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

NCT05307679 | Terminated Phase 2 Results FDA Drug

• 1 other identifier: BP42992
• Study Type: interventional
• Target: 7
• Locations: 3 countries
• Sites: 5

Brief Summary

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.

Conditions

Dup15q Syndrome

Keywords

dup15q; dup15q syndrome; 15q; duplication 15q; 15q duplication; chromosome 15q duplication; 15q duplication syndrome; duplication 15; triplication 15

Outcome Measures

Primary Outcomes (1)

• Vineland-3 Adaptive Behavior Scales, 3rd Edition Composite Scores

  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 Outcomes (17)

• Vineland-3 Gross and Fine Motor Subdomains Scores

  Baseline, Day 183, Day 365

• Vineland 3 Expressive and Receptive Communication Subdomains

  Baseline, Day 183, Day 365

• Vineland-3 Play and Leisure Time and Interpersonal Relationships Subdomains

  Baseline, Day 153, Day 365

• Mullen Scales of Early Learning (MSEL) Gross and Fine Motor Domains

  Baseline, Day 183, Day 365

• MSEL Visual Reception Domain Scores

  Baseline, Day 183

Study Arms (2)

Basmisanil

EXPERIMENTAL

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

Placebo

PLACEBO COMPARATOR

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

Interventions

Basmisanil DRUG

Participants will receive oral basmisanil at age-appropriate dosages

Basmisanil

Placebo DRUG

Participants will receive oral placebo

Placebo

Eligibility Criteria

• Age: 2 Years - 14 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Hoffmann-La Roche: lead

Study Sites (5)

Children's Hospital Los Angeles

Los Angeles, California, 90010, United States

Location

Rush University Medical Center

Chicago, Illinois, 60612-3244, United States

Location

Hospital Sant Joan De Deu

Esplugues de Llobregas, Barcelona, 08950, Spain

Location

Hospital Universitario La Paz

Madrid, 28046, Spain

Location

Evelina London Children's Hospital

London, SE1 7EH, United Kingdom

Location

Related Links

• https://forpatients.roche.com/

MeSH Terms

Conditions

Polyposis Syndrome, Hereditary Mixed, 1; Chromosome 15q, trisomy

Interventions

basmisanil

Limitations and Caveats

Data beyond certain timepoints (specified per outcome measure in the outcome measures section), or for timepoints for which n ≤ 1, is not reported due to concerns that certain demographic characteristics that may be present in only one treatment arm, or the duration a participant was in the trial, present an unacceptable risk of participant re-identification.

Results Point of Contact

• Title: Medical Communications
• Organization: Hoffmann-La Roche

genentech@druginfo.com

1-800-821-8590

Study Officials

• Clinical Trials

  Hoffmann-La Roche

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

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

Study Record Dates

• First Submitted: March 25, 2022
• First Posted: April 1, 2022
• Study Start: December 16, 2022
• Primary Completion: March 4, 2024
• Study Completion: March 4, 2024
• Last Updated: December 12, 2025
• Results First Posted: December 12, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share

Locations

US (2); ES (2); GB (1)