Pfizer obtains EC approval for first once-weekly subcutaneous hemophilia treatment

USA—Pfizer has received marketing authorisation from the European Commission (EC) to expand the approved use of Hympavzi (marstacimab) for treating haemophilia A or B patients with inhibitors aged 12 years and older.

The latest approval broadens access to the once-weekly therapy across the European Union and several neighboring countries, strengthening Pfizer’s haemophilia portfolio as the company advances newer treatment options for rare bleeding disorders.

The approval applies to adolescents and adults weighing at least 35 kilograms who have haemophilia A with factor VIII inhibitors or haemophilia B with factor IX inhibitors.

It also covers all 27 European Union member states, in addition to Iceland, Liechtenstein, and Norway.

Pfizer stated that Hympavzi is currently the only once-weekly subcutaneous treatment in the EU approved for people living with haemophilia A or B, regardless of inhibitor status.

Phase III trial data supports approval

The EC based its decision on data from Pfizer’s Phase III BASIS clinical trial, which evaluated the efficacy and safety of Hympavzi in adults and adolescents with severe haemophilia.

According to the company, the therapy achieved a 93% reduction in mean treated annualised bleeding rate compared with on-demand treatment.

Researchers also observed sustained efficacy and safety during follow-up periods extending up to 53 months.

Pfizer added that the treatment offers a simpler administration approach because patients can self-administer the therapy through a once-weekly subcutaneous injection without requiring routine laboratory monitoring.

The company believes this could reduce treatment burden for patients who currently rely on complex infusion-based regimens.

The most commonly reported adverse events in the trial included injection site reactions, headache, pruritus, hypertension, and rash.

Pfizer identified thrombosis as the most serious adverse event reported during clinical studies.

Alexandre de Germay, Pfizer’s chief international commercial officer and executive vice-president, said recurring bleeding episodes continue to disrupt daily life for people living with haemophilia and inhibitors, often causing long-term joint damage and mobility limitations.

He noted that the approval introduces an important new treatment option for patients who have historically faced limited therapeutic choices.

FDA priority review underway

Separately, the US Food and Drug Administration (FDA) has granted priority review for Pfizer’s supplemental biologics licence application seeking to expand Hympavzi’s indication in the United States.

The submission covers patients aged six years and older with haemophilia A or B with inhibitors, as well as children aged six to 11 years without inhibitors.

The FDA is expected to make its decision during the second quarter of 2026.

The company recently highlighted that, if approved, Hympavzi could become the first non-factor prophylactic treatment available for children aged six to 11 years living with haemophilia B.

Pfizer said the therapy may help address significant unmet needs among younger patients and those whose inhibitors reduce the effectiveness of traditional factor replacement therapies.