Epileptic EncephalopathyPhase 2Steamboat 2NCT05301894

Extension Study to Evaluate NBI-827104 in Pediatric Participants With Epileptic Encephalopathy With Continuous Spike-and-Wave During Sleep

A Phase 2 study testing NBI-827104 in people with Epileptic Encephalopathy and Continuous Spike and Wave During Sleep, run by Neurocrine Biosciences at 12 sites in 5 countries.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record

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Trial summary

The primary objective for this study is to evaluate the long-term safety and tolerability of NBI-827104 in pediatric participants with epileptic encephalopathy with continuous spike-and-wave during sleep (EECSWS). Read more about this study

Who is it for?: Ages 4 to 12 years
Conditions the study is for: Epileptic Encephalopathy, Continuous Spike and Wave During Sleep
What is being tested?: NBI-827104
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 19 participants
Where: 12 sitesin 5 countries
Study dates: 7 Jun 2022to 27 Jan 2025
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 4 to 12 years
All sexes
No healthy volunteers
Child

Who may be able to join

For participants who enroll directly following the completion of the Study NBI-827104-CSWS2010:
Completed 12 weeks of treatment in Study NBI-827104-CSWS2010.
For Participants Who Do Not Enroll Directly from or Did Not Participate in Study NBI-827104-CSWS2010:
Have diagnosis of EECSWS confirmed by the Diagnosis Confirmation Panel (DCP).

Who cannot join

For participants who enroll directly following the completion of the Study NBI-827104-CSWS2010:
Have developed any other disorder for which the treatment takes priority over treatment of EECSWS or is likely to interfere with study treatment or impair treatment compliance.
For Participants Who Do Not Enroll Directly from or Did Not Participate in Study NBI-827104-CSWS2010:
Body weight <15 kg at Day 1.
Clinically relevant findings related to cardiovascular or laboratory parameters at screening as determined by the investigator.
Presence of relevant neurological disorders other than EECSWS and its underlying conditions as judged by the investigator. Symptomatic conditions underlying EECSWS (for example, neonatal strokes) have to be stable for at least 1 year prior to screening.

Show all 9Show fewer

Planned surgical intervention related to structural abnormalities of the brain from screening through the Week 6 Visit.
Used any active investigational drug other than NBI-827104 in the context of a clinical study within 30 days or 5 half-lives (whichever is longer) before screening or plans to use such an investigational drug (other than NBI-827104) during the study.
Have developed any other disorder for which the treatment takes priority over treatment of EECSWS or is likely to interfere with study treatment or impair treatment compliance.

Trial locations and contacts

12 sites in 5 countries.

Country

City, postcode or hospital

12 sites in 5 countries

United States7 sites

Neurocrine Clinical Site
Aurora, Colorado, 80045
Neurocrine Clinical Site
Cleveland, Ohio, 44195
Neurocrine Clinical Site
Durham, North Carolina, 27705
Neurocrine Clinical Site
Miami, Florida, 33155
Neurocrine Clinical Site
Orange, California, 92868
Neurocrine Clinical Site
Rochester, Minnesota, 55905
Neurocrine Clinical Site
Washington D.C., District of Columbia, 20010

Other trials in United States

Spain2 sites

Neurocrine Clinical Site
Barcelona, 08950
Neurocrine Clinical Site
Madrid, 28034

Other trials in Spain

Denmark1 site

Neurocrine Clinical Site
Dianalund, 4293

Other trials in Denmark

Switzerland1 site

Neurocrine Clinical Site
Zurich, 8032

Other trials in Switzerland

United Kingdom1 site

Neurocrine Clinical Site
London, WC1N 3JH

Other trials in United Kingdom

About this study

Official title: Long-Term, Open-Label Extension Study to Evaluate the Safety and Tolerability of NBI-827104 in Pediatric Subjects With Epileptic Encephalopathy With Continuous Spike-and-Wave During Sleep

Read the detailed description

This study will enroll participants who completed treatment in the Phase 2, multicenter, randomized, double-blind, placebo-controlled, parallel-group Study NBI-827104-CSWS2010 (NCT04625101). Participants who did not participate in Study NBI-827104-CSWS2010 may also be eligible for enrollment.

Conditions: Epileptic Encephalopathy, Continuous Spike and Wave During Sleep
Being tested: NBI-827104
Keywords: Epilepsy, Epileptic Encephalopathy, Neurocrine, NBI-827104, Steamboat 2
Medical subject headings: Epilepsy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

NBI-827104Drug
T-type calcium channel blocker.

Study groups in NCT05301894
Study group	Role	What they receive
NBI-827104	Experimental	NBI-827104 administered orally Receives: Drug: NBI-827104

What is being measured

The primary outcome is the main question the study is designed to answer.

The Number of Participants With Serious Treatment-emergent Adverse Events (TEAEs)
A TEAE is an adverse event (AE) that was not present prior to the initiation of study treatment or was an already present condition that worsened either in intensity or frequency following the initiation of study treatment.
Measured: Up to 884 days of treatment and 4-week safety follow-up (mean duration of exposure was 649.7 days)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

7 Jun 202227 Jan 2025

First posted31 Mar 2022
Study start7 Jun 2022
Primary completion27 Jan 2025
Study completion27 Jan 2025

Why it stopped: Business decision

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Epileptic EncephalopathyStudies of the same condition, open and under way.
More trials run by Neurocrine BiosciencesThe sponsor's other registered studies.
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: 19 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05301894
Sponsor's protocol ID: NBI-827104-CSWS2025
Other IDs: 2021-006788-11
Acronym: Steamboat 2
Status last verified: Jul 2025
First submitted: 21 Mar 2022
Last updated: 13 Feb 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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Active, not recruitingPhase 3
A Phase 3, Placebo-Controlled Study to Investigate LP352 in Children and Adults With Dravet Syndrome (DS)
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RecruitingPhase 1/2
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All Epileptic Encephalopathy trials

Study at a glance

From the registry record, last updated by the sponsor on 13 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Long-Term, Open-Label Extension Study to Evaluate the Safety and Tolerability of NBI-827104 in Pediatric Subjects With Epileptic Encephalopathy With Continuous Spike-and-Wave During Sleep
ClinicalTrials.gov ID: NCT05301894
Acronym / sponsor ID: Steamboat 2 / NBI-827104-CSWS2025
Conditions: Epileptic Encephalopathy, Continuous Spike and Wave During Sleep
Keywords: Epilepsy, Epileptic Encephalopathy, Neurocrine, NBI-827104, Steamboat 2
Phase: Phase 2
Study type: Interventional
Recruitment status: TerminatedReason stopped: Business decision
Enrolment: 19 participants (actual)
Lead sponsor: Neurocrine BiosciencesIndustry (pharma, biotech, devices)
Study start: 7 Jun 2022 (actual)
Primary completion: 27 Jan 2025 (actual)
Study completion: 27 Jan 2025 (actual)
First posted: 31 Mar 2022 (actual)
Results: Posted 13 Feb 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
NBI-827104	Experimental	Drug: NBI-827104NBI-827104 administered orally

Who may qualify

Ages: 4 to 12 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Child

Key inclusion criteria (4 listed)

For participants who enroll directly following the completion of the Study NBI-827104-CSWS2010:
Completed 12 weeks of treatment in Study NBI-827104-CSWS2010.
For Participants Who Do Not Enroll Directly from or Did Not Participate in Study NBI-827104-CSWS2010:
Have diagnosis of EECSWS confirmed by the Diagnosis Confirmation Panel (DCP).

Key exclusion criteria (9 listed)

For participants who enroll directly following the completion of the Study NBI-827104-CSWS2010:
Have developed any other disorder for which the treatment takes priority over treatment of EECSWS or is likely to interfere with study treatment or impair treatment compliance.
For Participants Who Do Not Enroll Directly from or Did Not Participate in Study NBI-827104-CSWS2010:
Body weight <15 kg at Day 1.
Clinically relevant findings related to cardiovascular or laboratory parameters at screening as determined by the investigator.

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
NBI-827104T-type calcium channel blocker.	Drug	NBI-827104

Primary outcome

The Number of Participants With Serious Treatment-emergent Adverse Events (TEAEs)
Time frame: Up to 884 days of treatment and 4-week safety follow-up (mean duration of exposure was 649.7 days)
A TEAE is an adverse event (AE) that was not present prior to the initiation of study treatment or was an already present condition that worsened either in intensity or frequency following the initiation of study treatment.

Results and safety

Results posted to the registry on 13 Feb 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
NBI-827104	19	0

Primary outcome: The Number of Participants With Serious Treatment-emergent Adverse Events (TEAEs)

Time frame: Up to 884 days of treatment and 4-week safety follow-up (mean duration of exposure was 649.7 days). Count of participants. Unit: Participants

Measure	NBI-827104 n = 19
Value	2

Population analysed: All enrolled participants who took at least 1 dose of NBI-827104.

Adverse events

Time frame: Up to 884 days of treatment and 4-week safety follow-up (mean duration of exposure was 649.7 days). Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
NBI-827104	2 of 19 (10.5%)	17 of 19 (89.5%)	0 of 19

Limitations and caveats (from the sponsor): The study was terminated early by the Sponsor; therefore, no participants completed the study.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 13 Feb 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Epileptic Encephalopathy

Not yet recruitingPhase 3
Open-label, Single-arm Trial of Ganaxolone in CDD Patients 6 Months to Less Than 2 Years Old
CDKL5 Deficiency Disorder
RecruitingObservational study
Multi-biomarkers in DEE
Developmental and Epileptic Encephalopathies (DEE)
RecruitingObservational study
Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford
Rare Disorders, Undiagnosed Disorders
Active, not recruitingPhase 3
A Phase 3, Placebo-Controlled Study to Investigate LP352 in Children and Adults With Dravet Syndrome (DS)
Dravet Syndrome
RecruitingPhase 1/2
A Clinical Study to Evaluate the Safety and Efficacy of ETX101 in Infants and Children With SCN1A-Positive Dravet Syndrome
Dravet Syndrome

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.

Clinical Development Lead study director

Neurocrine Biosciences

12 sites in 5 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing NBI-827104 in people with Epileptic Encephalopathy and Continuous Spike and Wave During Sleep, run by Neurocrine Biosciences at 12 sites in 5 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 4 inclusion and 9 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: stopped early, as of the sponsor's last update on 13 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 12 sites in United States, Spain, Denmark, Switzerland, United Kingdom. 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?

Yes. Results are posted in the registry (first posted 13 Feb 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

The Number of Participants With Serious Treatment-emergent Adverse Events (TEAEs) (time frame: Up to 884 days of treatment and 4-week safety follow-up (mean duration of exposure was 649.7 days)). 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 NCT05301894.

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 13 Feb 2026.