Pfizer’s Hympavzi Indication Expanded in EU for Treatment of Hemophilia A or B With Inhibitors

Pfizer announced its Hympavzi (marstacimab) was granted marketing authorization by the European Commission (EC) to expand the drug’s approved indication. The expansion covers patients 12 years and older—weighing at least 35 kg (77 lbs.)—with either of two conditions.

The first of these is hemophilia A (congenital factor VIII [FVIII] deficiency) with FVIII inhibitors. The second, hemophilia B (congenital factor IX [FIX] deficiency) with FIX inhibitors.

Pfizer Provides Background on Hemophilia A, B

Approximately 20% of those with hemophilia A, and 3% with hemophilia B, are unable to continue factor replacement therapy. This is because they develop inhibitors to FVIII and FIX, respectively. As such, these patients often face higher treatment burdens and costs encompassing complications like hospitalization, and death, resulting from bleeding.

Hympavzi is a once-weekly subcutaneous injection that does not require routine treatment-related lab monitoring. Pfizer says it offers superior bleed protection when compared with on-demand treatment.

Applause for Expanded Hympavzi Indication

Laurent Frenzel, MD, PhD, Head of the Hemophilia Treatment and Research Center at the Necker-Enfants Malades Hospital, lauded the approval.

“Inhibitors present a substantial challenge for people living with hemophilia,” Frenzel said. “They neutralize traditional factor replacement therapies, in turn limiting treatment options and leaving patients vulnerable to uncontrolled bleeding episodes. The approval of Hympavzi offers adults and adolescents in the EU a once-weekly subcutaneous option.”

Also commenting, Pfizer Chief International Commercial Officer and Executive Vice President Alexandre de Germay.

“For people living with hemophilia with inhibitors, recurring bleeding episodes can lead to damaged joints,” de Germay said. “We look forward to working with regulators globally to continue bringing Hympavzi to those who can benefit from it.”

In the United States, the FDA approved Hympavzi for treatment of hemophilia A and B without inhibitors in October 2024. The FDA has since granted Priority Review for this expanded indication, potentially for patients as young as 6 in the U.S.