IV infusions of 4mg/kg golimumab at Week 0 and every 12 weeks thereafter with early escape (addition of MTX) and dose regimen adjustment (addition of MTX), depending on joint assessment results, at Week 16 and 24, respectively. The duration of the combined IV treatment period (initial treatment plus early escape and/or dose regimen adjustment) will be a minimum of 48 weeks. The IV treatment period will be followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, patients will receive placebo (sham MTX) capsules.

IV infusions of placebo at Week 0 and Week 12 with early escape (switch to 4mg/kg IV golimumab) and dose regimen adjustment (switch to 4mg/kg IV golimumab), depending on joint assessment results, at Week 16 and 24, respectively. The duration of the combined IV treatment period (placebo plus golimumab) will be a minimum of 48 weeks. The IV treatment period will be followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition patients will receive MTX at the same dose as that before study entry. Participants still receiving placebo injections at Week 48 are not eligible to enter the Extension Study.

Active MTX capsules, filled with microcrystalline cellulose (Avicel PH 102) and a 2.5 mg MTX tablet, will be administered at the same dose as before the study entry.

Placebo solution will be administered through IV infusion in Group V and oral placebo capsules (sham MTX) filled with microcrystalline cellulose (Avicel PH 102) will be administered in Group II and IV.

ACR 20 response is an improvement of greater than or equal to 20 percentage from baseline in both the tender and swollen joint count and in at least 3 of the 5 assessments (patient's assessment of pain, patient's global assessemnt of disease activity, Physician's global assessment of disease activity [based on a scale of 0=no disease to 10=severe disease), HAQ (20 questions on life activities] and CRP blood test to measure inflammation).

DAS28 using CRP is a measure of tender and swollen joints (28 joints each) and the patient's assessment of disease activity. Values range from 0 (best) to 10 (worst). A score of higher than 5.1 indicates high disease activity, and a score below 3.2 indicates low disease activity. A "Good" response is defined as a patient with a DAS28 score of <= 3.2 at Week 14 with improvement from Baseline in DAS28 score of > 1.2. A "Moderate" response is defined as a patient with DAS28 score of >3.2-5.1 at Week 14 with improvement from baseline in DAS28 score of >1.2 or a DAS28 score of <= 5.1 and improvement from baseline in DAS28 score of >0.6 to 1.2

The SF-36 consists of 8 multi-item scales: limitations in physical functioning due to health problems, usual role activities due to physical health problems, bodily pain, usual role activities due to personal or emotional problems, social functioning due to physical or mental health problems, general mental health (psychological distress and well-being), vitality and general health perception. The values are 100=best to 0=worst.

Participants received IV infusions of 2mg/kg golimumab at Week 0 and every 12 weeks thereafter for a minimum of 48 weeks followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, participants received placebo (sham MTX) capsules during the IV Period only.

Participants received IV infusions of 4mg/kg golimumab at Week 0 and every 12 weeks thereafter for a minimum of 48 weeks followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, participants received MTX at the same dose as before study entry.

Participants received IV infusions of 4mg/kg golimumab at Week 0 and every 12 weeks thereafter for a minimum of 48 weeks followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, participants received placebo (sham MTX) capsules during the IV Period only.

Participants received IV infusions of placebo at Week 0 and Week 12. At Week 24, depending on joint assessment results (dose regimen adjustment), participants were switched to IV infusions of 4mg/kg golimumab every 12 weeks for a minimum combined treatment period (placebo plus golimumab) of 48 weeks. This was followed by the option of subcutaneous (SC) injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition participants received MTX at the same dose as before study entry. Participants still receiving placebo infusions at Week 48 were not eligible to enter the Extension Study.

At Week 16 and Week 24 participants entered early escape (EE) and dose regimen adjustment (DRA), respectively, depending on joint assessment results and received IV infusions of 2mg/kg golimumab (as per protocol) for a minimum combined treatment period (initial treatment plus EE or DRA) of 48 weeks. This was followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, participants received MTX at the same dose as before study entry.

At Week 16 and Week 24 participants entered EE and DRA, respectively, depending on joint assessment results and received IV infusions of 4mg/kg golimumab (as per protocol) for a minimum combined treatment period (initial treatment plus EE or DRA) of 48 weeks. This was followed by the option of SC injections of 50mg golimumab every 4 weeks for a further 24 weeks (Extension Study). In addition, participants received MTX at the same dose as before study entry.