ACR20 responders are those subjects with at least 20 % improvement from Baseline (BL) for Tender Joint Count (TJC), Swollen Joint Count (SJC), and at least 3 of the 5 remaining core set measures: 1) Health Assessment Questionnaire-Disability Index (HAQ-DI), 2) C-reactive Protein (CRP), 3) Patient's Assessment of Arthritis Pain-Visual Analog Scale (PAAP-VAS), 4) Patient's Global Assessment of Disease Activity-Visual Analog Scale (PtGADA-VAS), 5) Physician's Global Assessment of Disease Activity-Visual Analog Scale (PhGADA-VAS).

Intention-to-treat dataset was the Randomized Set (RS). RS with non-responder imputation: subjects who withdrew for any reason or placebo subjects who used escape medication are considered as nonresponders from drop out timepoint or when escape therapy was initiated. Subjects with missing data at a visit are non-responders for that visit, too.

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 64 and 52 joints, respectively, with higher scores representing greater damage. mTSS (bone erosions) ranges from 0 (best possible outcome) to 320 (worst possible outcome); mTSS (joint space narrowing) ranges from 0 (best possible outcome) to 208 (worst possible outcome); and total score ranges from 0 (best possible outcome) to 528 (worst possible outcome). For the pre-defined analysis of this outcome measure, 0 was used for Baseline and the maximum observed mTSS value was used for Week 24 for those subjects which had less than 2 radiographs. The re-analysis is restricted to those subjects in the Randomized Set who have at least 2 x-ray values at scheduled visits, which are at least 8 weeks apart.

Intention-to-treat dataset was the Randomized Set (RS). RS with imputation: for subjects who withdrew for any reason, or subjects with missing Week 24 measurements, or placebo subjects who used escape medication, scores are linearly extrapolated from the last two radiographs prior to early withdrawal or Week 24 or before receiving CZP.

ACR20 responders are those subjects with at least 20 % improvement from Baseline for Tender Joint Count (TJC), Swollen Joint Count (SJC), and at least 3 of the 5 remaining core set measures: 1) Health Assessment Questionnaire-Disability Index (HAQ-DI), 2) C-reactive Protein (CRP), 3) Patient's Assessment of Arthritis Pain-Visual Analog Scale (PAAP-VAS), 4) Patient's Global Assessment of Disease Activity-Visual Analog Scale (PtGADA-VAS), 5) Physician's Global Assessment of Disease Activity-Visual Analog Scale (PhGADA-VAS).

Intention-to-treat dataset was the Randomized Set (RS). RS with non-responder imputation: subjects who withdrew for any reason or placebo subjects who used escape medication are considered as nonresponders from drop out timepoint or when escape therapy was initiated. Subjects with missing data at a visit are non-responders for that visit, too.

The HAQ-DI is a measure of function in Arthritis. There are 20 items in eight categories that represent a comprehensive set of functional activities on a scale from 0 (without difficulty) to 3 (unable to perform without assistance). The category scores are averaged into an overall HAQ-DI from 0 to 3. Scores of 0 to 1 generally represent mild to moderate difficulty, 1 to 2 represent moderate to severe disability, and 2 to 3 indicate severe to very severe disability. A negative value in HAQ-DI change from Baseline indicates an improvement from Baseline. The higher the negative value, the higher the improvement.

Intention-to-treat dataset was the Randomized Set (RS). RS with Last Observation Carried Forward (LOCF): for subjects who withdrew for any reason, or subjects with missing Week 24 measurements, or placebo subjects who used escape medication, last observation prior to early withdrawal or Week 24 or before receiving CZP is carried forward to Week 24.

The PASI75 response assessments are based on at least 75 % improvement in the PASI score from Baseline. The PASI score is a measure of the average redness, thickness, and scaliness of the psoriatic skin lesions (each graded on a 0 to 4 scale), weighted by the area of involvement.

Intention-to-treat dataset was the Randomized Set (RS). RS with non-responder imputation: subjects who withdrew for any reason or placebo subjects who used escape medication are considered as nonresponders from drop out timepoint or when escape therapy was initiated. Subjects with missing data at a visit are non-responders for that visit, too.

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 64 and 52 joints, respectively, with higher scores representing greater damage. mTSS (bone erosions) ranges from 0 (best possible outcome) to 320 (worst possible outcome); mTSS (joint space narrowing) ranges from 0 (best possible outcome) to 208 (worst possible outcome); and total score ranges from 0 (best possible outcome) to 528 (worst possible outcome).

For the analysis of this outcome measure, the change from Baseline to Week 48 was imputed using the median change from Baseline among all subjects for those subjects, which had less than 2 radiographs. The post-hoc analysis presented here is based on the subgroup of subjects which had a Baseline mTSS value greater than 6.

Randomized Set (RS) with imputation: for subjects who withdrew for any reason, or subjects with missing Week 48 measurements, and for all placebo subjects after the switch to CZP, Week 48 scores are linearly extrapolated from the last two available radiographs prior to early withdrawal or Week 24 or before receiving CZP.