CAMBRIDGE, Mass. and BEDFORD, Mass. — August 11, 2025 — Leads & Copy — Biogen Inc. and Stoke Therapeutics, Inc. have announced the first patient has been dosed in the global Phase 3 EMPEROR study of zorevunersen for the treatment of Dravet syndrome. Zorevunersen is an investigational antisense oligonucleotide.
The EMPEROR study will evaluate the efficacy and safety of zorevunersen compared to sham over a 52-week treatment period. Dravet syndrome is a rare genetic disease characterized by refractory seizures and neurodevelopmental impairments.
“The initiation of the EMPEROR study is a critical milestone in zorevunersen’s development,” said Katherine Dawson, M.D., Head of the Therapeutics Development Unit at Biogen. Joseph Sullivan, M.D., FAES, principal investigator of the study and Professor of Neurology and Pediatrics and Director of the Pediatric Epilepsy Center of Excellence at the University of California San Francisco, added that the potential to address the underlying genetic cause to also address neurodevelopmental symptoms signals a fundamentally new way of treating the disease.
The EMPEROR clinical trial has initiated in the United States, United Kingdom, Japan and is planned for Europe. Eligible participants will be offered ongoing treatment with zorevunersen as part of an open-label extension (OLE) study.
Contact:
Biogen Media Contact:
Allison Murphy
Public.affairs@biogen.com
+ 1 781 464 3260
Biogen Investor Contact:
Tim Power
IR@biogen.com
+1 781 464 2442
Stoke Media & Investor Contacts:
Dawn Kalmar
Chief Communications Officer
dkalmar@stoketherapeutics.com
781-303-8302
Doug Snow
Director, Communications & Investor Relations
IR@stoketherapeutics.com
508-642-6485
