Abstract
INTRODUCTION: Patients with rheumatoid arthritis (RA) with poor prognostic factors, such as seropositivity for anti-citrullinated protein antibodies and early erosions, may benefit from early intensive treatment. However, information to guide physicians on the best choice of therapy in these patients is limited. The objective of this study was to describe the efficacy of subcutaneous abatacept versus adalimumab over 2 years in patients with seropositive, erosive early RA in the AMPLE study. METHODS: This exploratory post hoc analysis compared clinical, functional and radiographic outcomes in two subsets of patients: patients with early RA (≤ 6 months' disease duration) who were seropositive for rheumatoid factor and/or anti-citrullinated protein antibodies and had > 1 radiographic erosion (Cohort 1); and patients with RA and absence of ≥ 1 of these inclusion criteria (Cohort 2). RESULTS: Of the 646 randomized patients, Cohort 1 included 38 patients receiving abatacept and 45 receiving adalimumab, and Cohort 2 included 280 patients receiving abatacept and 283 receiving adalimumab. Baseline demographics and disease characteristics were generally similar between treatment groups in both cohorts. Over 2 years, in Cohort 1, the adjusted mean change from baseline in the Disease Activity Score in 28 joints (using C-reactive protein) was numerically greater for abatacept than for adalimumab (mean difference at day 365 was 0.9, 95% confidence interval - 1.47 to - 0.33). Similar patterns of improvement were observed for other disease activity measures and physical function, but not for radiographic outcomes. No treatment-related differences were observed in Cohort 2. CONCLUSION: This analysis indicates a trend towards improved disease activity and physical function with abatacept versus adalimumab in patients with seropositive, erosive early RA. TRIAL REGISTRATION: ClinicalTrials.gov NCT00929864. FUNDING: Bristol-Myers Squibb.