A Study to Investigate the Effects and Safety of SPG601 for the Treatment of Fragile X Syndrome in Male Participants

NCT07439510 | Not Yet Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: SPG601-102 (CLARITY)
• Study Type: interventional
• Target: 248
• Locations: 0 countries
• Sites: N/A

Brief Summary

This Phase 2b/3, randomized, double-blind, placebo-controlled, 2-part study will evaluate the efficacy, safety and tolerability of different dose regimens of SPG601 in adult male participants with Fragile X syndrome.

Conditions

Fragile X Syndrome (FXS)

Keywords

Fragile X Syndrome; Fragile X Chromosome; cognitive outcomes

Outcome Measures

Primary Outcomes (3)

• Phase 2b: 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.

  8 weeks

• Phase 2b: Change from baseline in EEG resting state relative power bands during rest

  Resting-state EEG relative power changes from baseline are characterized by significant shifts in power bands such as gamma, alpha, theta and beta bands

  8 weeks

• Phase 3: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.

  12 weeks

Secondary Outcomes (21)

• Phase 2b: Change from baseline in Fluid Reasoning Composite Change Sensitive Scores from the NIH-TCB

  8 weeks

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

  8 weeks

• Phase 2b: Incidence, nature, and severity of adverse events (AEs) and serious adverse events (SAEs)

  8 weeks

• Phase 2b: Change from baseline in Columbia-Suicide Severity Rating Scale (C-SSRS) throughout the study

  8 weeks

• Phase 2b: The PK parameters of SPG601 concentrations in plasma-Cmax

  4 weeks

Study Arms (4)

Phase 2b: Active comparator

ACTIVE COMPARATOR

Phase 2b: Active SPG601 to be administered to participants with Fragile X Syndrome Participants with Fragile X Syndrome will be randomized to receive SPG601 daily for 4 weeks

Drug: SPG601

Phase 2b: Placebo

PLACEBO COMPARATOR

Participants with Fragile X Syndrome will be randomized to receive placebo over 4 weeks.

Drug: Placebo

Phase 3: Active comparator

ACTIVE COMPARATOR

Participants with Fragile X Syndrome will be randomized to receive dose of SPG601 determined from Phase 2b over 12 weeks

Drug: SPG601

Phase 3: Placebo

PLACEBO COMPARATOR

Participants with Fragile X Syndrome will be randomized to receive placebo for 12 weeks

Drug: Placebo

Interventions

SPG601 DRUG

synthetic small molecule

Phase 2b: Active comparator; Phase 3: Active comparator

Placebo DRUG

Placebo

Phase 2b: Placebo; Phase 3: Placebo

Eligibility Criteria

• Age: 18 Years - 45 Years
• Gender Eligibility Details: Male
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Adult males aged 18 to 45 years, inclusive
• Diagnosis of Fragile X as confirmed with genetic testing
• Patient must have caregiver
• Must be in good health with no significant medical history

You may not qualify if:

• 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 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
• Unable to swallow capsules

Sponsors & Collaborators

• Spinogenix: lead

MeSH Terms

Conditions

Fragile X Syndrome

Condition Hierarchy (Ancestors)

X-Linked Intellectual Disability; Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Sex Chromosome Disorders; Chromosome Disorders; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Genetic Diseases, Inborn; Genetic Diseases, X-Linked; Heredodegenerative Disorders, Nervous System

Central Study Contacts

Contact

CONTACT

(503) 673-3842; contact@spinogenix.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 18, 2026
• First Posted: February 27, 2026
• Study Start: March 1, 2026
• Primary Completion (Estimated): February 1, 2030
• Study Completion (Estimated): June 30, 2030
• Last Updated: February 27, 2026

Record last verified: 2026-02