Is long-term treatment with abatacept plus methotrexate safe and effective for rheumatoid arthritis patients?

This study assessed the long-term safety and efficacy of abatacept (Orencia) plus methotrexate (Rheumatrex, Trexall) in patients with rheumatoid arthritis who have not responsed to methotrexate alone.

Rheumatoid arthritis is a chronic (long-term) disease that leads to inflammation of the joints. Methotrexate is one of the most commonly used drugs for treating rheumatoid arthritis. However, some patients have an inadequate response to treatment with methotrexate, and other drugs are required. Abatacept is often added to methotrexate therapy if methotrexate alone fails. It is anti-inflammatory drug, which reduces the pain, stiffness and swelling experienced by patients. Because rheumatoid arthritis is a chronic illness, patients receive drug treatments for a long period of time. Therefore, it is important to determine the long-term safety and efficacy of treatments.

A total of 219 patients were included in this long-term study investigating the safety of abatacept plus methotrexate. Patients were initially randomly divided into two groups. Group one received injections of abatacept (10 or 2 mg/kg) plus methotrexate for 1 year. Patients in group 2 received methotrexate plus a placebo, a substance with no effect on the body used as a comparison, for 1 year. Patients who completed this first year were eligible to continue receiving 10 mg/kg injections of abatacept every month for 6 years. The safety of abatacept was assessed in patients who received at least one injection of abatacept. The effectiveness was assessed in patients who received 10mg/kg of abatacept from the beginning of the study.

52.1% of the patients who started the trial completed the full 7 years of treatment with abatacept plus methotrexate. 19.2% of patients did not complete the study due to adverse events. The most common adverse events included the common cold (31.4%), back pain (26.8%), headache (24.7%), diarrhea (21.3%) and high blood pressure (20.2%). Severe adverse events included pneumonia (lung infection; 2.4%), chest pain (2.4%) and joint pain (2.1%).

After 1 year of treatment with 10 mg/kg abatacept plus methotrexate 52% of patients’ symptoms had improved by 50%. This improvement continued throughout the 7 year treatment period. After 7 years 58.1% of patients’ symptoms had improved by 50%. Patients also reported improved physical function and health-related quality of life after receiving abatacept plus methotrexate.

This study concluded that long-term treatment with abatacept plus methotrexate is safe and effective for rheumatoid arthritis patients with an inadequate response to methotrexate alone. They also suggest that abatacept plus methotrexate may improve patients’ physical function and health-related quality of life.

This study was sponsored by Bristol Myers Squibb. Bristol Myers Squibb also developed abatacept.