SB-681323 In Subjects With Rheumatoid Arthritis

Inclusion Criteria: * Females cannot be pregnant or lactating. * Must use defined contraceptive methods if of child-bearing potential. * BMI range: 18.5-35.0 kg/m2. * Diagnosis of RA (rheumatoid arthritis) according to revised 1987 American College of Rheumatology (ACR) criteria. * If other RA-medication is used: Disease-Modifying Anti-Rheumatic Drug (DMARDS) must be stable for at least 8 weeks before first trial visit. * If other oral anti-RA therapies are used, these must have been stable at least 4 weeks before first trial visit. * If Methotrexate medication is used as RA-therapy, Folate supplement must be taken with stable red cell folate levels. * Must give informed consent. * Must abstain from alcohol during the trial participation. Exclusion Criteria: * Non-responder on biological RA treatment. * Has a positive alcohol screen. * Any history of liver disease. * Positive Hepatitis B surface antigen or Hepatitis C antibody result within 3 months of screening. * Have any significant disease that places the subject at unacceptable risk as a participant in this trial. * Acute infection. * History of active tuberculosis. * History of repeated or chronic infection. * History of malignancy. * History of HIV or other immunosuppressive diseases. * Participated in a clinical trial within the last 3 months for non-biological therapies and 6 months for biological therapies. * Uncontrolled diabetes or psoriasis.