Trial Outcomes & Findings for Study of SPG601 in Adult Men With Fragile X Syndrome (NCT NCT06413537)
NCT ID: NCT06413537
Last Updated: 2026-05-26
Results Overview
Change in clinician rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
COMPLETED
PHASE2
10 participants
15 days
2026-05-26
Participant Flow
Participant milestones
| Measure |
Sequence 1: SPG601 First, Placebo Second
Participants with Fragile X Syndrome will be randomized to receive SPG601 800 mg on day one, followed by eight placebo capsules on day eight of the study.
SPG601: synthetic small molecule
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Sequence 2: Placebo First SPG601 Second
Participants with Fragile X Syndrome will be randomized to receive eight placebo capsules on day one of the study, followed by SPG601 800 mg on day eight of the study.
SPG601: synthetic small molecule
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|---|---|---|
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Overall Study
STARTED
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5
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5
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Overall Study
COMPLETED
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5
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5
|
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Overall Study
NOT COMPLETED
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0
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0
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Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Study of SPG601 in Adult Men With Fragile X Syndrome
Baseline characteristics by cohort
| Measure |
The Study Was a Crossover Trial of Two Treatments Administered at Day 1 and Day 8 of the Study.
n=10 Participants
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.
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|---|---|
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Age, Categorical
<=18 years
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0 Participants
n=20 Participants
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Age, Categorical
Between 18 and 65 years
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10 Participants
n=20 Participants
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Age, Categorical
>=65 years
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0 Participants
n=20 Participants
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Sex: Female, Male
Female
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0 Participants
n=20 Participants
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Sex: Female, Male
Male
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10 Participants
n=20 Participants
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Ethnicity (NIH/OMB)
Hispanic or Latino
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0 Participants
n=20 Participants
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Ethnicity (NIH/OMB)
Not Hispanic or Latino
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10 Participants
n=20 Participants
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Ethnicity (NIH/OMB)
Unknown or Not Reported
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0 Participants
n=20 Participants
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Region of Enrollment
United States
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10 participants
n=20 Participants
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PRIMARY outcome
Timeframe: 15 daysPopulation: 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
Change in clinician rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Clinical Global Impressions Improvement Scale as Determined by the Treating Clinician
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3.8 score on a scale
Interval 3.399 to 4.26
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3.7 score on a scale
Interval 3.106 to 4.07
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PRIMARY outcome
Timeframe: 15 daysPopulation: This assessment not completed for 2 participants
Change in caregiver rated measures on scale of 1 to 7, higher value indicates more severe symptom presentation
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=8 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=8 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Clinical Global Impressions Improvement Scale as Determined by the Caregiver
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2.8 score on a scale
Interval 1.16 to 3.8
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2.9 score on a scale
Interval 1.1 to 3.6
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PRIMARY outcome
Timeframe: 15 daysChange 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
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Visual Analog Scale as Determined by the Patient Caregiver
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-6 score on a scale
Interval -16.25 to 5.334
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-6.5 score on a scale
Interval -18.61 to 4.408
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PRIMARY outcome
Timeframe: 15 daysAuditory 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).
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
SPG601: synthetic small molecule
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|---|---|---|
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Change in Auditory Response to Chirp Stimulus
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0.014 Inter Trial Coherence
Standard Deviation 0.062
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-0.012 Inter Trial Coherence
Standard Deviation 0.041
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SECONDARY outcome
Timeframe: 15 daysKiTAP 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.
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=7 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=5 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Change From Baseline in Attention and Inhibition Symptoms-Go/NoGo Subtest
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-17.6 milliseconds
Interval -145.8 to 112.6
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67.8 milliseconds
Interval -87.63 to 220.4
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SECONDARY outcome
Timeframe: 15 daysNational 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.
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=7 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=6 Participants
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.
SPG601: synthetic small molecule
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|---|---|---|
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Change in Cognitive Outcomes Measured by NIH Cognitive Toolbox
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1.7 score on a scale
Interval -26.52 to 23.13
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15.5 score on a scale
Interval -2.098 to 41.05
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SECONDARY outcome
Timeframe: 15 daysPopulation: not completed for one participant
RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) is scored from -4 to 4, with higher values indicate higher memory and cognitive assessment
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Change in Memory and Cognitive Assessment With RBANS List Learning.
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3.8 score on a scale
Interval 0.7873 to 5.213
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1.7 score on a scale
Interval -0.546 to 3.879
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SECONDARY outcome
Timeframe: 15 daysAuditory 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)
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Change in Auditory Response to Steady State Auditory Stimuli From Baseline
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0.014 ITC
Standard Deviation 0.0615
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-0.012 ITC
Standard Deviation 0.0417
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SECONDARY outcome
Timeframe: 15 daysIncidence, nature, and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=10 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Safety and Tolerability of SPG601 in Patients With Fragile X Syndrome
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0 participants
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1 participants
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SECONDARY outcome
Timeframe: 15 daysThe 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.
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=7 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=5 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Change From Baseline in Attention and Inhibition Symptoms-Flexibility Subtest
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-103.4 milliseconds
Interval -330.5 to 142.3
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-61.8 milliseconds
Interval -356.6 to 207.0
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SECONDARY outcome
Timeframe: 15 daysKiTAP 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.
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
|
Change From Baseline in Attention and Inhibition Symptoms-Alertness Subtest
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-133 milliseconds
Interval -405.5 to 138.8
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129.4 milliseconds
Interval -142.4 to 402.0
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SECONDARY outcome
Timeframe: 15 daysThe 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.
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=6 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
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Change From Baseline in Attention and Inhibition Symptoms-Distractability Subtest
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45.94 correct responses
Interval -63.14 to 155.0
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-54.7 correct responses
Interval -173.6 to 93.29
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SECONDARY outcome
Timeframe: 15 daysPopulation: unable to collect and record data due to technical difficulties with equipment. Pre-specified measurement values were not obtained and will not be collected or analyzed in the future.
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.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: 15 daysThis 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
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=9 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
|
Change in Eye Tracking Measured by Electroretinography
|
-1.15 milli volts
Standard Deviation 3.11
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-1.35 milli volts
Standard Deviation 1.78
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SECONDARY outcome
Timeframe: 15 daysThis 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
Outcome measures
| Measure |
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=8 Participants
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.
Placebo: Placebo
|
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=8 Participants
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.
SPG601: synthetic small molecule
|
|---|---|---|
|
Change in Eye Tracking Measured by Electroretinography
|
.03 milli volts
Standard Deviation 2.05
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-2.16 milli volts
Standard Deviation 4.88
|
Adverse Events
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Experimental: Active SPG601 to be Administered to Participants With Fragile X Syndrome
n=10 participants at risk
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.
SPG601: synthetic small molecule
|
Placebo Comparator: Placebo Comparator to be Administered to Participants With Fragile X Syndrome
n=10 participants at risk
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.
Placebo: Placebo
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|---|---|---|
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Psychiatric disorders
exacerbation of tic
|
10.0%
1/10 • Number of events 1 • Adverse event data was collected at study visits that happened weekly for 3 weeks.
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0.00%
0/10 • Adverse event data was collected at study visits that happened weekly for 3 weeks.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place