Study of aldesleukin in children aged 4 to 6 years with autism spectrum disorder whose mothers had immune system activation during pregnancy

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What is this study about?

This study looks at Autism Spectrum Disorder, a condition that affects how a person communicates and interacts with others. The study focuses on children between 4 and 6 years old whose mothers had an autoimmune disease, which is when the body’s defense system attacks its own tissues, or a maternal infection, which is an illness caused by germs, during pregnancy. The treatment being tested is ILT-101, which contains a substance called aldesleukin, a form of interleukin-2 given in low doses. Some children will receive ILT-101 as an injection under the skin, while others will receive placebo. The purpose of the study is to see if low doses of interleukin-2 can stimulate certain immune cells called Tregs in these children.

The study will measure changes in Tregs, which are special white blood cells that help control the body’s immune response, by comparing blood samples taken at the start of the study and after 8 days. Children participating in the study will be followed for several months, with regular check-ups to assess various aspects of their development and behavior. These assessments will look at social skills, communication abilities, daily living skills, repetitive behaviors, attention, and overall functioning. Blood samples will be taken at different times throughout the study to measure immune cells.

During the study, doctors will also monitor for any unwanted effects of the treatment to ensure the safety of the children. The study will track how the treatment affects the children’s symptoms and their families’ well-being over time through questionnaires and observations completed by parents and healthcare professionals. The entire study is expected to continue for several years to gather enough information about how well the treatment works and how safe it is for young children with Autism Spectrum Disorder.

1 Baseline assessment and first treatment administration

On day 0, baseline assessments will be conducted. These include blood tests to measure specific immune cells called Tregs (regulatory T cells, which help control immune responses) and Th17 cells (another type of immune cell). These measurements will show both the percentage of these cells among CD4+ cells (a type of white blood cell) and their absolute numbers.

Various assessments will be completed to evaluate behavior and functioning, including the Vineland II Adaptive Behavior Composite (which measures social skills, communication, and daily living abilities), the Brief Observation of Social Communication Change, the Social Responsiveness Scale, the Autism Diagnostic Observation Schedule-2, the Aberrant Behavior Checklist (which assesses repetitive behaviors), the ADHD Rating Scale (which measures hyperactivity), the Clinical Global Improvement scale, and the Caregiver Strain Index.

The Pediatric Adverse Event Rating Scale will be completed to assess any side effects.

The first dose of the study medication will be administered. This will be either ILT-101 (a solution containing low doses of interleukin-2, a substance that stimulates certain immune cells) or a placebo (an inactive substance with no medication). The medication will be given as an injection under the skin (subcutaneous injection).

2 First follow-up assessment

On day 8, blood tests will be repeated to measure Tregs and Th17 cells again. This will show how the immune cells have responded to the treatment.

The Pediatric Adverse Event Rating Scale will be completed to check for any side effects.

3 Second follow-up assessment

On day 29, blood tests will be performed again to measure Tregs and Th17 cells. The results from day 0 to day 29 will be analyzed to understand the pattern of immune cell changes over this period.

4 Third follow-up assessment

On day 85, blood tests will be conducted to measure Tregs and Th17 cells once more.

The behavioral and functional assessments will be repeated, including the Vineland II Adaptive Behavior Composite, the Brief Observation of Social Communication Change, the Social Responsiveness Scale, the Aberrant Behavior Checklist, the ADHD Rating Scale, the Clinical Global Improvement scale, and the Caregiver Strain Index.

The Pediatric Adverse Event Rating Scale will be completed to assess any side effects.

5 Fourth follow-up assessment

On day 169, blood tests will be performed to measure Tregs and Th17 cells. The results from day 29 to day 169 will be analyzed to assess longer-term immune cell patterns.

All behavioral and functional assessments will be repeated, including the Vineland II Adaptive Behavior Composite, the Brief Observation of Social Communication Change, the Social Responsiveness Scale, the Autism Diagnostic Observation Schedule-2, the Aberrant Behavior Checklist, the ADHD Rating Scale, the Clinical Global Improvement scale, and the Caregiver Strain Index.

The Pediatric Adverse Event Rating Scale will be completed to check for any side effects.

6 Final assessment

On day 275, the final blood tests will be conducted to measure Tregs and Th17 cells.

All behavioral and functional assessments will be completed for the last time, including the Vineland II Adaptive Behavior Composite, the Brief Observation of Social Communication Change, the Social Responsiveness Scale, the Autism Diagnostic Observation Schedule-2, the Aberrant Behavior Checklist, the ADHD Rating Scale, the Clinical Global Improvement scale, and the Caregiver Strain Index.

This marks the completion of participation in the study.

Who Can Join the Study?

The child must be between 4 and 6 years old
If the child is over 31 months old, the autism spectrum disorder (a condition affecting communication and behavior) must be considered moderate or severe in its level of difficulty
The child must meet the official medical guidelines called DSM-5 criteria for autism spectrum disorder
The child’s mother must have had one of the following during pregnancy: either an autoimmune disease (a condition where the body’s defense system attacks its own tissues) that started during the first or second three months of pregnancy, or an autoimmune disease that was already present before pregnancy and became worse during pregnancy requiring treatment changes
Alternatively, the child’s mother must have had a maternal infection (an illness caused by germs) during pregnancy, shown by a fever (body temperature) higher than 38.5 degrees Celsius lasting at least 48 hours and confirmed by a doctor visit or medical tests
The parents or legal guardians must give their consent (permission) for the child to participate
The family must have social security affiliation (health insurance coverage)
At least one parent must live in the specific area where the pediatric home care services are available

Who Cannot Join the Study?

No exclusion criteria have been specified for this clinical trial in the provided information.

Where you can join this trial?

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Other Sites

Site Name	City	Country	Status
Hopital Beaujon	Clichy	France

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	01.10.2025

Trial locations

Investigated drugs:

Aldesleukin

ILT-101 is a medication that contains low doses of interleukin-2, which is a substance that helps regulate the immune system. In this trial, it is being tested to see if it can help stimulate certain immune cells called Tregs in young children with autism spectrum disorders whose mothers had specific immune conditions during pregnancy.

Investigated diseases:

Autism spectrum disorder

Autism Spectrum Disorder – Autism Spectrum Disorder is a developmental condition that affects how a person communicates, interacts with others, and experiences the world around them. It typically appears in early childhood and continues throughout a person’s life. People with this condition may have difficulties with social communication and interaction, such as understanding social cues or maintaining conversations. They may also display repetitive behaviors, have specific interests, or show sensitivity to sensory experiences like sounds, lights, or textures. The severity and combination of symptoms can vary widely from person to person, which is why it is called a spectrum disorder. Some individuals may need significant support in daily life, while others may require less assistance.

Trial ID:

2025-522841-23-00

Protocol code:

APHP230867

Trial Phase:

Therapeutic exploratory (Phase II)

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Study of aldesleukin in children aged 4 to 6 years with autism spectrum disorder whose mothers had immune system activation during pregnancy

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