15q Duplication SyndromePhase 2NCT03694275
A Multicenter, Open-label, Pilot Study of Soticlestat (TAK-935/OV935) in Participants With 15Q Duplication Syndrome (Dup 15q) or Cyclin-Dependent Kinase-Like 5 (CDKL5) Deficiency Disorder (ARCADE STUDY)
A Phase 2 study testing Soticlestat in people with 15q Duplication Syndrome and CDKL5 Deficiency Disease, run by Takeda at 8 sites in United States.
Trial summary
The purpose of this study is to investigate the effect of soticlestat on the frequency of motor seizures for participants with Dup15q or CDD during the Maintenance Period. Read more about this study
- Who is it for?
- Ages 2 to 55 years
- Conditions the study is for
- 15q Duplication Syndrome, CDKL5 Deficiency Disease
- What is being tested?
- Soticlestat
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 8 sitesUnited States
- Study dates
- 10 Sep 2018to 31 Jul 2020
- 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 2 to 55 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Clinical diagnosis of Dup 15q or CDKL5 deficiency disorder.
- Currently taking 1 to 6 antiepileptic drugs (AEDs) at a stable dose.
Who cannot join
- Two or more episodes of convulsive status epilepticus per 3 months requiring hospitalization and intubation.
- Currently receiving a study drug or participated in a clinical study involving another investigational product in the previous month.
Trial locations and contacts
8 sites in 1 country.
8 sites in 1 country
United States8 sites
Research Institute Children's Hospital Colorado
Aurora, Colorado, 80045
Center for Rare Neurological Diseases (CRND)--Massachusetts General Hospital
Boston, Massachusetts, 02114
Boston Children's Hospital Translational Neuroscience Center
Boston, Massachusetts, 02115
UCLA
Los Angeles, California, 90095
New York University (NYU)
New York, New York, 10017
Columbia University Medical Center
New York, New York, 10032
Center for Rare Neurological Diseases
Norcross, Georgia, 30093
Minnesota Epilepsy Group, P.A.
Saint Paul, Minnesota, 55102
About this study
Official title: A Multicenter, Open-label, Pilot Study of TAK-935 (OV935) in Patients With 15Q Duplication Syndrome or CDKL5 Deficiency Disorder (ARCADE Study)
The purpose of this study is to investigate the effect of soticlestat on the frequency of motor seizures for participants with Dup15q or CDD during the Maintenance Period.
Read the detailed description
The drug being tested in this study is called soticlestat. Soticlestat is being tested to treat people with Dup 15q or CDD. This study will assess the effects of TAK-935 on seizure frequency, safety.
The study will enroll approximately 30 participants. Participants will be enrolled into 2 groups based on their diagnosis as: Dup 15q or CDD.
All participants will be asked to take soticlestat tablets twice daily with or without food.
The study comprises of 2 periods: Screening/Baseline Period and Treatment Period (Dose Optimization and Maintenance). The overall time to participate in this study is approximately 30 weeks, including 4 to 6 weeks Screening/Baseline Period, 20 weeks Treatment Period, 2 weeks Taper, and 2 weeks safety follow up period. Participants completing this study will have an option to enroll in the open-label extension (OLE) study, under a separate protocol.
- Conditions
- 15q Duplication Syndrome, CDKL5 Deficiency Disease
- Being tested
- Soticlestat
- Keywords
- Drug Therapy, 15q Duplication Syndrome (Dup15q), CDKL5 Deficiency Disorder (CDD), Brain Diseases, Epilepsy, Central Nervous System Diseases, Autism, Cholesterol 24S-hydroxylase inhibitor, Anti-epilepsy drug, Anticonvulsants
- Medical subject headings
- Polyposis Syndrome, Hereditary Mixed, 1, CDKL5 deficiency disorder, Brain Diseases, Epilepsy, Central Nervous System Diseases, Autistic Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SoticlestatDrug
Also called TAK-935
TAK-935 tablets
| Study group | Role | What they receive |
|---|---|---|
| Soticlestat Dup 15q | Experimental | Soticlestat tablets twice daily (BID) orally or via gastrostomy tube (G-tube)/ percutaneous endoscopic gastrostomy (PEG) tube, BID. Participants with Dup 15q weighing <60 kg at Baseline received total daily dose of study drug calculated based on body weight. Participants weighing ≥60 kg at Baseline, were administered with 200 mg/day followed by 400 mg/day, then 600 mg/day, up to Week 20. Receives: Drug: Soticlestat |
| Soticlestat CDD | Experimental | Soticlestat tablets BID orally or via G-tube/ PEG tube, BID. Participants with CDD weighing <60 kg at Baseline received total daily dose of study drug calculated based on body weight. Participants weighing ≥60 kg at Baseline, were administered with 200 mg/day followed by 400 mg/day, then 600 mg/day, up to Week 20. Receives: Drug: Soticlestat |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent Change From Baseline in Motor Seizure Frequency Per 28 Days During the Maintenance Period
Seizure frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period multiplied by 28. Percent Change from Baseline is defined as (frequency of seizures per 28 days during maintenance period - frequency of seizures per 28 days at Baseline) divided by frequency of seizures per 28 days at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease.
Measured: Maintenance Period: Weeks 9 to 20
Secondary outcomes (9)
Percent Change From Baseline in Motor Seizure Frequency Per 28 Days During the Treatment Period
Seizure frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period multiplied by 28. Percent Change from Baseline is defined as (frequency of seizures per 28 days during the treatment period - frequency of seizures per 28 days at Baseline) divided by frequency of seizures per 28 days at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease.
Measured: Treatment Period: Weeks 0 to 20
Percentage of Participants Considered as Treatment Responders During the Maintenance Period
Responders are defined as having over 50% motor seizure reduction compared to Baseline. Percent reduction from Baseline (%) is defined as [(Maintenance Period motor Seizure Frequency - Baseline Period motor Seizure Frequency) divided by Baseline motor Seizure Frequency] multiplied by 100. Data is reported as reduction of 25%, 50%, 75% and 100% or more in motor seizures from Baseline.
Measured: Maintenance Period: Weeks 9 to 20
Percent Change From Baseline in Frequency of Motor Seizures Longer Than 5 Minutes in Participants With CDD
Seizure frequency is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period. Percent Change from Baseline is defined as (frequency of seizures during Treatment period - frequency of seizures at Baseline) divided by frequency of seizures at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease. The data is reported only for CDD participants.
Measured: Treatment Period: Weeks 0 to 20
Proportion of Motor Seizure-free Days in Participants During the Maintenance Period
Seizure-free days is defined as number of days with zero motor seizure during the period the Maintenance Period divided by number of days participant was in the Maintenance Period.
Measured: Maintenance Period: Weeks 9 to 20
Change From Baseline in Clinician's Global Impression of Severity (CGI-S) Responses of Investigator
The CGI-S focuses on clinician's observations of the participant's cognitive, functional, and behavioral performance since the beginning of the study. The CGI-S is rated on a 7-point scale, with the severity of illness scale using a range of responses where, 1= normal, not at all ill, 2= borderline mentally ill, 3= mildly ill, 4= moderately ill, 5= markedly ill, 6= severely ill and 7=amongst the most extremely ill participants. Negative change from Baseline indicates improvement.
Measured: Baseline to Week 20
Percentage of Participants With Clinical Global Impression of Change (CGI-C) Responses as Per the Investigator Reported Impression
CGI-Change (CGI-C) treatment response ratings should take account of both therapeutic efficacy and treatment-related AEs. Each component of the CGI is rated separately; the instrument does not yield a global score. The CGI-C is rated on a 5-point scale, where, 0 = marked improvement and no side-effects, 1 = marked improvement and minimal side-effects, 2 = no change, 3 = minimal improvement and marked side-effects and 4 = unchanged or worse and side-effects outweigh the therapeutic effect. Lower scores indicated improvement.
Measured: Week 20
Percentage of Participants With Care Clinical Global Impression of Change (CGI-C) Responses of Parent/Family
CGI-Change (CGI-C) treatment response ratings should take account of both therapeutic efficacy and treatment-related AEs. Each component of the CGI is rated separately; the instrument does not yield a global score. The CGI-C is rated on a 7-point scale where, 1 = very much improved, 2 = much improved, 3 = slightly improved, 4= no change, 5= slightly worse, 6= much worse and 7= very much worse and marked side-effects. Lower scores indicated improvement.
Measured: Week 20
Change From Baseline of Plasma 24S-hydroxycholesterol (24HC) Levels
Measured: Baseline to Week 20
Change From Baseline in Seizure Frequency in Participants Treated With TAK-935 as an Adjunctive Therapy
Seizure Frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure during the period seizures were assessed multiplied by 28. Positive change from Baseline indicates seizure increase and negative change from Baseline indicates seizure decrease.
Measured: Baseline to Week 20
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Oct 2018
- Study start10 Sep 2018
- Primary completion13 Jul 2020
- Study completion31 Jul 2020
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.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for 15q Duplication SyndromeStudies of the same condition, open and under way.
- More trials run by TakedaThe 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
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Takeda
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Healx AI
- Responsible party
- Sponsor
- Investigators
- Medical Director Clinical Science, Study director, Takeda (Note: This product was divested to Mistrau Bio, Inc. in 2026)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03694275
- Sponsor's protocol ID
- TAK-935-18-002 (OV935)
- Other IDs
- U1111-1219-5787, 2022-001315-44
- Status last verified
- Aug 2026
- First submitted
- 27 Sep 2018
- Last updated
- 10 Sep 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.
Publications
Demarest S, Jeste S, Agarwal N, Arkilo D, Asgharnejad M, Hsiao S, Thibert R. Efficacy, safety, and tolerability of soticlestat as adjunctive therapy for the treatment of seizures in patients with Dup15q syndrome or CDKL5 deficiency disorder in an open-label signal-finding phase II study (ARCADE). Epilepsy Behav. 2023 May;142:109173. doi: 10.1016/j.yebeh.2023.109173. Epub 2023 Apr 1.
PubMed 37011526
Study at a glance
From the registry record, last updated by the sponsor on 10 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multicenter, Open-label, Pilot Study of TAK-935 (OV935) in Patients With 15Q Duplication Syndrome or CDKL5 Deficiency Disorder (ARCADE Study)
- ClinicalTrials.gov ID
- NCT03694275
- Acronym / sponsor ID
- TAK-935-18-002 (OV935)
- Conditions
- 15q Duplication Syndrome, CDKL5 Deficiency Disease
- Keywords
- Drug Therapy, 15q Duplication Syndrome (Dup15q), CDKL5 Deficiency Disorder (CDD), Brain Diseases, Epilepsy, Central Nervous System Diseases, Autism, Cholesterol 24S-hydroxylase inhibitor
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- TakedaIndustry (pharma, biotech, devices)
- Collaborators
- Healx AI
- Study start
- 10 Sep 2018 (actual)
- Primary completion
- 13 Jul 2020 (actual)
- Study completion
- 31 Jul 2020 (actual)
- First posted
- 3 Oct 2018 (actual)
- Results
- Posted 20 Apr 2021
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 this study is to investigate the effect of soticlestat on the frequency of motor seizures for participants with Dup15q or CDD during the Maintenance Period.
Detailed description
The drug being tested in this study is called soticlestat. Soticlestat is being tested to treat people with Dup 15q or CDD. This study will assess the effects of TAK-935 on seizure frequency, safety.
The study will enroll approximately 30 participants. Participants will be enrolled into 2 groups based on their diagnosis as: Dup 15q or CDD.
All participants will be asked to take soticlestat tablets twice daily with or without food.
The study comprises of 2 periods: Screening/Baseline Period and Treatment Period (Dose Optimization and Maintenance). The overall time to participate in this study is approximately 30 weeks, including 4 to 6 weeks Screening/Baseline Period, 20 weeks Treatment Period, 2 weeks Taper, and 2 weeks safety follow up period. Participants completing this study will have an option to enroll in the open-label extension (OLE) study, under a separate protocol.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Soticlestat Dup 15q | Experimental | Drug: SoticlestatSoticlestat tablets twice daily (BID) orally or via gastrostomy tube (G-tube)/ percutaneous endoscopic gastrostomy (PEG) tube, BID. Participants with Dup 15q weighing <60 kg at Baseline received total daily dose of study drug calculated based on body weight. Participants weighing ≥60 kg at Baseline, were administered with 200 mg/day followed by 400 mg/day, then 600 mg/day, up to Week 20. |
| Soticlestat CDD | Experimental | Drug: SoticlestatSoticlestat tablets BID orally or via G-tube/ PEG tube, BID. Participants with CDD weighing <60 kg at Baseline received total daily dose of study drug calculated based on body weight. Participants weighing ≥60 kg at Baseline, were administered with 200 mg/day followed by 400 mg/day, then 600 mg/day, up to Week 20. |
Who may qualify
- Ages
- 2 to 55 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (2 listed)
- Clinical diagnosis of Dup 15q or CDKL5 deficiency disorder.
- Currently taking 1 to 6 antiepileptic drugs (AEDs) at a stable dose.
Key exclusion criteria (2 listed)
- Two or more episodes of convulsive status epilepticus per 3 months requiring hospitalization and intubation.
- Currently receiving a study drug or participated in a clinical study involving another investigational product in the previous month.
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 |
|---|---|---|
| SoticlestatAlso: TAK-935TAK-935 tablets | Drug | Soticlestat CDD, Soticlestat Dup 15q |
Primary outcome
Percent Change From Baseline in Motor Seizure Frequency Per 28 Days During the Maintenance Period
Time frame: Maintenance Period: Weeks 9 to 20
Seizure frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period multiplied by 28. Percent Change from Baseline is defined as (frequency of seizures per 28 days during maintenance period - frequency of seizures per 28 days at Baseline) divided by frequency of seizures per 28 days at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease.
9 secondary outcomes
Percent Change From Baseline in Motor Seizure Frequency Per 28 Days During the Treatment Period
Time frame: Treatment Period: Weeks 0 to 20
Percentage of Participants Considered as Treatment Responders During the Maintenance Period
Time frame: Maintenance Period: Weeks 9 to 20
Percent Change From Baseline in Frequency of Motor Seizures Longer Than 5 Minutes in Participants With CDD
Time frame: Treatment Period: Weeks 0 to 20
Proportion of Motor Seizure-free Days in Participants During the Maintenance Period
Time frame: Maintenance Period: Weeks 9 to 20
Change From Baseline in Clinician's Global Impression of Severity (CGI-S) Responses of Investigator
Time frame: Baseline to Week 20
Percentage of Participants With Clinical Global Impression of Change (CGI-C) Responses as Per the Investigator Reported Impression
Time frame: Week 20
Percentage of Participants With Care Clinical Global Impression of Change (CGI-C) Responses of Parent/Family
Time frame: Week 20
Change From Baseline of Plasma 24S-hydroxycholesterol (24HC) Levels
Time frame: Baseline to Week 20
Change From Baseline in Seizure Frequency in Participants Treated With TAK-935 as an Adjunctive Therapy
Time frame: Baseline to Week 20
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Sep 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 37011526Demarest S, Jeste S, Agarwal N, Arkilo D, Asgharnejad M, Hsiao S, Thibert R. Efficacy, safety, and tolerability of soticlestat as adjunctive therapy for the treatment of seizures in patients with Dup15q syndrome or CDKL5 deficiency disorder in an open-label signal-finding phase II study (ARCADE). Epilepsy Behav. 2023 May;142:109173. doi: 10.1016/j.yebeh.2023.109173. Epub 2023 Apr 1.
- Individual participant dataSharing planned: Yes. Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.
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.
Medical Director Clinical Science study director
Takeda (Note: This product was divested to Mistrau Bio, Inc. in 2026)
8 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 Soticlestat in people with 15q Duplication Syndrome and CDKL5 Deficiency Disease, run by Takeda at 8 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 2 inclusion and 2 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: finished, as of the sponsor's last update on 10 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 8 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?
Yes. Results are posted in the registry (first posted 20 Apr 2021). 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?
Percent Change From Baseline in Motor Seizure Frequency Per 28 Days During the Maintenance Period (time frame: Maintenance Period: Weeks 9 to 20). 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 NCT03694275, 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 10 Sep 2026.