A Study to Evaluate the Safety and Efficacy of Basmisanil Treatment in Children Aged 2-14 Years With Dup15q Syndrome

July 24, 2026 updated by: Hoffmann-La Roche

A Phase II, Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study to Evaluate the Safety, Efficacy, and Pharmacodynamics of 52 Weeks of Treatment With Basmisanil in Participants Aged 2 to 14 Years Old With Dup15q Syndrome Followed by a 2-Year Optional Open-Label Extension

This study consists of two parts. Part 1 will evaluate the safety, efficacy, and pharmacodynamics of 52-weeks of basmisanil treatment in children and adolescents (aged 2-14 years) with Dup15q syndrome. Part 1 will test the hypothesis that negative allosteric modulation of a GABAA receptor subtype can address excessive receptor function and positively impact core neurodevelopmental disease feature in individuals with Dup15q syndrome. Part 2 is an optional 2-year open-label extension to evaluate long-term safety, tolerability, and to provide supportive evidence of benefit of continued treatment with basmisanil in selected efficacy outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Spain
      • Madrid, Spain, 28046
        • Hospital Universitario La Paz
    • Barcelona
      • Esplugues de Llobregas, Barcelona, Spain, 08950
        • Hospital Sant Joan de Déu
  • United Kingdom
      • London, United Kingdom, SE1 7EH
        • Evelina London Children's Hospital
  • United States
    • California
      • Los Angeles, California, United States, 90010
        • Children's Hospital Los Angeles
    • Illinois
      • Chicago, Illinois, United States, 60612-3244
        • Rush University Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

2 years to 11 years (Child)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Documented maternal duplication (3 copies) or triplication (4 copies) of the chromosome 15q11.2-q13.1 region that includes the Prader Willi/Angelman critical region defined as [BP2-BP3] segment
  • Dup15q syndrome Clinician Global Impression of Severity scale (Dup15q CGI-S) overall severity score ≥ 4 (at least moderately ill)
  • Body weight equal to or above the third percentile for age
  • Participant has a parent, caregiver, or legally authorized representative (hereinafter "caregiver") of at least 18 years of age, who is fluent in the local language at the site, and capable and willing to provide written informed consent for the participant, according to International Council for Harmonisation and local regulations
  • Participant's caregiver must be living with the participant and, in the opinion of the Investigator, able and willing to reliably assess the participant's ongoing condition, to accompany the participant to all clinic visits, and ensure compliance to study treatment throughout the study. The same caregiver is able and willing to complete the caregiver assessments and is available to the Investigational Site by telephone or email if needed
  • Participant's caregiver is able and willing to use electronic devices to record information on the participant's condition and to complete assessments at home and agrees to home nursing visits, if local regulations allow for it and if home nursing service is available in the country/region

Exclusion Criteria:

  • Uncontrolled epilepsy at screening (as defined by the protocol)
  • Lymphoma, leukemia, or any malignancy within the past 5 years, except for basal cell or squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years
  • Clinically significant ECG abnormalities at Screening
  • Clinically significant abnormalities in laboratory test results at screening (including positive results for HIV, hepatitis B and/or hepatitis C)
  • Allowed prior existing medication should be on a stable regimen (or frequency of intervention) for at least 6 weeks, and at least 8 weeks for anti-epileptic treatment, prior to Screening
  • Non-pharmacological / behavioral therapies should not be stopped or newly started at least 6 weeks prior to Screening and are expected to remain stable for the entire study duration (excluding changes related to standard age and educational interventional programs and minor interruptions such as illness or vacation
  • Concomitant use of prohibited medications
  • Participation in an investigational drug study within one month or within 6 × the elimination half-life, whichever is longer, prior to dosing in the study
  • Significant risk for suicidal behavior, as assessed through the suicidal behavior question adapted from the Columbia Classification Algorithm for Suicide Assessment (C-CASA) (participants ≥ 6 years of age only)
  • Known sensitivity to any of the study treatments or components thereof or drug or other allergy that, in the opinion of the Investigator, contraindicates the participation in the study, including severe lactose intolerance (e.g., unable to tolerate 250 mL [8 oz. or 1 cup] of milk, ice cream, or yogurt)
  • Concomitant clinically relevant disease or condition or any clinically significant finding at screening that could interfere with, or for which, the treatment might interfere with, the conduct of the study or that would pose an unacceptable risk to the participants in this study
  • Known active or uncontrolled bacterial, viral, or other infection (excluding fungal infections of nail beds) or any major clinically significant episode of infection or hospitalization (relating to the completion of the course of antibiotics) within 6 weeks prior to the start of drug administration

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Basmisanil
Participants will receive oral basmisanil twice daily (BID) on the first day of treatment, then three times per day (TID) until the end of Part 1 of the trial (Day 365) or the end of Part 2 (Day 1095)
Drug: Basmisanil
Participants will receive oral basmisanil at age-appropriate dosages
Placebo Comparator: Placebo
Participants will receive oral placebo BID on the first day of treatment, then TID until the end of Part 1 of the trial (Day 365).
Drug: Placebo
Participants will receive oral placebo

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Vineland-3 Adaptive Behavior Scales, 3rd Edition Composite Scores
Time Frame: Baseline, Day 183, Day 365
The Vineland-3 is an instrument that measures communication, daily living skills, socialization, and motor skills for those with intellectual and developmental disabilities. Items consist of open-ended questions related to activities and behavior and are scored as 2 = Usually, 1 = Sometimes, and 0 = Never. Items requiring a binary response are scored as 2 = Yes, 0. Standard scores for the adaptive behavior composite range from 20-160; lower scores indicate lower adaptive functioning.
Baseline, Day 183, Day 365

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Vineland-3 Gross and Fine Motor Subdomains Scores
Time Frame: Baseline, Day 183, Day 365
The Vineland-3 is an instrument that measures communication, daily living skills, socialization, and motor skills for those with intellectual and developmental disabilities. Items consist of open-ended questions related to activities and behavior and are scored as 2 = Usually, 1 = Sometimes, and 0 = Never. Items requiring a binary response are scored as 2 = Yes, 0. V-scale scores for the gross and fine motor domains range from 1-24; lower scores indicate lower adaptive functioning.
Baseline, Day 183, Day 365
Vineland 3 Expressive and Receptive Communication Subdomains
Time Frame: Baseline, Day 183, Day 365
The Vineland-3 is an instrument that measures communication, daily living skills, socialization, and motor skills for those with intellectual and developmental disabilities. Items consist of open-ended questions related to activities and behavior and are scored as 2 = Usually, 1 = Sometimes, and 0 = Never. Items requiring a binary response are scored as 2 = Yes, 0. V-scale scores for the expressive and receptive communication subdomains range from 1-24; lower scores indicate lower adaptive functioning.
Baseline, Day 183, Day 365
Vineland-3 Play and Leisure Time and Interpersonal Relationships Subdomains
Time Frame: Baseline, Day 153, Day 365
The Vineland-3 is an instrument that measures communication, daily living skills, socialization, and motor skills for those with intellectual and developmental disabilities. Items consist of open-ended questions related to activities and behavior and are scored as 2 = Usually, 1 = Sometimes, and 0 = Never. Items requiring a binary response are scored as 2 = Yes, 0. V-scale scores for the play and leisure time, and interpersonal relationships subdomains range from 1-24; lower scores indicate lower adaptive functioning.
Baseline, Day 153, Day 365
Mullen Scales of Early Learning (MSEL) Gross and Fine Motor Domains
Time Frame: Baseline, Day 183, Day 365
The MSEL are designed for a certified rater to provide an assessment of cognitive ability and motor development of typically developing children from birth through age 68 months. It was administered to all participants in this study irrespective of their chronological age. The instrument consists of 124 items across five scales measuring Gross Motor, Visual Reception, Fine Motor, Expressive Language, and Receptive Language. Each item is scored from 0-5 points with total raw score ranges of 0-100 (gross motor) and 0-78 (fine motor). Lower score indicate lower developmental abilities; higher scores indicate greater developmental abilities.
Baseline, Day 183, Day 365
MSEL Visual Reception Domain Scores
Time Frame: Baseline, Day 183
The MSEL are designed for a certified rater to provide an assessment of cognitive ability and motor development of typically developing children from birth through age 68 months. It was administered to all participants in this study irrespective of their chronological age. The instrument consists of 124 items across five scales measuring Gross Motor, Visual Reception, Fine Motor, Expressive Language, and Receptive Language. Each item is scored from 0-5 points with a total raw score range of 0-50. Lower score indicate lower developmental abilities; higher scores indicate greater developmental abilities.
Baseline, Day 183
MSEL Expressive and Receptive Language Subdomains
Time Frame: Baseline, Day 183
The MSEL are designed for a certified rater to provide an assessment of cognitive ability and motor development of typically developing children from birth through age 68 months. It was administered to all participants in this study irrespective of their chronological age. The instrument consists of 124 items across five scales measuring Gross Motor, Visual Reception, Fine Motor, Expressive Language, and Receptive Language. Each item is scored from 0-5 points with a total raw score range of 0-50 (expressive language) or 0-48 (receptive language). Lower score indicate lower developmental abilities; higher scores indicate greater developmental abilities.
Baseline, Day 183
Dup15q Syndrome Clinician Global Impression of Severity (CGI-S) Scale Scores
Time Frame: Baseline until Day 395, or early termination (prior to Day 395)
The Dup15q CGI-S is a 10-domain clinician-rated measure on a 6-point scale that measures global severity of illness at a given point in time. The ten domains are seizures, expressive communication difficulties, fine motor skills difficulties, gross motor skills difficulties, cognitive/intellectual impairment, impairment in activities of daily living/self-care, socialization, maladaptive behavior, sleep difficulties, and overall severity. Response options are 1-none, 2-very mild, 3-mild, 4-moderate, 5-severe, and 6-very severe.
Baseline until Day 395, or early termination (prior to Day 395)
Dup15q Syndrome Clinician Global Impression of Change Scale (CGI-C) Scores
Time Frame: Day 28 - Day 395 or early termination (prior to Day 395)
The Dup15q CGI-C is a 10-domain clinician-rated measure on a 7-point scale that assesses the clinician's impression of change in illness compared with baseline. The ten domains are seizures, expressive communication difficulties, fine motor skills difficulties, gross motor skills difficulties, cognitive/intellectual impairment, impairment in activities of daily living/self-care, socialization, maladaptive behavior, sleep difficulties, and overall severity. Response options are 1-very much improved, 2-much improved, 3-minimally improved, 4-no change, 5-minimally worse, 6-much worse, and 7-very much worse. The CGI does not yield a global score.
Day 28 - Day 395 or early termination (prior to Day 395)
Aberrant Behavior Checklist - Second Edition - Community Version (ABC-2-C) Domain Scores - Irritability
Time Frame: Baseline - Day 365, or early termination (prior to Day 365)
The ABC-2 is an updated, empirically derived, validated 58-item caregiver-completed rating scale that measures the severity of a range of maladaptive behaviors commonly observed in children, adolescents, and adults with intellectual and developmental disabilities. The Community version of the scale (ABC-2-C) will be used. It is designed for use in individuals who are not residing in institutional settings. The checklist assesses symptoms across five domains: irritability, social withdrawal, stereotypic behavior, hyperactive/noncompliance, and inappropriate speech. Items are scored on a 4-point scale from 0 (never) to 3 (severe problem). The irritability domain score range is 0-45, with higher score indicating greater severity.
Baseline - Day 365, or early termination (prior to Day 365)
ABC-2-C Domain Scores - Social Withdrawal
Time Frame: Baseline - Day 365, or early termination (prior to Day 365)
The ABC-2 is an updated, empirically derived, validated 58-item caregiver-completed rating scale that measures the severity of a range of maladaptive behaviors commonly observed in children, adolescents, and adults with intellectual and developmental disabilities. The Community version of the scale (ABC-2-C) will be used. It is designed for use in individuals who are not residing in institutional settings. The checklist assesses symptoms across five domains: irritability, social withdrawal, stereotypic behavior, hyperactive/noncompliance, and inappropriate speech. Items are scored on a 4-point scale from 0 (never) to 3 (severe problem). The social withdrawal domain score range is 0-48, with higher scores indicating greater severity.
Baseline - Day 365, or early termination (prior to Day 365)
ABC-2-C Domain Scores - Stereotypic Behavior
Time Frame: Baseline - Day 365, or early termination (prior to Day 365)
The ABC-2 is an updated, empirically derived, validated 58-item caregiver-completed rating scale that measures the severity of a range of maladaptive behaviors commonly observed in children, adolescents, and adults with intellectual and developmental disabilities. The Community version of the scale (ABC-2-C) will be used. It is designed for use in individuals who are not residing in institutional settings. The checklist assesses symptoms across five domains: irritability, social withdrawal, stereotypic behavior, hyperactive/noncompliance, and inappropriate speech. Items are scored on a 4-point scale from 0 (never) to 3 (severe problem). The stereotypic behavior subdomain score range is 0-21, with higher scores indicating greater severity.
Baseline - Day 365, or early termination (prior to Day 365)
ABC-2-C Domain Scores - Hyperactivity/Non-Compliance
Time Frame: Baseline until Day 365, or early termination (prior to Day 365)
The ABC-2 is an updated, empirically derived, validated 58-item caregiver-completed rating scale that measures the severity of a range of maladaptive behaviors commonly observed in children, adolescents, and adults with intellectual and developmental disabilities. The Community version of the scale (ABC-2-C) will be used. It is designed for use in individuals who are not residing in institutional settings. The checklist assesses symptoms across five domains: irritability, social withdrawal, stereotypic behavior, hyperactive/noncompliance, and inappropriate speech. Items are scored on a 4-point scale from 0 (never) to 3 (severe problem). The hyperactivity/non-compliance subdomain score range is 0-45, with higher scores indicating greater severity.
Baseline until Day 365, or early termination (prior to Day 365)
ABC-2-C Domain Scores - Inappropriate Speech
Time Frame: Baseline until Day 365, or early termination (prior to Day 365)
The ABC-2 is an updated, empirically derived, validated 58-item caregiver-completed rating scale that measures the severity of a range of maladaptive behaviors commonly observed in children, adolescents, and adults with intellectual and developmental disabilities. The Community version of the scale (ABC-2-C) will be used. It is designed for use in individuals who are not residing in institutional settings. The checklist assesses symptoms across five domains: irritability, social withdrawal, stereotypic behavior, hyperactive/noncompliance, and inappropriate speech. Items are scored on a 4-point scale from 0 (never) to 3 (severe problem). The inappropriate speech subdomain score range is 0-12, with higher scores indicating greater severity.
Baseline until Day 365, or early termination (prior to Day 365)
Incidence of Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: Up to 52 weeks
An adverse event is any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An adverse event can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events.
Up to 52 weeks
Plasma Concentration of Basmisanil
Time Frame: Day 1 - Day 183
Day 1 - Day 183
Plasma Concentration of the Basmisanil Metabolite M1
Time Frame: Day 1 - Day 183
Day 1 - Day 183
Quantitative EEG (qEEG) Beta-band Power
Time Frame: Baseline, Day 14
This is the average of the EEG parameter 10 x Log_10 of the total beta power between 16 and 32 Hz in microVolt^2.
Baseline, Day 14

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hoffmann-La Roche

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Clinical Trials, Hoffmann-La Roche

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 16, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 4, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 4, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 25, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 1, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • BP42992

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Qualified researchers may request access to individual patient level data through the clinical study data request platform (www.vivli.org). Further details on Roche's criteria for eligible studies are available here (https://vivli.org/ourmember/roche/). For further details on Roche's Global Policy on the Sharing of Clinical Information and how to request access to related clinical study documents, see here (https://www.roche.com/research_and_development/who_we_are_how_we_work/clinical_trials/our_commitment_to_data_sharing.htm).

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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