A Study of Effectiveness and Safety of CNTO 136 in Patients With Active Rheumatoid Arthritis Despite Methotrexate Therapy

This is a multicenter, double-blind (neither physician nor participants knows the treatment that the participant receives), randomized (study medication is assigned by chance), placebo-controlled (an inactive substance is compared with a medication to test whether the medication has a real effect in a clinical study) study. This study will be conducted in 2 parts (Part A and Part B). Each part consists of 3 phases: screening (approximately 1 month prior to the start of study medication), treatment phase (Part A: 22 weeks and Part B: 24 weeks), and follow-up phase (approximately 4 months after the last administration of study medication). In Part A, participants will be randomly assigned to 2 groups to receive CNTO 136 100 mg and placebo for 22 weeks. All participants in Part A, will be crossed over at Week 12 from placebo to CNTO 136 (for Group 1) and from CNTO 136 to placebo (for Group 2). In Part B, participants will be randomly assigned to 5 groups to receive placebo and/or 1 of 3 doses of CNTO 136 (100mg, 50mg or 25mg) for 24 weeks. Participants in Part B, Group 1 will be crossed over at Week 12 from placebo to CNTO 136. All participants should be maintained on a stable dose of MTX for at least 6 weeks prior to the start of study medication through Week 24. Safety will be evaluated by the assessment of adverse events, vital signs, clinical findings, 12-lead electrocardiogram, and clinical laboratory tests which will be monitored throughout the study. The total duration of study participation for a participant will be approximately 42 weeks.