Use of Low Doses of Interleukin-2 in Autism Spectrum Disorders

NCT07589842 | Not Yet Recruiting Phase 2 DMC

• 2 other identifiers: APHP2308672025-522841-23-00
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

Autism spectrum disorders (ASD) are neurodevelopmental disorders that affect around 1% of the population. Matenral immune activation (MIA) during pregnancy is a risk factor for ASD in children (Han 2021), mediated by maternal secretion of IL-17a, which disrupts neurodevelopment (Choi 2016). MIA causes a long-lasting disruption of the Tregs/Th17 balance in offspring (decrease in anti-inflammatory Tregs/increase in pro-inflammatory Th17s) via epigenetic mechanisms (Lim 2021; Ellul 2021). In a mouse model of MIA, adoptive transfer of Tregs was able to normalise autistic behaviour, highlighting the importance of Tregs in maintaining the autistic phenotype (Xu, 2021). In this same model, we have shown that IL-2fd (i) stimulates Tregs, (ii) corrects meningeal inflammation (iii) normalises synaptic connectivity and (iv) normalises autistic behaviour in the offspring (Ellul 2025). In humans, the use of low doses of interleukin-2 (IL2-fd) (ILT-101) leads to activation and selective expansion of Tregs and a reduction in Th17 (Klatzmann 2015), including in children (Rosenzwajg 2020). We hypothesise that the use of IL2-fd (ILT-101) in ASD patients born to mothers with a history of MIA could correct the Tregs deficiency and improve autistic symptoms.

Conditions

Autism Spectrum Disorder

Keywords

Autism Spectrum Disorder; ASI; Pregnancy; Interleukin-2

Outcome Measures

Primary Outcomes (1)

• Change in Tregs (in % of CD4+ cells and absolute value) between baseline and Day 8, compared with ILT-101 and placebo.

  To evaluate the stimulation of the Tregs of 6 to 8-years-old children with ASD whose mothers had MIA during pregnancy, by low doses of interleukin-2 (ILT-101) on day 8 versus placebo.

  At Day 8

Secondary Outcomes (9)

• Score of Vineland II Adaptive Behavior Composite- Total Score

  at Day 0, Day 85, Day 169 and Day 275

• Score of Brief Observation of Social

  at Day 0, Day 85, Day 169 and Day 275

• Score of Social Responsiveness Scale - total score

  at Day 0, Day 85, Day 169 and Day 275

• Score of Autism Diagnostic observation schedule-2

  at Day 0, Day 85, Day 169 and Day 275

• Score of Repetitive behaviour and stereotypies: Aberrant Behavior Checklist

  at Day 0, Day 85, Day 169 and Day 275

Study Arms (2)

Experimental

EXPERIMENTAL

Administration of Interlukin-2

Drug: ILT-101 ld-(IL2)

Control

PLACEBO COMPARATOR

Administration of Placebo NaCl 0.9%

Drug: NaCl (0,9%)

Interventions

ILT-101 ld-(IL2) DRUG

ILT-101 (0.8 MUI/m²/day) subcutaneously. Daily administration for 5 consecutive days (D1 to D5) every 4 weeks for 6 months (i.e. 7 courses of 5 days each).

Experimental

NaCl (0,9%) DRUG

Placebo (NaCl 0,9%), subcutaneously. Same administration schedule as for ILT-101.

Control

Eligibility Criteria

• Age: 6 Years - 8 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Age 6 to 8 years
• Meeting DSM-5 criteria for autism spectrum disorder
• ASD severity classified as moderate or severe on the ADOS
• Mother with :
• (i) an autoimmune disease (as listed by the American Autoimmune Related Diseases Association: https://www.aarda.org/diseaselist/) that began during the first and second trimesters of pregnancy, or that was present prior to pregnancy and experienced a relapse (defined as a change in disease activity leading to a change/modification of treatment) during pregnancy; (ii) a maternal infection (viral or bacterial) during pregnancy, defined as a fever greater than 38.5°C for at least 48 hours and documented (medical consultation, biological sample, prescription of antipyretic and/or antibiotic). Infections by a pathogen with a well-documented direct cerebral effect (CMV) will be excluded.
• Consent of parental authority and social security affiliation
• One of whose parents lives in the HAD pediatric intervention area.

You may not qualify if:

• Recent change in ASD management (behavioral therapy within 6 weeks, introduction of psychotropic molecules within 2 weeks)
• Contraindication to IL2 use (hypersensitivity, cancer history, active infection, obesity, transplant history, vaccination with live attenuated vaccine within 4 weeks)
• Participation in another therapeutic trial within the last 3 months
• BMI \>95th percentile or BMI \<5th percentile
• Participants who have already received a genetic diagnosis of ASD of the 'syndromic' type by DNA chip chromosome analysis
• Participants with hyperchloremia or hypernatremia
• Participant with uncontrolled epilepsy.
• Participants who are related to a person involved in the study at the investigating centre, the clinical research organisation (CRO) or the sponsor.

Sponsors & Collaborators

• Assistance Publique - Hôpitaux de Paris: lead
• Iltoo Pharma: collaborator

Study Sites (1)

Robert Debré Hospital

Paris, 75019, France

Location

MeSH Terms

Conditions

Autism Spectrum Disorder

Condition Hierarchy (Ancestors)

Child Development Disorders, Pervasive; Neurodevelopmental Disorders; Mental Disorders

Central Study Contacts

Pierre ELLUL, MD

CONTACT

0033140034131; pierre.ellul@aphp.fr

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: May 15, 2026
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): November 30, 2028
• Study Completion (Estimated): August 1, 2029
• Last Updated: May 15, 2026

Record last verified: 2026-05

Locations

FR (1)