A Multi-center, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Certolizumab Pegol in Combination With Methotrexate in the Treatment of Disease Modifying Antirheumatic Drugs (DMARD)-naïve Adults With Early Active Rheumatoid Arthritis

This Outcome Measure includes all subjects that have a DAS28 \[ESR\] \<= 3.2 from the start of RA0055 Period 2 (Week 52 of RA0055 Period 1) to Week 104 in RA0055 Period 2 without flaring.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

CDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), and Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm). 28 joints are examined. CDAI ranges from 0-76 with lower scores indicating less disease activity and higher scores indicating higher disease activity. A negative value in CDAI change from Baseline indicates an improvement from Baseline.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

DAS28\[ESR\] is calculated using the Tender Joint Count (TJC), Swollen Joint Count (SJC) Erythrocyte Sedimentation Rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x lognat (ESR) + 0.014 x PtGADA, where 28 joints are examined and a lower score indicates less disease activity. DAS28\[ESR\] ranges from 0-10 with higher values representing higher disease activity. A negative value in DAS28\[ESR\] change from Baseline indicates an improvement from Baseline.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Van der Heijde modified Total Sharp Score (mTSS) is a methodology to assess the degree of joint damage by quantifying the extent of bone erosions and joint space narrowing for 44 and 42 joints, respectively. The mTSS ranges from 0 to 448, with higher scores representing greater damage.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

SDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm) and C-Reactive Protein (CRP in mg/L). 28 joints are examined where a lower score indicates less disease activity. The SDAI score ranges from 0 to 86, with a negative value in SDAI change from Baseline indicating an improvement from Baseline.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

BRAF-MDQ total score ranges from 0 to 70 (with higher scores indicating worse fatigue), whereas the score for each dimension is different due to the varied number of questions (0 -22 for physical, 0- 21 for living, 0- 15 for cognition, and 0- 12 for emotion). A negative value in BRAF-MDQ change from Baseline indicates an improvement from Baseline.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Erosions were assessed in 16 locations per hand and 6 joints per foot. Erosions for each hand location were scored from 0 to 5, with 0 indicating no erosion. Scores 1 to 5 may have included combinations of discrete erosion(s) and/or large erosions. Erosions for each foot joint were scored from 0 to 10, with 0 indicating no erosions. The minimum possible total erosion score for all 32-hand joints was 0, the maximum possible erosion score for all 32-hand joints was 160. The minimum possible total erosion score for all 12-feet joints was 0, the maximum possible erosion score for all 12 feet joints was 120. Thus, the minimum possible total erosion score for hands and feet was 0, the maximum possible total erosion score for hands and feet was 280. Higher values represent greater damage.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

Joint space narrowing (JSN) was assessed in 15 locations per hand and 6 locations per foot. Joint space narrowing for each location was scored from 0 to 4, with 0 indicating no narrowing. The minimum possible score for JSN in all 30 hand joints was 0, the maximum possible score for JSN in all 30 hand joints was 120. The minimum possible score for JSN in all 12 feet joints was 0, the maximum possible score for JSN in all 12 feet joints was 48. Thus, the minimum possible total JSN score for hands and feet was 0, the the maximum possible total JSN score for Hands and feet was 168. Higher values represent greater damage.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

CDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), and Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm). 28 joints are examined. CDAI ranges from 0-76 with lower scores indicating less disease activity and higher scores indicating higher disease activity.A negative value in CDAI change from Baseline indicates an improvement from Baseline.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

DAS28\[ESR\] is calculated using the Tender Joint Count (TJC), Swollen Joint Count (SJC) Erythrocyte Sedimentation Rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x lognat (ESR) + 0.014 x PtGADA, where 28 joints are examined and a lower score indicates less disease activity. DAS28\[ESR\] ranges from 0-10 with higher values representing higher disease activity. A negative value in DAS28\[ESR\] change from Baseline indicates an improvement from Baseline.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Van der Heijde modified Total Sharp Score (mTSS) is a methodology to assess the degree of joint damage by quantifying the extent of bone erosions and joint space narrowing for 44 and 42 joints, respectively. The mTSS ranges from 0 to 448, with higher scores representing greater damage.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

SDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm) and C-Reactive Protein (CRP in mg/L). 28 joints are examined where a lower score indicates less disease activity. The SDAI score ranges from 0 to 86, with a negative value in SDAI change from Baseline indicating an improvement from Baseline.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Erosions were assessed in 16 locations per hand and 6 joints per foot. Erosions for each hand location were scored from 0 to 5, with 0 indicating no erosion. Scores 1 to 5 may have included combinations of discrete erosion(s) and/or large erosions. Erosions for each foot joint were scored from 0 to 10, with 0 indicating no erosions. The minimum possible total erosion score for all 32-hand joints was 0, the maximum possible erosion score for all 32-hand joints was 160. The minimum possible total erosion score for all 12-feet joints was 0, the maximum possible erosion score for all 12 feet joints was 120. Thus, the minimum possible total erosion score for hands and feet was 0, the maximum possible total erosion score for hands and feet was 280. Higher values represent greater damage.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

Joint space narrowing (JSN) was assessed in 15 locations per hand and 6 locations per foot. Joint space narrowing for each location was scored from 0 to 4, with 0 indicating no narrowing. The minimum possible score for JSN in all 30 hand joints was 0, the maximum possible score for JSN in all 30 hand joints was 120. The minimum possible score for JSN in all 12 feet joints was 0, the maximum possible score for JSN in all 12 feet joints was 48. Thus, the minimum possible total JSN score for hands and feet was 0, the the maximum possible total JSN score for Hands and feet was 168. Higher values represent greater damage.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

The Arthritis interference in the last month with household productivity is measured on a scale that ranges from 0 (no interference) to 10 (complete interference).

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

The Arthritis interference in the last month with work productivity is measured on a scale that ranges from 0 (no interference) to 10 (complete interference) for employed subjects. Only the employed subjects were analyzed.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO + MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Number of days missed of family/social/leisure activities in the last month.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Number of days with hired outside help days in the last month.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Number of days with no household work in the last month.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2.

Number of days with reduced household work productivity in the last month.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Number of work days missed in the last month for employed subjects.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO + MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Number of work days with reduced productivity in the last month for employed subjects. Only the employed subjects were analyzed.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

Good response is defined as: DAS28\[ESR\] \<= 3.2 and decrease from Baseline by \>1.2; moderate response is defined as achievement of one of the following: * DAS28\[ESR\] \<= 3.2 and decrease from Baseline \> 0.6 and ≤ 1.2 * DAS28\[ESR\] \> 3.2 and ≤ 5.1 and decrease from Baseline \> 0.6 * DAS28\[ESR\] \> 5.1 and decrease from Baseline \>1.2. LOCF= Last Observation Carried Forward

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with LOCF. FAS2 did not include subjects who had received PBO+MTX in Period1 as this was not part of the study objectives for the Period2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period2. They are included in the FAS2, but excluded from the SS2

LDA is defined as achieving a Disease Activity Score 28 \[Erythrocyte Sedimentation Rate\] (DAS28 \[ESR\]) \<= 3.2. DAS28 values range from 2.0 to 10.0 with a higher value indicating a higher disease activity.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

The ACR/EULAR 2011 remission criteria is defined as: Tender Joint Count (TJC) \<= 1, Swollen Joint Count (SJC) \<= 1, C-Reactive Protein (CRP) \<= 1 mg/dl and Patient's Global Assessment of Disease Activity (PtGADA) \<= 10 mm.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

The 2011 ACR/EULAR remission criteria simplified for clinical practice is defined as: Tender Joint Count (TJC) \<= 1, Swollen Joint Count (SJC) \<= 1 and Patient's Global Assessment of Disease Activity (PtGADA) \<= 10 mm.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

The assessments are based on a 20 % or greater improvement from Baseline in previous study RA0055 Period 1 in the number of tender joints, a 20 % or more improvement in the number of swollen joints, and a 20 % or greater improvement in 3 of the 5 remaining core set measures: Patient's Global Assessment of Disease Activity (PtGADA), Physician's Global Assessment of Disease Activity (PhGADA), Patient's Assessment of Arthritis Pain (PtAAP), physical function as assessed by the Health Assessment Questionnaire - Disability Index (HAQ-DI) and C-Reactive Protein (CRP).

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

The assessments are based on a 50 % or greater improvement from Baseline in previous study RA0055 Period 1 in the number of tender joints, a 50 % or more improvement in the number of swollen joints, and a 50 % or greater improvement in 3 of the 5 remaining core set measures: Patient's Global Assessment of Disease Activity (PtGADA), Physician's Global Assessment of Disease Activity (PhGADA), Patient's Assessment of Arthritis Pain (PtAAP), physical function as assessed by the Health Assessment Questionnaire - Disability Index (HAQ-DI) and C-Reactive Protein (CRP).

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

The assessments are based on a 70 % or greater improvement from Baseline in previous study RA0055 Period 1 in the number of tender joints, a 70 % or more improvement in the number of swollen joints, and a 70 % or greater improvement in 3 of the 5 remaining core set measures: Patient's Global Assessment of Disease Activity (PtGADA), Physician's Global Assessment of Disease Activity (PhGADA), Patient's Assessment of Arthritis Pain (PtAAP), physical function as assessed by the Health Assessment Questionnaire - Disability Index (HAQ-DI) and C-Reactive Protein (CRP).

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

Normative physical function is defined as HAQ-DI score \<= 0.5. The domains of the HAQ-DI are dressing and grooming, arising, eating, walking, hygiene, reach, grip and common daily activities. The total score ranges from 0 to 3 with lower scores meaning lower disability.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

CDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), and Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm). 28 joints are examined where a lower score indicates less disease activity.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

DAS28\[ESR\] is calculated using the Tender Joint Count (TJC), Swollen Joint Count (SJC) Erythrocyte Sedimentation Rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x lognat (ESR) + 0.014 x PtGADA, where 28 joints are examined and a lower score indicates less disease activity.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

DAS28\[ESR\] is calculated using the Tender Joint Count (TJC), Swollen Joint Count (SJC) Erythrocyte Sedimentation Rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x lognat (ESR) + 0.014 x PtGADA, where 28 joints are examined and a lower score indicates less disease activity.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: Full Analysis Set Period 2 (FAS2) with Non-Responder Imputation (NRI). FAS2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

DAS28\[ESR\] is calculated using the Tender Joint Count (TJC), Swollen Joint Count (SJC) Erythrocyte Sedimentation Rate (ESR in mm/hour), and the Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm) using the following formula: 0.56 x √(TJC) + 0.28 x √(SJC) + 0.70 x lognat (ESR) + 0.014 x PtGADA, where 28 joints are examined and a lower score indicates less disease activity.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

Radiographic nonprogression is defined as change in modified Total Sharp Score (mTSS) \<= 0.5. Van der Heijde modified Total Sharp Score (mTSS) is a methodology to assess the degree of joint damage by quantifying the extent of bone erosions and joint space narrowing for 44 and 42 joints, respectively. The mTSS ranges from 0 to 448, with higher scores representing greater damage.

Time frame: From Baseline (Week 0) in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

Radiographic nonprogression is defined as change in modified Total Sharp Score (mTSS) \<= 0.5. Van der Heijde modified Total Sharp Score (mTSS) is a methodology to assess the degree of joint damage by quantifying the extent of bone erosions and joint space narrowing for 44 and 42 joints, respectively. The mTSS ranges from 0 to 448, with higher scores representing greater damage.

Time frame: From Week 52 in RA0055 Period 1 to Week 104 in RA0055 Period 2

Population: The Radiographic Set Period 2 (RAD2) consisted of those subjects in the FAS2 who had provided valid radiographs at Baseline, at Week 52, and at Week 104 or the Withdrawal Visit.~RAD2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.

SDAI is calculated as the sum of tender joint count (TJC), swollen joint count (SJC), Patient's Global Assessment of Disease Activity - Visual Analog Scale (PtGADA-VAS in mm), Physician's Global Assessment of Disease Activity - Visual Analog Scale (PhGADA-VAS in mm) and C-Reactive Protein (CRP in mg/L). 28 joints are examined where a lower score indicates less disease activity. The SDAI score ranges from 0 to 86, with a negative value in SDAI change from Baseline indicating an improvement from Baseline.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 with NRI. FAS2 did not include subjects who had received PBO+MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2

Time to flare, defined as an increase of DAS28\[ESR\] \>= 0.6 above Week 52 DAS28\[ESR\] level, having a DAS28\[ESR\] \>= 3.2 and judged by the Investigator as due to RA and all three criteria confirmed at an additional visit two weeks thereafter, from Week 52 onwards. Data not available as \> 75% of the participants failed to meet flare criteria.

Time frame: Week 104 in RA0055 Period 2

Population: FAS2 did not include subjects who had received PBO + MTX in Period 1 as this was not part of the study objectives for the Period 2 efficacy analyses.~1 subject in the CZP+MTX/CZP Q2W+MTX and 1 in the CZP+MTX/PBO+MTX arm had post Week 52 assessments, but weren´t dosed in Period 2. They are included in the FAS2, but excluded from the SS2