A Phase 3 Study of Abatacept in Chinese Patients With Active Rheumatoid Arthritis and Inadequate Response to Methotrexate

The primary objective of this study is to demonstrate superior efficacy of abatacept 125mg administrated SC weekly comparing to placebo after 24 weeks treatment in Chinese subjects who have active rheumatoid arthritis, are receiving methotrexate and experiencing an inadequate response to methotrexate. This will be estimated by the proportion of subjects meeting the American College of Rheumatology (ACR) criteria for 20% improvement (ACR20).