Biogen Inc. and Stoke Therapeutics have announced new data presentations supporting the potential of zorevunersen, an investigational antisense oligonucleotide, as a disease-modifying treatment for Dravet syndrome. The results were presented at the 2025 American Epilepsy Society $(AES)$ Annual Meeting. Findings from long-term Phase 1/2a and open-label extension studies showed durable reductions in seizures, increased seizure-free days, and improvements in cognition, behavior, and quality of life for patients receiving zorevunersen in addition to standard anti-seizure medications. Analysis of electroencephalogram (EEG) data supports a disease-modifying mechanism of action. A propensity score weighted analysis comparing zorevunersen treatment to the natural history of the disease also demonstrated reductions in seizures and improvements in cognition and behavior at dose levels and timepoints consistent with the ongoing Phase 3 EMPEROR study. Long-term safety data indicated that some patients received up to 15 doses over more than four years.