Recruiting: Shionogi’s EXPERIENCE Phase 3 Clinical Trial of Zatolmilast in Fragile X Syndrome

Updated 2025-03-06. Additional sites will be added here as they open.

The EXPERIENCE clinical studies, Shionogi’s ongoing Phase 2b/3 studies for an investigational drug for Fragile X syndrome, are still enrolling qualified male participants aged 9-45 with FXS and confirmed FMR1 gene mutation (≥ 200 CGG repetitions) at sites across the U.S.

You may have heard about EXPERIENCE (Evaluation of Fragile X Experience in Cognition Expression) clinical trials as the Tetra studies or the studies of BPN14770 in Fragile X syndrome. The EXPERIENCE clinical studies are now being managed by Shionogi (the company that acquired Tetra Therapeutics Inc. in 2020).

Travel to and from sites for a study participant and his caregiver may be covered, and may also include transportation, lodging arrangements, and reimbursement for meals (limitations may apply).

Find out about EXPERIENCE at www.shionogi.com/FXS. You can also contact Shionogi directly at medinfo@shionogi.com or 1 (800) 849-9707.

These trials mark a major milestone for community-based drug development. FRAXA-funded research pointed the way to phosphodiesterase inhibitors to treat Fragile X many years ago. However, finding a good phosphodiesterase inhibitor was a challenge because there was so much interest in the pharmaceutical world in developing these drugs for Alzheimer's disease and other blockbuster indications.

FRAXA then partnered with Tetra Therapeutics to test their advanced PDE 4D inhibitor in Fragile X mice, with remarkable results.

The results in the mice justified clinical trials, so FRAXA and Tetra organized and co-funded the first Fragile X trials of this investigational drug. The outcome was a genuine breakthrough for the field: statistically significant improvement in Fragile X subjects on a wide range of outcome measures. Behavior improved, quality of life improved, electrophysiology improved, and most importantly of all, cognition improved markedly. There are no drugs currently approved to treat intellectual disability.

In 2020, Tetra Therapeutics became a wholly owned subsidiary of Shionogi & Co., Ltd., enabling the continuation and expansion of this research under Shionogi’s leadership.

If the new trials are successful, our community could see the first approved treatment for Fragile X syndrome on the market.

Tetra trial is recruiting

Enrollment Information

Participation in this clinical trial includes reimbursement for expenses. This can include prepaid travel arrangements (transportation and hotel accommodation) and meal expenses, subject to certain restrictions.

To Sign Up for this Fragile X clinical trial, contact a location listed below. 

UC Davis Health System
Davis, CA
Accepting males ages 9-45
Abigail Higareda Borbe
amoradelhigareda@ucdavis.edu
(916) 703-0281

Amnova Clinical Research
Irvine, CA
Accepting males ages 9-45
Erika Jacobo
erika.jacobo@amnovaresearch.com
(323) 348-0956

CHOC Thompson Autism Center
Orange, CA
Accepting males ages 9-45
Ulises Bustos
Ulises.Bustos@choc.org
(714) 288-7678

Children's Hospital Colorado
Aurora, CO
Accepting males ages 9-45
Erika Peterson
erika.peterson@childrenscolorado.org
(720) 777-8590

University of Miami
Miami, FL
Accepting males ages 9-45
Daniela Martinez
dmartinez2@med.miami.edu
(305) 243-3110

Emory University
Atlanta, GA
Accepting males ages 9-45
Jean Luan McColl
jean.luan@emory.edu
(404) 778-8619

Rush University
Chicago, IL
Accepting males ages 9-45
Loren Escot (Co-Coordinator)
Loren_Escot@rush.edu
(312) 942-2164
Abigail Ayemoba (Co-Coordinator)
abigail_ayemoba@rush.edu
(312) 942-2815

University of Kansas Medical Center
Kansas City, KS
Accepting males ages 9-45
Danielle Adam (Lead Coordinator)
dadam@kumc.edu
(913) 588-0494
Jasli Bonilla (Coordinator)
jbonilla@kumc.edu
(913) 945-9790

Boston Children's Hospital
Boston, MA
Accepting males ages 9-45
Michelle Coughlin
michelle.coughlin@childrens.harvard.edu
(617) 355-7025

UMass Chan Medical School
Worcester, MA
Accepting males ages 9-45
Lindsey Cincotta
lindsey.cincotta@umassmed.edu
(508) 856-7892

Kennedy Krieger Institute
Baltimore, MD
Accepting males ages 9-45
Maria Halaguena
halaguena@kennedykrieger.org
(443) 923-3826

Icahn School of Medicine
New York, NY
Accepting males ages 9-45
Venus Fan
venus.fan@mssm.edu
(929) 989-7016

Cincinnati Children's Hospital Medical Center
Cincinnati, OH
Accepting males ages 9-45
Elizabeth Blank
elizabeth.blank@cchmc.org
(513) 517-1550

Suburban Research Associates
Media, PA
Accepting males ages 9-45
Scott Comegys (Recruitment Specialist)
volunteer@atlas-clinical.com
610-891-7200

Clinic for Special Children
Strasburg, PA
Accepting males ages 9-45
Joelle Williamson
jwilliamson@clinicforspecialchildren.org
(717) 687-9407

Greenwood Genetic Center
Greenwood, SC
Accepting males ages 9-18
Nicole Johnston
njohnston@ggc.org
(864) 678-6912

University of Utah/Primary Children's Hospital
Salt Lake City, UT
Accepting males ages 9-18
Hina Yazdani
hina.yazdani@hsc.utah.edu
(801) 631-1067

Post Revisions

  • 2025/01 - Updated to reflect additional recruiting sites and the transition of Tetra Therapeutics to Shionogi.
  • 2024/02 - Updated to include new age range, protocol amendments and additional recruiting sites.
  • 2023/10 - Updated to include open label extension trial.
  • 2023/06 - Updated with additional recruiting sites.
  • 2022/10 - Updated as clinical trial now recruiting at first location.
  • 2022/07 - Original post published.

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FRAXA-funded researchers around the world are leading the way towards effective treatments and ultimately a cure.

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Global Leader in Fragile X Research

FRAXA-funded researchers around the world are leading the way towards effective treatments and ultimately a cure.

Explore Current Research Grants
Help Fund the Cure