This drug delayed rheumatoid arthritis for years after treatment ended

Published in The Lancet Rheumatology, the research extends findings from an earlier clinical trial reported by King's researchers in 2024. The original study followed 213 participants from the UK and the Netherlands for two years. The latest analysis tracked participants for between four and eight years, making it one of the longest follow up studies ever conducted in people at risk of rheumatoid arthritis.

Early Treatment Delays Rheumatoid Arthritis

Rheumatoid arthritis is a long term autoimmune disease that affects roughly half a million people in the UK. The condition occurs when the immune system mistakenly attacks the joints, leading to pain, swelling, fatigue, and, over time, permanent joint damage and disability.

People who are at risk of developing rheumatoid arthritis often experience challenges even before receiving a diagnosis. Many leave the workforce before the disease fully develops, creating financial and employment difficulties.

Although several treatments are available for people who already have rheumatoid arthritis, no approved therapy currently exists to prevent the disease in people who are known to be at high risk.

The researchers found that participants who received abatacept for 12 months developed rheumatoid arthritis much later than those who received a placebo. In some cases, the disease was delayed by as much as four years beyond the treatment period.

The drug did not completely stop rheumatoid arthritis from developing. However, the results suggest that intervening before the disease appears can meaningfully alter its course, potentially reducing the number of years people spend living with symptoms and related complications.

Professor Andrew Cope, Professor of Rheumatology in the Centre for Rheumatic Diseases at King's College London and lead author of the study, said: "Intervening early in people at high risk of RA can have lasting benefits. We have shown that this approach is safe and can prevent disease while patients are on treatment as well as substantially relieve symptoms. Importantly, it can also delay the onset of RA for several years, even after treatment has stopped. This could reduce how long people live with symptoms and complications, drastically improving their quality of life."

Greatest Benefit Seen in Highest Risk Patients

The study found that abatacept worked best in people with the highest likelihood of developing rheumatoid arthritis. These individuals were identified through blood tests that detected specific autoantibodies associated with the disease.

While this group faced the greatest risk of progressing to rheumatoid arthritis, they also experienced the largest benefits from early treatment.

During the period before rheumatoid arthritis developed, participants treated with abatacept reported improvements in symptoms such as joint pain and fatigue, along with better overall well-being. However, after treatment ended, symptom levels eventually became similar between the abatacept and placebo groups. According to the researchers, this suggests that ongoing immune system modulation may be needed to maintain symptom relief.

Long Lasting Effects With No New Safety Concerns

Researchers also reported that abatacept appeared to be safe. Serious adverse events occurred at similar rates in both the treatment and placebo groups, and no new safety issues linked to the drug were identified.

The team believes the findings strengthen the case for treating autoimmune diseases before they fully emerge. They say the results provide important evidence that targeted immune therapies can delay rheumatoid arthritis in people at highest risk and support further research into preventive strategies for autoimmune conditions.