Placebo-Controlled, Single-Dose Challenge Study of Gaboxadol in Adult Males With Fragile X Syndrome (FXS)

Phase

Condition

Fragile X Syndrome

Treatment

Gaboxadol

Placebo

Clinical Study ID

NCT06334419

2023-0795

Ages 18-40
Male

Study Summary

This is a single dose, placebo-controlled study. Male subjects aged 18 to 40 years (inclusive) with a diagnosis of FXS. Eligible subjects may enroll in this study comprised of two in home and two in clinic visits each 14 days apart, for a total of four visits. Subjects will be given single dose gaboxadol (10 mg) or matched placebo at each of these visits to take orally. Thus, all enrolled subjects will receive placebo at home and in clinic and receive gaboxadol at home and in clinic in a blinded fashion.

Eligibility Criteria

Inclusion

Inclusion Criteria:

Subject consents to participate, or if they are not their own legal guardian, offersassent supported by legally authorized representative consent
Subject is willing and able to comply with the study procedures as specified in theprotocol and to comply with the study drug administration. Caregiver also commits tothe study requirements prior to any study-related procedures
Subject and caregiver are both able to understand the spoken national languageclearly and caregiver can read and write to complete study assessments
Males age 18 to 40 years (inclusive)
Has FXS with molecular genetic confirmation of the full FMR1 mutation (>200cysteine-guanine-guanine [CGG] repeats). May have been confirmed historically or atScreening
Is in general good health as deemed by the Investigator, determined by physicalexamination, medical history, and laboratory tests
If receiving serotonin-selective reuptake inhibitor (SSRI), serotonin-norepinephrinereuptake inhibitor (SNRI), or serotonin antagonist and reuptake inhibitor (SARI), ison a stable, well-tolerated dose for the previous 3 months with no further changesanticipated
Is not sexually active or can confirm at least one form of contraceptive

Exclusion

Exclusion Criteria:

Any chronic major medical comorbid condition deemed by the Investigator aspresenting added risk to the subject, including but not limited to, refractoryhypertension, kidney disease, or liver disease
Diagnosed with diabetes (Type 1 or II) or receiving any anti-diabetic medication
Unstable seizure disorder, defined by any seizure within 6 months prior to baselinevisit and/or a change in any anti-convulsant drug dosing in the 60 days prior tostudy consent
Changes in psychotropic or anti-convulsant (where taken for reasons other thanseizure control) drug treatment within 30 days prior to Screening
Significant changes in any educational, behavioral, and/or dietary interventions themonth prior to Screening
Planned initiation of new, or modification of ongoing, interventions during thestudy
Unable or unwilling to take oral medication (whole capsule, despite assistance witha spoonful of applesauce, yoghurt, or equivalent liquid food)
Consumption of liver enzyme inducers or inhibitors including and not limited tofoods, medicines, herbal remedies and supplements three days prior to any Visit.Foods or beverages containing CYP3A4/5 inhibitors (e.g., grapefruit, pomegranate,pomelo, and star fruit) should be avoided before taking study medication and for upto 1 hour post dose throughout the study
Has abnormal baseline laboratory assessments including, but not limited to, alanineaminotransferase (ALT) or aspartate aminotransferase (AST) or total bilirubin >1.5 ×the upper limit of normal (ULN), serum creatinine >1.5 x ULN or other clinicallyrelevant laboratory abnormality
Has a clinically significant heart rate or blood pressure (BP) at Screening asjudged by the Investigator
Has received an investigational drug in any prior clinical study within 30 days or 5half-lives (whichever is longer) prior to Screening

Study Design