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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00788073
Recruitment Status : Completed
First Posted : November 10, 2008
Results First Posted : May 6, 2013
Last Update Posted : May 6, 2013
Information provided by (Responsible Party):
Seaside Therapeutics, Inc.

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Fragile X Syndrome Drug: STX209 Drug: Placebo Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 63 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: 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
Study Start Date : November 2008
Actual Primary Completion Date : March 2010
Actual Study Completion Date : May 2010

Resource links provided by the National Library of Medicine

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 Name: 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

Primary Outcome Measures :
  1. Aberrant Behavior Checklist Irritability Subscore [ Time Frame: After 4 weeks of treatment ]
    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).

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   6 Years to 40 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00788073

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United States, Arizona
Southwest Autism Research & Resource Center
Phoenix, Arizona, United States, 85006
United States, California
University of California-Los Angeles Neuropsychiatric Institute
Los Angeles, California, United States, 90024
M.I.N.D. Institute
Sacramento, California, United States, 95817
United States, Illinois
Rush University Medical Center
Chicago, Illinois, United States, 60612
United States, Indiana
Riley Hospital for Children
Indianapolis, Indiana, United States, 46202
United States, Massachusetts
Children's Hospital Boston
Boston, Massachusetts, United States, 02115
United States, New York
NYS Institute for Basic Research in Developmental Disabilities
Staten Island, New York, United States, 10314
United States, North Carolina
University of North Carolina Neurosciences Hospital
Chapel Hill, North Carolina, United States, 27514
United States, Pennsylvania
Suburban Research Associates
Media, Pennsylvania, United States, 19063
United States, Tennessee
Vanderbilt Kennedy Center
Nashville, Tennessee, United States, 37203
United States, Texas
Red Oaks Psychiatry Associates, P.A.
Houston, Texas, United States, 77090
United States, Washington
Seattle Children's Hospital
Seattle, Washington, United States, 98101
Sponsors and Collaborators
Seaside Therapeutics, Inc.
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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: James McCracken, MD University of California, Los Angeles
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: Shivkumar Hatti, MD Suburban Research Associates
Principal Investigator: Raun Melmed, MD Southwest Autism Research & Resource Center
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Responsible Party: Seaside Therapeutics, Inc. Identifier: NCT00788073    
Other Study ID Numbers: 22001
First Posted: November 10, 2008    Key Record Dates
Results First Posted: May 6, 2013
Last Update Posted: May 6, 2013
Last Verified: March 2013
Keywords provided by Seaside Therapeutics, Inc.:
fragile X syndrome
behavior problems
Additional relevant MeSH terms:
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Fragile X Syndrome
Pathologic Processes
Mental Retardation, X-Linked
Intellectual Disability
Neurobehavioral Manifestations
Neurologic Manifestations
Nervous System Diseases
Sex Chromosome Disorders
Chromosome Disorders
Congenital Abnormalities
Genetic Diseases, Inborn
Genetic Diseases, X-Linked
Heredodegenerative Disorders, Nervous System