A clinical trial led by University College London and Great Ormond Street Hospital, in collaboration with the University of Glasgow, published results in *The New England Journal of Medicine* on March 4, 2026, showing that an experimental drug called zorevunersen reduced convulsive seizures by up to 91% in children with Dravet syndrome — one of the most severe and treatment-resistant forms of childhood epilepsy, caused by mutations in the SCN1A gene that impair sodium channel function in nerve cells. Dravet syndrome typically begins in the first year of life, is notoriously resistant to existing anti-seizure medications, and is associated with a high rate of Sudden Unexpected Death in Epilepsy, or SUDEP, making it one of the most feared rare pediatric diagnoses in neurology. Zorevunersen works not by suppressing seizures chemically the way traditional anti-epileptic drugs do, but by directly targeting the SCN1A gene itself — boosting its function to restore the nerve cell signaling that the mutation has impaired, making it the first gene-regulation treatment ever to reach clinical trial for epilepsy.

The trial results go beyond seizure reduction in a way that separates zorevunersen from every prior Dravet treatment. Researchers reported early evidence of improvements in cognitive function and behavior — meaning the drug may be addressing the underlying neurological damage caused by years of uncontrolled seizures rather than simply suppressing the seizures themselves. Over the three-year observation period, children in the trial showed measurable quality-of-life improvements on standardized health assessment scales, and most of the side effects reported were mild and manageable. Patients who received the highest dose of 70mg experienced a 73.6% median reduction in convulsive seizures even six months after their last dose, suggesting a durable disease-modifying effect that persists well beyond the period of active drug administration.

The UCL and Great Ormond Street team has already launched a larger Phase 3 clinical trial to confirm these findings in a broader patient population, with the Phase 1/2a results providing the regulatory and scientific foundation for that expanded study. Zorevunersen is being developed by Stoke Therapeutics, which funded the trial, using antisense oligonucleotide technology — short synthetic strands of genetic material that bind to RNA and modulate how genes are expressed at the molecular level, the same platform underlying approved therapies for spinal muscular atrophy and Huntington's disease. If Phase 3 confirms the Phase 1/2a results, zorevunersen would represent the first disease-modifying therapy for Dravet syndrome and potentially a template for treating the broader family of SCN1A-related epilepsies that together affect tens of thousands of children worldwide.



EXCLUSIVE: A New Drug Just Cut Seizures by 91% in Children With One of the Worst Forms of Epilepsy & It May Also Repair How Their Brains Work 🧠