Pfizer's haemophilia B gene therapy gets EU green light

There will soon be two gene therapies available for patients with haemophilia B in the EU after the European Commission approved Pfizer's fidanacogene elaparvovec under the Durveqtix brand name.

The gene therapy – already available in the US as Beqvez – is an alternative to CSL Behring and uniQure's Hemgenix, which was approved in the EU in early 2023 and has already been cleared for reimbursement in various countries, including England, France, and Denmark.

Specifically, Durveqtix has been approved for adults with severe and moderately severe haemophilia B without a history of antibody inhibitors to Factor IX (FIX), the clotting factor deficient in the disease. It can also not be given to people with detectable antibodies to variant AAV serotype Rh74, the viral vector used to deliver the gene therapy.

Both gene therapies are designed to allow patients with haemophilia B to start producing FIX themselves with a one-time dose, rather than relying on intravenous FIX infusions given weekly or biweekly.

Pricing in Europe will vary depending on national negotiations, but in the US Beqvez and Hemgenix have the same list price of $3.5 million. That compares to FIX replacement therapies that can cost between $300,000 and $1 million a year in the US, depending on the disease severity and if patients have inhibitors that dimmish the benefits of treatment.

Pfizer's approach to US pricing has been to offer a warranty to payers, based on the durability of patients' response to the gene therapy, providing insurance against the risk that the treatment does not work as expected. CSL Behring is offering a similar guarantee with partial or full reimbursement of the cost of its treatment for inadequate responders.

"There is a substantial medical and treatment burden for people with haemophilia B that receive standard of care today, with frequent infusions and many remaining at risk of breakthrough bleeds that can lead to pain and restricted mobility," said Pfizer's chief international commercial officer, Alexandre de Germay, in a statement.

"Durveqtix has shown the potential to offer long-term bleed protection in a one-time dose, reducing or eliminating bleeds for the appropriate patients with haemophilia B. These outcomes and their impact could become potentially transformative for haemophilia B care in the EU," he added.

An estimated 38,000 patients are living with haemophilia B worldwide, according to the World Federation of Haemophilia (WFH). As the gene is carried on the X chromosome, haemophilia is almost entirely a male disease.

The EU approval comes shortly after Pfizer and partner reported phase 3 results with their haemophilia A gene therapy giroctocogene fitelparvovec, potentially setting up regulatory filings and a challenge to first-to-market Roctavian (valoctocogene roxaparvovec) from BioMarin.

Pfizer meanwhile is also waiting for a decision on marketing applications in the US and Europe for marstacimab – an antibody therapy for haemophilia A and B that would compete with Roche's near-$5 billion blockbuster Hemlibra (emicizumab) – later this year.