Abatacept for People with Active Rheumatoid Arthritis

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The summary below is from the full report titled "Effects of Abatacept in Patients with Methotrexate-Resistant Active Rheumatoid Arthritis. A Randomized Trial." It is in the 20 June 2006 issue of Annals of Internal Medicine (volume 144, pages 865-876). The authors are J.M. Kremer, H.K. Genant, L.W. Moreland, A.S. Russell, P. Emery, C. Abud-Mendoza, J. Szechinski, T. Li, Z. Ge, J.-C. Becker, and R. Westhovens.

What is the problem and what is known about it so far?

Rheumatoid arthritis is joint pain and stiffness caused by an immune reaction to joint tissue linings. It damages the joints and can even destroy them. Rheumatoid arthritis usually affects the hands, feet, knees, shoulders, and wrists, but it can develop in any joint. There is no cure, but treatment improves signs and symptoms and slows joint damage. Treatment is with drugs that alter the body's immune reactions. Abatacept is a new drug that targets specific components of the immune system. Abatacept inhibits the specific immune cells that cause rheumatoid arthritis and has been shown to improve symptoms in people with rheumatoid arthritis. It has not been directly compared with drugs that are commonly used to treat rheumatoid arthritis, such as methotrexate.

Why did the researchers do this particular study?

To compare the ability of abatacept and methotrexate to improve symptoms and slow joint damage in people with rheumatoid arthritis.

Who was studied?

652 adults with painful rheumatoid arthritis despite taking methotrexate for at least 3 months.

How was the study done?

The researchers assessed participants' symptoms and signs, ability to perform everyday activities, and quality of life before starting the study. They also looked at disease activity by measuring joint damage in x-rays. The researchers then randomly assigned participants to receive abatacept or placebo for 1 year. Abatacept was given intravenously twice in the first month, then once a month for 11 more months. Participants in both groups continued taking methotrexate. The researchers repeated their measurements every month to assess improvement.

What did the researchers find?

Participants taking abatacept improved more in all measures than participants taking placebo. Their symptoms and signs, everyday activities, and quality of life improved. Joint damage also progressed at half the rate. Participants in the 2 groups experienced similar adverse events. More participants taking abatacept experienced side effects, and they tended to develop infections more often. However, more participants taking placebo left the study prematurely because their symptoms and signs of rheumatoid arthritis did not improve.

What were the limitations of the study?

The study included participants who had had rheumatoid arthritis for more than a year and whose condition had not improved with methotrexate treatment. The findings may not apply to people with newer disease or to those who responded to methotrexate. The study lasted only a year. The benefits and risks of abatacept for longer periods require study.

What are the implications of the study?

Abatacept seems to be safe and effective for people with rheumatoid arthritis who do not respond to methotrexate treatment. The benefits and risks of taking abatacept for more than a year require more study. The role of the drug for different people at different stages of rheumatoid arthritis and its benefits and risks compared with other rheumatoid arthritis drugs also require further study.