A Double-blind Study Evaluating the Efficacy, Safety, and Tolerability of Zorevunersen in Patients With Dravet Syndrome
EMPEROR: A Multicenter, Randomized, Double-blind, Sham-controlled, Parallel Group, Phase 3 Study Evaluating the Efficacy, Safety, and Tolerability of Zorevunersen (STK-001) in Patients With Dravet Syndrome
2 other identifiers
interventional
170
7 countries
61
Brief Summary
The purpose of the study is to evaluate the efficacy, safety, and tolerability of zorevunersen in Patients with Dravet syndrome.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for phase_3
Started Jun 2025
Typical duration for phase_3
61 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
March 6, 2025
CompletedFirst Posted
Study publicly available on registry
March 12, 2025
CompletedStudy Start
First participant enrolled
June 4, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 1, 2028
April 13, 2026
April 1, 2026
1.7 years
March 6, 2025
April 9, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Measurement of Seizure Change
Measured by daily seizure diary
Week 28
Secondary Outcomes (3)
Measurement of Seizure Change
Week 52
Multi-component Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Outcome Score
Week 52
Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Subdomain Score
Week 52
Study Arms (2)
Zorevunersen
EXPERIMENTALEligible patients will be randomly assigned in a 1:1 ratio to zorevunersen:sham in Treatment Period 1 (approximately 52 weeks). Upon the completion of Treatment Period 1 all eligible patients, will enter Treatment Period 2 and receive zorevunersen, regardless of initial treatment assignment.
Sham Comparator
SHAM COMPARATOREligible patients will be randomly assigned in a 1:1 ratio to zorevunersen:sham
Interventions
Treatment Period 1: Zorevunersen group will receive study drug by intrathecal (IT) administration on Day 1 (after the 8-week Baseline Period), Day 57 (Week 8), Day 169 (Week 24), and Day 281 (Week 40) at a dose level of 70 mg on Day 1 and Day 57, and 45 mg on Day 169 and Day 281. Treatment Period 2: Group assigned to zorevunersen in Treatment Period 1 will receive 45 mg of zorevunersen on Day 393 (Week 56), Day 477 (Week 68), and Day 589 (Week 84).
Treatment Period 1: Sham group will not have drug administered. Sham group will have a procedure intended to mimic the drug administration. Treatment Period 2: Group assigned to sham in Treatment Period 1 will receive 70 mg of zorevunersen on Day 393 (Week 56) and on Day 477 (Week 68), and 45 mg of zorevunersen Day 589 (Week 84).
Eligibility Criteria
You may qualify if:
- Patients must be ≥2 and \<18 years of age.
- Patients must have a clinical diagnosis of DS confirmed by the Epilepsy Study Consortium, Inc. (ESCI) and as defined by:
- Onset, prior to 12 months (inclusive, \<13 months), of age, of recurrent focal with motor signs, hemiclonic, or generalized tonic-clonic seizures. No other known etiology causing clinical DS manifestations..
- Patient must have a documented pathogenic, likely pathogenic variant, or variant of uncertain significance in the sodium voltage-gated channel type 1 alpha subunit (SCN1A) gene. Patients who have SCN1A testing results of Negative (no variants identified) cannot be randomized.
- Patient must experience the required number of major motor seizures during the 6-week Observation Period. Major motor seizure types included are Seizure types included in counts are Hemiclonic, Focal with Motor Signs, Focal to Bilateral Tonic-Clonic, Generalized Tonic-Clonic, Tonic, Tonic/Atonic (Drop Attacks with fall or risk of fall), and Bilateral Clonic.
- Patient must have used at least 2 prior interventions for seizures. These can include anti-seizure medications (ASMs), ketogenic diet and/or vagus nerve stimulation (VNS) with either lack of adequate seizure control or discontinued due to an AE(s). These interventions can be ongoing therapies.
- Patient must be taking at least one ASM. Benzodiazepines or ASMs used on a standing basis (i.e., not as needed \[PRN\]) for any indication will be considered an ASM.
- Patients' maintenance ASMs and interventions for seizures (i.e., ketogenic diet or VNS), as well as any marijuana- or cannabinoid-based products, must have been stable (unless adjusted for weight) during the Baseline Period.
You may not qualify if:
- Patient has documented variant in the SCN1A gene associated with gain-of-function
- Patient is currently treated with a maintenance ASM acting primarily as a sodium channel blocker, including but not limited to phenytoin, carbamazepine, oxcarbazepine, lamotrigine, lacosamide, rufinamide, or cenobamate, given the mechanism of action of zorevunersen.
- Patient is currently treated with neuromodulation techniques (e.g., responsive neurostimulation, deep brain stimulation, or transcranial magnetic stimulation), with the exception of VNS.
- Patient has emergence of a new seizure type or reemergence of a past seizure type (seizure types that last occurred more than 12 months before Screening Visit A) during the Baseline Period, or has more than 1 hospitalization for seizures during the Baseline Period.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (61)
Phoenix Children's Hospital
Phoenix, Arizona, 85016, United States
Arkansas Children's Hospital
Little Rock, Arkansas, 72202, United States
Cedars Sinai Medical Center
Los Angeles, California, 90048, United States
Children's Hospital of Orange County
Orange, California, 92868, United States
USCF Medical Center
San Francisco, California, 94158, United States
Children's Hospital Colorado
Aurora, Colorado, 80045, United States
Children's National Medical Center
Washington D.C., District of Columbia, 20010, United States
Nemours Children's Health
Jacksonville, Florida, 32207, United States
Nicklaus Children's Hospital
Miami, Florida, 33155, United States
Advent Health Neuroscience Research Institute
Orlando, Florida, 32804, United States
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611, United States
University of Iowa Hospital and Clinics
Iowa City, Iowa, 52242, United States
Massachusetts General Hospital
Boston, Massachusetts, 02114, United States
Boston Children's Hospital
Boston, Massachusetts, 02115, United States
CS Mott Children's Hospital
Ann Arbor, Michigan, 48109, United States
Mayo Clinic
Rochester, Minnesota, 55905, United States
Washington University in St. Louis School of Medicine
St Louis, Missouri, 63110, United States
NYU Langone Health
New York, New York, 10016, United States
Weill Cornell Medicine
New York, New York, 10021, United States
University of Rochester Medical Center
Rochester, New York, 14642, United States
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, 27514, United States
Duke University Health System
Durham, North Carolina, 27705, United States
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, 45229, United States
Cleveland Clinic
Cleveland, Ohio, 44195, United States
Nationwide Children's Hospital
Columbus, Ohio, 43205, United States
Oregon Health & Science University (OHSU)
Portland, Oregon, 97239, United States
LeBonheur Children's Hospital
Memphis, Tennessee, 38103, United States
Cook Children's Medical Center
Fort Worth, Texas, 76104, United States
Texas Children's Hospital
Houston, Texas, 77030, United States
University of Utah Primary Children's Hospital
Salt Lake City, Utah, 84113, United States
UVA Health
Charlottesville, Virginia, 22903, United States
Hôpital de la Timone
Marseille, France
Hôpital Necker - Enfants Malades
Paris, France
Hôpital Robert Debré - Paris
Paris, France
Charité - Campus Virchow-Klinikum
Berlin, Germany
Universitaetsklinikum Bonn AoeR
Bonn, Germany
Universitaetsklinikum Frankfurt Goethe-Universitaet
Frankfurt, Germany
Universitaetsklinikum Freiburg
Friedberg, Germany
Universitaetsklinikum Heidelberg
Heidelberg, Germany
Integriertes Sozialpaediatrisches Zentrum
München, Germany
Azienda Ospedaliero Universitaria Ospedale Pediatrico Meyer
Florence, Italy
Istituto Giannina Gaslini-Ospedale Pediatrico IRCCS
Genova, Italy
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Roma, Italy
Ospedale Pediatrico Bambino Gesù
Roma, Italy
Fukuoka Children's Hospital
Fukuoka, Japan
Hokkaido University Hospital
Hokkaido, Japan
Kyoto University Hospital
Kyoto, Japan
Nagoya University Hospital
Nagoya, Japan
National Hospital Organization Nishi Niigata Central Hospital
Niigata, Japan
Okayama University Hospital
Okayama, Japan
Osaka City General Hospital
Osaka, Japan
Jichi Medical University Hospital
Shimotsuke, Japan
NHO Shizuoka
Shizuoka, Japan
National Center of Neurology and Psychiatry
Tokyo, Japan
Yokohama City University Medical Center
Yokohama, Japan
Hospital Blua Sanitas Valdebebas
Madrid, Spain
Hospital Ruber Internacional
Madrid, Spain
Clinica Universidad de Navarra
Pamplona, Spain
Royal Hospital for Children
Glasgow, G51 4TF, United Kingdom
Great Ormond Street Hospital for Children
London, WC1N 3JH, United Kingdom
Sheffield Children's Hospital
Sheffield, S10 2TH, United Kingdom
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
March 6, 2025
First Posted
March 12, 2025
Study Start
June 4, 2025
Primary Completion (Estimated)
March 1, 2027
Study Completion (Estimated)
October 1, 2028
Last Updated
April 13, 2026
Record last verified: 2026-04