Efficacy and safety of abatacept in routine care of patients with rheumatoid arthritis: Orencia® as Biological Intensive Treatment for RA (ORBIT) study

Objective. To investigate the efficacy and safety of abatacept for treating patients with rheumatoid arthritis (RA) in routine clinical practice. Methods. We performed a retrospective study of 137 RA patients who were treated with abatacept for 24 weeks between October 2010 and June 2011 at four rheumatology centers in Japan. Outcomes were compared between biologic-naïve and biologic-experienced patients. Disease activity was assessed using the Simplified Disease Activity Index (SDAI) and the 28-joint Disease Activity Score based on the erythrocyte sedimentation rate (DAS28-ESR). Results. The retention rate of abatacept at 24 weeks was 79.6%. SDAI (from 24.6 ± 12.5 to 12.9 ± 11.6) and DAS28-ESR (from 5.2 ± 1.4 to 3.9 ± 1.4) decreased significantly from baseline to Week 24 (both P < 0.001). Remission/low disease activity were achieved in 2.2%/11.2% (SDAI) and in 5.3%/2.3% (DAS28-ESR). The change in SDAI and the remission/low disease activity rates at Week 24 was greater in biologic-naïve patients than in biologic-experienced patients. Structural remission (van der Heijde-modified total Sharp score ≤ 0.5) was achieved by 63.4% of patients. Conclusions. The present results confirm that abatacept is effective in routine clinical practice and support its use as the first-line biologic agent in patients.