This study will investigate how LY2127399 works in participants with rheumatoid arthritis
(RA) who are not adequately responding to methotrexate. Participants will receive LY2127399
via an injection(s) under the skin at 4 week intervals for up to 52 weeks. Key study
procedures include biopsies of the lining of an inflamed joint and blood tests to measure RA
activity.