Six months after scoring FDA approval for hemophilia B gene therapy Beqvez, Pfizer has earned a nod from the U.S. regulator for another of its products in the indication.
On Friday, the FDA signed off on Hympavzi (marstacimab-hncq), an anti-tissue factor pathway inhibitor for patients age 12 and older with hemophilia A or B who have not developed antibodies to previous inhibitor treatments.
Hympavzi is a once-weekly subcutaneous injection that helps limit the bleeding episodes that accompany the blood-clotting disorder. It is the first U.S.-approved treatment for hemophilia to be administered by a user-friendly, pre-filled auto-injector pen. It is designed to be a convenient alternative to periodic infusions of proteins that boost blood clotting.
The company has placed a $795,600 wholesale acquisition cost (WAC) on Hympavzi. That compares to the $3.5 million Pfizer charges for Beqvez and matches the price CSL and uniQure have established for their hemophilia B gene therapy Hemgenix.
The price for Hympavzi "is in line with current WAC pricing for prophylactic treatments for hemophilia A or B currently available on the market," Pfizer said, adding that it expects to launch the product in this quarter.
“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,” Suchitra Acharya, M.D., the director of the Hemostasis and Thrombosis Center Northwell Health, said in an Oct. 11 release.
Hympavzi targets the Kunitz-2 domain of tissue factor pathway inhibitor (TFPI), a natural anticoagulation protein. In developing the treatment, Pfizer trailed Novo Nordisk’s investigational TFPI monoclonal antibody called concizumab, but the FDA rejected the treatment in May 2023 because of dosing and manufacturing issues.
The nod for Hympavzi is backed by results from a phase 3 trial of 116 patients with hemophilia A or B. Subjects received standard of care for six months and then switched to marstacimab for 12 months. Among those who received on-demand factor replacement intravenous therapy in the lead-in period, switching to Pfizer’s antibody reduced bleeds by 92%. Pfizer also showed the superiority of marstacimab compared to prophylaxis, with a 35% reduction in the annualized bleeding rate.
The most commonly reported side effects—which struck less than 3% of the patients in the study—were injection site reactions, headache and itching.
Pfizer has a deep pipeline of hemophilia candidates including another gene therapy, giroctocogene fitelparovec, which is in phase 3 testing for hemophilia A.
Roche’s Hemlibra, which racked up sales of CHF 4,147 million ($4.7 billion) in 2023, currently rules the hemophilia A market.
Hemophilia impacts more than 800,000 people globally and inhibits the blood’s ability to clot properly, increasing the risk of repeated bleeding inside the joints, which can lead to permanent damage. Despite significant progress in hemophilia treatment, many experience bleeding episodes and must manage their condition with intravenous infusions that may need to be administered multiple times a week, Pfizer said.