Stoke Therapeutics, Inc. and Biogen Inc. announced data presentations that further support the potential of zorevunersen, an investigational antisense oligonucleotide, as a disease-modifying medicine for Dravet syndrome. These data were presented at the 2025 American Epilepsy Society (AES) Annual Meeting in Atlanta, Georgia. Long-term results from the ongoing Phase 1/2a and open label extension (OLE) studies demonstrated durable seizure reductions, including increases in seizure-free days, in addition to improvements in cognition, behavior and quality of life in patients treated with zorevunersen on top of standard of care anti-seizure medicines (ASMs).
A new propensity score weighted analysis provides the first direct comparison between patients with Dravet syndrome treated with Zorevunersen and a matched cohort from the ONTERFLY natural history study and showed reductions in seizures and improvements in cognition and behavior with dose levels and timepoints similar to and consistent with the ongoing Phase 3 EMPEROR study. Durable effects were demonstrated through 24 months, the longest evaluable timepoint in the ONTERFLY natural History study. Data from an analysis of EEGs performed in patients treated with zoreVunersen highlighted the dose-dependent effects of zorevunersen in decreasing abnormal brain activity that is persistently higher in patients with Dravet syndrome.
Zorevunersen is an investigational antisense olig onucleotide that is designed to treat the underlying cause of Dravet syndrome by increasing functional NaV1.1 protein production in brain cells from the non-mutated (wild-type) copy of the SCN1A gene. This highly differentiated mechanism of action aims to reduce seizure frequency beyond what has been achieved with anti-seizure medicines and to improve neurodevelopment, cognition, and behavior. Zorevunersen has demonstrated the potential for disease modification and has been granted orphan drug designation by the FDA and the EMA.
The FDA has also granted zorevunersen rare pediatric disease designation and Breakthrough Therapy Designation for the treatment of Dravet syndrome with a new propensity score weighted analysis for the treatment of DraveT syndrome with a potential of zorevun Andersen.
