Fragile X SyndromePhase 4NCT05120505
Metformin in Children With Fragile X Syndrome
A Phase 4 study testing Metformin in people with Fragile X Syndrome and Metformin, run by Children's Hospital of Fudan University at 1 site in China.
Trial summary
This study is a controlled trial of metformin in children with fragile X syndrome(FXS). The age of FXS children range from 2 to 16 years old. Participants will be randomized in a double-blind design to either drug or placebo for 6-month period. Read more about this study
- Who is it for?
- Ages 2 to 16 years
- Conditions the study is for
- Fragile X Syndrome, Metformin
- What is being tested?
- Metformin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 37 participants
- Where
- 1 siteChina
- Study dates
- 29 Dec 2021to 30 Jan 2025
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 16 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Genetic testing confirms the diagnosis of FXS
- Participate in the study with the informed consent of the guardian
- BMI>the 3rd percentile
- Not taking more than 2 therapeutic drugs
- Able to receive regular follow-up visits
Who cannot join
- Malnutrition
- Primary heart disease
- Severe infection or acute clinical illness
- Gastrointestinal, renal, or hepatic disease
- Previous history of lactic acidosis
- previous use of metformin intolerant
Show all 9Show fewer
- Use of angiotensin converting enzyme inhibitors, use of anticoagulants, vitamin B12 deficiency, alcohol consumption
- Unstable systemic diseases other than FXS
- Changes in clinical medication
Trial locations and contacts
1 site in 1 country.
China1 site
Children's Hospital of Fudan University
Shanghai, Shanghai Municipality, 201102
About this study
Official title: Efficacy and Safety of Metformin in the Treatment of Fragile X Syndrome
This study is a controlled trial of metformin in children with fragile X syndrome(FXS). The age of FXS children range from 2 to 16 years old. Participants will be randomized in a double-blind design to either drug or placebo for 6-month period. The primary objectives are to assess metformin in treatment of behavior problems, cognitive and language with fragile X syndrome.
Read the detailed description
This is a single-center study at the Children's Hospital of Fudan University for FXS patients aged 2 to 16 years inclusive. It is a randomized, double-blind, placebo-controlled trial of metformin.
Studies showed that there were pathogenically over activates of mTOR and MAPK/ERK pathways in FXS. Metformin, a guanidine derivative ,has been shown to reduce mTORC1 pathway activity in an AMPK-dependent manner and has also been shown to reduce MAPK pathway activity. Metformin treatments for FXS have been reported in animal experiments, some open label trials of metformin in FXS patients had been reported. Therefore, metformin has potential to rescue symptoms in children with FXS.
In this study, researchers hope to investigate the improvement effect of metformin on FXS symptoms such as behavior problems, cognition, language.
The intervention period is 6 months, follow-up visit at 1 year. The researchers will also assess the side effects of the study medication throughout the trial.
- Conditions
- Fragile X Syndrome, Metformin
- Being tested
- Metformin, Placebo
- Medical subject headings
- Fragile X Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MetforminDrug
The patients in this group will be obtain Metformin starting from 50mg everyday at night, and gradually increase to maximum tolerable dose of 1-2g per day according to weights of patients for 6 months.
PlaceboDrug
The patients in this group will be obtain starch tablets (which had same appearance and size comparing to Metformin) starting from 50mg everyday to 1-2g per day according to weights of patients for 6 months.
| Study group | Role | What they receive |
|---|---|---|
| Metformin group | Experimental | The patients will be obtain Metformin starting from 50mg everyday to 1-2g per day for 6 months. Receives: Drug: Metformin |
| Placebo group | Placebo comparator | The patients will be obtain starch tablets starting from 50mg everyday to 1-2g per day for 6 months. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change of scores of Aberrant Behavior Checklist (ABC)
Difference on the scores of the ABC from baseline to the 6th month. ABC is a 58-item behavior scale ranked from 0("not a problem") to 3("severe problem") being the most severe for each item. 5 subscales include irritability, lethargy, stereotypy , hyperactivity and inappropriate speech. The same parent of patient will complete the checklist from baseline to 6th month. The global score changes of ABC will be measured as the primary outcome.
Measured: From baseline to the 6th month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Nov 2021
- Study start29 Dec 2021
- Primary completion30 Jan 2025
- Study completion30 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Fragile X SyndromeStudies of the same condition, open and under way.
- More trials run by Children's Hospital of Fudan UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 37 participants (actual)
Sponsor and investigators
- Lead sponsor
- Children's Hospital of Fudan University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05120505
- Sponsor's protocol ID
- FXS2021_1.0
- Status last verified
- Aug 2026
- First submitted
- 3 Nov 2021
- Last updated
- 25 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Zhu Y, Li D, Hu C, Tian Y, Lu P, Hagerman RJ, Xu X, Xu Q. Effects of Metformin on children with Fragile X Syndrome: a randomized, double-blind, placebo-controlled trial. Mol Autism. 2025 Nov 25;16(1):57. doi: 10.1186/s13229-025-00691-z.
PubMed 41291951
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy and Safety of Metformin in the Treatment of Fragile X Syndrome
- ClinicalTrials.gov ID
- NCT05120505
- Acronym / sponsor ID
- FXS2021_1.0
- Conditions
- Fragile X Syndrome, Metformin
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 37 participants (actual)
- Lead sponsor
- Children's Hospital of Fudan UniversityUniversity, hospital or other
- Study start
- 29 Dec 2021 (actual)
- Primary completion
- 30 Jan 2025 (actual)
- Study completion
- 30 Jan 2025 (actual)
- First posted
- 15 Nov 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a controlled trial of metformin in children with fragile X syndrome(FXS). The age of FXS children range from 2 to 16 years old. Participants will be randomized in a double-blind design to either drug or placebo for 6-month period. The primary objectives are to assess metformin in treatment of behavior problems, cognitive and language with fragile X syndrome.
Detailed description
This is a single-center study at the Children's Hospital of Fudan University for FXS patients aged 2 to 16 years inclusive. It is a randomized, double-blind, placebo-controlled trial of metformin.
Studies showed that there were pathogenically over activates of mTOR and MAPK/ERK pathways in FXS. Metformin, a guanidine derivative ,has been shown to reduce mTORC1 pathway activity in an AMPK-dependent manner and has also been shown to reduce MAPK pathway activity. Metformin treatments for FXS have been reported in animal experiments, some open label trials of metformin in FXS patients had been reported. Therefore, metformin has potential to rescue symptoms in children with FXS.
In this study, researchers hope to investigate the improvement effect of metformin on FXS symptoms such as behavior problems, cognition, language.
The intervention period is 6 months, follow-up visit at 1 year. The researchers will also assess the side effects of the study medication throughout the trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Metformin group | Experimental | Drug: MetforminThe patients will be obtain Metformin starting from 50mg everyday to 1-2g per day for 6 months. |
| Placebo group | Placebo comparator | Drug: PlaceboThe patients will be obtain starch tablets starting from 50mg everyday to 1-2g per day for 6 months. |
Who may qualify
- Ages
- 2 to 16 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Genetic testing confirms the diagnosis of FXS
- Participate in the study with the informed consent of the guardian
- BMI>the 3rd percentile
- Not taking more than 2 therapeutic drugs
- Able to receive regular follow-up visits
Key exclusion criteria (9 listed)
- Malnutrition
- Primary heart disease
- Severe infection or acute clinical illness
- Gastrointestinal, renal, or hepatic disease
- Previous history of lactic acidosis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MetforminThe patients in this group will be obtain Metformin starting from 50mg everyday at night, and gradually increase to maximum tolerable dose of 1-2g per day according to weights of patients for 6 months. | Drug | Metformin group |
| PlaceboThe patients in this group will be obtain starch tablets (which had same appearance and size comparing to Metformin) starting from 50mg everyday to 1-2g per day according to weights of patients for 6 months. | Drug | Placebo group |
Primary outcome
Change of scores of Aberrant Behavior Checklist (ABC)
Time frame: From baseline to the 6th month
Difference on the scores of the ABC from baseline to the 6th month. ABC is a 58-item behavior scale ranked from 0("not a problem") to 3("severe problem") being the most severe for each item. 5 subscales include irritability, lethargy, stereotypy , hyperactivity and inappropriate speech. The same parent of patient will complete the checklist from baseline to 6th month. The global score changes of ABC will be measured as the primary outcome.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Derived from this study: PubMed 41291951Zhu Y, Li D, Hu C, Tian Y, Lu P, Hagerman RJ, Xu X, Xu Q. Effects of Metformin on children with Fragile X Syndrome: a randomized, double-blind, placebo-controlled trial. Mol Autism. 2025 Nov 25;16(1):57. doi: 10.1186/s13229-025-00691-z.
- Individual participant dataSharing planned: No
Related trials for Fragile X Syndrome
Not yet recruitingPhase 2
Inhibition of Aggressive Behavior in Participants With Fragile X Syndrome
Aggressive Behavior in Fragile X Syndome
RecruitingObservational study
Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford
Rare Disorders, Undiagnosed Disorders
Not yet recruiting
Single Session Support for Parents of Children With Neurodevelopmental Disabilities Struggling With Anxious Avoidance
Neurodevelopmental Disorders, Autism Spectrum Disorder (ASD)
RecruitingObservational study
Development of Non-Invasive Prenatal Diagnosis for Single Gene Disorders
Invasive PreNatal Diagnosis in a Context of Family History of Single-gene Disorders, Including, Sickle Cell Disease
Not yet recruitingPhase 2/3
A Study to Investigate the Effects and Safety of Codabakalner for the Treatment of FXS in Male Participants and Adult Participants With ADS
Fragile X Syndrome (FXS), Autism Spectrum Disorder (ASD)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Metformin in people with Fragile X Syndrome and Metformin, run by Children's Hospital of Fudan University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change of scores of Aberrant Behavior Checklist (ABC) (time frame: From baseline to the 6th month). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05120505, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.