An Open Label Extension Study of STX209 in Subjects With Fragile X Syndrome

An Open Label Extension Study to Evaluate the Safety, Tolerability and Pharmacokinetics of STX209 in Subjects With Fragile X Syndrome

Status

Terminated

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01013480

Enrollment

Registered

2009-11-13

Start date

2009-11-30

Completion date

2012-12-31

Last updated

2012-12-20

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

Conditions

Fragile X Syndrome

Keywords

Fragile X Syndrome

Brief summary

Study 22001, A Double-Blind, Placebo-Controlled, Flexible-Dose Evaluation of the Efficacy, Safety, and Tolerability of STX209 in the Treatment of Irritability in Subjects with Fragile X Syndrome currently is evaluating the efficacy of STX209 (R-baclofen) for management of typical problem behaviors, such as irritability and aggression, in subjects with FXS. This study (22002) will enter subjects who complete Study 22001 into a long-term, open-label study.The open-label extension protocol will provide necessary data on the long-term safety and tolerability of STX209 among subjects with FXS who receive treatment under conditions more closely reflective of their general medical care.

Interventions

DRUGArbaclofen

A flexible dose titration will be utilized during the first four weeks to define the optimal titrated dose (OTD) for each subject. Investigators will use clinical judgment to adjust doses to the OTD. The starting dose will be 1 mg BID. The dose may be increased every four to five days to 2 mg BID, 3 mg BID, 5 mg BID and then 10 mg BID

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

6 Years to 40 Years

Healthy volunteers

Inclusion criteria

* Have completed all scheduled visits in protocol 22001 and have shown they can adequately follow the protocol, with sufficient medical justification to continue on open-label treatment with STX209, as assessed by the principal investigator

Exclusion criteria

* Subjects with a medical condition that might interfere with the conduct of the study, confound interpretation of the study results, or endanger their own well-being. * The occurrence or continuation of any adverse event or condition during study 22001 that, in the opinion of the Investigator, should exclude the subject from participating in this open-label extension.

Design outcomes

Primary

Measure	Time frame
Irritability subscale of the Aberrant Behavior Checklist	1 year

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 19, 2026