Inclusion Criteria:

• Male and female patients aged 18.5 - 65/75 years (depending on the dose group).
• Diagnosis of rheumatoid arthritis (ACR 1987 revised classification for criteria for RA) with a disease duration of at least 6 months prior to randomization.
• Active disease at screening and baseline evaluation (same evaluator) ) with more than 6 tender and 6 swollen joints of 28 examined (including any effused joint) and either a) Westergren erythrocyte sedimentation (ESR) ≥ 28 mm/hour, or b) CRP ≥ 6 mg/L.
• Patients should have failed at least 1 DMARD in the past, but should not be deemed "refractory to all therapies"
• Patients should have a current treatment regimen of ≥ 15 mg methotrexate/week and with the current dose stable for approximately 3 months.
• Patients were required to have an otherwise stable RA therapeutic regimen, consisting of either a stable dose of NSAIDs and/or a stable dose of oral corticosteroids (prednisone or equivalent < 10 mg daily) for at least 4 weeks prior to randomization.

Exclusion Criteria:

• Previous treatment with anti-TNF-α antibody therapy (or other biological therapy) within appropriate timeframe (considering the half life of the compound)
• Patients who have received intra-articular or systemic corticosteroid injections having been required for treatment of acute RA flare (not being part of a regular therapeutic regimen) within four weeks prior to randomization OR require narcotic analgesics other than those accepted by the investigator for analgesia (e.g., codeine, tramadol, dextropropoxyphene)

Other protocol-defined inclusion/exclusion criteria may apply.