ClinicalTrials.gov record NCT06872125

A Double-blind Study Evaluating the Efficacy, Safety, and Tolerability of Zorevunersen in Patients With Dravet Syndrome

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Aug 25, 2026

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

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.
Age2 years old to 17 years old
SexAll
LocationChina, France, Germany, Italy, Japan, Spain, United Kingdom, United States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

A Phase 3 randomized, double-blind, sham-controlled study testing zorevunersen in children with Dravet syndrome. In the first treatment period participants receive intrathecal zorevunersen or a sham procedure; after that all eligible participants receive zorevunersen in a second treatment period. The study measures change in major motor seizure frequency and also assesses behavior, cognition, clinical status, and health-related quality of life.

What it is studying. Whether giving intrathecal zorevunersen changes major motor seizure frequency and how it affects behavior, cognition, clinical status, and quality of life in patients with Dravet syndrome.

What the researchers hope to learn. To evaluate the efficacy, safety, and tolerability of zorevunersen in Dravet syndrome; to measure change from baseline in major motor seizure frequency; and to assess changes in behavior, cognition, clinical status, and health-related quality of life. The study is also designed to evaluate the potential for disease modification.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The purpose of the study is to evaluate the efficacy, safety, and tolerability of zorevunersen in Patients with Dravet syndrome.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • zorevunersen
Other
  • Sham Comparator

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • 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.
  • Key

Exclusion criteria

  • 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.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

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.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants complete initial observation and baseline periods (including a 6‑week observation to record seizures and an 8‑week baseline) with daily seizure diaries and stable background therapies. If randomized, they enter Treatment Period 1 (~52 weeks) and receive either zorevunersen by repeated intrathecal (spinal) administrations or a sham procedure that mimics the drug administration; after Treatment Period 1 eligible participants may enter Treatment Period 2 and receive zorevunersen. Visits include review of seizure diaries, safety monitoring, behavioral and cognitive assessments (for example Vineland‑3), quality‑of‑life measures, and the spinal procedures; routine tests for safety are also performed. Maintenance anti‑seizure therapies and other allowed interventions generally must remain stable during Baseline as required by the study.

How the study is structured. Randomized, double-blind, sham-controlled, parallel-group Phase 3 trial. Participants are assigned 1:1 to receive intrathecal zorevunersen or a sham procedure during Treatment Period 1 (about 52 weeks). After Treatment Period 1, eligible participants enter Treatment Period 2 in which all receive zorevunersen. Masking is quadruple (participants, caregivers, investigators, and outcome assessors are blinded). Seizures are tracked with a daily seizure diary and clinical assessments are done at scheduled visits.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The listed sites are in China, France, Germany, Italy, Japan, Spain, United Kingdom, United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on Dravet syndrome

This trial is also listed on this site under CDKL5 deficiency disorder.

Clinical trials22 trials listed for Dravet syndromeEvery trial the registry lists for Dravet syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Dravet syndrome researchLatest monthly update: September 2026. Includes: CBD in practice. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jun 4, 2025
Primary completion
March 2027 (estimated)
Study completion
October 2028 (estimated)
Target enrollment
170 participants (estimated)
Last updated on registry
Aug 24, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Stoke Therapeutics, Inc

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (61)

  • Phoenix Children's HospitalActive Not Recruiting

    Phoenix, Arizona, 85016 · United States

  • Arkansas Children's HospitalActive Not Recruiting

    Little Rock, Arkansas, 72202 · United States

  • Cedars Sinai Medical CenterActive Not Recruiting

    Los Angeles, California, 90048 · United States

  • Children's Hospital of Orange CountyActive Not Recruiting

    Orange, California, 92868 · United States

  • USCF Medical CenterActive Not Recruiting

    San Francisco, California, 94158 · United States

  • Children's Hospital ColoradoActive Not Recruiting

    Aurora, Colorado, 80045 · United States

  • Children's National Medical CenterActive Not Recruiting

    Washington D.C., District of Columbia, 20010 · United States

  • Nemours Children's HealthActive Not Recruiting

    Jacksonville, Florida, 32207 · United States

  • Nicklaus Children's HospitalActive Not Recruiting

    Miami, Florida, 33155 · United States

  • Advent Health Neuroscience Research InstituteActive Not Recruiting

    Orlando, Florida, 32804 · United States

Terms used on this page · explanations by MedicalUpdates.ai

randomized
Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
Baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
before Screening
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
Key Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Key Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
investigational
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
double-blind
Two types of people involved in the study do not know which intervention a participant is receiving. The ClinicalTrials.gov record specifies who is masked, for example participants, care providers, investigators or outcome assessors.
sham
A procedure designed to resemble the real procedure, for example the same visit and equipment, without its active part. It is the procedure equivalent of a placebo.
parallel group
Participants are divided into two or more groups, and each group receives a different intervention at the same time, so the groups can be compared.
endpoints
Something the study measures to judge its results, such as a symptom score, a blood test or survival. Outcomes are grouped as primary, secondary and sometimes exploratory.
primary endpoint
The main result the study is designed to measure and report on. Other results, called secondary outcomes, are also collected.
open label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
extension study
A continuation study in which participants who completed an earlier study can keep receiving the treatment, usually with everyone knowing what they are given.
eligibility criteria
The rules the study team uses to decide who may take part. They are usually split into inclusion criteria and exclusion criteria.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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