Safety, Tolerability and Efficacy Study of STX209 in Subjects With Fragile X Syndrome

A Double-Blind, Placebo-Controlled, Crossover, Flexible-Dose Evaluation of the Efficacy, Safety and Tolerability of STX209 in the Treatment of Irritability in Subjects With Fragile X Syndrome

The study objective is to explore the efficacy, safety and tolerability of STX209 for treatment of irritability in subjects with FSX. We hypothesize that STX209 will improve irritability and other typical problem behaviors associated with fragile X syndrome. We also hypothesize that STX209 will be safe and well tolerated.

Study Overview

• Status: Completed
• Conditions: Fragile X Syndrome
• Intervention / Treatment: Drug: STX209; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 63
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85006
      • Southwest Autism Research & Resource Center
  • California
    • Los Angeles, California, United States, 90024
      • University of California-Los Angeles Neuropsychiatric Institute
    • Sacramento, California, United States, 95817
      • M.I.N.D. Institute
  • Illinois
    • Chicago, Illinois, United States, 60612
      • Rush University Medical Center
  • Indiana
    • Indianapolis, Indiana, United States, 46202
      • Riley Hospital for Children
  • Massachusetts
    • Boston, Massachusetts, United States, 02115
      • Children's Hospital Boston
  • New York
    • Staten Island, New York, United States, 10314
      • NYS Institute for Basic Research in Developmental Disabilities
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27514
      • University of North Carolina Neurosciences Hospital
  • Pennsylvania
    • Media, Pennsylvania, United States, 19063
      • Suburban Research Associates
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Vanderbilt Kennedy Center
  • Texas
    • Houston, Texas, United States, 77090
      • Red Oaks Psychiatry Associates, P.A.
  • Washington
    • Seattle, Washington, United States, 98101
      • Seattle Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 years to 40 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male or female subjects 12 to 40 years of age eventually expanding to 6 years of age
• Molecular documentation of the fragile X mutation.
• Clinical Global Impression - Severity (CGI-S) rating for problem behavior of moderate or higher at screening and at Visit 1
• An Aberrant Behavior Checklist (ABC-C) Irritability Subscale score >12 and at least 3 items on the Irritability Subscale rated at least moderate or above.
• Current treatment with no more than three psychoactive medications, including anti-epileptics.
• Current pharmacological treatment regimen has been stable for at least 4 weeks.

Exclusion Criteria:

• Subjects with a history of seizure disorder who are not currently receiving treatment with antiepileptics.
• Subjects with any condition, including alcohol and drug abuse, which might interfere with the conduct of the study, confound interpretation of the study results, or endanger their own well-being. This includes, but is not limited to impairment of renal function, evidence or history of malignancy or any significant hematological, endocrine, cardiovascular, respiratory, hepatic, or gastrointestinal disease.
• Subjects who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study.
• Subjects who are currently receiving treatment with racemic baclofen.
• Subjects currently treated with vigabatrin or tiagabine.
• Subjects taking another investigational drug currently or within the last 30 days.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: STX209; STX209 variable dose from 1mg bid to 10mg tid, capsule, oral, 4 weeks	Drug: STX209; Variable dose from 1 mg bid to 10 mg tid, Capsule, Oral, 4 weeks; Other Names: arbaclofen
Placebo Comparator: Placebo; variable dose (same flexible dose titration protocol), bid to tid, capsule, Oral, 4 weeks	Drug: Placebo; variable dose (same flexible dose titration protocol), bid to tid, capsule, Oral, 4 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Aberrant Behavior Checklist Irritability Subscore	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).	After 4 weeks of treatment

Collaborators and Investigators

• Sponsor: Seaside Therapeutics, Inc.
• Investigators: Principal Investigator: James McCracken, MD, University of California, Los Angeles; Principal Investigator: Elizabeth Berry-Kravis, MD, PhD, Rush University Medical Center; Principal Investigator: Randi Hagerman, MD, M.I.N.D. Institute; Principal Investigator: Craig Erikson, MD, Riley Hospital for Children; Principal Investigator: Bryan King, MD, PhD, Seattle Children's Hospital; Principal Investigator: Jonathan Picker, MBChB, PhD, Boston Children's Hospital; Principal Investigator: Linmarie Sikich, MD, University of North Carolina Neurosciences Hospital; Principal Investigator: Jeremy Veenstra-VanderWeele, MD, Vanderbilt Kennedy Center; Principal Investigator: Ted Brown, MD, PhD, NYS Institute for Basic Research in Developmental Disabilities; Principal Investigator: Lawrence Ginsberg, MD, Red Oaks Psychiatry Associates, PA; Principal Investigator: Raun Melmed, MD, Southwest Autism Research & Resource Center

Study record dates

Study Major Dates

• Study Start: November 1, 2008
• Primary Completion (Actual): March 1, 2010
• Study Completion (Actual): May 1, 2010

Study Registration Dates

• First Submitted: November 7, 2008
• First Submitted That Met QC Criteria: November 7, 2008
• First Posted (Estimate): November 10, 2008

Study Record Updates

• Last Update Posted (Estimate): May 6, 2013
• Last Update Submitted That Met QC Criteria: March 22, 2013
• Last Verified: March 1, 2013

More Information

Terms related to this study

• Keywords: irritability; behavior problems; fragile X syndrome
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Disease; Congenital Abnormalities; Genetic Diseases, Inborn; Genetic Diseases, X-Linked; Mental Retardation, X-Linked; Intellectual Disability; Heredodegenerative Disorders, Nervous System; Chromosome Disorders; Sex Chromosome Disorders; Syndrome; Fragile X Syndrome
• Other Study ID Numbers: 22001