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Fragile X Syndrome (FXS)Phase 2/3NCT07439510

A Study to Investigate the Effects and Safety of Codabakalner for the Treatment of FXS in Male Participants and Adult Participants With ADS

A Phase 2/3 study testing Codabakalner in people with Fragile X Syndrome (FXS) and Autism Spectrum Disorder (ASD), run by Spinogenix.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This is a Study to Investigate the Effects and Safety of Codabakalner for the Treatment of Fragile X Syndrome in Male Participants and Adult Participants with Autism Spectrum Disorders Read more about this study

Who is it for?
Ages 18 to 45 years, men only
What is being tested?
Codabakalner
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
120 participants
Where
No sites listed yet
Study dates
1 Dec 2026to 30 Jun 2030
Phase
Phase 2/3
Are there results?
Not yet: the study is under way

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

  • Phase 2b: Adult males aged 18 to 45 years, inclusive Phase 3: Males aged 13-45 years, inclusive Mental age >/= 36mon
  • Diagnosis of Fragile X as confirmed with genetic testing and Stanford Binet testing or
  • Confirmed diagnosis ASD per DSM5-TR and EEG criteria
  • Patient must have caregiver
  • Must be in good health with no significant medical history

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 cannot be corrected
  • History of suicidal behaviour or suicidal ideation
  • Screening vital signs that are abnormal per protocol specification
  • ECG that are abnormal and clinically significant
Show all 9Show fewer
  • History of substance abuse or dependence within 6 months
  • Other investigational products within 30 days
  • Unable to swallow capsules

Trial locations and contacts

No sites are listed yet. Contact the study team or a site near you to ask about taking part.

About this study

Official title: A Phase 2b/3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Codabakalner in Male Participants With Full Mutation Fragile X Syndrome and Adult Participants With Autism Spectrum Disorders

This is a Study to Investigate the Effects and Safety of Codabakalner for the Treatment of Fragile X Syndrome in Male Participants and Adult Participants with Autism Spectrum Disorders

Read the detailed description

This Phase 2b/3, randomized, double-blind, placebo-controlled, 2-part study will evaluate the efficacy, safety and tolerability of different dose regimens of codabakalner in adult male participants with Fragile X syndrome. The results from Phase 2b will be hypothesis generating and will inform the Phase 3 design.

Phase 2b, dose-regimen finding, 4-arm parallel design: Eligible participants will be randomized 1:1:1:1 to receive codabakalner at different doses or matched placebo. Participants will receive study intervention over 4 weeks and will be followed up for 4 weeks after last dose of study intervention.

Phase 3, 2-arm parallel design: Eligible participants will be randomized 1:1 to receive codabakalner or matched placebo. The dose of codabakalner administered in the Phase 3 will be defined based on analysis of Phase 2b. Participants will receive study intervention over 12 weeks and will be followed up for 4 weeks after last dose of study intervention.

Being tested
Codabakalner, Placebo
Keywords
Fragile X Syndrome, Fragile X Chromosome, cognitive outcomes, Autism, Autism Spectrum Disorder
Medical subject headings
Fragile X Syndrome, Autism Spectrum Disorder, Autistic Disorder

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • CodabakalnerDrug

    Also called SPG601

    synthetic small molecule

  • PlaceboDrug

    Placebo

Study groups in NCT07439510
Study groupRoleWhat they receive
Phase 2b: ActiveActive comparatorPhase 2b: Participants with FXS or ASD will be randomized to receive a daily dose of codabakalner daily for 4 weeks
Receives: Drug: Codabakalner
Phase 2b: PlaceboPlacebo comparatorParticipants with FXS or ASD will be randomized to receive a daily dose of placebo over 4 weeks.
Receives: Drug: Placebo
Phase 3: ActiveActive comparatorParticipants with FXS will be randomized to receive a daily dose of codabakalner determined from Phase 2b over 12 weeks
Receives: Drug: Codabakalner
Phase 3: PlaceboPlacebo comparatorParticipants with FXS will be randomized to receive a daily dose of placebo for 12 weeks
Receives: Drug: Placebo

What is being measured

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

  1. Phase 2b: FXS- Change from baseline in Total Cognition Composite Change Sensitive Score from the NIH-TCB

    The NIH Toolbox (NIH-TCB) Total Cognition Composite Change-Sensitive Score (CSS) is used to measure cognitive change over time. Higher scores indicate higher level of functioning. The scores typically span across the developmental range, often extending well above and below the 500-point mark depending on the age and cognitive ability of the individual.

    Measured: 28 days

  2. Phase 2b: ASD - Change from Baseline at Day 28 on the Vineland Adaptive Behavior Scales in ASD(Vineland-III) Adaptive Behavior Composite Score

    Vineland Adaptive Behavior Composite (ABC) have a mean of 100 and a standard deviation of 15, where scores from 85 to 115 reflect expected or average adaptive functioning

    Measured: 28 days

  3. Phase 3: FXS - Change from baseline in Total Cognition Composite score from the NIH-TCB

    The NIH Toolbox (NIH-TCB) Total Cognition Composite Change-Sensitive Score (CSS) is used to measure cognitive change over time. It is calculated by combining the Crystallized Composite (reading/vocabulary) and Fluid Composite (memory/executive function/speed) scores. Higher scores indicate higher level of functioning.

    Measured: 12 weeks

Secondary outcomes (25)
  1. Phase 2b: FXS- Change from baseline in Fluid Reasoning Composite Change Sensitive Scores from the NIH-TCB

    The Fluid Cognition Composite (FCC) from the NIH Toolbox Cognition Battery (NIHTB-CB) is designed to measure changes to neurological functioning. It combines scores from five tests (Dimensional Change Card Sort, Flanker, List Sorting, Pattern Comparison, and Picture Sequence Memory) to provide a measure of executive function, memory, and processing speed. Higher scores indicate higher level of functioning. Superior ability is 130, average is approx. 100 and less than 70 is impairment.

    Measured: 28 days

  2. Phase 2b: FXS- Change from baseline in Flanker Scores from the NIH-TCB

    The Flanker test measures executive attention, inhibitory control, and attention by having participants identify the direction of a central arrow (or fish for young children) while ignoring surrounding flanking stimuli. Yields a standardized score scaled with a mean of 100 and a standard deviation of 15 (up to a maximum score of 130)

    Measured: 28 days

  3. Phase 2b- FXS Change from Baseline at Day 28 on the Vineland Adaptive Behavior Scales (Vineland-III) Adaptive Behavior Composite Score

    Vineland Adaptive Behavior Composite (ABC) have a mean of 100 and a standard deviation of 15, where scores from 85 to 115 reflect expected or average adaptive functioning

    Measured: 28 days

  4. Phase 2b: FXS and ASD: Change from baseline at Day 28 in Clinical global impression of severity (CGI-S) as assessed by the investigator

    This is a 7-point clinician-rated tool used to measure how ill a patient is at the time of assessment

    Measured: 28 days

  5. Phase 2b: FXS and ASD: Change from baseline at Day 28 in Clinical global impression of improvement as assessed by the investigator

    The Clinical Global Impression-Improvement (CGI-I) scale is a clinician rated scale used to assess treatment response. The score ranges from 1 to 7 (with 1 being "very much improved", 4 being "no change" to 7 being "very much worse")

    Measured: 28 days

  6. Phase 2b: FXS and ASD: Change from baseline at Day 28 in Caregiver global impression of change (CGI-C) as assessed by the caregiver

    The Caregiver Global Impression of Improvement (CGI-C) is a global measure to provide a caregiver's perspective of a subject's overall condition. The caregiver will use a 7-point scale to assess how the condition has changed from baseline. A higher number indicates worsening condition.

    Measured: 28 days

  7. Phase 2b: FXS and ASD: Change from baseline at Day 28 in the Numerical Rating Scale as completed by the caregiver

    Numerical rating scale (NRS) scores based on patient-specific behaviors within the domains of Daily Function, Language, and Academic Skill. Caregiver will rate individual from 0 to 10, where 0 indicates 'worst problem' and 10 indicates' no problem at all.'

    Measured: 28 days

  8. Phase 2b: FXS and ASD - Incidence, nature, and severity of adverse events (AEs) and serious adverse events (SAEs)

    Incidence, nature, and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)

    Measured: 28 days

  9. Phase 2b: FXS and ASD - Change from baseline in Columbia-Suicide Severity Rating Scale (C-SSRS) throughout the study

    Prospective suicidality assessment is performed using the Columbia-Suicide Severity Rating Scale (C-SSRS), a questionnaire to evaluate suicidal ideation and behavior. Answer "yes" on item 4 or 5 of the Suicidal Ideation section or "yes" on any item of the Suicidal Behavior section is considered positive. Range is 2-25

    Measured: 28 days

  10. Phase 2b: FXS and ASD - The PK parameters of codabakalner concentrations in plasma-Cmax

    Maximum concentration of drug in plasma following dose

    Measured: 28 days

  11. Phase 2b: FXS and ASD: Change from baseline to Day 28 in EEG resting state relative power in the alpha, theta, and gamma bands during rest

    EEG power bands categorize brain electrical activity into five primary frequency ranges that reflect different states of arousal, sleep, and cognition

    Measured: 28 days

  12. Phase 3: Change from baseline to week 12 in Total Cognition Composite score from the NIH-TCB

    The NIH Toolbox (NIH-TCB) Total Cognition Composite Change-Sensitive Score (CSS) is used to measure cognitive change over time. It is calculated by combining the Crystallized Composite (reading/vocabulary) and Fluid Composite (memory/executive function/speed) scores. Higher scores indicate higher level of functioning. The scores typically span across the developmental range, often extending well above and below the 500-point mark depending on the age and cognitive ability of the individual.

    Measured: 12 weeks

  13. Phase 3: Incidence, nature, and severity of adverse events (AEs) and serious adverse events (SAEs)

    Incidence, nature, and severity of treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)

    Measured: 12 weeks

  14. Phase 3: Change from baseline in Columbia-Suicide Severity Rating Scale (C-SSRS) throughout the study

    Prospective suicidality assessment is performed using the Columbia-Suicide Severity Rating Scale (C-SSRS), a questionnaire to evaluate suicidal ideation and behavior. Answer "yes" on item 4 or 5 of the Suicidal Ideation section or "yes" on any item of the Suicidal Behavior section is considered positive. Range is 2-25

    Measured: 12 weeks

  15. Phase 3: Change from baseline to Week 4, Week 8, and Week 12 in Flanker from the NIH-TCB

    Flanker Inhibitory control will assess inhibitory control and attention through asking participant to focus on one stimuli will not focusing on any stimuli surrounding it.

    Measured: 12 weeks

  16. Phase 3: Change from baseline to Week 4, Week 8, and Week 12 in Fluid Reasoning Composite Change Sensitive Scores from the NIH-TCB

    The Fluid Cognition Composite (FCC) from the NIH Toolbox Cognition Battery (NIHTB-CB) is designed to measure changes to neurological functioning. It combines scores from five tests (Dimensional Change Card Sort, Flanker, List Sorting, Pattern Comparison, and Picture Sequence Memory) to provide a measure of executive function, memory, and processing speed. Higher scores indicate higher level of functioning. Superior ability is 130, average is approx. 100 and less than 70 is impairment.

    Measured: 12 weeks

  17. Phase 3: Change from baseline to week 4 and week 8 in Total Cognition Composite score from the NIH-TCB

    The NIH Toolbox (NIH-TCB) Total Cognition Composite Change-Sensitive Score (CSS) is used to measure cognitive change over time. It is calculated by combining the Crystallized Composite (reading/vocabulary) and Fluid Composite (memory/executive function/speed) scores. Higher scores indicate higher level of functioning. The scores typically span across the developmental range, often extending well above and below the 500-point mark depending on the age and cognitive ability of the individual.

    Measured: 8 weeks

  18. Phase 3: The PK parameters of codabakalner concentrations in plasma-Cmax

    Maximum concentration of drug in plasma following dose

    Measured: 12 weeks

  19. Phase 3: Change in from baseline to Week 4, Week 8, and Week 12, in ABC total score and subscale scores (FXS scoring)

    The Aberrant Behavior Checklist-Community edition (ABC-C) is a 58-item, caregiver-rated symptom checklist for assessing problem behaviors of children and adults with mental retardation at home, in residential facilities, and work training centers. The assessment was done by attributing to each item a score from 0 ("not at all a problem") to 3 ("problem is severe in degree") The ABC will be scored using the FXS-specific factoring system (ABC-FX) for which the total score ranks from 0 to 165.

    Measured: 12 weeks

  20. Phase 3: Change from baseline to Week 4, Week 8, and Week 12 in behaviors and other symptoms on NRS by caregiver

    Numerical rating scale (NRS) scores based on patient-specific behaviors within the domains of Daily Function, Language, and Academic Skill. Caregiver will rate individual from 0 to 10, where 0 indicates 'worst problem' and 10 indicates' no problem at all.'

    Measured: 12 weeks

  21. Phase 3: Change from baseline to Week 12 in Vineland Adaptive Behavior Scale 3rd Edition

    Vineland-3 Adaptive Behavior Scale (Vineland-3), using the composite score and domain scores from communication, daily living skills, and socialization.

    The adaptive behavior composite standard score is computed from the sum of standard scores from the domains and converted into the adaptive behavior composite standard score. Higher scores indicate a higher adaptive level of functioning.

    Measured: 12 weeks

  22. Phase 3: Change from baseline in CGI-S as assessed by investigator

    This is a 7-point clinician-rated tool used to measure how ill a patient is at the time of assessment

    Measured: 12 weeks

  23. Phase 3: Change from baseline in CGI-I as assessed by investigator

    The Clinical Global Impression-Improvement (CGI-I) scale is a clinician rated scale used to assess treatment response. The score ranges from 1 to 7 (with 1 being "very much improved", 4 being "no change" to 7 being "very much worse")

    Measured: 12 weeks

  24. Phase 3: Change from baseline in Caregiver Global Impression of Improvement (CGI-C) assessments

    The Caregiver Global Impression of Improvement (CGI-C) is a global measure to provide a caregiver's perspective of a subject's overall condition. The caregiver will use a 7-point scale to assess how the condition has changed from baseline. A higher number indicates worsening condition.

    Measured: 12 weeks

  25. Phase 3: Change from baseline in the Numerical Rating Scale at Week 4, Week 8, and Week 12 as completed by the caregiver

    Numerical rating scale (NRS) scores based on patient-specific behaviors within the domains of Daily Function, Language, and Academic Skill. Caregiver will rate individual from 0 to 10, where 0 indicates 'worst problem' and 10 indicates' no problem at all.'

    Measured: 12 weeks

Timeline

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

  1. First posted27 Feb 2026
  2. Study start1 Dec 2026 (estimated)
  3. Primary completion1 Feb 2030 (estimated)
  4. Study completion30 Jun 2030 (estimated)

Resources

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 2/3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
120 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07439510
Sponsor's protocol ID
SPG601-102 (CLARITY)
Status last verified
Oct 2026
First submitted
18 Feb 2026
Last updated
9 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing Codabakalner in people with Fragile X Syndrome (FXS) and Autism Spectrum Disorder (ASD), run by Spinogenix.

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: opening soon, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

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 combined 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.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Contact ((310) 853-5695, contact@spinogenix.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Phase 2b: FXS- Change from baseline in Total Cognition Composite Change Sensitive Score from the NIH-TCB (time frame: 28 days). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 9 Oct 2026.

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