According to research published in the Archives of Rheumatic Diseases, prompt use of abatacept plus methotrexate is advisable for rheumatoid arthritis (RA) patients with early disease and poor prognostic factors, such as erosions and rheumatoid antibodies.

Researchers evaluated the efficacy and safety of abatacept in methotrexate-naive patients with early RA and poor prognostic factors. The double-blind, phase IIIb study involved 509 patients with RA for two years or less, who were randomised to receive abatacept (approximately 10 mg/kg) plus methotrexate, or placebo plus methotrexate. Patients were methotrexate-naive and seropositive for rheumatoid factor (RF), anti-cyclic citrullinated protein (CCP) type 2 or both and had radiographic evidence of joint erosions. The co-primary endpoints were the proportion of patients achieving disease activity score in 28 joints (DAS28)-defined remission (C-reactive protein) and joint damage progression (Genant-modified Sharp total score; TS) at year 1. At baseline, patients had a mean DAS28 of 6.3, a mean TS of 7.1 and mean disease duration of 6.5 months; 96.5% and 89.0% of patients were RF or anti-CCP2 seropositive, respectively.

The following results were reported:
• At year 1, a statistically significantly greater proportion of abatacept plus methotrexate-treated patients achieved remission (41.4% vs 23.3%; p<0.001) and there was less radiographic progression (mean change in TS 0.63 vs 1.06; p = 0.040) versus methotrexate alone.
• Over 1 year, the frequency of adverse events (84.8% vs 83.4%), serious adverse events (7.8% vs 7.9%), serious infections (2.0% vs 2.0%), autoimmune disorders (2.3% vs 2.0%) and malignancies (0.4% vs 0%) was comparable for abatacept plus methotrexate versus methotrexate alone.

The researchers concluded that in a methotrexate-naive population with early RA and poor prognostic factors, the combination of abatacept and methotrexate provided better clinical and radiographic efficacy compared with methotrexate alone and had a comparable, favourable safety profile.