Groundbreaking one-time therapy offers hope for hemophilia B patients, promising long-term benefits.

The U.S. Food and Drug Administration has approved the first gene therapy for hemophilia B, a rare genetic blood-clotting disorder that primarily affects men. Named Hemgenix, the groundbreaking treatment comes with a $3.5 million price tag and is expected to significantly reduce healthcare costs over time by minimising the need for frequent clotting treatments.

Developed by CSL Behring, Hemgenix is administered as a one-time intravenous infusion. The therapy introduces a functioning gene into the liver, enabling the production of a critical protein required for blood clotting. Current treatments involve regular and expensive IV infusions of this protein to prevent life-threatening bleeding episodes.

“This approval marks a milestone for patients with hemophilia B,” said Dr Peter Marks from the FDA. “It represents a major step forward in the development of innovative therapies.”

The therapy’s long-term efficacy remains unclear, but CSL Behring anticipates it will offer years of reduced bleeding and improved clotting. The approval was based on two studies, one of which demonstrated a 54% reduction in bleeding incidents and a decreased reliance on standard treatments.

Hemophilia B affects roughly 1 in 40,000 people and accounts for about 15% of hemophilia cases. The disorder is caused by mutations in a gene responsible for producing a key clotting protein. Without treatment, even minor injuries can lead to severe or fatal bleeding, with the condition often causing joint and internal organ damage.

The $3.5 million cost positions Hemgenix among the most expensive gene therapies to date, surpassing others priced at over $2 million. CSL Behring justifies the cost by emphasising long-term savings on treatment and healthcare. Insurers, including private providers and government programs, are expected to cover most of the expense.

Gene therapies are transforming the landscape of medicine, offering treatments that modify or correct genetic mutations for cancers and rare diseases. While Hemgenix is the first gene therapy for hemophilia, similar treatments for the more common hemophilia A are in development. Earlier this year, European regulators approved a comparable therapy for hemophilia A, developed by BioMarin, which is currently under review by the FDA.

The approval of Hemgenix provides new hope for those living with hemophilia B, offering a potentially life-changing solution to a disorder that has long required burdensome and costly management.