Past and Present Clinical Trials in Fragile X Syndrome

There have been quite a few clinical trials in Fragile X syndrome. We provide the table below to document current and past clinical trials and will keep it updated as we learn of new trials.

How Clinical Trials Work: Learn more about clinical trials, including what they are, how they work, and how you can participate.

Search MyFXResearch Portal: Search for currently available clinical trial and study opportunities.

All columns are sortable. Click on the column head titles (END YR, START YR, PHASE, etc.) to change A–Z to Z–A (or 1–10 and 10–1). The default sort shows from most to least recent. To sort the full list, you might want to first choose to show all, then sort your columns.

There are multiple pages. You can advance from page to page using the links at the bottom right of the table. You can also choose to show more or all rows (10, 25, 50, 100) without pagination by using the Show ___ entries dropdown at the top left of the table.

The plus sign — Click for more on this clinical trial — provides more information. Click on the plus sign to the left of any row to see more about that clinical trial: Measure (primary outcome measure), sponsor, trial size, a link to each ClinicalTrials.gov identifier, and, once completed, any results that are available. 

We have footnotes and a glossary to help you understand abbreviations and terms. If you’re unfamiliar with any of the abbreviations or terminology — see the footnotes and glossary at the end of this page. Or contact us for additional help.

You can search for any keyword. Use the Search box at the top right of the table to search, for example, a drug name, sponsor name, or indication terms (memory, behavior, etc.)

Need help? Please contact Hilary Rosselot with your questions.

ClinicalTrials.gov↗
A database of privately and publicly funded clinical studies. Also, see NCT Link.

EEG
 A recording of electrical brain activity (brain waves) made by an electroencephalograph (EEG).

Indication
The symptom indicates the need for a certain medical treatment.

NCT Link
This is the ClinicalTrials.gov unique identifier, also referred to as “NCT number↗,” assigned to each clinical study record. Example: NCT04130360.

Measure
This is the abbreviated version we use for “primary outcome measure,” which is the main outcome measure↗ the clinical study has identified to determine the intervention or treatment’s effectiveness. Many also have secondary outcome measures, which can be found using the NCT link.

Phase
The current phase↗, or stage, of a clinical trial. Also see our article How Clinical Trials Work: From Start to Finish.

Primary Outcome Measure
See Measure.

ABC-C — Aberrant Behavior Checklist-Community

ABC-Cfx — Aberrant Behavior Checklist-Community, Fragile X Factor Structure

AE — Adverse Events

ADAMS — Anxiety Depression and Mood Scale

ADHD-RS — Attention Deficit Hyperactivity Disorder – Rating Scale

APP — Amyloid Precursor Protein

CGI — Clinical Global Impression

CNT — Contingency Naming Test

Conners — Conners’ Rating Scales

ELS — Expressive Language Sampling

MSEL — Mullen Scales of Early Learning

NDW — Number of Different Words

PILI — Parent-Implemented Language Intervention

SAE — Serious Adverse Events

TEAE — Treatment Emergent Adverse Events

VAS — Visual Analogue Scale

Fragile X Drug Trials
Chart showing clinical trials by start date over time.

A visual overview of the clinical trials listed in the table below. Click for larger view.

Past and Present Clinical Trials in Fragile X Syndrome

End Yr: Start Yr: Drug: Phase: Primary Outcome Measure: Gender: Age: Sponsor: Trial Size: NCT Link: Notes:
2013 2009 Donepezil 2 Executive functioning All 12-29 Stanford University 45 NCT01120626 Icon: Open in a new window

Results: Effectiveness and Safety of Donepezil in Boys With Fragile X Syndrome: A Double-Blind, Randomized, Controlled Pilot Study
2020 2018 Zygel (ZYN002) 2/3 Fragile X behaviors – ABC-Cfx All 3-17 Zynerba Pharmaceuticals 212 NCT03614663 Icon: Open in a new window

Full drug name: Zygel (ZYN002) – CBD Transdermal Gel
Phases: Phase 2: ZYN002 – CBD Transdermal Gel; Phase 3: Placebo Transdermal Gel
Results: A phase 1/2, open-label assessment of the safety, tolerability, and efficacy of transdermal cannabidiol (ZYN002) for the treatment of pediatric fragile X syndrome
2015 2014 Trofinetide 2 Safety (secondary included physiological, behavior, and global/ functional assessments) Males 12-45 Neuren Pharmaceuticals 72 NCT01894958 Icon: Open in a new window

Results: A Double-Blind, Randomized, Placebo-Controlled Clinical Study of Trofinetide in the Treatment of Fragile X Syndrome
2015 2012 Sertraline 2 Cognition, language – Mullen and CGI All 2.5-5 UC Davis 57 NCT01474746 Icon: Open in a new window

Results: A Randomized, Double-Blind, Placebo-Controlled Trial of Low-Dose Sertraline in Young Children With Fragile X Syndrome
2017 2016 Minocycline and Lovastatin 2 Fragile X behaviors All 13-40 Université de Sherbrooke 23 NCT02680379 Icon: Open in a new window

Results: Drug duo delivers brain, behavioral benefits for fragile X syndrome
2011 2010 Minocycline n/a Clinical impression – CGI and VAS behavior All 3.5-16 UC Davis 66 NCT01053156 Icon: Open in a new window

Results: A randomized double-blind, placebo-controlled trial of minocycline in children and adolescents with fragile x syndrome
2010 2007 Oxytocin 2 Fragile X behaviors – Eye contact challenge task Males 13-29 Stanford University 10 NCT01254045 Icon: Open in a new window

Results: Effects of intranasal oxytocin on social anxiety in males with fragile X syndrome
2021 2018 Metformin (U.S.) 2/3 Fragile X symptoms (language, behavior, weight) – ELS mean NDW score All 6-25 UC Davis 55 NCT03479476 Icon: Open in a new window

Results: Metformin treatment in young children with fragile X syndrome
2020 2018 Metformin (Canada) 2 Safety (secondary was behavior and cognition) – AE and ABC-C All 10-45 Université de Sherbrooke 15 NCT03722290 Icon: Open in a new window

Results: Metformin treatment in young children with fragile X syndrome
2015 2014 Metadoxine (MG01CI) 2 Inattention – ADHD RS All 15-55 Alcobra 62 NCT02126995 Icon: Open in a new window

Results: Alcobra Announces Results From Phase 2 Clinical Trial of MDX for Fragile X Syndrome
2009 2008 Mavoglurant (AFQ056) 2 Fragile X behaviors – ABC-Cfx Males 18-35 Novartis 30 NCT00718341 Icon: Open in a new window

Results: Mavoglurant in fragile X syndrome: Results of two randomized, double-blind, placebo-controlled trials
2023 2017 AFQ056 (Mavoglurant) and Language Intervention 2 Language – Weighted child intentional communication score All 2.5-6 Elizabeth Berry-Kravis, Rush University Medical Center 99 NCT02920892 Icon: Open in a new window

This trial is complete, the results will be published soon.
2013 2010 Mavoglurant (AFQ056) 2 Fragile X behaviors – ABC-Cfx All 18-45 Novartis 175 NCT01253629 Icon: Open in a new window

Results: Epigenetic modification of the FMR1 gene in fragile X syndrome is associated with differential response to the mGluR5 antagonist AFQ056
2020 2016 Lovastatin and PILI 4 Fragile X behaviors, language – ELS All 10-17 UC Davis 30 NCT02642653 Icon: Open in a new window

Results: Controlled trial of lovastatin combined with an open-label treatment of a parent-implemented language intervention in youth with fragile X syndrome
2016 2012 Ganaxolone 2 Clinical impression – CGI All 6-17 Marinus Pharmaceuticals 59 NCT01725152 Icon: Open in a new window

Results: A randomized double-blind, placebo-controlled trial of ganaxolone in children and adolescents with fragile X syndrome
2020 2018 Gaboxadol (OV101) 2 Safety – Incidence of AEs (secondary was ABC-C and CGI-I) Males 13-22 Ovid Therapeutics 23 NCT03697161 Icon: Open in a new window

Results: Gaboxadol in Fragile X Syndrome: A 12-Week Randomized, Double-Blind, Parallel-Group, Phase 2a Study
2014 2011 Mavoglurant (AFQ056) 2 Fragile X behaviors – ABC-Cfx All 12-17 Novartis 139 NCT01357239 Icon: Open in a new window

Results: Mavoglurant in adolescents with fragile X syndrome: analysis of Clinical Global Impression-Improvement source data from a double-blind therapeutic study followed by an open-label, long-term extension study
2021 2018 BPN14770 2 Safety, tolerability – Treatment emergent AE (TEAE) Males 18-45 Tetra Discovery Partners 30 NCT03569631 Icon: Open in a new window

Results: Inhibition of phosphodiesterase-4D in adults with fragile X syndrome: a randomized, placebo-controlled, phase 2 clinical trial
2014 2012 Basimglurant (RO4917523) 2 Safety All 5-13 Hoffmann-La Roche 47 NCT01750957 Icon: Open in a new window

Results: From a presentation of the International Society of Autism Research (ISAR): Safety and Exploratory Efficacy of Basimglurant in Pediatric Patients with Fragile X Syndrome: A Randomized, Double-Blind, Placebo-Controlled Study
2014 2012 Basimglurant (RO4917523) 2 Anxiety, depression – ADAMS All 14-50 Roche 185 NCT01517698 Icon: Open in a new window

Results: Effect of Two Doses of Basimglurant on Behavioral Symptoms in Adolescent and Adult Patients with Fragile X Syndrome; Results from Fragxis, a Double-Blind, Placebo Controlled Study
2020 2018 AZD7325 1 Safety – APP All 18-50 CCHMC 15 NCT03140813 Icon: Open in a new window

n/a
2015 2010 Ascorbic Acid and Alpha-Tocopherol 2 Hyperactivity – Conners Males 6-18 The Mediterranean Institute for the Advance of Biotechnology and Health Research 30 NCT01329770 Icon: Open in a new window

Ascorbic acid is Vitamin C and alpha-tocopherol is Vitamin E.
Results: A combination of ascorbic acid and α-tocopherol to test the effectiveness and safety in the fragile X syndrome: study protocol for a phase II, randomized, placebo-controlled trial
2010 2008 Arbaclofen 2 Irritability – ABC-C All 6-40 Seaside Therapeutics 45 NCT01013480 Icon: Open in a new window

Results: Effects of STX209 (arbaclofen) on neurobehavioral function in children and adults with fragile X syndrome: a randomized, controlled, phase 2 trial
2013 2011 Arbaclofen 3 Lethargy, social withdrawal – ABC-C All 5-11 Seaside Therapeutics 172 NCT01325220 Icon: Open in a new window

Results: Effects of STX209 (arbaclofen) on neurobehavioral function in children and adults with fragile X syndrome: a randomized, controlled, phase 2 trial
2013 2011 Arbaclofen 3 Social avoidance – ABC-C All 12-50 Seaside Therapeutics 125 NCT01282268 Icon: Open in a new window

Results: Effects of STX209 (arbaclofen) on neurobehavioral function in children and adults with fragile X syndrome: a randomized, controlled, phase 2 trial
2005 2002 Ampakine CX516 (Ampalex®) 2 Memory – various measures All 18-50 RespireRx 49 NCT00054730 Icon: Open in a new window

Results have been submitted, but are not yet available. Also see: Effect of CX516, an AMPA-modulating compound, on cognition and behavior in fragile X syndrome: a controlled trial
2020 2016 Acamprosate, Lovastatin, Minocycline and Baclofen 1 Brain activity, clinical impression – EEG and CGI-I All 15-55 Children's Hospital Medical Center, Cincinnati 29 NCT02998151 Icon: Open in a new window

Results: Neurophysiological and Acute Pharmacological Studies in FXS Patients — Study Results
2018 2013 Acamprosate 1 Social avoidance – ABC-C All 5-23 Children's Hospital Medical Center, Cincinnati 46 NCT01911455 Icon: Open in a new window

n/a

*Closed for recruiting.

This table has been adapted from the Drug development for neurodevelopmental disorders: lessons learned from fragile X syndrome (2017) publication and updated based on ClinicalTrials.gov. 

Berry-Kravis, E. M., Lindemann, L., Jønch, A. E., Apostol, G., Bear, M. F., Carpenter, R. L., Crawley, J. N., Curie, A., Des Portes, V., Hossain, F., Gasparini, F., Gomez-Mancilla, B., Hessl, D., Loth, E., Scharf, S. H., Wang, P. P., Von Raison, F., Hagerman, R., Spooren, W., & Jacquemont, S. (2018). Drug development for neurodevelopmental disorders: lessons learned from fragile X syndrome. Nature reviews. Drug discovery, 17(4), 280–299. https://doi.org/10.1038/nrd.2017.221

This table has been adapted from the Drug development for neurodevelopmental disorders: lessons learned from fragile X syndrome (2017)↗ publication and updated based on ClinicalTrials.gov↗.

Berry-Kravis, E. M., Lindemann, L., Jønch, A. E., Apostol, G., Bear, M. F., Carpenter, R. L., Crawley, J. N., Curie, A., Des Portes, V., Hossain, F., Gasparini, F., Gomez-Mancilla, B., Hessl, D., Loth, E., Scharf, S. H., Wang, P. P., Von Raison, F., Hagerman, R., Spooren, W., & Jacquemont, S. (2018). Drug development for neurodevelopmental disorders: lessons learned from fragile X syndrome. Nature reviews. Drug discovery, 17(4), 280–299. https://doi.org/10.1038/nrd.2017.221

Questions?

If you have questions about anything research-related, we’d love to hear from you! You can reach out to Hilary Rosselot directly, or submit your question or comment through our contact form below.

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Hilary Rosselot, Director of Research Facilitation
 hilary@fragilex.org | (202) 747-6208

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