EU Approves Pfizer's HYMPAVZI™ for Severe Hemophilia A or B in Adults and Adolescents

NEW YORK, NY, USA I November 20, 2024 I Pfizer Inc. (NYSE: PFE) has announced that the European Commission (EC) has granted marketing approval for HYMPAVZI™ (marstacimab), intended for the routine prophylaxis of bleeding episodes in patients aged 12 and older weighing at least 35 kg. This approval covers those with severe hemophilia A (congenital factor VIII deficiency, FVIII <1%) without FVIII inhibitors and severe hemophilia B (congenital factor IX deficiency, FIX <1%) without FIX inhibitors.

HYMPAVZI becomes the first and only anti-tissue factor pathway inhibitor (anti-TFPI) approved in the European Union (EU) for treating hemophilia A or B. It is also the first hemophilia medication in the EU to be administered via a pre-filled, auto-injector pen. This treatment provides a subcutaneous option with a once-weekly dosing schedule, requiring minimal preparation.

Dr. Laurent Frenzel, Head of the Hemophilia Treatment and Research Center at the Necker-Enfants malades Hospital in Paris, highlighted the significant burden associated with traditional hemophilia treatments. These often involve time-consuming infusions and injections, which can lead to missed doses and an increased risk of bleeding. He noted that HYMPAVZI offers a significant advancement for eligible patients due to its potential to prevent bleeds and its convenient once-weekly administration.

Hemophilia is a group of rare genetic blood disorders caused by a deficiency in clotting factors (FVIII in hemophilia A and FIX in hemophilia B), affecting over 800,000 people globally. Typically diagnosed in early childhood, hemophilia prevents the blood from clotting properly, leading to a higher risk of repeated joint bleeding and potential permanent joint damage. Despite recent advancements in treatment, many patients still experience bleeding episodes and manage their conditions with frequent intravenous infusions.

Alexandre de Germay, Chief International Commercial Officer and Executive Vice President at Pfizer, emphasized that HYMPAVZI represents a first-in-class treatment for people with hemophilia, which often leads to recurring joint bleeds affecting daily activities. He stated that this approval is a testament to Pfizer's long-standing commitment to improving hemophilia care and that the new treatment reduces bleeding episodes and requires less preparation, meeting a critical need for patients.

The approval by the EC is based on results from the pivotal Phase 3 BASIS study (NCT03938792), which evaluated the efficacy and safety of marstacimab in patients aged 12 and older with severe hemophilia A or B without inhibitors. The study showed that HYMPAVZI significantly reduced the annualized bleeding rate (ABR) for treated bleeds by 35% (ABR of 5.08 vs. 7.85, p-value 0.0376) over a 12-month period, demonstrating both non-inferiority and superiority compared to routine prophylaxis with FVIII or FIX. The safety profile of HYMPAVZI was consistent with earlier trial results, with the most commonly reported adverse events being injection site reactions, headache, pruritus, and hypertension.

The marketing authorization for HYMPAVZI is effective across all 27 EU member states, as well as in Iceland, Liechtenstein, and Norway. The EC's approval follows a similar regulatory approval in the United States in October.

Pfizer's extensive history in advancing hemophilia treatment includes the introduction of recombinant treatments and other advanced treatment modalities. Beyond the recent approvals for HYMPAVZI, Pfizer announced positive results from a Phase 3 program for a gene therapy candidate in hemophilia A (giroctocogene fitelparvovec) and received regulatory approvals for its hemophilia B gene therapy BEQVEZ™ (fidanacogene elaparvovec) in Europe and the U.S.

HYMPAVZI, discovered by Pfizer scientists, is a rebalancing agent targeting the Kunitz 2 domain of tissue factor pathway inhibitor (TFPI), a natural anticoagulation protein. This innovative treatment aims to restore hemostasis by preventing blood clots.