Dravet SyndromePhase 3NCT06872125
A Double-blind Study Evaluating the Efficacy, Safety, and Tolerability of Zorevunersen in Patients With Dravet Syndrome
A Phase 3 study testing zorevunersen in people with Dravet Syndrome, run by Stoke Therapeutics, Inc at 61 sites in 8 countries.
Trial summary
The purpose of the study is to evaluate the efficacy, safety, and tolerability of zorevunersen in Patients with Dravet syndrome. Read more about this study
- Who is it for?
- Ages 2 to 17 years
- Conditions the study is for
- Dravet Syndrome
- What is being tested?
- zorevunersen
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 170 participants
- Where
- 61 sitesin 8 countries
- Study dates
- 4 Jun 2025to Oct 2028
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 17 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
61 sites in 8 countries.
61 sites in 8 countries
United States28 sites
CS Mott Children's Hospital
Ann Arbor, Michigan, 48109
Children's Hospital Colorado
Aurora, Colorado, 80045
Massachusetts General Hospital
Boston, Massachusetts, 02114
Boston Children's Hospital
Boston, Massachusetts, 02115
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, 27514
UVA Health
Charlottesville, Virginia, 22903
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
Cleveland Clinic
Cleveland, Ohio, 44195
Nationwide Children's Hospital
Columbus, Ohio, 43205
Duke University Health System
Durham, North Carolina, 27705
Cook Children's Medical Center
Fort Worth, Texas, 76104
Texas Children's Hospital
Houston, Texas, 77030
Nemours Children's Health
Jacksonville, Florida, 32207
Arkansas Children's Hospital
Little Rock, Arkansas, 72202
Cedars Sinai Medical Center
Los Angeles, California, 90048
LeBonheur Children's Hospital
Memphis, Tennessee, 38103
Nicklaus Children's Hospital
Miami, Florida, 33155
NYU Langone Health
New York, New York, 10016
Weill Cornell Medicine
New York, New York, 10021
Children's Hospital of Orange County
Orange, California, 92868
Advent Health Neuroscience Research Institute
Orlando, Florida, 32804
Phoenix Children's Hospital
Phoenix, Arizona, 85016
Oregon Health & Science University (OHSU)
Portland, Oregon, 97239
Mayo Clinic
Rochester, Minnesota, 55905
University of Rochester Medical Center
Rochester, New York, 14642
University of Utah Primary Children's Hospital
Salt Lake City, Utah, 84113
USCF Medical Center
San Francisco, California, 94158
Children's National Medical Center
Washington D.C., District of Columbia, 20010
Japan11 sites
Fukuoka Children's Hospital
Fukuoka
Hokkaido University Hospital
Hokkaido
Kyoto University Hospital
Kyoto
Nagoya University Hospital
Nagoya
National Hospital Organization Nishi Niigata Central Hospital
Niigata
Okayama University Hospital
Okayama
Osaka City General Hospital
Osaka
Jichi Medical University Hospital
Shimotsuke
NHO Shizuoka
Shizuoka
National Center of Neurology and Psychiatry
Tokyo
Yokohama City University Medical Center
Yokohama
Germany6 sites
Charité - Campus Virchow-Klinikum
Berlin
Universitaetsklinikum Bonn AoeR
Bonn
Universitaetsklinikum Frankfurt Goethe-Universitaet
Frankfurt
Universitaetsklinikum Freiburg
Friedberg
Universitaetsklinikum Heidelberg
Heidelberg
Integriertes Sozialpaediatrisches Zentrum
München
Italy4 sites
Azienda Ospedaliero Universitaria Ospedale Pediatrico Meyer
Florence
Istituto Giannina Gaslini-Ospedale Pediatrico IRCCS
Genova
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Roma
Ospedale Pediatrico Bambino Gesù
Roma
China3 sites
Peking University First Hospital
Beijing
The Second Affiliated Hospital of Guangzhou Medical university
Guangzhou
Wuhan Children's Hospital
Wuhan
France3 sites
Hôpital de la Timone
Marseille
Hôpital Necker - Enfants Malades
Paris
Hôpital Robert Debré - Paris
Paris
Spain3 sites
Hospital Blua Sanitas Valdebebas
Madrid
Hospital Ruber Internacional
Madrid
Clinica Universidad de Navarra
Pamplona
United Kingdom3 sites
Royal Hospital for Children
Glasgow, G51 4TF
Great Ormond Street Hospital for Children
London, WC1N 3JH
Sheffield Children's Hospital
Sheffield, S10 2TH
About this study
Official title: 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
The purpose of the study is to evaluate the efficacy, safety, and tolerability of zorevunersen in Patients with Dravet syndrome.
Read the detailed description
Zorevunersen is an investigational new medicine for the treatment of Dravet syndrome. It is an antisense oligonucleotide (ASO) that is intended to increase the level of productive SCN1A messenger RNA (mRNA) and consequently increase the expression of the sodium channel Nav1.1 protein. This RNA-based approach is not gene therapy, but rather RNA modulation, as it does not manipulate nor insert genetic deoxyribonucleic acid (DNA).
Zorevunersen is designed to upregulate Nav1.1 protein expression from the nonmutant (wild-type) copy of the SCN1A gene to restore physiological Nav1.1 levels. Nav1.1 levels are reduced in people with Dravet syndrome.
This is a global, multicenter, randomized, double-blind, sham-controlled, parallel group Phase 3 study to assess the efficacy, safety, and tolerability of zorevunersen in patients with Dravet syndrome. The study duration and endpoints are designed to evaluate the potential of zorevunersen for disease modification. The study consists of two parts, Treatment Period 1 and Treatment Period 2. The primary and secondary endpoints will be assessed at the conclusion of Treatment Period 1. These endpoints will be assessed again at the end of Treatment Period 2. The primary endpoint is the change from baseline in major motor seizure frequency. Secondary endpoints include the change in behavior and cognition, clinical status, and health-related quality of life in patients with Dravet syndrome.
Patients will have the opportunity to enroll in an open label extension study and receive zorevunersen if they meet eligibility criteria at the end of the study.
- Conditions
- Dravet Syndrome
- Being tested
- zorevunersen, Sham Comparator
- Keywords
- Pediatric epilepsy, Epileptic Encephalopathies, Refractory Myoclonic Epilepsy, Severe Myoclonic Epilepsy in Infancy, STK-001
- Medical subject headings
- Epilepsies, Myoclonic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
zorevunersenDrug
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).
Sham ComparatorOther
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).
| Study group | Role | What they receive |
|---|---|---|
| Zorevunersen | Experimental | Eligible 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. Receives: Drug: zorevunersen |
| Sham Comparator | Sham comparator | Eligible patients will be randomly assigned in a 1:1 ratio to zorevunersen:sham Receives: Other: Sham Comparator |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measurement of Seizure Change
Measured by daily seizure diary
Measured: Week 28
Secondary outcomes (3)
Measurement of Seizure Change
Measured by daily seizure diary
Measured: Week 52
Multi-component Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Outcome Score
Measurement of change from baseline for multi-component score. Scoring is non-parametric and based on rank between treatment and sham groups. Individual items are scored on a scale of 0, 1, or 2, indicating never, sometimes, or usually or often, or on a scale of 0 or 2, indicating no or yes, with higher scores indicating greater performance
Measured: Week 52
Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Subdomain Score
Measurement of change from baseline for individual subdomains. Scoring is point-based on a scale that varies, depending on subdomain, Individual items are scored on a scale of 0, 1, or 2, indicating never, sometimes, or usually or often, or on a scale of 0 or 2, indicating no or yes, with higher scores indicating greater performance.
Measured: Week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Mar 2025
- Study start4 Jun 2025
- Primary completionMar 2027 (estimated)
- Study completionOct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dravet SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 170 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stoke Therapeutics, Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06872125
- Sponsor's protocol ID
- STK-001-DS-301
- Other IDs
- 2024-519555-28
- Status last verified
- Aug 2026
- First submitted
- 6 Mar 2025
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT06872125
- Acronym / sponsor ID
- STK-001-DS-301
- Conditions
- Dravet Syndrome
- Keywords
- Pediatric epilepsy, Epileptic Encephalopathies, Refractory Myoclonic Epilepsy, Severe Myoclonic Epilepsy in Infancy, STK-001
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 170 participants (estimated)
- Lead sponsor
- Stoke Therapeutics, IncIndustry (pharma, biotech, devices)
- Study start
- 4 Jun 2025 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Oct 2028 (estimated)
- First posted
- 12 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to evaluate the efficacy, safety, and tolerability of zorevunersen in Patients with Dravet syndrome.
Detailed description
Zorevunersen is an investigational new medicine for the treatment of Dravet syndrome. It is an antisense oligonucleotide (ASO) that is intended to increase the level of productive SCN1A messenger RNA (mRNA) and consequently increase the expression of the sodium channel Nav1.1 protein. This RNA-based approach is not gene therapy, but rather RNA modulation, as it does not manipulate nor insert genetic deoxyribonucleic acid (DNA).
Zorevunersen is designed to upregulate Nav1.1 protein expression from the nonmutant (wild-type) copy of the SCN1A gene to restore physiological Nav1.1 levels. Nav1.1 levels are reduced in people with Dravet syndrome.
This is a global, multicenter, randomized, double-blind, sham-controlled, parallel group Phase 3 study to assess the efficacy, safety, and tolerability of zorevunersen in patients with Dravet syndrome. The study duration and endpoints are designed to evaluate the potential of zorevunersen for disease modification. The study consists of two parts, Treatment Period 1 and Treatment Period 2. The primary and secondary endpoints will be assessed at the conclusion of Treatment Period 1. These endpoints will be assessed again at the end of Treatment Period 2. The primary endpoint is the change from baseline in major motor seizure frequency. Secondary endpoints include the change in behavior and cognition, clinical status, and health-related quality of life in patients with Dravet syndrome.
Patients will have the opportunity to enroll in an open label extension study and receive zorevunersen if they meet eligibility criteria at the end of the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Zorevunersen | Experimental | Drug: zorevunersenEligible 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 comparator | Other: Sham ComparatorEligible patients will be randomly assigned in a 1:1 ratio to zorevunersen:sham |
Who may qualify
- Ages
- 2 to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (8 listed)
- 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.
Key exclusion criteria (4 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| zorevunersenTreatment 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). | Drug | Zorevunersen |
| Sham ComparatorTreatment 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). | Other | Sham Comparator |
Primary outcome
Measurement of Seizure Change
Time frame: Week 28
Measured by daily seizure diary
3 secondary outcomes
Measurement of Seizure Change
Time frame: Week 52
Multi-component Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Outcome Score
Time frame: Week 52
Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) Subdomain Score
Time frame: Week 52
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
61 sites in 8 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing zorevunersen in people with Dravet Syndrome, run by Stoke Therapeutics, Inc at 61 sites in 8 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 61 sites in United States, Japan, Germany, Italy, China and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measurement of Seizure Change (time frame: Week 28). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026.