A recent clinical trial suggests that the drug abatacept, marketed as Orencia, can significantly reduce the likelihood of individuals with palindromic rheumatism (PR) progressing to rheumatoid arthritis (RA). The study, published in Nature Medicine, found that abatacept cut the risk of developing RA by more than half compared to hydroxychloroquine, a common treatment for PR.
Palindromic rheumatism is a rare inflammatory condition characterized by sudden, recurrent attacks of joint pain and swelling. While these attacks typically resolve without permanent joint damage, up to 60% of individuals with PR eventually develop rheumatoid arthritis, a chronic autoimmune disease that can lead to lifelong joint pain, stiffness, and disability.
Trial Findings
The randomized trial, conducted across 14 rheumatology centers in Spain, enrolled 73 adults diagnosed with palindromic rheumatism. These participants tested positive for rheumatoid factor (RF) and anti-cyclic citrullinated peptide (ACPA) antibodies, indicating a high risk of developing RA.
Participants received either injectable abatacept weekly for the first year and bi-weekly for the second, or daily hydroxychloroquine pills for two years. Over the 24-month study period, only 20.6% of patients treated with abatacept developed RA, compared to 50% of those taking hydroxychloroquine. This represents an absolute risk reduction of 29.4%.
Abatacept also appeared to improve symptoms for those with palindromic rheumatism. Patients receiving abatacept reported less intense joint attacks and were more than twice as likely to experience no more than one attack within a 12-month period compared to the hydroxychloroquine group. Fifty-six percent of patients on abatacept experienced one or no flare-ups over a year, versus 23% on hydroxychloroquine.
Early Intervention in RA
The study builds on existing research indicating that intervening in the early, or 'pre-clinical,' stages of RA, before irreversible joint damage occurs, could alter the disease's trajectory. Previous trials have also shown abatacept to delay or prevent RA in high-risk individuals, though RA rates rebounded after treatment cessation in those studies. The current trial's two-year treatment duration suggests that longer-term use of abatacept may sustain its protective effects.
Researchers are currently conducting a five-year follow-up to assess whether the benefits of abatacept continue after treatment is stopped. Both medications were generally well-tolerated, with no deaths reported and only one patient discontinuing abatacept due to mild side effects. Palindromic rheumatism affects approximately 16,000 Americans, typically striking individuals in their 40s.