Folinic Acid as a Treatment for Autism Spectrum Disorder in Children (FOLIN-A)

June 1, 2026 updated by: Wong Chui Mae, KK Women's and Children's Hospital

Folinic Acid as a Treatment for Autism Spectrum Disorder in Children: A Double-blind Randomised Placebo-controlled Trial With Open Label Extension (FOLIN-A Trial)

Autism spectrum disorder (ASD) is a neurodevelopmental condition that affects communication, behavior, and social interaction in children. Current treatments are limited and mainly focus on managing symptoms. This study aims to evaluate whether folinic acid is safe and effective in improving symptoms of autism spectrum disorder in children. Participants will be randomly assigned to receive either folinic acid or a placebo during the double-blind treatment phase. After this phase, all participants will have the option to receive folinic acid in an open-label extension. The results of this study may help determine whether folinic acid could be a potential treatment option for children with autism spectrum disorder.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a double-blind, randomised, placebo-controlled clinical trial designed to evaluate the safety and effectiveness of folinic acid in children with autism spectrum disorder (ASD). Eligible participants will be randomly assigned to receive either 2 mg/kg/day of folinic acid or a matching placebo during a 12-week double-blind randomised controlled trial (RCT) treatment phase. Neither the participants, caregivers, nor study staff will know which treatment is assigned during this period. The primary aim is to assess whether folinic acid improves symptoms of autism spectrum disorder. Following completion of the double-blind phase, participants will enter a 12-week open-label extension, during which all participants will receive 2 mg/kg/day of folinic acid. This extension phase will allow for further evaluation of longer-term safety and potential benefits. The findings from this study may contribute to a better understanding of the role of folinic acid as a potential treatment option for children with autism spectrum disorder.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
184

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Singapore
    • Singapore
      • Singapore, Singapore, Singapore
        • Recruiting
        • KK Women's and Children's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Children aged 3 years 0 months to 10 years 11 months at the time of enrolment
  • Weight ≥ 10 kg and ≤ 30 kg at the time of enrolment
  • Confirmed diagnosis of Autism Spectrum Disorder (ASD) based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) or Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, supported by standardized diagnostic assessments
  • Stable on regular behavioral interventions and any medications for at least 6 months prior to enrolment
  • At least one parent or legal guardian able to understand and complete study questionnaires in English
  • Written informed consent obtained from a parent or legal guardian

Exclusion Criteria:

  • Known allergy or intolerance to folinic acid
  • Current or prior supplementation with folinic acid or other folate preparations (folic acid supplementation permitted)
  • Vitamin B12 (cobalamin) deficiency or pernicious anemia
  • Concurrent use of medications known to interfere with folate metabolism (e.g., methotrexate, trimethoprim, fluorouracil, capecitabine, glucarpidase)
  • Known genetic, metabolic, or chromosomal disorder, or structural brain abnormalities
  • History of epilepsy or seizures (except simple febrile seizures) or current use of antiepileptic or antipsychotic medication
  • Significant sensory (hearing or visual) or motor impairment
  • Participation in another interventional clinical trial for autism within the past 6 months
  • Unable or unwilling to comply with study visits and procedures

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Folinic Acid
Participants in this arm will receive folinic acid during the double-blind randomised controlled trial (RCT) phase of the study. After completion of the double-blind phase, participants will continue into an open-label extension in which folinic acid is provided.
Drug: Folinic Acid
Oral folinic acid administered during the double-blind randomised controlled trial (RCT) phase, followed by open-label folinic acid treatment.
Placebo Comparator: Placebo
Participants in this arm will receive a matching placebo during the double-blind randomised controlled trial (RCT) phase of the study. After completion of the double-blind phase, participants will continue into an open-label extension in which folinic acid is provided.
Drug: Placebo
Matching oral placebo administered during the double-blind randomised controlled trial (RCT) phase.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Pervasive Developmental Disorder-Behavior Inventory (PDDBI) Autism Composite T-Score
Time Frame: Baseline to Week 12
The Pervasive Developmental Disorder-Behavior Inventory (PDDBI) is a validated caregiver-completed instrument used to assess adaptive and maladaptive behaviors in individuals with autism spectrum disorder (ASD). The Autism Composite T-score is a standardized score (mean = 50, standard deviation = 10) that summarizes overall autism symptom severity, with higher scores indicating greater symptom severity. This outcome measure evaluates the change from baseline to Week 12 in PDDBI Autism Composite T-score. Lower T-scores indicate improvement in autism-related symptoms. Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in language function as measured by the Clinical Evaluation of Language Fundamentals (CELF)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in standardized language function scores as assessed using the Clinical Evaluation of Language Fundamentals (CELF), a standardized individually administered assessment of receptive and expressive language skills in children. CELF standardized scores have a mean of 100 and a standard deviation of 15, with higher scores indicating better language performance. Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in receptive vocabulary score as measured by the Receptive One-Word Picture Vocabulary Test (ROWPVT)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in standardized receptive vocabulary scores as assessed using the Receptive One-Word Picture Vocabulary Test (ROWPVT), a standardized individually administered assessment of a child's ability to understand spoken words. Scores are standardized with a mean of 100 and a standard deviation of 15, where higher scores indicate better receptive vocabulary ability. Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in expressive vocabulary score as measured by the Expressive One-Word Picture Vocabulary Test (EOWPVT)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in standardized expressive vocabulary scores as assessed using the Expressive One-Word Picture Vocabulary Test (EOWPVT), a standardized individually administered assessment of a child's ability to produce spoken words. Scores are standardized with a mean of 100 and a standard deviation of 15, where higher scores indicate better expressive vocabulary ability. Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in Clinical Global Impression-Severity and Improvement scores as measured by the Clinical Global Impression Scale (CGI-S and CGI-I)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I) scores, assessed using the Clinical Global Impression Scale, a standardized assessor-rated measure of illness severity and overall clinical improvement. CGI-S scores range from 1 (normal, not at all ill) to 7 (among the most extremely ill), where lower scores indicate better outcomes, and CGI-I scores range from 1 (very much improved) to 7 (very much worse), where lower scores indicate greater improvement. Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in Aberrant Behavior Checklist total score as measured by the Aberrant Behavior Checklist (ABC)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in total scores on the Aberrant Behavior Checklist (ABC), a standardized caregiver-completed questionnaire that assesses behavioural symptoms in children across domains such as irritability, lethargy, stereotypy, hyperactivity, and inappropriate speech. Total scores range from 0 to 174, with higher scores indicating greater severity of behavioural problems (worse outcomes). Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in total problem score as measured by the Child Behavior Checklist (CBCL)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in total problem scores on the Child Behavior Checklist (CBCL), a standardized caregiver-reported questionnaire that assesses a broad range of emotional and behavioural problems in children. Total scores are standardised T-scores (typically ranging from approximately 30 to 100, with a mean of 50 and standard deviation of 10), where higher scores indicate greater behavioural and emotional problems (worse outcomes). Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in adaptive behavior composite score as measured by the Vineland Adaptive Behavior Scales (VABS)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in standardised adaptive behavior scores as assessed using the Vineland Adaptive Behavior Scales (VABS), a standardized caregiver-reported assessment of a child's adaptive functioning across domains such as communication, daily living skills, socialization, and motor skills. Adaptive behavior composite scores are standardised (typically ranging from approximately 20 to 160, with a mean of 100 and standard deviation of 15), where higher scores indicate better adaptive functioning (better outcomes). Changes in scores will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Change from baseline in proportion of gaze duration to social stimuli as measured by eye-tracking assessment
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in eye-tracking measures of visual attention, specifically the proportion of total gaze duration directed toward social stimuli (e.g., faces or biological motion) compared with non-social stimuli, assessed using a standardized eye-tracking paradigm. Higher proportions indicate greater relative attention to social stimuli. Changes in proportions will be compared between participants receiving folinic acid and those receiving placebo.
Baseline to Week 12
Incidence of adverse events and serious adverse events as measures of safety and tolerability of folinic acid
Time Frame: Baseline to Week 24
Change from baseline to Week 24 in the incidence of adverse events (AEs) and serious adverse events (SAEs), monitored throughout the study period to assess the safety and tolerability of folinic acid treatment.
Baseline to Week 24

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in plasma glutathione redox ratio (GSH:GSSG)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in plasma glutathione redox ratio (reduced glutathione:oxidized glutathione; GSH:GSSG), a biomarker of oxidative stress balance. Higher ratios indicate a more reduced (favorable) redox state. Plasma reduced glutathione (GSH, µM) and oxidized glutathione (GSSG, µM) will be measured at baseline (T1) and Week 12 (T2).
Baseline to Week 12
Change from baseline in plasma methylation ratio (S-adenosylmethionine:S-adenosylhomocysteine; SAM:SAH)
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in plasma methylation ratio (S-adenosylmethionine:S-adenosylhomocysteine; SAM:SAH), a biomarker of methylation capacity. Higher ratios indicate greater methylation potential (better outcomes). Additional biomarkers related to one-carbon metabolism, including plasma homocysteine (µmol/L), will measured where available.
Baseline to Week 12
Change in Plasma Ergothioneine Levels
Time Frame: Baseline to Week 12
Change from baseline to Week 12 in plasma ergothioneine concentration (ET, nM). Plasma ergothioneine (ET, nM), hercynine (nM), and ophthalmic acid will be measured at baseline (T1) and Week 12 (T2).
Baseline to Week 12
Change in Folate Status Biomarkers
Time Frame: Baseline to Week 12
Change from baseline in serum and plasma folate status biomarkers. Folate status biomarkers include measures related to one-carbon metabolism and amino acid pathways. Plasma amino acid concentrations (µmol/L) will be interpreted with reference to established age-specific clinical ranges.
Baseline to Week 12
Association of FRAA Status With Treatment Response
Time Frame: Baseline to Week 12
Association between folate receptor autoantibody (FRAA) status and change in autism outcome measures. FRAA status will be classified as positive or negative based on the assay-specific cutoff defined by the testing laboratory: Blocking FRAA (pmol blocked per mL) and binding FRAA (optical density [OD] units per µL).
Baseline to Week 12
Sustained Effects of Folinic Acid on Autism Symptoms
Time Frame: Baseline to Week 24
Change from baseline in autism outcome measures following 24 weeks of folinic acid treatment.
Baseline to Week 24

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
KK Women's and Children's Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Nanyang Technological University
Singapore Health Services
National University of Singapore

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 19, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 8, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 1, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 5, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 1, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FOLIN-A-01
  • MOH-CIRG24jan-0004 (Other Grant/Funding Number: National Medical Research Council (NMRC), Singapore)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

At this time, there is no confirmed plan to share individual participant data (IPD) collected in this study. The study team will consider requests for access to de-identified individual participant data, including the analyzable dataset and relevant supporting documentation, on a case-by-case basis following completion of the study. Any data sharing will be subject to applicable institutional review board (IRB) requirements, data protection regulations, and data sharing agreements to ensure participant confidentiality and appropriate use.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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