Dravet SyndromePhase 2NCT04740476
An Open-Label Extension Study of STK-001 for Patients With Dravet Syndrome
A Phase 2 study testing zorevunersen (STK-001) in people with Dravet Syndrome, run by Stoke Therapeutics, Inc at 17 sites in United States.
Trial summary
Stoke Therapeutics is evaluating the long-term safety \& tolerability of repeated doses of zorevunersen (STK-001) in patients with Dravet syndrome who previously participated in studies of zorevunersen. Read more about this study
- Who is it for?
- Ages 30 months and older
- Conditions the study is for
- Dravet Syndrome
- What is being tested?
- zorevunersen (STK-001)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 17 sitesUnited States
- Study dates
- 20 Jan 2021to 31 Mar 2029
- Phase
- Phase 2
- 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 30 months and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Completed dosing with zorevunersen and the End of Study Visit in Study STK-001-DS-101 or Study STK-001-DS-102, with an acceptable safety profile per Investigator judgment.
- Had satisfactory compliance with study visits and procedures in Study STK-001-DS-101 or Study STK-001-DS-102 per Investigator and Sponsor judgment.
- Completed Study STK-001-DS-101 or STK-001-DS-102 within 4 weeks of the start of their participation in Study STK-001-DS-501 unless approved by sponsor.
Who cannot join
- Met any withdrawal criteria from Study STK-001-DS-101 or STK-001-DS-102.
- Currently treated with an antiepileptic drug (AED) acting primarily as a sodium channel blocker, as maintenance therapy, including phenytoin, carbamazepine, oxcarbazepine, lamotrigine, lacosamide or rufinamide (with the exception of cenobamate, which is permitted).
- Clinically significant unstable medical conditions other than epilepsy.
- Clinically relevant symptoms or a clinically significant illness (in the judgment of the Investigator) at Screening or prior to dosing on Day 1, other than epilepsy.
- Spinal deformity or other condition that may alter the free flow of CSF or has an implanted CSF drainage shunt.
- Treated (or is being treated) with an investigational product (other than zorevunersen) since participating in Study STK-001-DS-101 or STK-001-DS-102.
- Participating in an observational study, they are excluded unless approved by the Sponsor.
Trial locations and contacts
17 sites in 1 country.
17 sites in 1 country
United States17 sites
Michigan Medicine
Ann Arbor, Michigan, 48109
Children's Hospital Colorado
Aurora, Colorado, 80045
Massachusetts General Hospital
Boston, Massachusetts, 02114
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
Cook Children's Medical Center
Fort Worth, Texas, 76104
University of Iowa Children's Hospital
Iowa City, Iowa, 52242
UT LeBonheur Pediatric Specialists, Inc.
Memphis, Tennessee, 38103
Nicklaus Children's Hospital
Miami, Florida, 33155
NYU Comprehensive Epilepsy Center
New York, New York, 10016
Florida Hospital for Children
Orlando, Florida, 32803
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Oregon Health & Science University
Portland, Oregon, 97239
Mayo Clinic
Rochester, Minnesota, 55905
University of California San Francisco Medical Center
San Francisco, California, 94158
Seattle Children's Hospital
Seattle, Washington, 98105
MultiCare Health System Institute for Research and Innovation
Tacoma, Washington, 98405
Children's National Medical Center
Washington D.C., District of Columbia, 20010
About this study
Official title: An Open-Label Extension Study for Patients With Dravet Syndrome Who Previously Participated in Studies of STK-001
Stoke Therapeutics is evaluating the long-term safety \& tolerability of repeated doses of zorevunersen (STK-001) in patients with Dravet syndrome who previously participated in studies of zorevunersen. Change in seizure frequency and overall clinical status, and quality of life will be measured as secondary endpoints in this open-label study.
Read the detailed description
This study is a multi-center, open-label, multiple-dose, safety extension study for patients who have completed another study of zorevunersen and meet study eligibility criteria. zorevunersen is an investigational new medicine for the treatment of Dravet syndrome. Zorevunersen 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. Stoke has generated preclinical data demonstrating proof-of-mechanism for zorevunersen.
- Conditions
- Dravet Syndrome
- Being tested
- zorevunersen (STK-001)
- Keywords
- Pediatric epilepsy, Epileptic Encephalopathies, Refractory Myoclonic Epilepsy, Severe Myoclonic Epilepsy in Infancy
- Medical subject headings
- Epilepsies, Myoclonic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
zorevunersen (STK-001)Drug
zorevunersen drug product is an antisense oligonucleotide administered as an intrathecal injection.
| Study group | Role | What they receive |
|---|---|---|
| zorevunersen (STK-001) multiple dose levels | Experimental | Enrollment of patients after completion of Study STK-001-DS-101 or Study STK-001-DS-102 if eligible. Patients will receive IT administration of study drug zorevunersen at the dose level they received while participating in Study STK-001-DS-101 or STK-001-DS-102, or at a dose level recommended by the Safety Monitoring Committee (SMC).The highest dose administered in this study may not exceed that which has already been evaluated in an zorevunersen Phase 1/2 study, and doses above 45 mg/dose in this study require approval from the Food and Drug Administration (FDA). Patients will initially receive 3 doses, one every approximately 4 months (16 weeks). Patients who are tolerating treatment may continue treatment with doses approximately every 4 months, with an End of Study/Follow-up Visit 24 weeks after the last dose of study drug. Patients who do not continue treatment after the third dose will have a Follow-up Visit (V5) at Week 48 and an End of Study Visit at Week 56. Receives: Drug: zorevunersen (STK-001) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety of multiple doses of zorevunersen
Safety variables for analysis include the incidence, type, severity, and seriousness of AEs, and changes in vital signs, ECG, laboratory, immunogenicity, physical examination, and outcomes on the cerebellar function clinical screening battery.
Measured: Screening (Day -1) until 6 months after multiple drug dosing
Secondary outcomes (5)
Pharmacokinetic (PK) Parameters
Analysis of plasma concentrations of zorevunersen
Measured: Dosing (Day 1) until 6 months after multiple drug dosing
Exposure of zorevunersen in Cerebrospinal Fluid (CSF)
Measurement of zorevunersen concentrations
Measured: Dosing (Day 1) and every 4 months until last study drug dosing day
Measurement of Seizure Frequency
Measurement of Seizure Frequency (by paper diary)
Measured: Screening (Day -1) until 6 months after multiple drug dosing
Change in overall clinical status
Change in overall clinical status as measured by the Clinical Global Impression of Change (CGIC) and the Caregiver Global Impression of Change (CaGIC)
Measured: Screening (Day -1) until 6 months after multiple drug dosing
Change in Quality of Life
Change in quality of life as measured by the EuroQoL-five dimensions, youth version (EQ-5D-Y) instrument
Measured: Screening (Day -1) until 6 months after multiple drug dosing
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2021
- Study start20 Jan 2021
- Primary completion31 Mar 2029 (estimated)
- Study completion31 Mar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stoke Therapeutics, Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Ann Dandurand, MD, Study director, Medical Director
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04740476
- Sponsor's protocol ID
- STK-001-DS-501
- Status last verified
- Feb 2026
- First submitted
- 2 Feb 2021
- Last updated
- 4 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Laux L, Sullivan J, Perry MS, Brunklaus A, Desurkar A, Schreiber JM, Roberts CM, Knupp KG, Wheless JW, Wirrell EC, Ventola P, Wang F, Meena, Lynch J, Parkerson KA, Ticho B, Cross JH; MONARCH, ADMIRAL, SWALLOWTAIL, and LONGWING Study Groups. Zorevunersen in Children and Adolescents with Dravet Syndrome. N Engl J Med. 2026 Mar 5;394(10):969-982. doi: 10.1056/NEJMoa2506295.
PubMed 41780062
Study at a glance
From the registry record, last updated by the sponsor on 4 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label Extension Study for Patients With Dravet Syndrome Who Previously Participated in Studies of STK-001
- ClinicalTrials.gov ID
- NCT04740476
- Acronym / sponsor ID
- STK-001-DS-501
- Conditions
- Dravet Syndrome
- Keywords
- Pediatric epilepsy, Epileptic Encephalopathies, Refractory Myoclonic Epilepsy, Severe Myoclonic Epilepsy in Infancy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Stoke Therapeutics, IncIndustry (pharma, biotech, devices)
- Study start
- 20 Jan 2021 (actual)
- Primary completion
- 31 Mar 2029 (estimated)
- Study completion
- 31 Mar 2029 (estimated)
- First posted
- 5 Feb 2021 (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.
Stoke Therapeutics is evaluating the long-term safety \& tolerability of repeated doses of zorevunersen (STK-001) in patients with Dravet syndrome who previously participated in studies of zorevunersen. Change in seizure frequency and overall clinical status, and quality of life will be measured as secondary endpoints in this open-label study.
Detailed description
This study is a multi-center, open-label, multiple-dose, safety extension study for patients who have completed another study of zorevunersen and meet study eligibility criteria. zorevunersen is an investigational new medicine for the treatment of Dravet syndrome. Zorevunersen 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. Stoke has generated preclinical data demonstrating proof-of-mechanism for zorevunersen.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| zorevunersen (STK-001) multiple dose levels | Experimental | Drug: zorevunersen (STK-001)Enrollment of patients after completion of Study STK-001-DS-101 or Study STK-001-DS-102 if eligible. Patients will receive IT administration of study drug zorevunersen at the dose level they received while participating in Study STK-001-DS-101 or STK-001-DS-102, or at a dose level recommended by the Safety Monitoring Committee (SMC).The highest dose administered in this study may not exceed that which has already been evaluated in an zorevunersen Phase 1/2 study, and doses above 45 mg/dose in this study require approval from the Food and Drug Administration (FDA). Patients will initially receive 3 doses, one every approximately 4 months (16 weeks). Patients who are tolerating treatment may continue treatment with doses approximately every 4 months, with an End of Study/Follow-up Visit 24 weeks after the last dose of study drug. Patients who do not continue treatment after the third dose will have a Follow-up Visit (V5) at Week 48 and an End of Study Visit at Week 56. |
Who may qualify
- Ages
- 30 months and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- Completed dosing with zorevunersen and the End of Study Visit in Study STK-001-DS-101 or Study STK-001-DS-102, with an acceptable safety profile per Investigator judgment.
- Had satisfactory compliance with study visits and procedures in Study STK-001-DS-101 or Study STK-001-DS-102 per Investigator and Sponsor judgment.
- Completed Study STK-001-DS-101 or STK-001-DS-102 within 4 weeks of the start of their participation in Study STK-001-DS-501 unless approved by sponsor.
Key exclusion criteria (7 listed)
- Met any withdrawal criteria from Study STK-001-DS-101 or STK-001-DS-102.
- Currently treated with an antiepileptic drug (AED) acting primarily as a sodium channel blocker, as maintenance therapy, including phenytoin, carbamazepine, oxcarbazepine, lamotrigine, lacosamide or rufinamide (with the exception of cenobamate, which is permitted).
- Clinically significant unstable medical conditions other than epilepsy.
- Clinically relevant symptoms or a clinically significant illness (in the judgment of the Investigator) at Screening or prior to dosing on Day 1, other than epilepsy.
- Spinal deformity or other condition that may alter the free flow of CSF or has an implanted CSF drainage shunt.
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 |
|---|---|---|
| zorevunersen (STK-001)zorevunersen drug product is an antisense oligonucleotide administered as an intrathecal injection. | Drug | zorevunersen (STK-001) multiple dose levels |
Primary outcome
Safety of multiple doses of zorevunersen
Time frame: Screening (Day -1) until 6 months after multiple drug dosing
Safety variables for analysis include the incidence, type, severity, and seriousness of AEs, and changes in vital signs, ECG, laboratory, immunogenicity, physical examination, and outcomes on the cerebellar function clinical screening battery.
5 secondary outcomes
Pharmacokinetic (PK) Parameters
Time frame: Dosing (Day 1) until 6 months after multiple drug dosing
Exposure of zorevunersen in Cerebrospinal Fluid (CSF)
Time frame: Dosing (Day 1) and every 4 months until last study drug dosing day
Measurement of Seizure Frequency
Time frame: Screening (Day -1) until 6 months after multiple drug dosing
Change in overall clinical status
Time frame: Screening (Day -1) until 6 months after multiple drug dosing
Change in Quality of Life
Time frame: Screening (Day -1) until 6 months after multiple drug dosing
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 4 Feb 2026.
- Derived from this study: PubMed 41780062Laux L, Sullivan J, Perry MS, Brunklaus A, Desurkar A, Schreiber JM, Roberts CM, Knupp KG, Wheless JW, Wirrell EC, Ventola P, Wang F, Meena, Lynch J, Parkerson KA, Ticho B, Cross JH; MONARCH, ADMIRAL, SWALLOWTAIL, and LONGWING Study Groups. Zorevunersen in Children and Adolescents with Dravet Syndrome. N Engl J Med. 2026 Mar 5;394(10):969-982. doi: 10.1056/NEJMoa2506295.
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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.
Ann Dandurand, MD study director
Medical Director
17 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing zorevunersen (STK-001) in people with Dravet Syndrome, run by Stoke Therapeutics, Inc at 17 sites in United States.
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 3 inclusion and 7 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 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 17 sites in United States. 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. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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?
Safety of multiple doses of zorevunersen (time frame: Screening (Day -1) until 6 months after multiple drug dosing). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04740476, which also lists 1 linked publication.
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 4 Feb 2026.