Biogen, Stoke Therapeutics Present New Data on Zorevunersen for Dravet Syndrome at EPNS Congress

Biogen and Stoke Therapeutics presented data showing improvements in cognition and behavior at Week 68 in Dravet syndrome patients using zorevunersen. The Phase 3 dosing regimen demonstrated substantial reductions in major motor seizure frequency over two years. Zorevunersen is a first-in-class disease-modifying treatment for Dravet syndrome, affecting up to 38,000 people in primary markets. The investigational medicine targets the underlying genetic causes of Dravet syndrome, representing a potential breakthrough in addressing an unmet medical need.

Biogen and Stoke Therapeutics have presented compelling data on the efficacy of zorevunersen in treating Dravet syndrome. The Phase 3 dosing regimen demonstrated significant improvements in cognition and behavior at Week 68, as well as substantial reductions in major motor seizure frequency over two years. These findings were presented at the 16th European Paediatric Neurology Society (EPNS) Congress on July 10, 2025 [1].

Zorevunersen is an investigational antisense oligonucleotide designed to treat the underlying genetic cause of Dravet syndrome by increasing NaV1.1 protein production in brain cells. The drug has shown potential for disease modification and has been granted orphan drug designation by the FDA and the EMA. It is currently being evaluated in a Phase 3 study.

The data presented at the EPNS Congress supports the inclusion of key secondary endpoints assessing cognition and behavior in the Phase 3 EMPEROR study. The results contrast with outcomes observed in natural history data, indicating that zorevunersen may offer a new approach to treating Dravet syndrome.

Dravet syndrome is a severe developmental and epileptic encephalopathy characterized by severe, recurrent seizures and significant cognitive and behavioral impairments. Currently, there are no approved disease-modifying therapies for people living with Dravet syndrome. The condition affects up to 38,000 people in primary markets, including the United States, United Kingdom, EU-4, and Japan [1].

The Phase 3 EMPEROR study is designed to evaluate the efficacy and safety of zorevunersen in patients with Dravet syndrome. The study will assess the drug's ability to reduce seizure frequency and improve cognition and behavior. The results of this study will be crucial in determining the drug's potential for approval and commercialization.

Biogen and Stoke Therapeutics are collaborating to develop and commercialize zorevunersen for Dravet syndrome. Under the collaboration, Stoke retains exclusive rights for zorevunersen in the United States, Canada, and Mexico, while Biogen receives exclusive rest of world commercialization rights.

The data presented at the EPNS Congress is a significant milestone in the development of zorevunersen. It provides early evidence that this new genetically-targeted approach could address the underlying cause of Dravet syndrome, resulting in additional seizure control and improvements in cognition and behavior. The results of the Phase 3 EMPEROR study will be closely watched by investors and financial professionals, as they could have a significant impact on the market for Dravet syndrome treatments.

References:
[1] https://investor.stoketherapeutics.com/news-releases/news-release-details/stoke-therapeutics-and-biogen-announce-presentation-data-studies