Drug treatments for rheumatoid arthritis – comparison of abatacept versus anti-TNF

This study compared the effectiveness of two different rheumatoid arthritis drugs in patients with prior anti-TNF use. 

Rheumatoid arthritis (RA) is an autoimmune disease, caused by the immune system attacking healthy tissue. Blocking the immune system with disease-modifying antirheumatic drugs (DMARDs) such as methotrexate (Rheumatrex and Trexall) can slow the progression of RA. If DMARD treatment is unsuccessful, patients may try anti-TNF drugs which block the activity of tumor-necrosis factor, a protein that causes inflammation.

Common anti-TNF drugs include infliximab (Remicade), etanercept (Enbrel), adalimumab (Humira), and certolizumab (Cimzia).

However, little is known about what to do when patients do not respond to the first TNF inhibitor drug. Abatacept (Orencia) is another option; it has a different mechanism of action to TNF-inhibitors. It blocks the activity of T-cells, a type of white blood cell that drives inflammation. However, it is unclear whether switching a different brand of TNF-inhibitor, or to abatacept, is a more effective treatment. 

This study involved 803 RA patients who had not responded to anti-TNF treatment. Of these patients, 272 switched to abatacept and 531 switched to another anti-TNF drug. Patient responses to drug treatment were measured at 6 and 12 months after treatment using criteria such as: number of swollen joints, patient assessment of pain, and health questionnaires.

The authors found that while both drugs improved patient symptoms, neither drug performed significantly better than the other. At 6 months, a 50% improvement in symptoms was seen in 19.7% of abatacept users compared to 14.5% in anti-TNF users. Also, remission (absence of disease symptoms) occurred in 20.2% of abatacept users versus 17.3% in anti-TNF users. At 12 months, response rates seemed to favor anti-TNF users. However, none of these results were considered clinically significant. 

The authors conclude that there is no difference when comparing abatacept with anti-TNF treatments, in patients who were previously unresponsive to anti-TNF. 

While there is no difference between abatacept and anti-TNF, more studies are needed to check the effectiveness of switching to a different non-TNF drug versus anti-TNF.

If you have concerns about treatment with abatacept or anti-TNF drugs, please discuss them with your doctor.