Abstract
INTRODUCTION: Abatacept efficacy in older patients with rheumatoid arthritis (RA) has been primarily demonstrated via retrospective comparisons with younger patients. The objective of this study was to compare efficacy of abatacept in older vs. younger patients with RA, and efficacy of abatacept with that of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) in both age groups. METHODS: This prospective, multicenter, observational study (UMIN000014913) enrolled csDMARD-refractory patients without previous biological DMARD treatment. Abatacept (A) or csDMARDs (C) were administered at the treating physician's discretion to older (O, ≥ 65 years) and younger (Y, 20-64 years) patients, producing AO, AY, CO, and CY groups. Clinical efficacy after 24 weeks was evaluated using European League Against Rheumatism (EULAR) erythrocyte sedimentation rate response criteria. RESULTS: Overall, 202 patients were evaluated. Compared with the CO group, more patients in the AO group achieved a EULAR good or moderate response (p < 0.0001). Compared with the CY group, more patients in the AY group achieved a EULAR good or moderate response (p < 0.01). Similar proportions of patients in the AO and AY groups achieved a EULAR good response or a good or moderate response. Few adverse events were reported. CONCLUSIONS: This prospective study demonstrated that abatacept is efficacious and safe in older patients with RA and a history of being refractory to csDMARDs. Abatacept was shown to be more efficacious than adding or switching to a new csDMARD in both younger and older csDMARD-refractory patients with RA. TRIAL REGISTRATION: UMIN000014913.