FDA Approves Pfizer Hemophilia Drug

The Food and Drug Administration (FDA) has granted approval for Pfizer's Hympavzi, a new medication designed to treat hemophilia in both its A and B forms. This approval extends to adults and children aged 12 and older who have not developed inhibitors that hinder the effectiveness of clotting drugs. Hympavzi is administered once weekly through subcutaneous injection.

Traditional hemophilia treatments typically involve replacing the missing clotting factor in patients. However, Hympavzi operates differently. It reduces the activity of a protein known as tissue factor pathway inhibitor (TFPI), which normally acts as an anticoagulant. By inhibiting this protein, Hympavzi boosts the presence of enzymes that promote blood clotting, thereby preventing bleeding episodes.

The introduction of Hympavzi expands Pfizer’s hemophilia treatment portfolio. Earlier this year, Pfizer received U.S. approval for a gene therapy targeting hemophilia B. Additionally, the company's gene therapy for hemophilia A has shown positive results in late-stage studies. Aamir Malik, Pfizer's U.S. commercial chief, expressed enthusiasm about launching Hympavzi. He highlighted the company's now extensive range of hemophilia treatments, which includes an anti-TFPI medication, gene therapy, and recombinant factor treatments, catering to diverse patient needs.

This new generation of hemophilia treatments significantly broadens the therapeutic landscape for patients. Roche's Hemlibra has set a new standard for preventive care in hemophilia A, and Sanofi has introduced Altuviiio, a long-acting factor replacement drug. The arrival of these new therapies has complicated the adoption of gene therapy, which offers a long-term solution with a single infusion but has seen slow uptake from CSL Behring, BioMarin Pharmaceutical, and now Pfizer.

Hympavzi offers notable flexibility, with its weekly dosing schedule and suitability for both hemophilia A and B patients. Clinical testing indicated that preventive use of Hympavzi was more effective than on-demand factor replacement, significantly reducing annual bleeding rates. Additionally, it outperformed preventive factor treatments in lowering bleeding incidents.

Common side effects of Hympavzi included injection site reactions, headaches, and itching. The FDA's label for the drug also cautions about potential risks such as blood clots, hypersensitivity, and toxicity to embryos or fetuses.

In Europe, regulatory authorities have recommended the approval of Hympavzi, and it is now awaiting marketing authorization from the European Commission. This regulatory progress is a positive development for Pfizer, which has faced multiple research challenges and growth concerns, highlighted by recent public scrutiny from activist investor Starboard Value.