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Landmark study into preschool wheezing reaches major milestone
Media release
31 March 2026
A major clinical trial aiming to reduce hospital admissions among preschoolers who experience wheezing episodes has reached a significant milestone with the recruitment of its 1,000th child.
The ARROW Trial is testing a new treatment for childhood wheeze and involves 46 hospitals participating in the Children’s Inpatient Research Collaboration of Australia and New Zealand (CIRCAN).
Study lead Professor Peter Vuillermin, a paediatrician from the Barwon Health and Deakin University Clinical Trials Alliance, said wheezing illnesses were the leading cause of hospital admissions among preschool-aged children worldwide.
‘Wheeze episodes are distressing for children and their families and are a strong predictor of asthma in later life,’ Professor Vuillermin said.
‘Over a third of young children admitted to hospital with a wheeze episode will be readmitted within a year with another episode. Unfortunately, we still don’t have a treatment that we know substantially reduces this risk.
‘There is strong evidence that children who are exposed to a wider range of environmental bacteria in early life, such as those who grow up on farms with livestock, have lower rates of wheezing illnesses and asthma,' Professor Vuillermin said.
Early defence for little lungs
ARROW stands for ‘Assessing the Reduction of Recurrent admissions using OM-85 for the treatment of preschool Wheeze’.
'We are testing whether an oral medication, OM-85, that boosts immunity by delivering a dose of inactive (broken-down) bacteria, is effective in preventing hospital admissions among young children with recurrent, severe wheezing illnesses,' Professor Vuillermin said.
Dr Jessica Costa-Pinto, a paediatrician and PhD scholar, who is playing a key role in the ARROW Trial said previous studies had shown that OM-85 could reduce respiratory tract infections and may reduce wheeze episodes in children.
‘This large clinical trial will tell us if it can also prevent hospital admissions from wheeze,’ Dr Costa-Pinto said.
ARROW Trial: Preventing Preschool Wheeze Hospitalisations
The ARROW Trial is a randomised, double-blind, placebo-controlled trial that aims to recruit 1,088 children, from one to six years old, with a history of recurrent wheeze requiring hospital admission. Participants receive either OM-85 or a placebo for the first 10 days of each month over 12 months. Families complete weekly electronic diaries to track respiratory symptoms and healthcare presentations, and information about hospital presentations is collected using medical records.
A specially developed web application allows clinicians from participating CIRCAN hospitals to refer patients to the trial. Families are provided with study information through digital links and videos. Families of children aged between 1 and 6 years who have a wheeze-related hospital admission in the last 12 months can also self-refer.
Recruitment of the 1,088 children will be completed in the coming months.
Professor Vuillermin said reaching the milestone of 1,000 children reflects the extraordinary commitment of paediatric doctors and nurses, researchers and the participating families.
‘The ARROW Trial has the potential to improve the health of kids with recurrent wheezing illnesses in Australia, New Zealand and around the world. It has been a huge collective effort, and we are very proud of our team and grateful to all who have contributed,’ Dr Costa-Pinto said.
Funding for the ARROW Trial has been provided by the National Health and Medical Research Council (NHMRC), Cure Kids, the Starship Foundation, and OM-Pharma. The ARROW Trial’s remote-based design provides an innovative, cost-effective way to expand access to clinical trials for children in metropolitan and rural communities and accelerate the generation of high-impact evidence to improve patient outcomes.
Clinicians or families interested in becoming involved are encouraged to contact the team at arrowtrial@deakin.edu.au.