Pfizer Inc. (NYSE: PFE) has announced that the U.S. Food and Drug Administration (FDA) has approved HYMPAVZI™ (marstacimab-hncq) for routine prophylaxis aimed at preventing or reducing bleeding episodes in adults and pediatric patients aged 12 and older with hemophilia A (congenital factor VIII deficiency) and hemophilia B (congenital factor IX deficiency) who do not have factor VIII (FVIII) or factor IX (FIX) inhibitors.
HYMPAVZI is a groundbreaking treatment, being the first anti-tissue factor pathway inhibitor (anti-TFPI) approved in the U.S. for hemophilia A or B, as well as the first hemophilia medication in the U.S. that can be administered via a pre-filled auto-injector pen. This option provides a subcutaneous treatment with a once-weekly dosing schedule and requires minimal preparation for each administration.
“The approval of HYMPAVZI represents a significant advancement for individuals with hemophilia A or B who lack inhibitors, offering an effective means of bleed prevention with a generally manageable safety profile and easy once-weekly subcutaneous administration,” said Dr. Suchitra S. Acharya, Director of the Hemostasis and Thrombosis Center at Northwell Health and Program Head of the Bleeding Disorders and Thrombosis Program at Cohen Children’s Medical Center. “HYMPAVZI aims to alleviate the treatment burden on patients, many of whom currently endure frequent and time-consuming intravenous infusion regimens.”
Hemophilia is a rare genetic blood disorder caused by deficiencies in clotting factors (FVIII in hemophilia A and FIX in hemophilia B), affecting over 800,000 individuals worldwide. Typically diagnosed in early childhood, hemophilia disrupts the blood’s clotting ability, leading to a heightened risk of recurrent internal bleeding, particularly in joints, which can result in permanent damage. Despite advancements in hemophilia care, many patients still face ongoing bleeding episodes and must manage their condition through multiple intravenous infusions each week.
“HYMPAVZI is Pfizer’s second hemophilia treatment to gain FDA approval this year, reflecting our long-standing commitment to enhancing care for individuals living with hemophilia over the past 40 years,” stated Aamir Malik, Chief U.S. Commercial Officer and Executive Vice President at Pfizer. “We are excited to introduce this medical breakthrough, now offering three distinct classes of hemophilia treatments—anti-TFPI, gene therapy, and recombinant factor therapies—to cater to the diverse needs of patients.”
The FDA’s approval of HYMPAVZI is supported by results from the Phase 3 BASIS trial (NCT03938792), which evaluated adults and adolescents with hemophilia A or B who do not have inhibitors. In this trial, HYMPAVZI reduced the annualized bleeding rate (ABR) for treated bleeds by 35% compared to routine prophylaxis (RP) and by 92% when compared to on-demand (OD) treatment after 12 months of active treatment. The safety profile of HYMPAVZI aligns with earlier Phase 1/2 study findings, with the most common adverse reactions (≥3% of patients) reported being injection site reactions, headaches, and pruritus.
Phil Gattone, President and CEO of the National Bleeding Disorders Foundation, remarked, “The hemophilia community continually seeks innovations in care that can enhance the quality of life for those affected. We commend Pfizer for their pioneering work in developing this novel treatment option, which addresses the ongoing challenges faced by individuals with hemophilia A and B. The availability of this therapy marks a significant advancement in care for many families within the bleeding disorders community.”
Additionally, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has provided a positive opinion for marstacimab, endorsing it for routine prophylaxis in adults and adolescents aged 12 and older with severe hemophilia A without FVIII inhibitors, or severe hemophilia B without FIX inhibitors. Alongside HYMPAVZI, Pfizer has recently secured regulatory approvals for its hemophilia B gene therapy, BEQVEZ™ (fidanacogene elaparvovec), in the U.S., EU, and Canada, and has announced promising results from a Phase 3 program for its hemophilia A gene therapy, giroctocogene fitelparvovec.
