A Phase 3 interventional study of Arbaclofen and Placebo in Autism Spectrum Disorders, sponsored by Hospital General Universitario Gregorio Marañon. Recruiting at 5 sites in 2 countries. Open to participants aged 0 Years to 64 Years. Per ClinicalTrials.gov, last updated 2026-06-17.
Sponsored by Hospital General Universitario Gregorio Marañon · Phase 3, Interventional, and Treatment
study with arbaclofen (4 weeks of titration and then 6 weeks of active/stable treatment). The effects of arbaclofen on target EEG and ERG metrics will be associated with the clinical response in measures of social and general function, adaptive behaviour, social anxiety, sensory behaviours, global functioning, and quality of life in Children and Adolescents with Autism Spectrum Disorders
1,724 studies on the registry are indexed under Autism Spectrum Disorder; 500 are open to participants now.
This study's planned enrollment of 103 is above the median of 52 across 1,368 interventional studies indexed under Autism Spectrum Disorder.
Browse Autism Spectrum Disorder studies →Hospital General Universitario Gregorio Marañon is the lead sponsor of 60 studies on the registry; 7 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Arbaclofen
Other: Placebo
initial single dose arbaclofen
initial single dose placebo
Change in power in the low frequency bands (theta/alpha) (between visits 1 and 2).
To predict long term response to arbaclofen based on a single dose response during the placebo-controlled randomized single dose double blind stage.
Time frame: baseline to day 7
Latency of N170 change (between visits 1 and 2).
To test the effect of arbaclofen on an EEG biomarker for response to faces during the placebo-controlled randomized single dose double blind stage.
Time frame: baseline to day 7
Change of Autism Impact Measure (AIM total (Kanne et al., 2014b, Silkey et al., 2023) and subscales. • Change in the Social Responsiveness Scale (SRS total and subscales; Constantino & Gruber, 2012a).
To explore the effect of arbaclofen on other measures of defining features of autism.
Time frame: from baseline to end of treatment
Change in power in the higher frequency bands (gamma/beta); connectivity in the theta and alpha bands; (between visits 1 and 2).
To explore EEG marker sensitive to excitatory/inhibitory changes.
Time frame: baseline to day 7
Plan to share: Yes — De-identified data will be entered in a GDPR compliant EDC by individual sites, and after thorough checks shared with the sponsor, according to the CTA. Data will possibly be shared after thorough data cleaning and checks of de-identification of individuals, with other parties of the consortium, if participants have agreed to that in the Informed Consent Form. Examples of these data would be EEG data, that would be uploaded in a secured server, and analysed by a consortium partner.
Supporting information: Clinical study report
Time frame: 365 days after study finalizes
No publications or documents are linked to this record.
Started Nov 2025 (actual). Primary completion is estimated for Dec 2026, 13 months after the start.
Of 18 phase 3 interventional studies under Autism Spectrum Disorder, half reached primary completion within 33 months of starting (the median), counting those still running; a quarter within 25 and three quarters within 38. This study's planned 13 months is below that.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
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Studies of the drug tested here: Arbaclofen
Hospital General Universitario Gregorio Marañon