Dear Fragile X family member,

Seaside Therapeutics is studying the science of the brain and working to deliver treatments that improve the underlying causes of developmental disorders like Fragile X syndrome. Right now, Seaside is testing an investigational medicine called STX209 (arbaclofen) for individuals with Fragile X syndrome with social impairment. Thanks to the dedication and efforts of families, one of the clinical trials is almost complete.

We are reaching out to you because you may be a caregiver to a person with Fragile X syndrome and your family member may be eligible for the next study, the Harbor-C trial.

This trial is 70% completed and your family’s participation in this clinical trial can help drive this study to completion, furthering the advancement of new potential treatments for Fragile X syndrome.

  • HARBOR-C is seeking children with Fragile X syndrome (ages 5 to 11)

Please go to to learn more about this clinical study and consider contacting the most convenient clinical study site to your home to inquire further. For your convenience, we have included the list of clinical study sites on the below.

Social impairment seen in people with Fragile X syndrome can appear in many different ways. If your family member shows any of the following behaviors, or any others that limit their ability to form social connections (compared to typically developing children or adults), he or she may be eligible to participate in the Harbor Trials:

  • Is not able to read social cues
  • Has difficulty with social behavior
  • Is unable to understand social nuances
  • Is difficult to reach or contact
  • Has a negative response to affection
  • Is socially awkward

The Harbor Trials are designed to test the safety and effectiveness of the investigational drug STX209 (arbaclofen) versus placebo (inactive pills) in improving social function in people with Fragile X syndrome. Eligible participants will receive up to 2 months of treatment with the study drug (STX209 or placebo) and can continue on STX209 in a long-term follow up study. Travel cost reimbursement is available.
This study is sponsored by Seaside Therapeutics. 27 sites in the U.S. are currently enrolling. Additional information may be found on or (references # NCT01282268 and NCT01325220).

To learn more about participating in the Harbor-C trial, please contact a clinical study coordinator at the clinical site nearest you.

Clinic Study Sites and Contact Info

Southwest Autism Research and Resource Center
Phoenix, AZ
Study Coordinator: Sajitha Puthalath
(602) 218-8195

Miller Children’s Hospital
Long Beach, CA
Study Coordinator: Nan O’Donnell
(562) 933-5607

Psychiatric Associates of San Diego
San Diego, CA
Study Coordinator: Christine Moloney
(619) 692-1003

University of California-Davis, M.I.N.D. Institute
Sacramento, CA
Study Coordinator: Lindsey Partington
(916) 703-0471

University of Colorado Denver, Children’s Hospital
Aurora, CO
Study Coordinator: Susan Howell
(720) 777-8361

University of Miami, Miller School of Medicine, Mailman Center for Child Development
Miami, FL
Study Coordinator: Elsa Salazar
(305) 243-6562

Lake Mary Pediatrics
Orange City, FL
Study Coordinator: Heidi Andersen
(386) 960-8282

Emory University School of Medicine, Division of Medical Genetics
Decatur, GA
Study Coordinator: Heather Clark
(404) 778-8484

Rush University Medical Center
Chicago, IL
Study Coordinator: Shaguna Mathur
(312) 563-9533

University of Kansas Medical Center
Kansas City, KS
Study Coordinator: Phyllis Young
(913) 588-5741

Kennedy Krieger Institute
Baltimore, MD
Study Coordinator: Kennedy Krieger, Victor Talisa
(443) 923-7721

University of Massachusetts
Worcester, MA
Study Coordinator: Kara Manchester
(508) 856-2041

Children’s Hospital of Michigan (Coming Soon)
Detroit, MI

University of Missouri, Thompson Research Center for Autism & Neurodevelopmental Disorders
Columbia, MO
Study Coordinator: Patsy Weis
(573) 882-5595

New York
Mount Sinai School of Medicine
New York, NY
Study Coordinator: Lauren Bush
(212) 241-3692

NYS Institute of Basic Research in Developmental Disabilities
Staten Island, NY
Study Coordinator: Angelo Porto
(718) 494-8028

North Carolina
Duke University Medical Center
Durham, OH
Study Coordinator: Wan Lan Liang
(919) 6680972

Cincinnati Children’s Hospital (Coming Soon)
Cincinnati, OH

University of Oklahoma, Physician’s Child Study Center
Oklahoma City, OK
Study Coordinator: Lora Tusing
(405) 271-4401

Suburban Research Associates /Associates / Elwyn Genetics
Media, PA
Study Coordinator: Maureen O’Donnell
(610) 891-9024 ext. 103

South Carolina
Greenwood Genetics Center (Coming Soon)
Greenwood, SC

Vanderbilt University
Nashville, TN
Study Coordinator: Jessica Smith
(615) 936-3288

Children’s Medical Center (Coming Soon)
Dallas, TX

Red Oaks Psychiatry Associates, P.A.
Houston, TX
Study Coordinator: Elissa Molloy
(832) 824-4275

Texas Children’s Hospital
Houston, TX
Study Coordinator: Brenda Noggy
(832) 824-4275

Road Runner Research
San Antonio, TX
Study Coordinator: Katie Johanningmeier
(210) 949-0505

Seattle Children’s Hospital
Seattle, WA
Study Coordinator: Denise Ward
(206) 884-1168