Xenon Therapy for Children With Autism Spectrum Disorder (ASD; Xe)

Efficacy of Xenon in Children With Autism Spectrum Disorder: a Multicenter, Randomized, Controlled Study

This study aims to evaluate the efficacy and safety of inhaled xenon for the treatment of children with autism spectrum disorder (ASD). The primary objective is to determine whether short-term inhalational xenon therapy can improve social functioning in children with ASD, as measured by changes in the Social Responsiveness Scale (SRS). Safety and tolerability of xenon inhalation in the pediatric population will also be assessed.

In this randomized, placebo-controlled trial, participants will receive either inhaled xenon or a placebo gas (medical air without xenon) to compare treatment effects.

Participants will:

Inhale 25% xenon or placebo for 10 minutes per day for 10 consecutive days Attend two clinical visits: one immediately after completion of the intervention and one at 3 months post-intervention for follow-up assessments and safety evaluations

Study Overview

• Status: Not yet recruiting
• Conditions: Autism; Autism Spectrum Disorder (ASD)
• Intervention / Treatment: Drug: Xenon

• Study Type: Interventional
• Enrollment (Estimated): 72
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Jin piao Zhu, Associate fellow; Phone Number: 0571-81732399; Email: zhujinpiao@zju.edu.cn

Study Locations

• China
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310000
      • Children's Hospital Affiliated to Zhejiang University School of Medicine (Binjiang Campus)
      • Contact: Ai Mei Ma; Phone Number: 0571-86029132; Email: zuchiec@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 4-18 years, with no gender restriction.
• Meeting the diagnostic criteria for Autism Spectrum Disorder (ASD) as specified in the Diagnostic and Statistical Manual of Mental Disorders (5th Edition) (DSM-5), with the diagnosis confirmed by assessment using the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2).
• The total T-score on the Social Responsiveness Scale, Second Edition (SRS-2) is ≥90.
• No treatment such as neuromodulation (transcranial magnetic stimulation, transcranial electrical stimulation) has been received for at least 1 month prior to randomization.
• For participants who have previously taken psychotropic medications prior to randomization, it is required that the medications have been discontinued for a minimum of 5 half-lives or 4 weeks, whichever is longer.
• The participants and their legal guardians confirm that they will not add new or alter the existing established treatment regimens such as behavioral rehabilitation during the study period.
• The legal guardians of the participants have a full understanding of the study content, participate voluntarily, and sign a written informed consent form.

Exclusion Criteria:

• Having other major neurological diseases (e.g., epilepsy, cerebral palsy), severe physical illnesses, or genetic syndromes.
• Having severe auditory or visual impairments that prevent the completion of assessments with cooperation.
• A history of anaphylaxis or adverse reactions to Xenon.
• Currently participating in or having participated in other interventional clinical trials within the recent 3 months.
• The investigator judges that there is any condition that may increase the risk to the participant or interfere with the conduct of the trial and the assessment of its results.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Participants inhaled 30% oxygen, 10 min/day, for 10 days; Children aged 4-8 years with autism spectrum disorder in the control group underwent a daily 10-minute inhalation of 30% oxygen (delivered via face mask at 2 L/min) for 10 consecutive days.	Drug: Xenon; Children aged 4-18 with autism spectrum disorder inhaled a mixture of 25% Xenon via a face mask at an oxygen flow rate of 2 L/min, for 10 minutes per day for 10 day.; Other Names: Xe
Experimental: Participants inhaled a mixture of 25% Xenon, 10 min/day, for 10 days; Children aged 4-8 years with autism spectrum disorder in the treatment group underwent a daily 10-minute inhalation of 25% Xenon (delivered via face mask at 2 L/min) for 10 consecutive days.	Drug: Xenon; Children aged 4-18 with autism spectrum disorder inhaled a mixture of 25% Xenon via a face mask at an oxygen flow rate of 2 L/min, for 10 minutes per day for 10 day.; Other Names: Xe

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Core symptom outcomes	For the assessment of core symptom outcomes, the social responsiveness scale, Second Edition was used.Raw scores were converted to age- and sex-normed T-scores, with a minimum obtainable T-score of 30. A total T-score of 60 or higher indicates clinically significant symptom severity, whereas T-scores of 59 or below are considered within the normal range.	From enrollment to the end of treatment at 3 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Core symptom outcomes	For the assessment of core symptom outcomes, the Autism Diagnostic Observation Schedule (ADOS-2) was used.	From enrollment to the end of treatment at 3 months.
Aberrant behavior outcomes	For the assessment of aberrant behavior outcomes, the Aberrant behavior Checklist (ABC) scale was used.	From enrollment to the end of treatment at 3 months.
Treatment efficacy	For the assessment of treatment efficacy, the Autism Treatment Evaluation Checklist scale was used. The Autism Treatment Evaluation Checklist total score ranges from a minimum of 0 (no autism symptoms) to a maximum of 179 (severe impairment), with lower scores indicating fewer symptoms and higher scores indicating greater severity.	From enrollment to the end of treatment at 3 months.
Severity	For the assessment of behavioral severity, the Clinical Impressions Severity of illness (CGI-S) was used.	From enrollment to the end of treatment at 3 months.
Improvements	For the assessment of behavioral improvements after treatment, the Clinical Global Impressions scale for Improvement (CGI-I) scale was used.The Clinical Global Impressions-Improvement scale is a 7-point scale ranging from 1 ("Very much improved") to 7 ("Very much worse"), with a score of 4 indicating "No change."	From enrollment to the end of treatment at 3 months.
Sleep problems	For the assessment of sleep problems, the Children's Sleep Habits Questionnair (CSHQ) was used.	From enrollment to the end of treatment at 3 months.
Brain functions	For the assessment of brian functions, the MRI imaging was used.	From enrollment to the end of treatment at 3 months.

Collaborators and Investigators

• Sponsor: The Children's Hospital of Zhejiang University School of Medicine

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): March 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: February 5, 2026
• First Submitted That Met QC Criteria: February 24, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 24, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Neurodevelopmental Disorders; Child Development Disorders, Pervasive; Autism Spectrum Disorder; Autistic Disorder; Inorganic Chemicals; Elements; Gases; Noble Gases; Xenon
• Other Study ID Numbers: 2026-IRB-0023-IR-01; CHZJU2025IIT006 (Other Grant/Funding Number: Children's Hospital, Zhejiang University School of Medicine)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No