A groundbreaking UK clinical trial is exploring whether a widely available and inexpensive diabetes drug could become a vital new treatment for a potentially fatal vascular condition. The study will assess if metformin can halt the progression of abdominal aortic aneurysms (AAA), which are responsible for around 4,000 deaths annually in the UK.
First UK Patient Enrolled in Landmark Study
The UK arm of the international trial has recruited its first participant, 80-year-old Philip Gosling from Leicestershire. Mr Gosling, who still helps on his family farm, was referred to a specialist after a routine screening detected a small AAA. When told his 4cm aneurysm was not yet large enough for surgical intervention, he asked what could be done to prevent its growth and was informed about the new research project.
"I believe in research, I see the results of it every day on the farm," said Mr Gosling. "When they told me about the trial I had to get involved. My condition is very closely monitored, which can only be a good thing. Hopefully it will help a lot of people like me in the future." His AAA means he has had to avoid activities like lifting heavy objects.
How the Metformin AAA Trial Will Work
Funded by a £1.2 million grant from the British Heart Foundation (BHF), this is the largest drug trial ever conducted for AAA. It aims to recruit 1,000 patients across the UK, Australia, and New Zealand over two years. Participants with a small AAA will be randomly assigned to take either metformin or a placebo tablet daily. They will continue until their aneurysm requires surgical repair, typically for a minimum of two years.
Mr Gosling began the first phase in July 2025, gradually increasing his metformin dose over six weeks to ensure he could tolerate it. He is now in the second stage, where he takes either the active drug or a placebo, with regular scans to monitor any change in the size of his aneurysm.
Currently, patients with small AAAs are offered no treatment, only regular surveillance scans to check for growth. Once an aneurysm expands to a critical size, invasive surgery is required, which carries significant risks. This trial offers the first real hope of a pharmacological intervention to slow or stop that growth.
Scientific Hope for a New Treatment
Professor Matt Bown, BHF professor of vascular surgery at the University of Leicester and lead for the UK trial branch, explained the rationale. "Evidence suggests metformin could be the treatment for AAA we’ve long been looking for," he said. "Research in the lab indicates it could be working to prevent AAA growth by blocking inflammation in the aorta, a key factor that causes AAA enlargement."
Professor Bryan Williams, chief scientific and medical officer at the BHF, emphasised the unmet need. "To date we don’t have effective drug treatments to limit the expansion of these aneurysms," he stated. "This important clinical trial will reveal whether this simple treatment can stop aneurysm growth and, if it does, this would be a major breakthrough, providing reassurance for patients affected by this condition."
The trial specifically targets the group most at risk: men over the age of 64, who are offered routine NHS screening. If successful, daily metformin could provide a safe, low-cost way to manage AAA, preventing dangerous growth and sparing thousands from major surgery.
