Dup15Q SyndromePhase 2NCT07846215
A Phase II Study of Basmisanil in Children and Adolescents With Dup15q Syndrome
A Phase 2 study testing Basmisanil in people with Dup15Q Syndrome, run by Newleos Therapeutics, Inc. at 1 site in United States.
Trial summary
The primary goal of this Phase 2 clinical trial is to determine the effects of a selective negative allosteric modulator (NAM) of GABAA α5 receptor, Basmisanil (NTX-1511), on brain wave (EEG) characteristics in children and adolescents with Dup15q syndrome. Read more about this study
- Who is it for?
- Ages 2 to 14 years
- Conditions the study is for
- Dup15Q Syndrome
- What is being tested?
- Basmisanil
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Dec 2026to 1 May 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 2 to 14 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Parent, caregiver, or legally authorized representatives has provided written informed consent for the study and is willing to comply with all requirements of the protocol
- Male or female aged 2 to 14 years inclusive at time of informed consent signature
- Documented duplication (3 copies) or triplication (4 copies) of the chromosome 15q11.2.-q13.1 (BP2-BP3) segment.
- Dup15q syndrome Clinician Global Impression of Severity Scale (Dup15q CGI-S) overall severity score ≥ 3 (at least mildly impaired)
Who cannot join
- Pathogenic or likely pathogenic genomic variant outside of the BP2-BP3 segment. Individuals with an isodicentric 15q chromosome and a history of epilepsy
- Uncontrolled epilepsy (in individuals with interstitial BP2-BP3 duplication or triplication) indicated by: - Use of rescue medication(s) to treat more than one seizure episode or seizure cluster per month, on average in the past 6 months, or -Concomitant chronic use of more than four anti-epileptic medications, or -Status epilepticus within the past 6 months requiring hospitalization for treatment of the status epilepticus, or -Any implanted devices to treat drug-resistant epilepsy
- Changes to medications within 6-8 weeks prior to screening
- Changes to non-pharmacological/behavioral therapies within 6 weeks prior to screening
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
NTX-1511 Clinical Study Site
Chicago, Illinois, 60612
NTX-1511 Clinical Study Site, 978-780-5937, clinicaltrials@newleos.com
About this study
Official title: A Phase II, Randomized, Double-blind, Placebo-controlled, Parallel Group Study to Evaluate the Safety, Efficacy, and Pharmacodynamics of Basmisanil in Participants Aged 2 to 14 Years Old With Dup15q Syndrome
The primary goal of this Phase 2 clinical trial is to determine the effects of a selective negative allosteric modulator (NAM) of GABAA α5 receptor, Basmisanil (NTX-1511), on brain wave (EEG) characteristics in children and adolescents with Dup15q syndrome. The main questions this trial aims to answer are:
- How does NTX-1511 affect brain waves (as measured by EEG) in subjects with Dup15q syndrome?
- Does NTX-1511 impact other developmental features of subjects with Dup15q syndrome?
Read more
Researchers will compare the effects of NTX-1511 with matching placebo (look-alike granules that contain no drug).
Participants will:
- Take NTX-1511 or matching placebo 3 times every day for 12 weeks
- Visit the clinic 7 times over the course of 23 weeks
- Conditions
- Dup15Q Syndrome
- Being tested
- Basmisanil, Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BasmisanilDrug
Three times daily (TID) x 12 weeks
PlaceboDrug
Three times daily (TID) x 12 weeks
| Study group | Role | What they receive |
|---|---|---|
| Experimental: NTX-1511 | Active comparator | Not described Receives: Drug: Basmisanil |
| Placebo Comparator: Placebo | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in quantitative electroencephalogram (qEEG) beta-band power
Measured: Baseline to Week 12
Secondary outcomes (9)
Change in Dup15q Clinical global impression of severity (CGI-s) and change (CGI-C)
The Dup15q Syndrome Clinician Global Impression of Severity (Dup15q CGI-S) is a clinician-rated measure of global severity of illness at a given point in time. Each domain scoreranges from 1-6. Higher scores indicate higher severity of illness. The Dup15q Syndrome Clinician Global Impression of Change (Dup15q CGI-C) is a clinician-rated measure assessing the clinician's impression of change in illness compared with baseline. Each domain score ranges from 1-7. Lower scores indicate improved symptoms, and higher scores indicate worsening symptoms.
Measured: Baseline to Week 12
Change in Vineland Adaptive Behavior Scales -Third Edition (Vineland-3) subdomain Growth Scale Value (GSV) scores
The Vineland Adaptive Behavior Scales -Third Edition (Vineland-3) measures adaptive behavior in 3 domains: Communication (subdomains Expressive, Reception, and Written), Socialization (subdomains Interpersonal, Play \& Leisure, Coping Skills), and Daily Living Skills (Personal, Domestic, Community), and also yields an overall Adaptive Behavior Composite score. The domains and the Composite are reported as a standard score (population mean 100; standard deviation 15; range 20-140). The subdomains are reported as v-scale scores (population mean 10, standard deviation 3; range 1-24). Higher scores indicate higher adaptive behavior abilities
Measured: Baseline to Week 12
Change in Behavior Assessment System for Children - Third Edition (BASC-3) composite and scale scores
The Behavior Assessment System for Children (BASC-3) assesses behavioral and emotional concerns. It has multiple scales: Externalizing Problems (subscales Hyperactivity, Aggression; Conduct Problems); Internalizing Problems (Anxiety, Depression Somatization); additional subscales of Attention Problems, Atypicality, and Withdrawal, and an overall Behavioral Symptoms Index. Each of these scales and subscales is scored as a T-score (population mean of 50, standard deviation of 10; range 20-120). Higher T-scores indicate greater behavioral challenges.
Measured: Baseline to Week 12
Change in Aberrant Behavior Checklist - Second Edition Community Version (ABC-2-C) domain scores
The Aberrant Behavior Checklist (ABC-2-C) domain scores assess challenging behaviors. The domain scores each have different ranges: Irritability from 0-45; Lethargy/Social Withdrawal 0-48; Stereotypy 0-21; Hyperactivity 0-48; Inappropriate Speech 0-12. Higher scores indicate more severe symptoms.
Measured: Baseline to Week 12
Incidence and severity of adverse events (AEs) and severe AEs (SAEs)
Measured: Baseline to Week 12
Incidence of treatment discontinuations due to Adverse Events
Measured: Baseline to Week 12
Incidence of abnormalities in vital signs, electrocardiograms (ECGs) (PR, QRS, and QT intervals, as well as any other dysrhythmias or abnormal wave), laboratory results (chemistry, hematology and urinalysis), and/or physical examination
Measured: Baseline to Week 12
Change from baseline in frequency, duration, and type of any seizures as reported in a seizure diary by caregivers
Measured: Baseline to Week 12
Treatment-emergent abnormal changes in electroencephalograms
For this safety assessment, electroencephalograms (EEGs) will undergo a typical clinical interpretation by a qualified pediatric epileptologist. Any and all treatment-emergent changes will be recorded.
Measured: Baseline to Week 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start1 Dec 2026 (estimated)
- Primary completion1 May 2029 (estimated)
- Study completion1 May 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dup15Q 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Newleos Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846215
- Sponsor's protocol ID
- NTX-1511-201
- Status last verified
- Sep 2026
- First submitted
- 18 Sep 2026
- Last updated
- 29 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase II, Randomized, Double-blind, Placebo-controlled, Parallel Group Study to Evaluate the Safety, Efficacy, and Pharmacodynamics of Basmisanil in Participants Aged 2 to 14 Years Old With Dup15q Syndrome
- ClinicalTrials.gov ID
- NCT07846215
- Acronym / sponsor ID
- NTX-1511-201
- Conditions
- Dup15Q Syndrome
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Newleos Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 1 Dec 2026 (estimated)
- Primary completion
- 1 May 2029 (estimated)
- Study completion
- 1 May 2029 (estimated)
- First posted
- 29 Sep 2026 (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.
The primary goal of this Phase 2 clinical trial is to determine the effects of a selective negative allosteric modulator (NAM) of GABAA α5 receptor, Basmisanil (NTX-1511), on brain wave (EEG) characteristics in children and adolescents with Dup15q syndrome. The main questions this trial aims to answer are:
- How does NTX-1511 affect brain waves (as measured by EEG) in subjects with Dup15q syndrome?
- Does NTX-1511 impact other developmental features of subjects with Dup15q syndrome?
Researchers will compare the effects of NTX-1511 with matching placebo (look-alike granules that contain no drug).
Participants will:
- Take NTX-1511 or matching placebo 3 times every day for 12 weeks
- Visit the clinic 7 times over the course of 23 weeks
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Experimental: NTX-1511 | Active comparator | Drug: Basmisanil |
| Placebo Comparator: Placebo | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 2 to 14 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (4 listed)
- Parent, caregiver, or legally authorized representatives has provided written informed consent for the study and is willing to comply with all requirements of the protocol
- Male or female aged 2 to 14 years inclusive at time of informed consent signature
- Documented duplication (3 copies) or triplication (4 copies) of the chromosome 15q11.2.-q13.1 (BP2-BP3) segment.
- Dup15q syndrome Clinician Global Impression of Severity Scale (Dup15q CGI-S) overall severity score ≥ 3 (at least mildly impaired)
Key exclusion criteria (4 listed)
- Pathogenic or likely pathogenic genomic variant outside of the BP2-BP3 segment. Individuals with an isodicentric 15q chromosome and a history of epilepsy
- Uncontrolled epilepsy (in individuals with interstitial BP2-BP3 duplication or triplication) indicated by: - Use of rescue medication(s) to treat more than one seizure episode or seizure cluster per month, on average in the past 6 months, or -Concomitant chronic use of more than four anti-epileptic medications, or -Status epilepticus within the past 6 months requiring hospitalization for treatment of the status epilepticus, or -Any implanted devices to treat drug-resistant epilepsy
- Changes to medications within 6-8 weeks prior to screening
- Changes to non-pharmacological/behavioral therapies within 6 weeks prior to screening
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 |
|---|---|---|
| BasmisanilThree times daily (TID) x 12 weeks | Drug | Experimental: NTX-1511 |
| PlaceboThree times daily (TID) x 12 weeks | Drug | Placebo Comparator: Placebo |
Primary outcome
Change in quantitative electroencephalogram (qEEG) beta-band power
Time frame: Baseline to Week 12
9 secondary outcomes
Change in Dup15q Clinical global impression of severity (CGI-s) and change (CGI-C)
Time frame: Baseline to Week 12
Change in Vineland Adaptive Behavior Scales -Third Edition (Vineland-3) subdomain Growth Scale Value (GSV) scores
Time frame: Baseline to Week 12
Change in Behavior Assessment System for Children - Third Edition (BASC-3) composite and scale scores
Time frame: Baseline to Week 12
Change in Aberrant Behavior Checklist - Second Edition Community Version (ABC-2-C) domain scores
Time frame: Baseline to Week 12
Incidence and severity of adverse events (AEs) and severe AEs (SAEs)
Time frame: Baseline to Week 12
Incidence of treatment discontinuations due to Adverse Events
Time frame: Baseline to Week 12
Incidence of abnormalities in vital signs, electrocardiograms (ECGs) (PR, QRS, and QT intervals, as well as any other dysrhythmias or abnormal wave), laboratory results (chemistry, hematology and urinalysis), and/or physical examination
Time frame: Baseline to Week 12
Change from baseline in frequency, duration, and type of any seizures as reported in a seizure diary by caregivers
Time frame: Baseline to Week 12
Treatment-emergent abnormal changes in electroencephalograms
Time frame: Baseline to Week 12
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 29 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Dup15Q Syndrome
Enrolling by invitation
Parent and Infant Inter(X)Action Intervention (PIXI)
Fragile X Syndrome, Angelman Syndrome
Not yet recruitingPhase 2
Investigating the Therapeutic Efficacy of All-trans Retinoic Acid in Autism Spectrum Disorder Patients With 15q11-13 Duplication Syndrome
Dup15q Syndrome, Autism Spectrum Disorder
RecruitingObservational study
Structural-functional Connectome in Drug-resistant Epilepsies and Neurodevelopmental Syndromes With Epilepsy
Epilepsy, Angelman 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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Basmisanil in people with Dup15Q Syndrome, run by Newleos Therapeutics, Inc. at 1 site 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 4 inclusion and 4 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: opening soon, as of the sponsor's last update on 29 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 1 site 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. Some participants in this study may receive a placebo. 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?
Contact Newleos Therapeutics Clinical Trial Team (978-780-5937, clinicaltrials@newleos.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in quantitative electroencephalogram (qEEG) beta-band power (time frame: Baseline to Week 12). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 29 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.