A Rheumatoid Arthritis Study in Participants

The primary purpose of this study is to help answer if LY2127399 is safe and effective in the treatment of rheumatoid arthritis with or without background disease-modifying anti-rheumatic drug (DMARD) therapy.

This study is comprised of 2 periods:

Period 1 - 24-week blinded treatment

Period 2 - 48-week post-treatment follow-up

In consideration of disease severity, all participants were assessed for non-response at Week 16. A total of 66 joints were examined for swelling, and a total of 66 joint were examined for tenderness. For participants who had at least 5 swollen and 5 tender joints at baseline, Week 16 non-responders (NRs) were defined as participants with \<20% improvement from baseline in both tender joint counts and swollen joint counts. For participants who did not have at least 5 swollen and 5 tender joints at baseline, Week 16 NRs were defined as participants who had at least 2 additional tender and 2 additional swollen joints from baseline. All Week 16 NRs and all participants who discontinued study treatment at any time, for any reason, were defined as NRs starting at that timepoint and going forward for all American College of Rheumatology (ACR) imputed analyses, including the Week 24 endpoint.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of Rheumatoid Arthritis (RA) of more than 6 months and less than 15 years
* Global Assessment of Disease Activity visual analog scale (VAS) greater than or equal to 20/100 millimeters (mm)
* If on one or more conventional disease-modifying anti-rheumatic Drugs (DMARDs) at randomization, must have been on a stable dose for at least 8 weeks prior to study start.
* Women must not be pregnant, breastfeeding, or become pregnant during the study

Exclusion Criteria:

* Use of unstable doses of non-steroidal inflammatory drugs (NSAIDS) in the past 6 weeks
* Steroid injection or intravenous (IV) infusion in the last 6 weeks
* Use of more than 10 milligrams per day (mg/day) of oral steroids in the last 6 weeks
* Use of biologic DMARD concurrently or recently
* History of a serious reaction to other biological DMARDs
* Use of an oral calcineurin inhibitor (for example, cyclosporin or tacrolimus) in the last 8 weeks
* Surgery on a joint or other major surgery less than 2 months prior to study start, or plans to have joint surgery or major surgery during the study
* Active fibromyalgia, juvenile chronic arthritis, spondyloarthropathy, Crohn's disease, ulcerative colitis, psoriatic arthritis, or other systemic inflammatory condition except RA
* Cervical cancer or squamous skin cancer within the past 3 years, or other cancer within the past 5 years
* Received a live vaccine within the past 12 weeks (for example, vaccines for measles, mumps, rubella, and chicken pox, and nasal-spray flu vaccines)
* Hepatitis or human immunodeficiency virus (HIV)
* A serious bacterial infection (for example, pneumonia or cellulitis) within 3 months or a serious bone or joint infection within 6 months
* Symptoms of herpes zoster or herpes simplex within the last month
* Active or latent tuberculosis (TB)
* Current symptoms of a serious disorder or illness
* Use of an investigational drug within the last month