Global, pivotal Phase 3 study will evaluate 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, with no currently approved medicines that address the underlying cause of the disease
Stoke Therapeutics, Inc. (Nasdaq: STOK), a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine, and Biogen Inc. (Nasdaq: BIIB), today announced that the first patient has been dosed in the global Phase 3 EMPEROR study of zorevunersen for the treatment of Dravet syndrome. Zorevunersen, an investigational antisense oligonucleotide, has the potential to be the first disease-modifying treatment for Dravet syndrome.
“Our Phase 1/2 and open-label extension studies have provided a large dataset to support our understanding of zorevunersen and guide the EMPEROR study design, including dosing, duration and selection and powering of the endpoints,” said Barry Ticho, M.D., Ph.D., Chief Medical Officer of Stoke Therapeutics. “Given the severity of this disease and the limitations of current treatments, the substantial and durable reductions in seizures and continuing improvements in cognition and behavior support our belief that zorevunersen may improve outcomes for patients with Dravet syndrome.”
“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. “Despite treatment with available anti-seizure medicines, no approved medications currently address the underlying cognitive and behavioral aspects of this rare, genetic disease. Together with Stoke, we look forward to working in collaboration with the hope of bringing forward zorevunersen as the first disease-modifying treatment option, if approved, for Dravet syndrome.”
EMPEROR Pivotal Phase 3 Design Summary
- Anticipated Enrollment: Patients with Dravet syndrome between the ages of 2 and up to 18 years of age with a confirmed variant in the SCN1A gene not associated with gain of function.
- Duration: Following an 8-week baseline period, participants will be randomized 1:1 to receive either zorevunersen or sham for a 52-week treatment period.
- Treatment Arms: Patients in the active treatment arm will receive two 70mg loading doses (Day 1 and Week 8) followed by two 45mg maintenance doses (Week 24 and Week 40). All patients will continue to receive standard of care medicines throughout the study.
- Primary Endpoint: Change in major motor seizure frequency measured at Week 28.
- Key Secondary Endpoints: Change in major motor seizure frequency measured at Week 52. Change in behavior and cognition as measured by the Vineland-3 subdomains, including expressive communication, receptive communication, interpersonal relationships, coping skills and personal skills measured at Week 52.
- Eligible participants will be offered ongoing treatment with zorevunersen as part of an open-label extension (OLE) study.
“Dravet syndrome is one of the most well studied genetic epilepsies so we know the significant and life-altering effects it can have on patients and their caregivers,” said 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. “Providing additional relief from seizures remains an important clinical outcome, but the potential to address the underlying genetic cause to also address neurodevelopmental symptoms signals a fundamentally new way of treating the disease. The urgent need for treatments is evident in the high degree of interest in the EMPEROR study.”
The EMPEROR clinical trial has initiated in the United States, United Kingdom, Japan and is planned for Europe. For more information on the EMPEROR study, please visit https://www.emperorstudy.com/ and https://clinicaltrials.gov/study/NCT06872125.
