People at risk of developing rheumatoid arthritis could benefit from taking an existing medication prescribed for established cases of the condition.
A clinical trial found abatacept to be “effective in preventing the onset” of rheumatoid arthritis.
Researchers said their findings could be “promising news” for the health service as it works to keep up with an ageing population.
Abatacept is currently prescribed to people who already have rheumatoid arthritis, but a team led by King’s College London set out to explore if it can prevent the disease in those deemed at risk.
The drug – administered in hospital through a drip or at home with weekly injections – works by targeting the cause of inflammation.
Some 213 patients were recruited from 28 hospital-based early arthritis clinics in the UK and the Netherlands. They were all evaluated to be at risk of rheumatoid arthritis by researchers.
Of the total, 110 were given abatacept and the remainder assigned to a placebo group.
The estimated proportion of patients remaining arthritis-free at 12 months was 92.8% in the abatacept group and 69.2% in the placebo group.
After two years, 27 (25%) members of the abatacept group had progressed to rheumatoid arthritis compared to 38 (37%) in the placebo group.
Professor Andrew Cope, of King’s College London, said: “This is the largest rheumatoid arthritis prevention trial to date and the first to show that a therapy licensed for use in treating established rheumatoid arthritis is also effective in preventing the onset of disease in people at risk.”
Prof Cope said the “initial results” – published in The Lancet – could be “good news for people at risk of arthritis”.
“This is also promising news for the NHS as the disease affects people as they age and will become more expensive to treat with a growing aging population,” he added.
Rheumatoid arthritis is a long-term condition that causes painful swelling and stiffness in the joints.
It is estimated that 450,000 adults in the UK have been diagnosed with the disease.
The trial also showed other outcomes of using abatacept, such as lower pain scores and higher quality of life measurements among patients.
One patient, Philip Day, 35, of Eltham in London, was enrolled in the trial in 2018 and was prescribed abatacept.
Joint pain has prevented the once-keen footballer from taking part in the sport.
He said: “The pain got so terrible I stopped going to football, and I got lazier and felt progressively worse physically and mentally. The pain was unpredictable, it would show up in my knees one day, my elbows the next, and then my wrists or even my neck.
“At the time, my wife and I wanted to have children and I realised my future was pretty bleak if the disease progressed. I’d always wanted to be the kind of dad that played football with his son and I knew the pain would stop me from realising that dream.”
Mr Day described the trial as a “ray of hope at a dark time”. He added: “Within a few months I had no more aches or pains and five years on I’d say I’ve been cured. Now, I can play football with my three-year-old son and have a normal life.”
Prof Cope said: “There are currently no drugs available that prevent this potentially crippling disease.
“Our next steps are to understand people at risk in more detail so that we can be absolutely sure that those at highest risk of developing rheumatoid arthritis receive the drug.”
Professor Lucy Donaldson, director for research and health intelligence at the charity Versus Arthritis, said: “At Versus Arthritis, we welcome the findings of this study which demonstrate how we might be able to delay – or even prevent – the onset of rheumatoid arthritis in people most at risk of the disease.
“An accurate arthritis diagnosis often takes months or years, which is simply unacceptable.
“Treatment delays resulting from a prolonged diagnosis can cause irreversible joint damage, with chronic pain, fatigue and disability hugely impacting a person’s life.
“A prompt diagnosis followed by personalised treatment and support can make all the difference between someone being able to work and care for their family, or in losing their independence altogether.
“This research highlights how important it is to spot the early signs of arthritis to give us a chance at stopping it in its tracks, offering hope to thousands of people living with – or at risk of developing – rheumatoid arthritis.”