The purpose of this study was to confirm and extend the data from previous studies and to demonstrate the efficacy (in terms of signs and symptoms) and safety of monotherapy with CDP870 administered SC every 4 weeks compared to placebo in patients with active RA who had failed at least one DMARD.

Inclusion Criteria:

• male/female, 18-75 years old, inclusive
• diagnosis of adult-onset RA
• had active disease
• had received methotrexate
• on a stable dose of folic acid

Exclusion Criteria:

• contraindication for methotrexate or anti-TNF