Fragile X SyndromePhase 2NCT06413537

Study of SPG601 in Adult Men With Fragile X Syndrome

A Phase 2 study testing SPG601 in people with Fragile X Syndrome, run by Spinogenix at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

This Phase 2 study described herein will evaluate the safety, efficacy, tolerability, pharmacokinetics and pharmacodynamics of SPG601 in adult men with Fragile X syndrome. Read more about this study

Who is it for?: Ages 18 to 45 years, men only
Conditions the study is for: Fragile X Syndrome
What is being tested?: SPG601
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 10 participants
Where: 1 siteUnited States
Study dates: 5 Jul 2024to 31 Dec 2024
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 18 to 45 years
Men only
No healthy volunteers
Adult

Who may be able to join

Adult males aged 18 to 45 years
Diagnosis of Fragile X as confirmed with genetic testing
Patient must have caregiver
Must be in good health with no significant medical history
Clinical laboratory values within normal range or < 1.2 times ULN
Contraceptive use by men or women consistent with local regulations
Able and willing to provide written informed consent
Stable dosing of psychotropic drugs for at least 4 weeks

Who cannot join

Any physical or psychological condition that prohibits study completion
Uncontrolled seizures or history of epilepsy with a seizure in the past 6 months.
Auditory or visual impairments that can not be corrected
History of suicidal behavior or suicidal ideation
Screening vital signs that are abnormal per protocol specification
ECG that are clinically significant abnormal
History of substance abuse or dependence within 6 months
Other investigational products within 30 days

Trial locations and contacts

1 site in 1 country.

United States1 site

Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, 45229

Other trials in United States

About this study

Official title: A Phase 2a, Randomized, Double-Blinded, Study Evaluating the Neurophysiologic vs Clinical Effects of Single-Dose SPG601 and Placebo in Adult Men With Fragile X Syndrome

This Phase 2 study described herein will evaluate the safety, efficacy, tolerability, pharmacokinetics and pharmacodynamics of SPG601 in adult men with Fragile X syndrome.

Read the detailed description

This study is a Phase 2 randomized, double blind, placebo-controlled, cross over, single dose of SPG601 and matching Placebo in patients with Fragile X syndrome.

This study will entail 2 in person clinic visits to administer oral doses of SPG601 or matching placebo. Participants will receive a dose of either SPG601 or placebo at first visit, and will cross over to receive the other product at the second visit.

Conditions: Fragile X Syndrome
Being tested: SPG601, Placebo
Keywords: Fragile X Syndrome, Fragile X Chromosome, cognitive outcomes
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.

SPG601Drug
synthetic small molecule
PlaceboDrug
Placebo

Study groups in NCT06413537
Study group	Role	What they receive
Experimental: Active SPG601 to be administered to participants with Fragile X Syndrome	Active comparator	Participants with Fragile X Syndrome will be randomized to receive SPG601 or placebo (8 capsules of 100 mg) one time on days 1 and 8 of the study. Receives: Drug: SPG601
Placebo Comparator: Placebo comparator to be administered to participants with Fragile X Syndrome	Placebo comparator	Participants with Fragile X Syndrome will be randomized to receive SPG601 or placebo (8 capsules of 100 mg) one time on days 1 and 8 of the study. Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Clinical Global Impressions Improvement Scale as Determined by the Treating Clinician
Change in clinician rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Measured: 15 days
Clinical Global Impressions Improvement Scale as Determined by the Caregiver
Change in caregiver rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Measured: 15 days
Visual Analog Scale as Determined by the Patient Caregiver
Change from baseline in notation on Visual Analog scale as determined by the patient caregiver. Rater will indicate on linear measurement scale of 1 to 100 centimeters, with higher score indicating more severe symptoms
Measured: 15 days
Change in Auditory Response to Chirp Stimulus
Auditory test will be evaluated for difference in responses to stimuli, as demonstrated by the Inter-Trial Coherence (ITC). ITC is a measure of phase consistency across trials, expressed as a dimensionless value ranging from 0 to 1. A value of 0 indicates completely random phase across trials, while 1 denotes a perfectly phase-locked response across trials. Higher ITC values reflect greater phase consistency of neural oscillations. ITC is a unit of measure as frequency (40Hz) vs time (msec).
Measured: 15 days

Secondary outcomes (11)

Change From Baseline in Attention and Inhibition Symptoms-Go/NoGo Subtest
KiTAP Tests of Attentional Performance for Children, to measure alertness and assessments of visual reactions. The Go-NoGo subtest measures impulsivity by requiring subjects to tap a button when the target stimulus is presented, while refraining from hitting the button for the non-target stimulus. Summary statistics presented for change in reaction time from baseline.
Measured: 15 days
Change in Cognitive Outcomes Measured by NIH Cognitive Toolbox
National Institute of Health (NIH)- Toolbox Cognitive Battery (TCB):
A series of tests will be conducted to assess reading, vocabulary, and speed matching. These tests are scored from zero to 100. A higher score indicate better performance.
Measured: 15 days
Change in Memory and Cognitive Assessment With RBANS List Learning.
RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) is scored from -4 to 4, with higher values indicate higher memory and cognitive assessment
Measured: 15 days
Change in Auditory Response to Steady State Auditory Stimuli From Baseline
Auditory test will be evaluated for difference in responses to stimuli. Auditory Steady State Response (ASSR) is measured following a short stream of click trains with a 500 msec inter-train interval (duration), at standard tone and at 40Hz tone. The magnitude of ITC represents the phase consistency of oscillatory activities. ITC is a measure of phase consistency across trials, expressed as a dimensionless value ranging from 0 to 1. A value of 0 indicates completely random phase across trials, while 1 denotes a perfectly phase-locked response across trials. Higher ITC values reflect greater phase consistency of neural oscillations. ITC as a unit of measure is expressed as frequency (40Hz) vs time (msec)
Measured: 15 days
Safety and Tolerability of SPG601 in Patients With Fragile X Syndrome
Incidence, nature, and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)
Measured: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Flexibility Subtest
The KiTAP is a computerized executive function battery that consists of eight nonverbal subtests measuring different basal as well as higher-order components of attention and executive functioning. The alertness subtest requires subjects to tap a button every time a stimulus appears on the screen. Mean reaction time was measured over 90 seconds and change from baseline was calculated. A lower reaction time (net decrease in reaction time) indicates better performance.
Measured: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Alertness Subtest
KiTAP Tests of Attentional Performance for Children, to measure alertness and assessments of visual reactions. The alertness subtest records the number of times a subject taps a button when a stimulus appears on screen. Change in Baseline summary statistics for reaction time presented below. A lower number indicates lower reaction time and better performance.
Measured: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Distractability Subtest
The KiTAP is a computerized executive function battery that consists of eight nonverbal subtests measuring components of attention and executive functioning. The distractibility subtest measures how easily the subject is distracted by extraneous stimuli. This subtest requires subjects to tap a button when a target stimulus appears on the screen while ignoring distractions. Mean number of correct responses were recorded, and change from baseline was calculated, and a higher mean number of correct responses indicates better performance.
Measured: 15 days
Change in Eye Tracking for Social Gaze
This test will measure eye tracking and movement in response to stimuli, and social gaze version, with a Likert scale of 1-5 for behavior rating.
Measured: 15 days
Change in Eye Tracking Measured by Electroretinography
This test will measure the electrical activity in the retina in response to stimuli, evaluating change in stimuli response post dose minus stimuli pre dose-RIGHT EYE
Measured: 15 days
Change in Eye Tracking Measured by Electroretinography
This test will measure the electrical activity in the retina in response to stimuli, evaluating change in stimuli response post dose minus stimuli pre dose-LEFT EYE
Measured: 15 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

5 Jul 202431 Dec 2024

First posted14 May 2024
Study start5 Jul 2024
Primary completion31 Dec 2024
Study completion31 Dec 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Fragile X SyndromeStudies of the same condition, open and under way.
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 2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Crossover
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 10 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT06413537
Sponsor's protocol ID: SPG601-01
Status last verified: Feb 2026
First submitted: 9 May 2024
Last updated: 26 May 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Fragile X Syndrome trials

Study at a glance

From the registry record, last updated by the sponsor on 26 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase 2a, Randomized, Double-Blinded, Study Evaluating the Neurophysiologic vs Clinical Effects of Single-Dose SPG601 and Placebo in Adult Men With Fragile X Syndrome
ClinicalTrials.gov ID: NCT06413537
Acronym / sponsor ID: SPG601-01
Conditions: Fragile X Syndrome
Keywords: Fragile X Syndrome, Fragile X Chromosome, cognitive outcomes
Phase: Phase 2
Study type: Interventional
Recruitment status: Completed
Enrolment: 10 participants (actual)
Lead sponsor: SpinogenixIndustry (pharma, biotech, devices)
Collaborators: Avance Clinical Pty Ltd.
Study start: 5 Jul 2024 (actual)
Primary completion: 31 Dec 2024 (actual)
Study completion: 31 Dec 2024 (actual)
First posted: 14 May 2024 (actual)
Results: Posted 26 May 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

This Phase 2 study described herein will evaluate the safety, efficacy, tolerability, pharmacokinetics and pharmacodynamics of SPG601 in adult men with Fragile X syndrome.

Detailed description

This study is a Phase 2 randomized, double blind, placebo-controlled, cross over, single dose of SPG601 and matching Placebo in patients with Fragile X syndrome.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Crossover
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 2

Arm	Type	Receives
Experimental: Active SPG601 to be administered to participants with Fragile X Syndrome	Active comparator	Drug: SPG601Participants with Fragile X Syndrome will be randomized to receive SPG601 or placebo (8 capsules of 100 mg) one time on days 1 and 8 of the study.
Placebo Comparator: Placebo comparator to be administered to participants with Fragile X Syndrome	Placebo comparator	Drug: PlaceboParticipants with Fragile X Syndrome will be randomized to receive SPG601 or placebo (8 capsules of 100 mg) one time on days 1 and 8 of the study.

Who may qualify

Ages: 18 to 45 years
Sex: Male only
Healthy volunteers: Not accepted
Age groups: Adult

Key inclusion criteria (8 listed)

Adult males aged 18 to 45 years
Diagnosis of Fragile X as confirmed with genetic testing
Patient must have caregiver
Must be in good health with no significant medical history
Clinical laboratory values within normal range or < 1.2 times ULN

Key exclusion criteria (8 listed)

Any physical or psychological condition that prohibits study completion
Uncontrolled seizures or history of epilepsy with a seizure in the past 6 months.
Auditory or visual impairments that can not be corrected
History of suicidal behavior or suicidal ideation
Screening vital signs that are abnormal per protocol specification

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
SPG601synthetic small molecule	Drug	Experimental: Active SPG601 to be administered to participants with Fragile X Syndrome
PlaceboPlacebo	Drug	Placebo Comparator: Placebo comparator to be administered to participants with Fragile X Syndrome

Primary outcome

Clinical Global Impressions Improvement Scale as Determined by the Treating Clinician
Time frame: 15 days
Change in clinician rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Clinical Global Impressions Improvement Scale as Determined by the Caregiver
Time frame: 15 days
Change in caregiver rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Visual Analog Scale as Determined by the Patient Caregiver
Time frame: 15 days
Change from baseline in notation on Visual Analog scale as determined by the patient caregiver. Rater will indicate on linear measurement scale of 1 to 100 centimeters, with higher score indicating more severe symptoms
Change in Auditory Response to Chirp Stimulus
Time frame: 15 days
Auditory test will be evaluated for difference in responses to stimuli, as demonstrated by the Inter-Trial Coherence (ITC). ITC is a measure of phase consistency across trials, expressed as a dimensionless value ranging from 0 to 1. A value of 0 indicates completely random phase across trials, while 1 denotes a perfectly phase-locked response across trials. Higher ITC values reflect greater phase consistency of neural oscillations. ITC is a unit of measure as frequency (40Hz) vs time (msec).

11 secondary outcomes

Change From Baseline in Attention and Inhibition Symptoms-Go/NoGo Subtest
Time frame: 15 days
Change in Cognitive Outcomes Measured by NIH Cognitive Toolbox
Time frame: 15 days
Change in Memory and Cognitive Assessment With RBANS List Learning.
Time frame: 15 days
Change in Auditory Response to Steady State Auditory Stimuli From Baseline
Time frame: 15 days
Safety and Tolerability of SPG601 in Patients With Fragile X Syndrome
Time frame: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Flexibility Subtest
Time frame: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Alertness Subtest
Time frame: 15 days
Change From Baseline in Attention and Inhibition Symptoms-Distractability Subtest
Time frame: 15 days
Change in Eye Tracking for Social Gaze
Time frame: 15 days
Change in Eye Tracking Measured by Electroretinography
Time frame: 15 days
Change in Eye Tracking Measured by Electroretinography
Time frame: 15 days

Results and safety

Results posted to the registry on 26 May 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Sequence 1: SPG601 First, Placebo Second	5	5
Sequence 2: Placebo First SPG601 Second	5	5

Primary outcome: Clinical Global Impressions Improvement Scale as Determined by the Treating Clinician

Time frame: 15 days. Mean (95% Confidence Interval). Unit: score on a scale

Measure	Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome n = 10	Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome n = 10
Value	3.7 (3.106 to 4.07)	3.8 (3.399 to 4.26)

Population analysed: cross-over study, with all 10 participants receiving active drug or placebo at one study visit, and receive the other treatment arm at subsequent study visit

Primary outcome: Clinical Global Impressions Improvement Scale as Determined by the Caregiver

Time frame: 15 days. Mean (95% Confidence Interval). Unit: score on a scale

Measure	Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome n = 8	Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome n = 8
Value	2.9 (1.1 to 3.6)	2.8 (1.16 to 3.8)

Population analysed: This assessment not completed for 2 participants

Primary outcome: Visual Analog Scale as Determined by the Patient Caregiver

Time frame: 15 days. Mean (95% Confidence Interval). Unit: score on a scale

Measure	Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome n = 10	Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome n = 10
Value	-6.5 (-18.61 to 4.408)	-6 (-16.25 to 5.334)

Primary outcome: Change in Auditory Response to Chirp Stimulus

Time frame: 15 days. Mean (Standard Deviation). Unit: Inter Trial Coherence

Measure	Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome n = 9	Placebo Comparator: Placebo to be Administered to Participants With Fragile X Syndrome n = 9
Value	-0.012 (0.041)	0.014 (0.062)

11 secondary outcomes are reported in the full results.

Adverse events

Time frame: Adverse event data was collected at study visits that happened weekly for 3 weeks.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome	0 of 10 (0%)	1 of 10 (10%)	0 of 10
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome	0 of 10 (0%)	0 of 10 (0%)	0 of 10

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 26 May 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

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
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Not yet recruiting
Single Session Support for Parents of Children With Neurodevelopmental Disabilities Struggling With Anxious Avoidance
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RecruitingObservational study
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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.

Craig Erickson, MD principal investigator

Children's Hospital Medical Center, Cincinnati

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing SPG601 in people with Fragile X Syndrome, run by Spinogenix at 1 site in United States.

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 8 inclusion and 8 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 26 May 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 United States. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 26 May 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Clinical Global Impressions Improvement Scale as Determined by the Treating Clinician (time frame: 15 days). The study lists 4 primary outcomes in all. 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 NCT06413537.

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 26 May 2026.