Comparing The Effectiveness And Safety Of 2 Doses Of An Experimental Drug, CP-690,550, To Methotrexate (MTX) In Patients With Rheumatoid Arthritis Who Have Not Previously Received MTX

Inclusion Criteria:

- Adults with moderate to severe RA (Rheumatoid Arthritis) who have not been treated
with methotrexate.

- Diagnosis of RA based on the American College of Rheumatology 1987 revised criteria.

- Active disease as defined by both >=6 tender or painful joints on motion and >= 6
joints swollen; and either an erythrocyte sedimentation rate (ESR) > 28 mm or a
C-reactive protein (CRP) concentration > 7 mg/dL

Exclusion Criteria:

- Blood dyscrasias including confirmed: Hemoglobin <9 g/dL or Hematocrit <30%; White
blood cell count <3.0 x 109/L; Absolute neutrophil count <1.2 x 109/L; Platelet count
<100 x 109/L

- History of any other rheumatic autoimmune disease other than Sjogren's syndrome

- No malignancy or history of malignancy

- History of infection requiring hospitalization, parenteral antimicrobial therapy, or
as otherwise judged clinically significant by the investigator, within the 6 months
prior to the first dose of study drug

- No chronic liver disease, recent or active hepatitis or other contraindication to
methotrexate therapy