“Today’s approval provides a new treatment option for patients with hemophilia B and represents important progress in the development of innovative therapies,” said the FDA's Dr. Peter Marks.
The agency did not specify how long the treatment works. But CSL Behring said patients should benefit— in terms of reduced bleeding and increased clotting — for years.
Hemophilia almost always strikes males and is caused by mutations in the gene for a protein needed for blood clotting. Small cuts or bruises can be life-threatening, and many people need treatments once or more a week to prevent serious bleeding. Left untreated, the condition can cause bleeding that seeps into joints and internal organs, including the brain.
Hemgenix delivers a working gene for the clotting protein to the liver, where it is made.
Hemophilia B affects about 1 in 40,000 people and accounts for roughly 15% of those with the disease, according to the FDA.
The FDA said it granted approval based on two small studies, including one that showed those taking the drug had increased levels of the clotting protein, reduced need for standard treatment and a 54% drop in bleeding problems.
Earlier this year, European regulators approved a similar gene therapy for hemophilia A. That drug, from drugmaker BioMarin, is still under review at the FDA.
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