US FDA approves Pfizer's drug for rare bleeding disorder

The US Food and Drug Administration approved Pfizer's once-a-week injection for the two main types of a rare bleeding disorder called haemophilia, the company said on Friday.

The drug, Hympavzi, is given under the skin through an auto-injector pen to prevent or reduce bleeding episodes in haemophilia A or B patients aged 12 years and older.

The disorder primarily affects men and causes spontaneous and potentially severe bleeding after injuries or surgery. It impacts an estimated 33,000 men in the United States, according to government data.

Hympavzi is Pfizer's second haemophilia treatment to receive FDA approval this year after the agency greenlit its haemophilia B gene therapy Beqvez in April.

Other existing treatments include gene therapies such as those made by Australia's CSL and BioMarin Pharmaceutical.

Analysts expect sales of Hympavzi to reach $300 million by 2030, according to estimates compiled by LSEG.

"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," said Suchitra Acharya, director of the bleeding disorders program at Cohen Children's Medical Center.

The approval was based on a late-stage study in 116 haemophilia A or B patients, where the drug showed superiority to standard-of-care treatment with a 92% reduction in bleeding episodes after 12 months.

The drug is approved for patients without antibodies that stop the production of the blood-clotting proteins called factor VIII or factor IX.

Other experimental haemophilia drugs include fitusiran by partners Sanofi and Alnylam Pharmaceuticals, and Novo Nordisk's concizumab.

Pfizer is also developing a gene therapy with Sangamo Therapeutics for the treatment of haemophilia A.