HAQ-DI includes 20 questions concerning participant's activities of daily life, grouped in 8 scales of 2 to 3 questions for each activity. To respond to each question, a four-level response (score of 0 to 3 points), with higher scores showing larger functional limitations, was chosen. Scoring was as follows with respect to performance of participant's everyday activities: 0 (equals)=without difficulties; 1= with some difficulties; 2=with great difficulties; and 3=unable to perform these actions at all. Minimum score was 0, maximum score was 3. Relevant clinical improvement was defined as a reduction of at least 0.22 points in HAQ-DI.

ITT Population

Participants were asked to rate their assessment of disease activity using a visual analog scale (VAS) of 0 to 100 millimeters (mm), where 0 represented no symptoms and 100 represented severe symptoms. Participants were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; number (n) = number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Participants were asked to rate their assessment of disease activity using a VAS of 0 to 100 mm, where 0 represented no symptoms and 100 represented severe symptoms. Participants were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; 3 participants were randomized to the placebo treatment group but received tocilizumab. n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Physicians were asked to assess disease activity of the participants using a VAS of 0 to 100 mm, where 0 represented no symptoms and 100 represented severe symptoms. Physicians were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Physicians were asked to assess disease activity of the participants using a VAS of 0 to 100 mm, where 0 represented no symptoms and 100 represented severe symptoms. Physicians were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; 3 participants were randomized to the placebo treatment group but received tocilizumab. n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Participants were asked to rate their assessment of pain using a VAS of 0 to 100 mm, where 0 represented no pain and 100 represented intolerable pain. Participants were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Participants were asked to rate their assessment of pain using a VAS of 0 to 100 mm, where 0 represented no pain and 100 represented intolerable pain. Participants were asked to mark the line corresponding to their assessment and the distance from the left edge was measured. A negative value in change from Baseline indicates an improvement.

ITT Population; 3 participants were randomized to the placebo treatment group but received tocilizumab. n=number of participants assessed at a specific visit

Synovitis was assessed by ultrasonography (B-mode ultrasound and Power Doppler) and scored from "0" to "3", for each of 40 joints (5 metacarpal phalangeal [MCP; left and right] joints, 5 proximal interphalangeal [PIP; left and right] joints, left and right wrists, elbows, shoulders, knees, and ankles, and 5 metatarsal phalangeal [MTP; left and right] joints); synovitis scores were calculated by adding the sum of scores for each joint for a total score ranging from 0 to 120. A score of 0 indicated no damage and a score of 120 indicated most severe damage. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4. A negative change from baseline indicated improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Synovitis was assessed by ultrasonography (B-mode ultrasound and Power Doppler) and scored from "0" to "3", for each of 40 joints (5 MCP [left and right] joints, 5 PIP [left and right] joints, left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints); synovitis scores were calculated by adding the sum of scores for each joint for a total score ranging from 0 to 120 (higher score=more severe disease). Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4. Negative change from baseline indicated improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Synovitis was assessed by ultrasonography (B-mode ultrasound and Power Doppler) and scored from "0" to "3", for each of 40 joints (5 MCP [left and right] joints, 5 PIP [left and right] joints, left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints); synovitis scores were calculated by adding the sum of scores for each joint for a total score ranging from 0 to 120 (higher score=more severe disease). Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4. Relative change was the percentage (%) change from baseline.

One-Year Efficacy Population: all randomized participants with at least 1 tocilizumab infusion (completed or not). n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Synovitis was assessed by ultrasonography (B-mode ultrasound and Power Doppler) and scored from "0" to "3", for each of 40 joints (5 MCP [left and right] joints, 5 PIP [left and right] joints, left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints); synovitis scores were calculated by adding the sum of scores for each joint for a total score ranging from 0 to 120 (higher score=more severe disease). Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4. Relative change was the percentage change from baseline.

One-Year Efficacy Population: all randomized participants with at least 1 tocilizumab infusion (completed or not). n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Erythrocyte sedimentation rate is a biological marker of inflammation, measured in mm per hour (mm/hr). A reduction in ESR indicates improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Erythrocyte sedimentation rate is a biological marker of inflammation. A negative change indicates improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Erythrocyte sedimentation rate is a biological marker of inflammation, measured in mm/hr. A reduction in ESR indicates improvement. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

C-Reactive protein (CRP) is a biological marker of inflammation and is measured in nanograms per milliliter (ng/mL). A reduction in CRP indicates improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

C-Reactive protein (CRP) is a biological marker of inflammation. Negative changes from baseline indicate improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

C-reactive protein is a biological marker of inflammation and is measured in nanograms per milliliter (ng/mL). Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Serum Amyloid A (SAA) component is a biological marker of inflammation and is measured in mg/L. A reduction in SAA indicates improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Serum Amyloid A (SAA) component is a biological marker of inflammation. A negative change from baseline indicates improvement.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Serum Amyloid A (SAA) component is a biological marker of inflammation measured in mg/L. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Beta 2 Microglobulin is a biological marker of inflammation measured in micrograms per milliliter (mcg/mL). Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

One-Year Efficacy Population;n=number of participants assessed for the specified parameter at a given visit.

Beta 2 Microglobulin is a biological marker of inflammation measured in micrograms per milliliter (mcg/mL).

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Beta 2 Microglobulin is a biological marker of inflammation. If baseline value was equal to 0, it was replaced by 0.1 to calculate the change from baseline.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

To describe bone mineral density (BMD), standardized values were calculated for lumbar spine, hip, femoral neck, and trochanter, taking into account the type of Dual energy X ray absorptiometry (DXA) used. All DXA at baseline were taken into account (done from before screening to Week 8). DXA at end of study were taken into account if they were done after at least 6 infusions of tocilizumab. Values were measured in milligrams per square centimeter (mg/cm^2).

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

S-Sclerostin and P-Dkk1 are biological markers of bone and cartilage metabolism measured as picograms/milliliter (pg/mL). Baseline is the closest value plus or minus (+/-) 1 month around the first tocilizumab infusion. If values before and after the first infusion were eligible, the value before was taken into account.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

S-PIIINP, S-CTX-I, and S-PINP are biological markers of bone and cartilage metabolism. Baseline is the closest value +/- 1 month around the first tocilizumab infusion. If values before and after the first infusion were eligible, the value before was taken into account.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

S-OGP is a biological marker of bone and cartilage metabolism measured as picomoles per liter (pmol/L). Baseline is the closest value +/- 1 month around the first tocilizumab infusion. If values before and after the first infusion were eligible, the value before was taken into account.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Before entering the study, participants had to be treated with MTX for at least 12 weeks and at a stable dose for at least 8 weeks before the screening visit (10-25 mg per week [mg/week] of oral or parenteral MTX). During the study, treatment with MTX had to be stable during the first month and then could be continued or modified, at the investigator's discretion.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

HAQ-DI: participant-reported assessment of ability to perform tasks in 8 categories of daily living activities: dress/groom; arise; eat; walk; reach; grip; hygiene; and common activities over past week. Each item scored on 4-point scale from 0 to 3: 0=no difficulty; 1=some difficulty; 2=much difficulty; 3=unable to do. Overall score was computed as the sum of domain scores and divided by the number of domains answered. Total possible score range 0-3 where 0 = least difficulty and 3 = extreme difficulty.

ITT Population; n=number of participants assessed for the specified parameter at a given visit.

HAQ-DI: participant-reported assessment of ability to perform tasks in 8 categories of daily living activities: dress/groom; arise; eat; walk; reach; grip; hygiene; and common activities over past week. Each item scored on 4-point scale from 0 to 3: 0=no difficulty; 1=some difficulty; 2=much difficulty; 3=unable to do. Overall score was computed as the sum of domain scores and divided by the number of domains answered. Total possible score range 0-3 where 0 = least difficulty and 3 = extreme difficulty.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

FACIT-F is a 13-item questionnaire. Participants scored each item on a 5-point scale: 0 (Not at all) to 4 (Very much). The larger the participant's response to the questions (with the exception of 2 negatively stated), the greater the patient's fatigue. For all questions, except for the 2 negatively stated ones, the code was reversed and a new score was calculated as (4 minus the participant's response). The sum of all responses resulted in the FACIT-F score for a total possible score of 0 (worse score) to 52 (better score). A higher score reflects an improvement in the participant's health status. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

ITT Population; n=number of participants assessed for the specified parameter at a given visit.

FACIT-F is a 13-item questionnaire. Participants scored each item on a 5-point scale: 0 (Not at all) to 4 (Very much). The larger the participant's response to the questions (with the exception of 2 negatively stated), the greater the patient's fatigue. For all questions, except for the 2 negatively stated ones, the code was reversed and a new score was calculated as (4 minus the participant's response). The sum of all responses resulted in the FACIT-F score for a total possible score of 0 (worse score) to 52 (better score). A higher score reflects an improvement in the participant's health status. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

ITT Population; n=number of participants assessed for the specified parameter at a given visit.

FACIT-F is a 13-item questionnaire. Participants scored each item on a 5-point scale: 0 (Not at all) to 4 (Very much). The larger the participant's response to the questions (with the exception of 2 negatively stated), the greater the patient's fatigue. For all questions, except for the 2 negatively stated ones, the code was reversed and a new score was calculated as (4 minus the participant's response). The sum of all responses resulted in the FACIT-F score for a total possible score of 0 (worse score) to 52 (better score). A higher score reflects an improvement in the participant's health status. Baseline = Last available value before Day 0 (screening or Day 0) for participants with first tocilizumab infusion at Day 0 and last value available before Week 4 (Week 1 or Week 4) for participants with first tocilizumab infusion at Week 4.

ITT Population; n=number of participants assessed for the specified parameter at a given visit.

Hemoglobin concentrations were determined at each visit to evaluate anemia in participants and measured as grams per deciliter (g/dL).

ITT Population; n=number of participants assessed for the specified parameter at a given visit.

Hemoglobin concentrations were determined at each visit to evaluate anemia in participants and measured as g/dL.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Twenty-eight joints were assessed for tenderness. Joints were classified as tender (1)/not tender (0) giving a total possible TJC score of 0 to 28. Baseline = value at Day 0 if available, value at screening otherwise.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Twenty-eight joints were assessed for tenderness. Joints were classified as tender (1)/not tender (0) giving a total possible TJC score of 0 to 28.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Twenty-eight joints were assessed for tenderness and joints were classified as tender (1)/not tender (0), giving a total possible tender joint count score of 0 to 28. Baseline = Last value available before Day 0 (selection or Day 0) for placebo and last value available before Week 4 (Week 1 or Week 4) for tocilizumab group.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Forty joints were assessed for tenderness (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as tender (1)/not tender (0) giving a total possible TJC score of 0 to 40. Baseline = value at Day 0 if available, value at screening otherwise.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Forty joints were assessed for tenderness (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as tender (1)/not tender (0) giving a total possible TJC score of 0 to 40.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Forty joints were assessed for tenderness (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as tender (1)/not tender (0) giving a total possible TJC score of 0 to 40. Baseline = Last value available before Day 0 (selection or Day 0) for placebo and last value available before Week 4 (Week 1 or Week 4) for tocilizumab group.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Twenty-eight joints were assessed for swelling. Joints were classified as swollen (1)/not swollen (0) giving a total possible SJC score of 0 to 28. Baseline = value at Day 0 if available, value at screening otherwise.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Twenty-eight joints were assessed for swelling. Joints were classified as swollen (1)/not swollen (0) giving a total possible SJC score of 0 to 28.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Twenty-eight joints were assessed for swelling (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints) . Joints were classified as swollen (1)/not swollen (0) giving a total possible SJC score of 0 to 28. Baseline = Last value available before Day 0 (selection or Day 0) for placebo and last value available before Week 4 (Week 1 or Week 4) for tocilizumab group.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

Forty joints were assessed for swelling (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as swollen (1)/not swollen (0) giving a total possible SJC score of 0 to 40. Baseline = value at Day 0 if available, value at screening otherwise.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Forty joints were assessed for swelling (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as swollen (1)/not swollen (0) giving a total possible SJC score of 0 to 40.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

Forty joints were assessed for swelling (5 MCP [left and right] joints, 5 PIP [left and right joints], left and right wrists, elbows, shoulders, knees, and ankles, and 5 MTP [left and right] joints). Joints were classified as swollen (1)/not swollen (0) for a total possible score of 0 to 40. Baseline = Last value available before Day 0 (selection or Day 0) for placebo and last value available before Week 4 (Week 1 or Week 4) for tocilizumab group.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.

DAS28 calculated from the number of swollen joints and tender joints using the 28-joint count, the erythrocyte sedimentation rate and global health assessment (participant-rated global assessment of disease activity using 10-mm VAS); DAS28 score ranged from 0 to 10, where higher scores correspond to greater disease activity. DAS28 less than or equal to (≤3.2) = low disease activity, DAS28 greater than (>)3.2 to 5.1 = moderate to high disease activity.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

DAS28 calculated from the number of swollen joints and tender joints using the 28-joint count, the erythrocyte sedimentation rate and global health assessment (participant-rated global assessment of disease activity using 10-mm VAS); DAS28 score ranged from 0 to 10, where higher scores correspond to greater disease activity. DAS28 less than or equal to (≤3.2) = low disease activity, DAS28 greater than (>)3.2 to 5.1 = moderate to high disease activity.

One-Year Efficacy Population n=number of participants assessed for the specified parameter at a given visit.

DAS40 calculated from the number of swollen joints and tender joints using the 40-joint count, the erythrocyte sedimentation rate and global health assessment (participant-rated global assessment of disease activity using 10-mm VAS); DAS28 score ranged from 0 to 10, where higher scores correspond to greater disease activity.

ITT Population; n=number of participants assessed for the specified parameter at a given visit. Changes from baseline were described for participants without missing data.

DAS40 was calculated from the number of swollen joints and tender joints using the 40-joint count, the erythrocyte sedimentation rate, and global health assessment (participant-rated global assessment of disease activity using 10-mm VAS); DAS40 score ranged from 0 to 10, where higher scores correspond to greater disease activity.

One-Year Efficacy Population; n=number of participants assessed for the specified parameter at a given visit.