Biogen and Stoke Therapeutics to share latest results from zorevunersen studies in Dravet syndrome at IEC 2025

Biogen Inc and Stoke Therapeutics Inc, a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine, announced presentations of new clinical data from studies of zorevunersen at the 36^th International Epilepsy Congress (IEC), taking place August 30 – September 3, 2025 in Lisbon, Portugal. Zorevunersen, an investigational antisense oligonucleotide, is being evaluated as a potential disease-modifying medicine for the treatment of Dravet syndrome in the global pivotal EMPEROR Phase III study.

“With these additional clinical data, we are developing a long-term understanding of the potential for zorevunersen to improve outcomes for patients by addressing the underlying genetic cause of Dravet syndrome,” said Barry Ticho, M.D., Ph.D., Chief Medical Officer of Stoke Therapeutics. “The substantial and durable reductions in seizures and improvements in cognition and behavior in patients already receiving standard anti-seizure medicines support the potential for disease modification. We look forward to sharing and discussing our latest zorevunersen data, including new analyses related to improvements in seizure free days and quality of life, with the world’s leading epilepsy experts at this premier congress.”

“The zorevunersen data generated to date are encouraging and support the design of the Phase 3 EMPEROR study now enrolling and dosing patients,” said Katherine Dawson, M.D., Head of the Therapeutics Development Unit at Biogen. “The effects observed so far are bringing greater awareness to Dravet syndrome as a neurodevelopmental disorder while generating increasing interest in EMPEROR.”

Details of the presentations at IEC are as follows:

• Title: Zorevunersen demonstrates potential as a disease‑modifying therapy in patients with Dravet syndrome through durable seizure reduction and improvements in cognition, behavior, and functioning with up to 36 months of maintenance dosing in open-label extension studies
  Oral Presentation Date & Time: Sunday, August 31, 3:15 – 4:15 PM WEST/ GMT +1 (10:15 – 11:15 AM ET)
  Oral Presenter: Andreas Brunklaus, M.D., Consultant Paediatric Neurologist at the Royal Hospital for Children, Glasgow, Honorary Professor at the University of Glasgow, member of Dravet Syndrome UK’s Medical Advisory Board

• Title: Substantial improvements in overall seizure burden and seizure free days in patients with Dravet syndrome treated with zorevunersen: Results from Phase 1/2a and open-label extension studies
  Poster Presentation Date & Time: Monday, September 1, 1:45 – 3:15 PM WEST/ GMT +1 (8:45 – 10:15 AM ET)
  Poster Presenter: J Helen Cross, MB ChB, Ph.D., Professor, The Prince of Wales’s Chair of Childhood Epilepsy and Head of the Developmental Neuroscience Programme at University College London Great Ormond Street Institute of Child Health, Honorary Consultant in Paediatric Neurology, President of the International League Against Epilepsy
  Poster Number: P351

• Title: EMPEROR Phase 3 study design: Evaluation of zorevunersen as a potential disease-modifying therapy for Dravet syndrome
  Poster Presentation Date & Time: Monday, September 1, 1:45 – 3:15 PM WEST/ GMT +1 (8:45 – 10:15 AM ET)
  Poster Presenter: Joseph Sullivan, M.D., FAES, Professor of Neurology and Pediatrics and Director of the Pediatric Epilepsy Center of Excellence at the University of California San Francisco
  Poster Number: P358

Additional Company Presentation:

• Title: Emerging Concepts and Therapeutics in Dravet Syndrome: From Burden to Breakthroughs
  Date & Time: Tuesday, September 2, 1:55 – 3:05 PM WEST/ GMT +1 (8:55 – 10:05 ET)
  Presenters: Stéphane Auvin, M.D., Ph.D., FAES, Epileptologist and Child Neurologist, Chair of the Pediatric Neurology Department at Robert Debré University Hospital & Université Paris; Kelly G. Knupp, M.D., Professor, Pediatrics-Neurology, University of Colorado Anschutz Medical Campus, Children’s Hospital Colorado; and Scott Perry, M.D., Medical Director, Neurology; Co-Director, Jane and John Justin Neurosciences Center; Medical Director, Genetic Epilepsy Clinic, Cook Children’s Hospital.