Inclusion Criteria:

• Men and women, >=18 to <=75 years of age.
• Diagnosis of RA according to the revised 1987 criteria of the American Rheumatism Association (Arnett et al., 1988). The disease should have been diagnosed at least 6 months prior to Screening.

• Patients have active disease, in the opinion of the physician, despite the concomitant use of DMARDS. Evidence of active disease may include any of the following:

  6 or more swollen or tender joints; and 2 of the following

  • Morning stiffness >45 minutes
  • C-reactive protein >2.0 mg/L
  • ESR >28 mm/h
• Patients must have been using oral or parenteral MTX for at least 2 months with no break(s) in treatment of more than 2 weeks total during this period. Patients must have been on a stable dose of >=7.5 mg/wk (IM, SQ, PO) for at least 8 weeks prior to Screening.
• Men and women of childbearing potential must be using adequate birth control measures (abstinence, oral contraceptives, IUD, barrier method with spermicide or, surgical sterilization) and should continue such precautions for 6 months after receiving the last infusion.
• Patients must be on a stable dose of folic acid prophylaxis for at least 4 weeks prior to Screening.
• Patients using oral corticosteroids or NSAIDs, must have been on a stable dose for at least 4 weeks prior to Screening, and must continue during the treatment period. If currently not using corticosteroids or NSAIDs, the patient must have not received corticosteroids or NASIDs for at least 4 weeks prior to Screening.
• Patients must be able to adhere to the program visit schedule and other protocol requirements.
• Patients must be capable of giving informed consent and the consent must have been obtained prior to any screening procedures.

Exclusion Criteria:

• Pregnant women, nursing mothers or a planned pregnancy within 1.5 years of enrollment
• Patients who are incapacitated, largely or wholly bedridden or confined to a wheelchair, and who have little or no ability for self-care.
• Patients who have any current systemic inflammatory condition with signs and symptoms that might confound the evaluations of benefit from the Remicade therapy, eg, Lyme disease, or a rheumatic disease other than RA.
• Use of DMARDS other than MTX within 4 weeks prior to Screening.
• Use of intra-articular, IM, or IV. corticosteroids (including IM ACTH) within 4 weeks prior to Screening.
• Prior administration any other therapeutic agent targeted at reducing TNF (eg, Etanercept, pentoxifylline, thalidomide or anti-CD4+ antibody) within the previous 6 months.
• Treatment with any investigational drug within the previous 6 months.
• A history of known allergies to murine proteins.
• Serious infections, such as hepatitis, pneumonia, pyelonephritis in the previous 3 months. Less serious infections in the previous 3 months, such as acute upper respiratory tract infection (colds) or uncomplicated urinary tract infection need not be considered exclusions at the discretion of the treating physician.
• History of opportunistic infections such as herpes zoster within 2 months of Screening. Evidence of active CMV, active pneumocystis carinii, drug resistant atypical mycobacterium, etc.
• Documented HIV infection.
• Current signs or symptoms of severe, progressive or uncontrolled renal, hepatic, hematologic, endocrine, pulmonary, cardiac, neurologic or cerebral disease.
• Any currently known malignancy or pre-malignant lesions or any history of malignancy within the past 5 years.
• Patients with alcoholism, alcoholic liver disease, or other chronic liver disease.
• Patients with a positive PPD within 3 months and chest X-Ray suggestive of active TB or a previous exposure to TB.
• Patients with CHF, even if asymptomatic or not requiring medication must be excluded.