Efficacy and Safety Study of STX209 (Arbaclofen) for the Treatment of Social Withdrawal in Children With Fragile X Syndrome (Harbor-C)
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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. |
ClinicalTrials.gov Identifier: NCT01325220 |
Recruitment Status :
Completed
First Posted : March 29, 2011
Last Update Posted : July 31, 2013
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Fragile X Syndrome | Drug: arbaclofen Drug: Placebo | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 172 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Randomized, Double-Blind, Placebo-Controlled, Fixed-Dose Study of the Efficacy, Safety, and Tolerability of STX209 (Arbaclofen) Administered for the Treatment of Social Function in Children With Fragile X Syndrome |
Study Start Date : | June 2011 |
Actual Primary Completion Date : | June 2013 |

Arm | Intervention/treatment |
---|---|
Active Comparator: STX209 5 mg BID |
Drug: arbaclofen
5 mg bid
Other Name: R-baclofen, STX209 |
Active Comparator: STX209 10 mg BID |
Drug: arbaclofen
10 mg bid
Other Name: R-baclofen, STX209 |
Active Comparator: STX209 10 mg TID |
Drug: arbaclofen
10 mg tid
Other Name: R-baclofen, STX209 |
Placebo Comparator: Placebo |
Drug: Placebo
tid |
- Aberrant Behavior Checklist-Lethargy Social Withdrawal subscale [ Time Frame: at 8 weeks of treatment ]This is a single subscale of the aberrant behavior checklist entitiled Lethargy Social Withdrawal

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Ages Eligible for Study: | 5 Years to 11 Years (Child) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Molecular documentation of the full FMR1 mutation
- Current pharmacological treatment regimen has been stable for at least 4 weeks prior to Screening.
- Subjects with a history of seizure disorder must currently be receiving treatment with antiepileptics and must have been seizure free for 6 months, or must be seizure free for 3 years if not currently receiving antiepileptics.
- 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 2 months prior to Screening
Exclusion Criteria:
- 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.
- Subjects who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study.
- Subjects who have taken another investigational drug within the last 30 days.
- Subjects who are not able to take oral medications

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 ClinicalTrials.gov identifier (NCT number): NCT01325220

United States, Arizona | |
Southwest Autism Research & Resource Center | |
Phoenix, Arizona, United States, 85006 | |
United States, California | |
Miller Children's Hospital | |
Long Beach, California, United States, 90806 | |
University of California-Davis, M.I.N.D. Institute | |
Sacramento, California, United States, 95817 | |
Psychiatric Centers at San Diego | |
San Diego, California, United States, 92108 | |
United States, Colorado | |
University of Colorado Denver, Children's Hospital | |
Aurora, Colorado, United States, 80045 | |
United States, Florida | |
University of Miami, Mailman Center for Child Development | |
Miami, Florida, United States, 33136 | |
Lake Mary Pediatrics | |
Orange City, Florida, United States, 32763 | |
United States, Georgia | |
Emory University School of Medicine | |
Decatur, Georgia, United States, 30033 | |
United States, Illinois | |
Rush University Medical Center | |
Chicago, Illinois, United States, 60612 | |
United States, Kansas | |
Kansas University Clinical Research Center | |
Fairway, Kansas, United States, 66205 | |
United States, Maryland | |
Kennedy Krieger Institute | |
Baltimore, Maryland, United States, 21205 | |
United States, Massachusetts | |
University of Massachusetts | |
Worcester, Massachusetts, United States, 01605 | |
United States, Michigan | |
Children's Hospital of Michigan | |
Detriot, Michigan, United States, 48201 | |
United States, Missouri | |
University of Missouri, Thompson Research Center for Autism & Neurodevelopmental Disorders | |
Columbia, Missouri, United States, 65211 | |
United States, New York | |
Seaver Autism Center, Mount Sinai Medical Center | |
New York, New York, United States, 10029 | |
New York State Institute for Basic Research in Developmental Disabilities | |
Staten Island, New York, United States, 10314 | |
United States, North Carolina | |
Duke Clinical Research Unit | |
Durham, North Carolina, United States, 27710 | |
United States, Ohio | |
Akron Children's Hospital | |
Akron, Ohio, United States, 44308 | |
Cincinnati Children's Hospital | |
Cincinnati, Ohio, United States, 45229 | |
United States, Oklahoma | |
University of Oklahoma, Physician's Child Study Center | |
Oklahoma City, Oklahoma, United States, 73117 | |
United States, Pennsylvania | |
Suburban Research Associates/Elwyn Genetics | |
Media, Pennsylvania, United States, 19063 | |
United States, South Carolina | |
Greenwood Genetics Center | |
Greenwood, South Carolina, United States, 29646 | |
United States, Tennessee | |
Vanderbilt Kennedy Center | |
Nashville, Tennessee, United States, 37203 | |
United States, Texas | |
Childrens Medical Center Dallas | |
Dallas, Texas, United States, 75235 | |
Texas Children's Hospital | |
Houston, Texas, United States, 77030 | |
Red Oaks Psychiatry Associates, P.A. | |
Houston, Texas, United States, 77090 | |
Road Runner Research | |
San Antonio, Texas, United States, 78258 | |
United States, Washington | |
Seattle Children's Hospital | |
Seattle, Washington, United States, 98101 |
Study Director: | Paul Wang, M.D. | Seaside Therapeutics, Inc. |
Responsible Party: | Seaside Therapeutics, Inc. |
ClinicalTrials.gov Identifier: | NCT01325220 |
Other Study ID Numbers: |
209FX302 |
First Posted: | March 29, 2011 Key Record Dates |
Last Update Posted: | July 31, 2013 |
Last Verified: | July 2013 |
Fragile X Syndrome Syndrome Disease 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 Baclofen Muscle Relaxants, Central Physiological Effects of Drugs Neuromuscular Agents Peripheral Nervous System Agents GABA-B Receptor Agonists GABA Agonists GABA Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action |