TerminatedPhase 2

A Study of Soticlestat in Adults and Children With Rare Epilepsies

Stopped: Due to negative results from phase 3 SKYLINE and SKYWAY studies and unrelated to patient safety it has been determined that supplementary data from TAK-935-18-001 study is no longer necessary. Therefore, Takeda has made a decision to close this study

United States, Australia, Canada156 participantsStarted 2018-07-19

Plain-language summary

The main aim is to assess the long-term safety and tolerability of soticlestat when used along with other anti-seizure treatment. Participants will receive soticlestat twice a day. Participants will visit the study clinic every 2-6 months throughout the study. Study treatments may continue as long as the participant is receiving benefit from it.

Who can participate

Age range

2 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Participants must have participated in a previous soticlestat study and meet one of the following conditions:
. In the opinion of the investigator, the participant has the potential to benefit from the administration of soticlestat

Exclusion criteria

. Clinically significant disease, that, in the investigator's opinion, precludes study participation.
. Enrollment in any other clinical trial involving an investigational drug, device, or treatment in the past 90 days (with the exception of an antecedent study involving Soticlestat).
. Participant is currently pregnant or breastfeeding or is planning to become pregnant during the study or within 30 days of the last study drug administration.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Percentage of Participants Who Experienced At Least One Treatment-emergent Adverse Event (AE)

Timeframe: From screening up to end of the study (up to approximately 84 months)

Change From Baseline in Behavioral and Adaptive Functional Measures Using the Vineland Adaptive Behavior Scale (VABS)

Timeframe: Baseline, Week 338

Change From Baseline in Behavior Measures Using Total Scores of the Aberrant Behavior Checklist-Community Edition (ABC-C) for Participants Greater Than Equal to (≥) 6 Years of Age

Timeframe: Baseline, Week 338

Change From Baseline in Behavior Measures Using Subscale Scores of the Aberrant Behavior Checklist-Community Edition (ABC-C) for Participants Greater Than Equal to (≥) 6 Years of Age

Timeframe: Baseline, Week 338

Number of Participants With Changes From Baseline in the Columbia-Suicide Severity Rating Scale (C-SSRS) Categorization Based on Columbia Classification Algorithm of Suicide Assessment Categories 1,2,3,4, and 5 for Participants ≥6 Years of Age

Timeframe: Baseline, Week 338

Change From Baseline in Clinical Laboratory Parameters: Serum Chemistry (Grams Per Liter (g/L))

Trial details

NCT IDNCT03635073

SponsorTakeda

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-07-30

Results submitted2026-01-20

View on ClinicalTrials.gov More Epilepsy trials

A Study of Soticlestat in Adults and Children With Rare Epilepsies

United States, Australia, Canada156 participantsStarted 2018-07-19

Plain-language summary

Who can participate

Age range

2 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Participants must have participated in a previous soticlestat study and meet one of the following conditions:
. In the opinion of the investigator, the participant has the potential to benefit from the administration of soticlestat

Exclusion criteria

. Clinically significant disease, that, in the investigator's opinion, precludes study participation.
. Enrollment in any other clinical trial involving an investigational drug, device, or treatment in the past 90 days (with the exception of an antecedent study involving Soticlestat).
. Participant is currently pregnant or breastfeeding or is planning to become pregnant during the study or within 30 days of the last study drug administration.

What they're measuring

Percentage of Participants Who Experienced At Least One Treatment-emergent Adverse Event (AE)

Timeframe: From screening up to end of the study (up to approximately 84 months)

Change From Baseline in Behavioral and Adaptive Functional Measures Using the Vineland Adaptive Behavior Scale (VABS)

Timeframe: Baseline, Week 338

Change From Baseline in Behavior Measures Using Total Scores of the Aberrant Behavior Checklist-Community Edition (ABC-C) for Participants Greater Than Equal to (≥) 6 Years of Age

Timeframe: Baseline, Week 338

Change From Baseline in Behavior Measures Using Subscale Scores of the Aberrant Behavior Checklist-Community Edition (ABC-C) for Participants Greater Than Equal to (≥) 6 Years of Age

Timeframe: Baseline, Week 338

Change From Baseline in Clinical Laboratory Parameters: Serum Chemistry (Grams Per Liter (g/L))