Pioneering gene therapy may treat a deadly seizure disorder

"Dravet syndrome is typically diagnosed in a child's first or second year of life and results in frequent seizures and intellectual disability. It can often be deadly—roughly 15 to 20 percent of children with the syndrome die before they reach adulthood. Doctors currently prescribe antiseizure drugs and therapeutic diets to manage the seizures that characterize the condition. But these treatments are often ineffective."

"Instead of treating the symptoms, the new drug aims to treat the underlying cause of Dravet syndrome by targeting the gene that typically causes it—SCN1A. Researchers gave zorevunersen at varying doses to 81 patients aged two to 18 in the U.S. and the U.K. The medication significantly reduced the number of seizures patients experienced and improved their day-to-day functioning and quality of life."

"Over the course of 20 months, patients had between 59 percent and 91 percent fewer seizures than before they started the treatment. Most side effects were moderate or mild. The studies were designed to test the safety and tolerability of the medication at varying dosages. Another study, a phase 3 randomized control trial, is underway, and it will more rigorously test how well the medication treats Dravet syndrome."

Dravet syndrome is a rare seizure disorder typically diagnosed in early childhood, causing frequent seizures and intellectual disability with a 15-20% mortality rate before adulthood. Current treatments using antiseizure medications and therapeutic diets are often ineffective at achieving seizure freedom. Zorevunersen represents a novel gene therapy approach that targets the SCN1A gene responsible for the condition rather than just managing symptoms. Clinical trials involving 81 patients aged 2-18 demonstrated significant efficacy, with patients experiencing 59-91% fewer seizures over 20 months. The medication improved daily functioning and quality of life with mostly mild to moderate side effects. Phase 3 randomized controlled trials are underway to further validate the treatment's effectiveness.

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