ClinicalTrials.gov record NCT07654114

Safety, Tolerability, and Preliminary Effectiveness of CTH120 in Fragile X Syndrome

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

Evaluation of the Safety, Tolerability, and Effectiveness of CTH120 in Adult Males With Fragile X Syndrome

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 2A study that tests whether a treatment has the intended effect and continues to check safety, usually in a larger group than phase 1.
Age18 years old and older
SexMale
LocationSpain
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Phase 2, randomized, placebo-controlled study testing CTH120 in adult males with Fragile X syndrome. About 30 participants are randomized 1:1 to receive CTH120 75 mg twice daily or matching placebo. Participation lasts roughly three months including screening, a treatment period, and a short safety follow-up. The study collects safety data, drug levels, and exploratory measures of behaviour, cognition, sleep, EEG, and blood biomarkers.

What it is studying. The study is testing whether CTH120 can be given safely and tolerated in adult males with Fragile X syndrome. It also measures how the drug behaves in the body (pharmacokinetics) and collects early, exploratory data on behaviour, cognition, sleep patterns, brain activity (EEG), and blood markers such as FMRP, BDNF, and miRNA profiles.

What the researchers hope to learn. To evaluate safety and tolerability of CTH120 in adult males with Fragile X syndrome; to describe the drug's pharmacokinetics; and to collect exploratory data on behaviour, cognition, sleep, EEG patterns, and blood biomarkers (including FMRP, BDNF, and miRNA) that may inform future research.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The purpose of this Phase IIa study is to evaluate the safety, tolerability, and effectiveness of CTH120 in adult males with Fragile X syndrome.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • CTH120
Other
  • CTH120 placebo hard capsules

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Adult male participants.
  • Aged ≥ 18 and ≤ 45 years.
  • Weight ≥ 50 kg and ≤ 100 kg.
  • Body mass index (BMI) ≥ 18.5 and ≤ 32.
  • Clinical and molecular diagnosis of Fragile X syndrome (> 200 CGG repeats in the promoter region of the FMR1 gene).
  • Participants must have a parent, or other reliable caregiver, who agrees to accompany the participant to all study visits, provide information about the participant as required by the protocol, and ensure compliance with study tests.
  • Legal representative understands and accepts the study procedures. If only one parent signs, he/she should confirm that the other parent does not object to the patient's participation in the study.
  • Participant assenting and/or willing to participate.
  • Signed informed consent by legal representative prior to any study-mandated procedure.
  • Participant with a CGI-S score ≥ 3 evaluated by a clinician with experience on Fragile X syndrome, independently mobile and having sufficient vision and hearing to participate in study evaluations. They must be able to be understood most of the time and must not depend upon other forms of communication, signs, symbol boards or devices as their primary form of communication.
  • Participants are expected to complete all procedures scheduled during the study visits.
  • VCI scaled score >4 on the WISC-V, based on mental age.

Exclusion criteria

  • Personal history of infantile spasms/convulsions/epilepsy, severe head trauma or CNS infections (e.g. meningitis), except for infantile febrile seizures.
  • Participants with a current diagnosis of severe (Level 3) autism spectrum disorder or any primary psychiatric diagnosis according to DSM-5 (Diagnostic and Statistical Manual of Mental Disorders-DSM-5). Diagnoses that are secondary, such as attention deficit hyperactivity disorder, depressive disorders, anxiety disorders and conduct disorders are allowed if they are considered to not interfere with study conduct and are stable during the 8 weeks prior to screening. Related allowed treatments must be on stable dosing for the last 3 months.
  • Substance use disorder according to the DSM-5 criteria.
  • Epileptiform abnormalities on EEG (excluding isolated sharp waves and beyond those expected for age).
  • Any life-threatening medical disease.
  • Any other clinically relevant concomitant disease or condition or finding at screening that in the judgment of the investigator could interfere with the treatment, the conduct of the study and related procedures and/or might bias the study results interpretation or could jeopardize the participant's safety.
  • Any clinically significant findings on physical examination including clinically significant vital sign abnormalities, from the perspective of the investigator.
  • Any clinically significant laboratory or ECG abnormalities, from the perspective of the investigator, at Screening and/or prior to the initiation of the study medication.
  • Known hypersensitivity or intolerance to any component of the investigational medicinal product or its excipients.
  • Neuroleptic or antidepressant (SSRI) drugs within the 8 weeks prior to screening, except for sertraline at maximum 100 mg/day, and with no changes in the 8 weeks prior the initiation of the study.
  • More than 3 psychotropic medications simultaneously in the 8 weeks prior to Screening and also during the study.
  • Any new prescription or over the counter drug (except occasional use of paracetamol) in the last 2 weeks before Day 1.
  • Participation in a clinical study with investigational treatments in the last 8 weeks prior to screening.
  • Auditory or visual impairments that cannot be corrected.
  • Positive EtG/EtS test in urine.
  • Positive drug test in urine.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Detailed description from the registry

A total of 30 randomized adult participants with Fragile X syndrome will participate in the clinical trial (randomization ratio 1:1 treated vs placebo arms). The expected distribution between sites will be 1:1. This trial will consist of a Screening period of up to 28 days prior to treatment period. A final follow-up period for safety of 14 days (± 2 days) is planned after the end of treatment. The duration of the study will be approximately 3 months for each participant.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

After a screening period (up to 28 days), participants are randomized to receive oral study capsules twice daily (after breakfast and after dinner) for the treatment period (the study lasts about 3 months per participant, with an end‑of‑study visit around Day 56 and a 14‑day safety follow‑up). Study visits include safety checks (vital signs, ECGs, physical exams, routine blood and urine tests), multiple blood draws for drug levels and biomarker testing, and urine drug/alcohol tests. Participants will also have EEG recordings (mobile wireless helmet), eye‑tracking, wear a wrist actigraph for at least 7 days, and complete clinician ratings, cognitive tests and caregiver questionnaires. The study requires a caregiver to attend visits and to help ensure compliance with procedures and assessments.

How the study is structured. Adults are randomly assigned to one of two groups: CTH120 capsules or matching placebo, taken by mouth twice daily. The study is blinded so participants, caregivers, and study staff do not know who receives the drug or placebo. Visits include baseline assessments, on-treatment visits with safety checks and blood sampling for drug levels, and a final short safety follow-up; total participation is about three months.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
  • The listed sites are in Spain. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on fragile X syndrome

Clinical trials20 trials listed for fragile X syndromeEvery trial the registry lists for fragile X syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in fragile X syndrome researchLatest monthly update: September 2026. Includes: Multiple behavior challenges. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
May 21, 2026
Primary completion
May 2027 (estimated)
Study completion
May 2027 (estimated)
Target enrollment
30 participants (estimated)
Last updated on registry
Jul 17, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Connecta Therapeutics, S.L.
Collaborators
  • Hospital del Mar Research Institute (IMIM)
  • Corporacion Parc Tauli
  • Ministry of Science and Innovation, Spain
  • Astrum CRO, S.L.

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (2)

Terms used on this page · explanations by MedicalUpdates.ai

Legal representative
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
prior to screening
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
ECG
A recording of the heart's electrical activity. QTc is one measurement from it; some drugs are avoided if it is prolonged.
investigational
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
randomized
Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
randomization ratio
How many participants go to each group. In a 2:1 ratio, two are assigned to the first group for every one assigned to the second.
placebo
A treatment that looks like the study treatment but contains no active ingredient. Some participants receive it instead of the study treatment, usually without knowing which they got.
follow-up
The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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