To those of you who have family members with Fragile X, thank you for being interested in clinical trials! This is a challenging phase for all of us, and as exciting as it is, we know many of you have questions about what it means to be in a clinical trial.

Each study is supervised by a doctor that specializes in Fragile X. These trials are free, you do not have to tell your insurance company, and you can leave any time you want. Travel costs are usually covered.

The FDA requires two successful large-scale clinical trials before it will consider approving a new treatment. If studies are successful and the FDA approves new drugs, others with Fragile X can also have access to these medicines.

Clinical Trials and Studies recruiting patients


  • More about this trial

    The purpose of this study is to assess the safety and efficacy of two dose levels of NNZ-2566 when compared to placebo in adolescent and adult males (ages 14-40) who have been diagnosed with FXS.

    Neuren Brochure on Fragile X Syndrome

    Brochure to download and print

    NNZ-2566 has a novel mechanism of action compared with other drugs that have been tested for Fragile X syndrome. It is a modified version of a biologically active part of Insulin-like Growth Factor (IGF-1). IGF-1 is a protein that helps cells grow and respond to stress or damage. In the brain, IGF-1 contributes to the growth of brain cells and the connections between them (synapses).

    The biologically active part of IGF-1 is called glypromate or GPE and supports the function of brain cells in a different way than IGF-1.  GPE occurs naturally in the brain. NNZ-2566 is a version of GPE modified to make it available to take as an oral medication. NNZ-2566 may help improve brain function by enhancing functions normally performed by GPE and by increasing IGF-1 levels in the brain. NNZ-2566 has been shown in animal models of Fragile X to improve performance in tests of behavior and cognition.

    FDA has granted two special designations for Neuren’s development of NNZ-2566 in Fragile X: Fast Track Designation and Orphan Drug Designation.

    This trial will include 60 participants between the ages of 14-40. Taking part in this study involves 8 visits to the doctor’s office over 10 weeks. The study medication and all study-related evaluations will be provided at no cost. Some support for travel is available. 

  • Trial Sites


    Children’s National Hospital – Not yet recruiting
    Washington, District of Columbia, United States, 20010
    Contact: Lyndsey Keyte 202-476-2813
    Principal Investigator: Adelaide Robb, MD
    Kennedy Krieger Institute – Not yet recruiting
    Baltimore, Maryland, United States, 21205
    Contact: Rebecca Hinton 443-923-9326
    Principal Investigator: Robert Findling, MD
    University of Michigan – Not yet recruiting
    Ann Arbor, Michigan, United States, 48109
    Contact: Kailey Owens
    Principal Investigator: Jeffrey Innis, MD
    University of Nebraska – Not yet recruiting
    Omaha, Nebraska, United States, 68588
    Contact: Jackie Hankins
    Principal Investigator: Howard Needelman, MD
    Greenwood Genetic Center Not yet recruiting
    Greenwood, South Carolina, United States, 29646
    Contact: Fran Annese
    Principal Investigator: Steve Skinner, MD
    Vanderbilt University Medical Center
    Nashville, Tennessee, United States, 37235
    Contact: Sarah Marler 615-936-3288
    Principal Investigator: Kevin Sanders, MD
    Texas Children’s Hospital
    Houston, Texas, United States, 77030 – Not yet recruiting
    Contact: Chiemenam Amaechi
    Principal Investigator: Diane Treadwell-Deering, MD
    Seattle Children’s Hospital, Seattle, Washington, United States, 98105 – Not yet recruiting
    Contact: Denise Ward
    Principal Investigator: Bryan King, MD
    Davis, California
    UC Davis MIND Institute
    Principal Investigator: Randi Hagerman, MD
    Contact: Lindsey Partington 916-703-0427
    Atlanta, Georgia
    Emory University – Recruiting
    Principal Investigator: Jeannie Visootsak, MD
    Contact: Krista Charen    404-778-8479<
    Chicago, Illinois
    Rush University Medical Center
    Principal Investigator: Elizabeth M Berry-Kravis, MD
    Contact: Jamie A Chin    (312) 942-0025
    Worcester, Massachusetts
    University of Massachusetts Medical School
    Principal Investigator: Jean Frazier, MD
    Contact: Ann Foley    774-455-4103
    NYC, New York     (click for flyer)
    Mount Sinai School of Medicine
    Principal Investigator: Alexander Kolevzon, MD
    Contact: Hillary Rieger  212-241-2826
    Cincinnati, Ohio
    Cincinnati Children’s Hospital Medical Center
    Principal Investigator: Craig Erickson, MD
    Contact: Bridget Crippen or Kaela O’Brien
    Lewisburg, Pennsylvania
    Geisinger Autism & Developmental Medicine Institute
    Principal Investigator: Thomas Challman, M.D.
    Contact: Margaret King, Ph.D. (570)-522-9438
    Media, Pennsylvania
    Suburban Research Associates
    Principal Investigator: Shivkumar Hatti, MD
    Contact: Nathan Blubaugh    610-891-9024 ext 103
    or Contact: Nikki Thomas    610-891-7200
    Denver, Colorado
    Children’s Hospital Colorado
    Principal Investigator: Nicole Tartaglia, MD
    Contact: Nanastasia Welnick    720-777-8608


Alcobra’s metadoxine trial has completed recruiting.  Learn more about it at at

  • Details

    The study enrolls eligible young men with FXS, ages 18-24, from around the world, and includes:
    · One visit, lasting several days, to the NIH Clinical Center, in Bethesda, Maryland.
    · Assessment by physicians
    · Blood draw, Two brain scans (PET & MRI), possible sedation
    · Travel, food, and lodging are covered and include the patient and one or two accompanying family members.
    · Compensation is paid for your time and assistance.Please consider enrolling your child in our clinical research study of FXS. If you would like to participate, be on our mailing list, be contacted in case of future studies, or would simply like to have more information: Please call Inna Loutaev, +1 301 496 4707, or E-mail, or visit our website: of Health & Human Services, National Institutes of Health, National Institute of Mental Health, 06-M-0214


Completed Clinical Trials funded by FRAXA


For all Fragile X medication trials visit

To learn how trials work, visit