Shares of Ultragenyx jumped Thursday after the Food and Drug Administration approved a first-of-its-kind treatment for pediatric patients with a rare neurodevelopmental disease.

The FDA said in a press release that it approved Ultragenyx's Fayuvi, a treatment for pediatric patients with mucopolysaccharidosis type IIIA, which is a rare inherited disease that progressively damages the brain and nervous system, triggering the loss of developmental abilities in children over time.

Ultragenyx stock jumped 12% to $14.46.

The treatment is administered only once through a standard infusion. It goes straight into the bloodstream like a normal drip. To get the treatment inside the brain, scientists use AAV9, a harmless, modified virus that crosses from the blood into the brain and central nervous system.

Before Thursday, doctors could only manage individual symptoms, but there was no FDA-approved therapy designed to stop or change the root of the disease.