Benefits of Injectable Abatacept Using Magnetic Resonance Imaging (MRI) in Rheumatoid Arthritis (RA) Patients

Inclusion Criteria: * Able and willing to give written informed consent * Patients must have a diagnosis of rheumatoid arthritis \> 3 months * Patients must have been receiving methotrexate for 12 weeks prior to screening at a dose of 10mg - 25 mg weekly. * Patient must have had an inadequate response after receiving or previously receiving one (1) but no more than two (2) anti-TNF biologic agents * Age \>/= 18 yrs * Must have active RA as defined by a DAS28 (Erythrocyte sedimentation rate) score \>4.4 * Must have synovitis of at least two joints in one hand/wrist at screening and baseline * Must have a negative Pregnancy test and use adequate method of contraception throughout the trial * Stable use of Corticosteroids is permitted * Stable use of Non-steroidal anti-inflammatory drugs is permitted Exclusion Criteria: * Functional Class IV * Pregnancy or breastfeeding * History of any other inflammatory arthritis * Sexually active patients who are not using acceptable birth control * Subjects who have undergone metacarpophalangeal (MCP) arthroplasty or anticipate the need for such a procedure * Subjects with a history of cancer in the last five years other than non melanoma skin cancers * Subjects who are unable to comply with study and followup procedures * Subjects who have current or severe symptoms of renal, hepatic, hematologic, gastrointestinal, pulmonary cardiac, neurologic, or cerebral disease * Subjects who currently abuse drugs or alcohol * Subjects with evidence of active or latent bacterial or viral infections at the time of enrollment * Subjects who have received live vaccines within 4 months of first dose of study medication * Subjects with herpes zoster or cytomegalovirus that resolved less than two months prior to dosing * Subjects at risk for tuberculosis (TB). Specifically excluded will be subjects with a history of active TB within the last 3 years and subjects with latent TB must have a negative chest X-ray and be started on treatment for at least 28 days prior to dosing. * Prior treatment with Rituximab within 12 months * Prior treatment with more than 2 TNFs * Intramuscular(IM), Intravenous(IV) Intra-articular (IA) corticosteroids within 28 days prior to baseline * Subjects who have a metal device affected by MRI (e.g. any type of electronic, mechanical or magnetic implant, metal slivers, metal objects, cardioverter defibrillator) * Subjects who have received any disease modifying agent (DMARD) other than methotrexate within the past 28 days prior to baseline