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Open-Label Study of the Safety and Tolerability of STX209 in Subjects With Autism Spectrum Disorders

An Open-Label, Flexible-Dose Evaluation of the Safety and Tolerability of STX209 for Treatment of Irritability in Subjects With Autism Spectrum Disorders

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00846547
Enrollment
32
Registered
2009-02-18
Start date
2009-02-28
Completion date
2010-09-30
Last updated
2013-06-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Autism Spectrum Disorders

Keywords

Autism, Autism Spectrum Disorders, irritability, aberrant behavior

Brief summary

The study objective is to explore the safety and tolerability of STX209 in subjects with Autism Spectrum Disorders and to obtain preliminary data on several measures of efficacy in treating irritability. We hypothesize that STX209 will be safe and well-tolerated.

Interventions

variable dose from 1mg bid to 10 mg tid, oral capsule, 8 week treatment period

Sponsors

Seaside Therapeutics, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
6 Years to 17 Years
Healthy volunteers
No

Inclusion criteria

* Male or female subjects 6 to 17 years of age, inclusive. * Diagnosis of Autistic spectrum disorders * Clinical Global Impression - Severity (CGI-S) rating for aberrant behavior of moderate or higher at screening and at Visit 1 (Day 1). * An Aberrant Behavior Checklist (ABC-C) Irritability Subscale score ≥16 at screening and at Visit 1 (Day 1). * If the subject is already receiving stable non-pharmacologic educational, behavioral, and/or dietary interventions, participation in these programs must have been continuous during the 3 months prior to Screening (Visit 1) and subjects and their parent/caregiver/legally authorized representative (LAR) will not electively initiate new or modify ongoing interventions for the duration of the study. *

Exclusion criteria

* Subjects with known genetic disorders associated with PDD such as fragile X syndrome. * Subjects with a history of a seizure disorder who are not currently receiving treatment with antiepileptic medication. * Subjects with any medical condition, including alcohol and drug abuse that might interfere with the conduct of the study, confound interpretation of the study results, or endanger their own well-being. * Subjects who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study. * Subjects currently treated or have been treated in the last 2 weeks with any psychotropic medication except anti-epileptics or who have been treated with fluoxetine in the last 4 weeks. * Subjects currently treated with vigabatrin or tiagabine. * Subjects taking another investigational drug currently or within the last 30 days. * Subjects who have a history of hypersensitivity to racemic baclofen.

Design outcomes

Primary

MeasureTime frameDescription
Irritability Subscale of the Aberrant Behavior Checklist, Community VersionAt 8 weeks during the treatment periodThe Aberrant Behavior Checklist-Community Edition (ABC-C) is a 58-item questionnaire composed of five different independent subscales. The questionnaire is completed by the parent/caregiver and lists aberrant behaviors and asks about the severity of the problem. ABC-Irritability is one of the subscales and comprises of 15 items. Minimum score is 0, maximum is 45. A decreased score indicates few aberrant behaviors and clinical improvement. The entire ABC-C assessment is administered at baseline and then at the end of each Intervention Period (4 weeks after Baseline).

Countries

United States

Participant flow

Participants by arm

ArmCount
Arbaclofen
Arbaclofen (STX209) : variable dose from 1mg bid to 10 mg tid, oral capsule, 8 week treatment period
32
Total32

Baseline characteristics

CharacteristicArbaclofen
Age, Categorical
<=18 years
32 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
0 Participants
Age Continuous11.8 years
STANDARD_DEVIATION 3.13
Region of Enrollment
United States
32 participants
Sex: Female, Male
Female
3 Participants
Sex: Female, Male
Male
29 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
28 / 32
serious
Total, serious adverse events
1 / 32

Outcome results

Primary

Irritability Subscale of the Aberrant Behavior Checklist, Community Version

The Aberrant Behavior Checklist-Community Edition (ABC-C) is a 58-item questionnaire composed of five different independent subscales. The questionnaire is completed by the parent/caregiver and lists aberrant behaviors and asks about the severity of the problem. ABC-Irritability is one of the subscales and comprises of 15 items. Minimum score is 0, maximum is 45. A decreased score indicates few aberrant behaviors and clinical improvement. The entire ABC-C assessment is administered at baseline and then at the end of each Intervention Period (4 weeks after Baseline).

Time frame: At 8 weeks during the treatment period

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
ArbaclofenIrritability Subscale of the Aberrant Behavior Checklist, Community Version-8.9 Points on a scaleStandard Error 1.73

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026