Targeting the Neurobiology of RRB in Autism Using N-acetylcysteine: Trial

NCT05664789 | Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: IRB-683534R00HD101702-03
• Study Type: interventional
• Target: 144
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to target the neurobiology of restricted and repetitive behaviors in children with autism spectrum disorder using N-acetylcysteine (NAC), a well-tolerated nutritional supplement that has shown promise for reducing symptom severity in recent small-scale trials. The findings from this research will shed light on the mechanisms of action underlying the clinical benefits of NAC and the effects of NAC on altering restricted and repetitive behavior symptom severity in children with autism spectrum disorder. This is a 12-week double-blind, randomized, placebo-controlled trial of NAC.

Conditions

Autism Spectrum Disorder

Keywords

Magnetic resonance imaging; N-acetyl cysteine; Restricted and repetitive behaviors; Electroencephalography

Outcome Measures

Primary Outcomes (2)

• Change in Children's Yale Brown-Obsessive Compulsive Scale for Autism Spectrum Disorder (CYBOCS-ASD) at 12 weeks

  Severity of restricted and repetitive behaviors, higher scores indicate more severe behaviors

  Screening and week 12

• Change in Glutamatergic neurometabolites at 12 weeks

  Glu and Glx measured by magnetic resonance imaging

  Baseline and week 12

Secondary Outcomes (2)

• Change in Restricted and Repetitive Behavior Scale Revised (RBS-R) at 12 weeks

  Baseline and week 12

• Change in Gamma band activity at 12 weeks

  Baseline and week 12

Study Arms (2)

N-acetylcysteine

ACTIVE COMPARATOR

12 week administration of active study compound

Drug: N acetyl cysteine

Placebo

PLACEBO COMPARATOR

12 week administration of matched placebo

Drug: Placebo

Interventions

Placebo DRUG

matched placebo

Placebo

N acetyl cysteine DRUG

N-acetylcysteine (NAC) is an over-the-counter dietary supplement that is relatively well tolerated and exhibits minimal side effects, even at high dosages. N

N-acetylcysteine

Eligibility Criteria

• Age: 3 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• children between 3 years and 12 years 11 months
• diagnosis of autism spectrum disorder confirmed with the Autism Diagnostic Interview- Revised and the Autism Diagnostic Observation Schedule-2, Brief Observation of Symptoms of Autism, or Childhood Autism Rating Scale
• at least moderate severity of restricted and repetitive behaviors defined by a Children's Yale-Brown Obsessive Compulsive Scale for Autism Spectrum Disorder score ≥ 11
• physical development indicative of prepubescence as defined by criteria for Tanner Stage 1
• if home address is within 300 miles of the primary study site, participants must pass MR safety screening (e.g., no metal in the body) and attempt baseline neuroimaging (MRI or EEG), otherwise baseline neuroimaging is not required for participation
• have stable medication regimens (≥ 30 days) and psychosocial treatments (≥ 60 days) prior to randomization with no anticipated changes during the trial

You may not qualify if:

• presence of known genetic abnormalities associated with ASD (e.g. Fragile X)
• current or life-time diagnosis of severe psychiatric disorder (e.g., schizophrenia)
• presence of significant medical problems
• the inability of at least one caregiver to speak and read English to a sufficient level
• participants taking glutathione agents/prodrugs
• history of any adverse effects to glutathione agents/prodrugs
• the inability to drink a sample study compound dissolved in liquid

Sponsors & Collaborators

• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): collaborator
• Stanford University: lead

Study Sites (1)

Department of Psychiatry and Behavioral Sciences

Palo Alto, California, 94304, United States

RECRUITING

MeSH Terms

Conditions

Autism Spectrum Disorder

Interventions

Acetylcysteine

Condition Hierarchy (Ancestors)

Child Development Disorders, Pervasive; Neurodevelopmental Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Cysteine; Amino Acids, Sulfur; Sulfur Compounds; Organic Chemicals; Amino Acids; Amino Acids, Peptides, and Proteins

Study Officials

• John Hegarty, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Brianna Alconcher

CONTACT

(650)723-7845; autismresearch@stanford.edu

John Hegarty, PhD

CONTACT

(650)723-7845; autismresearch@stanford.edu

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The placebo compound will match the active N-acetylcysteine in appearance, odor, taste, and packaging.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Assistant Professor

Model Details: Double-blind, randomized, placebo-controlled trial 2 arms, N-acetylcysteine and placebo

Study Record Dates

• First Submitted: December 7, 2022
• First Posted: December 27, 2022
• Study Start: April 26, 2023
• Primary Completion (Estimated): January 31, 2028
• Study Completion (Estimated): July 31, 2028
• Last Updated: January 20, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Time Frame: The data will be shared on January 15th and July 15th each year
• Access Criteria: Researchers with access to the National Database for Autism Research (NDAR) will be able to obtain the submitted data

Locations

US (1)