A Phase IIIB Multi-center, Randomized, Double-Blind Study to Evaluate Remission and Joint Damage Progression in Methotrexate Naive Early Erosive RA Subjects Treated With Abatacept Plus Methotrexate Compared With Methotrexate

Number of Participants in DAS 28 C-reactive Protein (CRP) Remission at Month 12

时间窗: Month 12

Number of participants who achieved remission at Month 12 of treatment, as defined by a Disease Activity Score (DAS) 28-CRP score of \<2.6. DAS 28-CRP is a continuous measure, a composite of 4 variables: number of tender joints out of 28 joints, number of swollen joints out of 28 joints, CRP (in mg/L), and subject assessment of disease activity measure on a Visual Analogue Scale (VAS) of 100 millimeters (mm). The DAS28 scale=0 (best) to 10 (worst), indicating the current activity of the rheumatoid arthritis. A DAS28 \>5.1 = high disease activity; \<=3.2 = low disease activity; \<2.6 = remission.

Incidence Rates of Autoimmune Disorders in ABA-Treated Participants

时间窗: Double Blind Period (+56 days post last dose in double-blind period or start of open-label period, whichever came first). Open-label period (56 days post last dose in the open-label period or start of maintenance sub-study, whichever came first).

The incidence rates of autoimmune disorders are defined as the (number of patients experiencing the event/exposure within the period)\*100 and are expressed in 100 person-years. Subjects experiencing the event had their exposure censored at the time of the 1st event.

Incidence Rates of Malignant Neoplasm Adverse Events in ABA-Treated Participants

时间窗: Double Blind Period (+56 days post last dose in double-blind period or start of the open-label period, whichever came first). Open-label period (56 days post last dose in open-label period or start of maintenance sub-study, whichever came first).

The incidence rates of malignant neoplasms are defined as the (number of patients experiencing the event /exposure within the period)\*100 and are expressed in 100 person-years. Subjects experiencing the event had their exposure censored at the time of the 1st event.

Number of Participants With a Serious Acute-Infusional AE of Anaphylactic Shock During Open-Label Period

时间窗: Open-Label Period (Month 12 to Month 24)

There were 107 Prespecified, acute-infusional SAEs (occurring within 1 hour after the start of study drug infusion) pre-specified in the protocol; anaphylactic shock was the only one occuring in this study.

Number of Participants With SAEs With an Outcome of Death During the Open-label Period

时间窗: Continuously through open-label period (from Month 12 to Month 24). Includes data up to 56 days post last dose in the open-label period or start of the maintenance sub-study, whichever occurred first.

Any untoward medical occurrence (SAE) that resulted in death

Mean Change From Baseline in Radiographic Total Score to Month 12

时间窗: Baseline, Month 12

To assess joint damage progression, the Genant-modified Sharp scoring method was used to evaluate radiographs of hands/wrists and feet for erosions and joint space narrowing (JSN). The total Genant-modified Sharp score ranges from 0 (no radiographic damage) to 290 (worst possible radiographic damage) and is the sum of the erosion score (range 0-145) and the joint space narrowing score (range 0-145). Higher scores indicated more damage.

Number of Subjects With Adverse Events (AEs), Serious Adverse Events (SAEs), Deaths, and Discontinuations Due to AEs During the Open-Label Period

时间窗: Continuously through open-label period (from Month 12 to Month 24). Includes data up to 56 days post last dose in the open-label period or start of the maintenance sub-study, whichever occurred first.

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition in a subject administered an investigational product and that does not necessarily have a causal relationship with this treatment. Related AE/SAE=Certain, Probable, Possible, or Missing. SAE=any untoward medical occurrence that results in death, is life-threatening, requires or prolongs inpatient hospitalization (including elective surgery), results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event.

Number of Participants With Serious Adverse Events Reported During the Open-Label Period

时间窗: Continuously through open-label period (from Month 12 to Month 24). Includes data up to 56 days post last dose in the open-label period or start of the maintenance sub-study, whichever occurred first.

SAE=any untoward medical occurrence that results in death, is life-threatening, requires or prolongs inpatient hospitalization (including elective surgery), results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event.

Number of Participants With Hematology Laboratory Values Meeting the Marked Abnormality Criteria During the Open-Label Period

时间窗: Continuously from start of open-label period up to 56 days post the last dose in the open-label period or start of the maintenance sub-study, whichever occurred first.

Marked abnormalities in hemoglobin \>3 g/dL decrease from PRE-RX; hematocrit \<0.75x PRE-RX; erythrocytes \<0.75x PRE-RX; platelet count \<0.67x lower limit of normal (LLN) or \>1.5x ULN or if PRE-RX \<LLN then \<0.5x PRE-RX and \<100,000/mm3; leukocytes \<0.75x LLN or \>1.25x ULN or if PRE-RX \<LLN then \<0.8x PRE-RX or \>ULN if PRE-RX \>ULN then \>1.2x PRE-RX or \<LLN; neutrophils if value \<1.00 x10\^3 c/uL; lymphocytes if value \<.750 x10\^3 c/uL or if value \>7.50 x10\^3 c/uL; monocytes if value \>2000/MM3; basophils if value \>400/mm3; eosinophils if value \>.750 x10\^3 c/uL

Incidence Rates of Infections and Infestations of Adverse Events in ABA-Treated Participants

时间窗: Double Blind Period (+56 days post last dose in double-blind period or start of the open-label period, whichever came first). Open-label period (56 days post last dose in open-label period or start of maintenance sub-study, whichever came first).

The incidence rates of infections and infestations are defined as the (number of patients experiencing the event /exposure within the period)\*100 and are expressed in 100 person-years. Subjects experiencing the event had their exposure censored at the time of the 1st event.

Number of Participants With Select Blood Chemistry Laboratory Values Meeting the Marked Abnormality Criteria During the Open-Label Period

时间窗: Continuously through open-label period (from Month 12 to Month 24). Includes data up to 56 days post last dose in the open-label period or start of the maintenance sub-study, whichever occurred first.

Number of subjects with high liver function and kinedy tests: alkaline phosphatase (ALP) \>2x upper limit of normal (ULN) or if pretreatment (PRE-RX) \>ULN then \>3x PRE-RX; aspartate aminotransferase (AST) \>3x ULN or if PRE-RX \>ULN then \>4x PRE-RX; alanine aminotransferase (ALT) \>3x ULN or if PRE-RX \>ULN then \>4x PRE-RX; g-glutamyl transferase (GGT)\>2x ULN or if PRE-RX \>ULN then \>3x PRE-RX; total bilirubin \>2x ULN or if PRE-RX \>ULN then \>4x PRE-RX; blood urea nitrogen \>2x PRE-RX; creatinine \>1.5x PRE-RX.