Metformin Enters Largest-Ever Clinical Trial for Abdominal Aortic Aneurysm Treatment
Key Insights
A £1.2 million British Heart Foundation-funded trial is evaluating metformin's potential to halt abdominal aortic aneurysm (search) growth, representing the largest drug trial ever conducted for this condition.
The international study aims to recruit 1,000 patients across the UK, Australia, and New Zealand, with participants receiving daily metformin or placebo until surgical intervention becomes necessary.
Laboratory research suggests metformin may prevent aneurysm enlargement by blocking aortic inflammation, offering hope for patients who currently have no treatment options for small aneurysms.
Scientists have launched the largest clinical trial ever conducted for abdominal aortic aneurysm (search) (AAA) treatment, investigating whether metformin, a widely-used diabetes (search) medication, can halt the progression of this life-threatening vascular condition. The £1.2 million study, funded by the British Heart Foundation (BHF), aims to recruit 1,000 patients over two years across the UK, Australia, and New Zealand.
Philip Gosling, an 80-year-old farmer from Leicestershire, became the first UK participant in the groundbreaking trial. Gosling's 4-centimeter aneurysm was deemed too small for surgical intervention, leaving him in the challenging position of waiting and monitoring for potential growth. "My aneurysm is 4cm wide, so isn't big enough to operate on. I asked what I could do to stop it growing, and that's when they told me about the trial," Gosling explained.
Addressing Critical Unmet Medical Need
Abdominal aortic aneurysms manifest as balloon-like swellings in the aorta (search), the major blood vessel transporting blood from the heart to the abdomen. While many aneurysms remain asymptomatic, larger formations pose critical rupture risks that can prove fatal. These aneurysms are linked to approximately 4,000 deaths annually across the UK.
Currently, patients with small AAAs face a treatment gap, receiving only regular monitoring until their aneurysm grows large enough to warrant surgical intervention. Professor Bryan Williams, chief scientific and medical officer at the BHF, emphasized this challenge: "To date we don't have effective drug treatments to limit the expansion of these aneurysms."
Trial Design and Mechanism of Action
The randomized, placebo-controlled trial involves men and women with small AAAs who receive either metformin or placebo tablets daily until their aneurysm requires surgical repair, typically lasting at least two years. Gosling completed the first trial stage in July, receiving metformin in gradually increasing doses over six weeks to ensure drug tolerance, before progressing to the second stage with either active treatment or placebo.
Professor Matt Bown, BHF professor of vascular surgery at the University of Leicester and UK trial leader, explained the scientific rationale: "Research in the lab indicates it could be working to prevent AAA growth by blocking inflammation in the aorta (search), a key factor that causes AAA enlargement."
Clinical Implications and Patient Impact
The trial addresses a significant clinical need for patients who currently "can do nothing but wait for their aneurysm to grow to a dangerous size," according to Professor Bown. Success could enable patients to avoid major AAA surgery, which carries inherent risks.
Screening for AAAs is offered to all men over 64 years of age, as they represent the highest-risk population. When aneurysms are detected below the surgical threshold, patients receive regular scans to monitor growth, with referral to specialists occurring once aneurysms reach concerning sizes.
Potential for Medical Breakthrough
Professor Williams highlighted the trial's transformative potential: "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 study represents a drug repurposing approach, investigating whether metformin's anti-inflammatory properties, well-established in diabetes (search) treatment, can be leveraged for vascular protection. If successful, the trial could establish the first pharmacological intervention for small AAAs, fundamentally changing the standard of care for thousands of patients facing this life-threatening condition.