Long-term safety and effectiveness of abatacept in Japanese patients with rheumatoid arthritis: 3-year follow-up of a postmarketing surveillance

Objectives: To analyse the long-term safety and effectiveness of abatacept for rheumatoid arthritis using real-world, Japanese, postmarketing surveillance data, focusing on serious infections and malignancies as priority events.

Methods: This 3-year, multicentre surveillance registered patients undergoing abatacept treatment by intravenous infusion between July 2011 and October 2012.

Results: The safety and effectiveness analysis sets included 647 and 596 patients, respectively. The total observation period for the safety analysis was 1280 patient-years. Over the 3-year follow-up, the incidence rates of adverse drug reactions (ADRs) and serious ADRs were 19.92 per 100 patient-years (22.87% of patients) and 4.06 per 100 patient-years (6.65% of patients), respectively. Infections and infestations were the most common ADRs (14.68%), followed by respiratory, thoracic, and mediastinal disorders (3.09%). Incidence rates of serious infections as ADRs and malignancy as adverse events were 1.95 and 1.02 per 100 patient-years, respectively. Retention rates at 1 and 3 years were 67.4% and 43.9%, respectively. Significant decreases from baseline were observed in Disease Activity Score (DAS) 28-erythrocyte sedimentation rate and DAS28-C-reactive protein, as well as Health Assessment Questionnaire-Disability Index (HAQ-DI) and modified HAQ scores.

Conclusions: No new safety signals were detected during the 3-year observation period and effectiveness was maintained over time.