NCT07846215

Brief 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. 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

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at P25-P50 for phase_2

Timeline
29mo left

Started Dec 2026

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

September 18, 2026

Completed
11 days until next milestone

First Posted

Study publicly available on registry

September 29, 2026

Completed
2 months until next milestone

Study Start

First participant enrolled

December 1, 2026

Expected
2.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2029

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 1, 2029

Last Updated

September 29, 2026

Status Verified

September 1, 2026

Enrollment Period

2.4 years

First QC Date

September 18, 2026

Last Update Submit

September 25, 2026

Conditions

Dup15Q Syndrome

Outcome Measures

Primary Outcomes (1)

  • Change in quantitative electroencephalogram (qEEG) beta-band power

    Baseline to Week 12

Secondary Outcomes (9)

  • Change in Dup15q Clinical global impression of severity (CGI-s) and change (CGI-C)

    Baseline to Week 12

  • Change in Vineland Adaptive Behavior Scales -Third Edition (Vineland-3) subdomain Growth Scale Value (GSV) scores

    Baseline to Week 12

  • Change in Behavior Assessment System for Children - Third Edition (BASC-3) composite and scale scores

    Baseline to Week 12

  • Change in Aberrant Behavior Checklist - Second Edition Community Version (ABC-2-C) domain scores

    Baseline to Week 12

  • Incidence and severity of adverse events (AEs) and severe AEs (SAEs)

    Baseline to Week 12

  • +4 more secondary outcomes

Study Arms (2)

Experimental: NTX-1511

ACTIVE COMPARATOR
Drug: Basmisanil

Placebo Comparator: Placebo

PLACEBO COMPARATOR
Drug: Placebo

Interventions

BasmisanilDRUG

Three times daily (TID) x 12 weeks

Experimental: NTX-1511
PlaceboDRUG

Three times daily (TID) x 12 weeks

Placebo Comparator: Placebo

Eligibility Criteria

Age2 Years - 14 Years
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17)

You may qualify if:

  • 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)

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

NTX-1511 Clinical Study Site

Chicago, Illinois, 60612, United States

Location

MeSH Terms

Interventions

basmisanil

Central Study Contacts

Newleos Therapeutics Clinical Trial Team

CONTACT

978-780-5937clinicaltrials@newleos.com

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 18, 2026

First Posted

September 29, 2026

Study Start (Estimated)

December 1, 2026

Primary Completion (Estimated)

May 1, 2029

Study Completion (Estimated)

May 1, 2029

Last Updated

September 29, 2026

Record last verified: 2026-09

Data Sharing

IPD Sharing
Will not share

Locations

US(1)