, activities or travel.

Hemophilia is a genetic blood disease that blocks the blood's ability to clot properly, causing bleeding inside the joints and permanent damage. Its cause is a deficiency of clotting factor, specifically, factor VIII in hemophilia A and factor IX in hemophilia B.

Not only is the existing prophylaxis IV therapy for hemophilia burdensome and injurious to patients' mental health, it is also costly. A 2018 study cited by the The American Journal of Managed Care showed that prophylaxis IV therapy costs about $200,000 a year per patient.

The U.S. Centers for Disease Control and Prevention estimates that about 33,000 males in the United States are living with hemophilia, with hemophilia A being about 3 times more common than hemophilia B.

"The approval of Hympavzi is a meaningful advancement for people living with hemophilia A or B without inhibitors for bleed prevention, with a generally manageable safety profile and a straightforward once-weekly subcutaneous administration," said Dr. Suchitra Acharya of Cohen Children's Medical Center in New York.

"Hympavzi aims to reduce the current treatment burden by meeting an important need for these patients, including many who have required frequent, time-consuming intravenous treatment infusion regimens," she said in a statement issued by Pfizer.

FDA scientists said the treatment is also unique in the battle against hemophilia because rather than trying to replace clotting factor missing in patients, it instead works by reducing a naturally occurring anticoagulation protein called tissue factor pathway inhibitor, thus allowing the creation of more thrombin, an enzyme that is critical in blood clotting.

"Today's approval of Hympavzi provides patients with hemophilia a new treatment option that is the first of its kind to work by targeting a protein in the blood clotting process," said Dr. Ann Farrell of the FDA's Center for Drug Evaluation and Research. "This new type of treatment underscores the FDA's commitment to advance the development of innovative, safe and effective therapies."