The primary objective of this clinical research study is to compare the efficacy and the safety of 3 dose levels of oral TMI-005 in comparison with placebo in subjects with active Rheumatoid Arthritis (RA) who have been receiving stable doses of Methotrexate (MTX).

Inclusion Criteria:

• Meet American College of Rheumatology (ACR) criteria for RA
• Have active RA
• Disease duration of at least 6 months
• Disease onset at > 16 years of age.

Exclusion Criteria:

• Any prior use of anti-TNF alpha biologics, rituximab, receipt of anti-CD4 or diphtheria interleukin-2 fusion protein or other immunosuppressive biologics (except for anakinra)
• Largely or wholly incapacitated with the subject bedridden or confined to a wheelchair, permitting limited or no self-care
• Pregnant or breastfeeding women or women planning to become pregnant during the study or within 12 weeks after the last dose of test article