Abatacept and Infliximab in Combination With Methotrexate in Subjects With Rheumatoid Arthritis

DB; Adjusted Mean Change From Baseline to Day 197 in DAS 28 Score (ESR) For INF Versus PLA (LOCF Analysis)

The DAS28 is a continuous disease measure which is a composite of 4 variables: the 28 tender joint count, the 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. The DAS28 has numeric thresholds that define high disease activity (\> 5.1), low disease activity (\< 3.2) and remission (\< 2.6). A clinically significant response is a decrease in DAS28 score of \>1.2 from baseline.

Time frame: Baseline (Day 1), 6 months (Day 197)

DB; DAS 28 (ESR) Area Under The Curve (AUC) Over 12 Months For ABA Versus INF

The DAS28 is a continuous disease measure which is a composite of 4 variables: the 28 tender joint count, the 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. The DAS28 has numeric thresholds that define high disease activity (\> 5.1), low disease activity (\< 3.2) and remission (\< 2.6). Clinically significant response= decrease in DAS28 score of \>1.2 from baseline. DAS28 AUC can be calculated from the DAS28 score versus time curve, which provides an assessment of changes in disease activity over time.

Time frame: From Day 1 through Day 365 (12 months)

DB; Percentage of Participants With Clinically Meaningful Health Assessment Questionnaire-Disability Index (HAQ-DI) Response at Day 197

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: DB Day 197

DB; Percentage of Participants With Clinically Meaningful Health Assessment Questionnaire-Disability Index (HAQ-DI) Response at Day 365

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: DB Day 365

DB; Adjusted Mean Change From Baseline to Day 197 in HAQ-DI (LOCF Analysis)

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: Baseline (Day 1), 6 months (Day 197)

DB; Adjusted Mean Change From Baseline to Day 365 in HAQ-DI (LOCF Analysis)

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: Baseline (Day 1), 12 months (Day 365)

DB; Adjusted Mean Change From Baseline to Day 197 in SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS)

The SF-36 is a validated instrument measuring health-related quality of life across multiple disease states. It has 36 questions with 8 subscale scores and 2 summary scores (1) physical component summary=physical functioning, role-physical, bodily pain, and general health; (2) mental component summary=vitality, social functioning, role-emotional, and mental health. There is no total overall score; scoring is done for both subscores and summary scores. For subscores and summary scores, 0 =worst score (or quality of life) and 100=best score. Change from Baseline= post-Baseline - Baseline value.

Time frame: Baseline (Day 1), 6 months (Day 197)

DB; Adjusted Mean Change From Baseline to Day 365 in SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS)

The SF-36 is a validated instrument measuring health-related quality of life across multiple disease states. It has 36 questions with 8 subscale scores and 2 summary scores (1) physical component summary=physical functioning, role-physical, bodily pain, and general health; (2) mental component summary=vitality, social functioning, role-emotional, and mental health. There is no total overall score; scoring is done for both subscores and summary scores. For subscores and summary scores, 0 =worst score (or quality of life) and 100=best score. Change from Baseline= post-Baseline - Baseline value.

Time frame: Baseline (Day 1), 12 months (Day 365)

DB; Percentage of Participants With Good, Moderate, or No Response According to European League Against Rheumatism (EULAR) at Day 365

The DAS28 is a continuous disease measure composite of 4 variables: 28 tender joint count, 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. High disease activity= \> 5.1, low disease activity= \< 3.2, and remission= \< 2.6. Clinically significant response= decrease of \>1.2 from baseline. Utilizing EULAR response criteria, DAS28 categorical responses define a good (absolute: \<3.2 or \>1.2 improvement from baseline \[BL\]), moderate (absolute: 3.2-5.1 or 0.6-1.2 change from BL), or no response (absolute: \>5.1 or \<0.6 change from BL)

Time frame: DB Day 365

DB; Percentage of Participants With American College of Rheumatology (ACR) Responses at Day 197

The ACR 20 definition of improvement is a 20% improvement from baseline in the number of tender and swollen joint counts, and a 20% improvement from baseline in 3 of the remaining 5 core set measures: participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function and acute phase reactant value (C-reactive protein \[CRP\]). The evaluation for 50% improvement (ACR 50) and 70% improvement (ACR 70) follow similarly.

Time frame: DB Day 197

DB; Percentage of Participants With American College of Rheumatology (ACR) Responses at Day 365

The ACR 20 definition of improvement is a 20% improvement from baseline in the number of tender and swollen joint counts, and a 20% improvement from baseline in 3 of the remaining 5 core set measures: participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function and acute phase reactant value (C-reactive protein \[CRP\]). The evaluation for 50% improvement (ACR 50) and 70% improvement (ACR 70) follow similarly.

Time frame: DB Day 365

DB; Number of Participants With Death, Serious Adverse Events (SAEs), Related SAEs, SAEs Leading to Discontinuation, AEs, Related AEs, and AEs Leading to Discontinuation From Day 1 Through Day 197

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. SAE=any untoward medical occurrence that at any dose: results in death, is life-threatening, requires inpatient hospitalization or causes prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, results in development of drug dependency or drug abuse, is an important medical event.

Time frame: From Baseline (Day 1) through Day 197, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With AEs of Special Interest From Day 1 Through Day 197

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. AEs of special interest are those AEs that may be associated with the use of immunomodulatory drugs, including all infections, serious infections, autoimmune disorders; malignancies; and acute infusional AEs (pre-specified AEs occurring within 1 hour of start of infusion).

Time frame: From Baseline (Day 1) through Day 197, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Death, Serious Adverse Events (SAEs), Related SAEs, SAEs Leading to Discontinuation, AEs, Related AEs, and AEs Leading to Discontinuation From Day 1 Through Day 365

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. SAE=any untoward medical occurrence that at any dose: results in death, is life-threatening, requires inpatient hospitalization or causes prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, results in development of drug dependency or drug abuse, is an important medical event.

Time frame: From Baseline (Day 1) through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Death, Serious Adverse Events (SAEs), Related SAEs, SAEs Leading to Discontinuation, AEs, Related AEs, and AEs Leading to Discontinuation From Day 198 Through Day 365 in Participants Receiving Placebo Switched to Abatacept

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. SAE=any untoward medical occurrence that at any dose: results in death, is life-threatening, requires inpatient hospitalization or causes prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, results in development of drug dependency or drug abuse, is an important medical event.

Time frame: From Day 198 through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With AEs of Special Interest From Day 1 Through Day 365

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. AEs of special interest are those AEs that may be associated with the use of immunomodulatory drugs, including all infections, serious infections, autoimmune disorders; malignancies; and acute infusional AEs (pre-specified AEs occurring within 1 hour of start of infusion).

Time frame: From Baseline (Day 1) through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With AEs of Special Interest From Day 198 Through Day 365 in Participants Receiving Placebo Switched to Abatacept

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with this treatment. AEs of special interest are those AEs that may be associated with the use of immunomodulatory drugs, including all infections, serious infections, autoimmune disorders; malignancies; and acute infusional AEs (pre-specified AEs occurring within 1 hour of start of infusion).

Time frame: From Day 198 through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Significant Changes in Mean Systolic and Diastolic Blood Pressure During Days 1 Through 197 and Days 1 Through 365

Seated Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) were assessed as clinically significant or relevant at the discretion of the Clinical Investigator. Criteria may have varied between institutions.

Time frame: From Baseline (Day 1) through Day 197, or Day 1 through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Significant Changes in Mean Heart Rate During Days 1 Through 197 and Days 1 Through 365

Heart Rate (HR) was assessed as clinically significant or relevant at the discretion of the Clinical Investigator. Criteria may have varied between institutions.

Time frame: From Baseline (Day 1) through Day 197, or Day 1 through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Significant Changes in Mean Temperature During Days 1 Through 197 and Days 1 Through 365

Temperature (T) was assessed as clinically significant or relevant at the discretion of the Clinical Investigator. Criteria may have varied between institutions.

Time frame: From Baseline (Day 1) through Day 197, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Select Hematologic and Blood Chemistry Laboratory Abnormalities on Days 1 Through 197

High=greater than Upper Normal Limit (ULN), Low=lower than Lower Normal Limit (LLN). LLN/ULN= Hemoglobin (HGB): \>3 g/dL decrease from Baseline (BL); Hematocrit: \<0.75 x BL; Platelets (PLT): \<0.67 x LLN/\>1.5 x ULN; Leukocytes: \<0.75 x LLN/ \>1.25 x ULN; neutrophils+bands: \<1.0 x 10\^3 c/uL; aspartate aminotransferase (AST): \>3 x ULN; alanine aminotransferase (ALT): \>3 x ULN; creatinine: \>4 x BL

Time frame: From Baseline (Day 1) through Day 197, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Select Hematologic and Blood Chemistry Laboratory Abnormalities on Days 1 Through 365

High=greater than Upper Normal Limit (ULN), Low=lower than Lower Normal Limit (LLN). LLN/ULN= Hemoglobin (HGB): \>3 g/dL decrease from Baseline (BL); Hematocrit: \<0.75 x BL; Platelets (PLT): \<0.67 x LLN/\>1.5 x ULN; Leukocytes: \<0.75 x LLN/ \>1.25 x ULN; neutrophils+bands: \<1.0 x 10\^3 c/uL; aspartate aminotransferase (AST): \>3 x ULN; alanine aminotransferase (ALT): \>3 x ULN; creatinine: \>4 x BL

Time frame: From Baseline (Day 1) through Day 365, and up to 56 days after last dose if occurring on-study

DB; Number of Participants With Anti-Abatacept Antibodies From Day 1 Through Day 365 (Electrochemiluminescent [ECL] Immunoassay)

ECL screened sera for drug-specific antibodies, immunocompetition was used to identify specific anti-Abatacept reactivity. Cytotoxic leukocyte antigen 4 (CTLA4) and Possibly Immunoglobulin (Ig) Category=reactivity against extracellular domain of human CTLA4, constant regions of human IgG1, or both (CTLA4Ig; Abatacept molecule). Ig and/or Junction Category=reactivity against constant regions and/or hinge region of human IgG1. Drug-induced seropositivity was defined as a post-baseline titer higher than Baseline, or any post-baseline positivity if Baseline value was missing.

Time frame: Day 1 through day 365

DB; Percentage of Participants With Antibodies Against Infliximab (Human Anti-chimeric Antibody [HACA]) From Day 1 Through Day 365

Infliximab levels were measured using a microplate enzyme-linked immunosorbant assay (ELISA) with infliximab bound to immobilized recombinant tumor necrosis factor (TNF)-alpha. Bound infliximab is detected utilizing a horseradish peroxidase-conjugated anti-human IgG Fc(fragment, crystallizable region)-specific). The enzyme turns over the substrate O-phenlenediamine to a chromogenic product that is measured at 490 nm. The cut-off value was 1.40 ug/mL; this was based on the mean (+ 3 SD) value in serum samples from 40 participants who had never received infliximab.

Time frame: Day 1 through day 365

OL; Mean Change From Baseline Over Time in DAS 28 (ESR) Score

The DAS28 is a continuous disease measure which is a composite of 4 variables: the 28 tender joint count, the 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. The DAS28 has numeric thresholds that define high disease activity (\> 5.1), low disease activity (\< 3.2) and remission (\< 2.6). A clinically significant response is a decrease in DAS28 score of \>1.2 from baseline.

Time frame: Baseline (Day 1), Day 365, Day 533, Day 729

OL; Percentage of Participants With DAS28 (ESR) Remission and Low Disease Activity (LDAS) Over Time

The DAS28 is a continuous disease measure which is a composite of 4 variables: the 28 tender joint count, the 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. The DAS28 has numeric thresholds that define high disease activity (\> 5.1), low disease activity (\< 3.2) and remission (\< 2.6). A clinically significant response is a decrease in DAS28 score of \>1.2 from baseline.

Time frame: Baseline (Day 1), Day 365, Day 533, Day 729

OL; Percentage of Participants With Good, Moderate, or No Response According to European League Against Rheumatism (EULAR) Over Time

The DAS28 is a continuous disease measure composite of 4 variables: 28 tender joint count, 28 swollen joint count, ESR or CRP, and participant assessment of disease activity measure on a visual analogue scale. High disease activity= \> 5.1, low disease activity= \< 3.2, and remission= \< 2.6. Clinically significant response= decrease of \>1.2 from baseline. Utilizing EULAR response criteria, DAS28 categorical responses define a good (absolute \<3.2 or \>1.2 improvement from baseline \[BL\]), moderate (absolute 3.2-5.1 or 0.6-1.2 change from BL), or no response (absolute \>5.1 or \<0.6 change from BL)

Time frame: DB Days 365, 533, and 729

OL; Percentage of Participants With American College of Rheumatology (ACR) Responses Over Time

The ACR 20 definition of improvement is a 20% improvement from baseline in the number of tender and swollen joint counts, and a 20% improvement from baseline in 3 of the remaining 5 core set measures: participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function and acute phase reactant value (C-reactive protein \[CRP\]). The evaluation for 50% improvement (ACR 50) and 70% improvement (ACR 70) follow similarly.

Time frame: DB Day 197, Day 365, Day 533, Day 729

OL; Percentage of Participants Who Achieved Major Clinical Response

Major Clinical Response was defined as a continuous ACR 70 for six months.

Time frame: Defined from the date of achieving ACR 70 response to 6 months post response

OL; Percentage of Participants With Clinically Meaningful Health Assessment Questionnaire-Disability Index (HAQ-DI) Response Over Time

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: OL Days 197, 253, 281, 309, 337, 365, 449, 533, 617, and 729

OL; Adjusted Mean Change From Baseline to Day 729 in HAQ-DI

The disability section of the full HAQ includes 20 questions to assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip and common activities. The questions are evaluated on a 4-point scale: 0=without any difficulty, 1= with some difficulty, 2= with much difficulty, and 3= unable to do. Higher scores= greater dysfunction. A disability index was calculated by summing the worst scores in each domain and dividing by the number of domains answered. Clinically meaningful HAQ response=an improvement of at least 0.3 units from baseline in HAQ disability Index.

Time frame: Day 1 (Baseline), Day 729