Three new drugs for rheumatoid arthritis (RA) have ushered in a new era of treatment for this difficult and debilitating condition.
The findings are reported in a New Drug Class study published early Online and in an upcoming edition of The Lancet.
RA is the most common of all chronic inflammatory joint diseases, affecting 0.5-1% of the population in the industrialised world. Its typical symptoms are joint pain, stiffness, and swelling due to synovial inflammation and effusion.
Professor Josef Smolen, Division of Rheumatology, Medical University of Vienna, Austria and colleagues did a comprehensive study of the three new drugs – rituximab, abatacept and tocilizumab – and their effects as sole therapies or working in conjunction with existing treatments. They explore the pathogenesis of RA and the various routes for targeting treatments, including new therapeutic strategies, and also provide a comprehensive overview on ways to assess treatment response.
The authors say: “The enormous consequences for the individual and for health-care and socioeconomic systems can only be prevented by effective treatments.”
Traditional treatments for RA include non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, and disease-modifying antirheumatic drugs (DMARDs). Only DMARDs, and to some extent glucocorticoids, can impede or stop the inflammatory and destructive disease processes. Methotrexate is the most widely used DMARD and is a cornerstone of most RA treatment regimens.
Of the three new drugs, rituximab and abatacept have been approved for RA treatment, while the third, tocilizumab, is in phase III trials. Rituximab targets the CD20 antigen in certain cells, and leads to a reduction in the CD20 cell count. Trials of rituximab showed it reduced RA symptoms by more than 50% for more than a third of patients.
Abatacept works by interfering in the T-cell activation response, viewed as vital in the mechanism of RA. A trial combining abatacept at 10mg per kg bodyweight for patients with their existing methotrexate treatment also found a reduction of RA symptoms of around 50% in some 40% of patients. This effect was much more pronounced than in patients given placebo instead of abatacept.