Trial to test whether drug that targets gut bacteria can improve irritability in teenagers with autism

A new trial will test whether a medication that targets gut bacteria can also improve irritability in teenagers with autism spectrum disorder.

The Tapestry study, a collaboration between the Murdoch Children’s Research Institute, Queensland Children’s Hospital, University of Sydney, Southern Adelaide Local Health Network and Flinders University is recruiting adolescents, aged 13-17, in Australia, the US and New Zealand with moderate to severe autism and who experience irritability such as aggression, self-harm and severe tantrums.

The trial medication, AB-2004, is designed to soak up certain toxins produced by bacteria in the gut to prevent them from entering the bloodstream and reaching the brain. Scientific studies have shown there may be a link between changes and irregularities in gut bacteria and the brain, which could contribute to certain neurological conditions, including irritability in children with autism. Gut bacteria are influenced by anxiety, poor diet and an unsettled sleep and stomach.

Murdoch Children’s Professor David Amor, who is leading the randomised-controlled trial in Melbourne alongside Dr Catherine Marraffa, said the study would test whether lowering levels of certain substances produced by gut bacteria could be a potential treatment for irritability in teenagers with autism spectrum disorder. 

“There is a significant difference in the gut bacteria of children with autism compared to those who are not on the spectrum,” he said. This difference may lead to higher levels of certain substances that are produced by bacteria in the gut.

“The therapy we are trialling is designed to absorb the substances associated with some autism characteristics in the gut to reduce their entry into the brain via the bloodstream. We hope this will improve traits of irritability and anxiety, offering families an alternative to anti-psychotic treatments.”

The medication is designed to act in the gut only and does not enter other bodily tissues, lessening the potential for side effects across other parts of the body. AB-2004 was shown to be safe and well tolerated in a previous study involving adolescents on the spectrum.

Murdoch Children’s Dr Kylie Crompton said the severity of daily challenges faced by some children with autism, combined with the lack of safe and effective treatment options, had resulted in a significant unmet need for innovative medical interventions. 

“Children with autism need better options for managing anxiety and irritability or distress,” she said. This trial offers potential hope for children who too often struggle with anxiety and irritability in all aspects of their daily life.”

The trial, sponsored by Axial Therapeutics, across 25 hospital sites in Australia, the US and New Zealand, is seeking 140 participants. Axial is a pharmaceutical company dedicated to improving the lives of people with neurological conditions.

Dr Crompton said the trial was possible with the backing of The Lorenzo and Pamela Galli Charitable Trust, administered by the University of Melbourne, which supports researchers across the Parkville medical precinct in the areas of cancer and developmental disorders.

“With the support of the Galli Trust we can generate new evidence about the causes of neurodevelopmental disability and determine whether new and existing therapies are effective in improving outcomes and quality of life for these children and their families,” she said.

The 16-week trial includes taking the medication for eight weeks, six in-clinic visits and three telehealth appointments and the collection of blood, urine and stool samples as well as completing questionnaires.

The medication, a powder taken by mouth three times per day, is tasteless and odorless and is mixed with any soft food.

To see if your child is eligible for the study a pre-screening questionnaire can be accessed by visiting www.theautismstudy.com