Trial Outcomes & Findings for Abatacept With Methotrexate- Phase IIB (NCT NCT00162266)

Last Updated: 2012-06-01

Results Overview

ACR 20 response requires a participant to have a 20% reduction in the number of swollen and tender joints, and a reduction of 20% in three of the following five parameters: physician global assessment of disease, participant global assessment of disease, participant assessment of pain, C-reactive protein or erythrocyte sedimentation rate, and degree of disability in Health Assessment Questionnaire score. A participant achieved a sustained ACR 20 response if the participant had ACR 20 observed for at least 2 consecutive study visits.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

524 participants

Primary outcome timeframe

Day 180

Results posted on

2012-06-01

Participant Flow

Of 524 subjects who were enrolled in this study, 185 were not randomized (1 reason unknown; 2 adverse event; 9 withdrawal of consent; 160 failure to meet inclusion and/or exclusion criteria; 1 death; 12 for other reasons).

Participant milestones

Participant milestones
Measure	Double-Blind (DB) Abatacept 10 mg/kg + Methotrexate (MTX) Participants in the DB study received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Abatacept 2 mg/kg + Methotrexate Participants in the DB study received a weight-tiered dose of 2 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Placebo + Methotrexate Participants in the DB study received a placebo that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Double-Blind Period STARTED	115	105	119	0
Double-Blind Period Completed Day 1 to Day 181	98	80	78	0
Double-Blind Period COMPLETED	90	74	71	0
Double-Blind Period NOT COMPLETED	25	31	48	0
Open-Label Period STARTED	0	0	0	219
Open-Label Period COMPLETED	0	0	0	82
Open-Label Period NOT COMPLETED	0	0	0	137

Reasons for withdrawal

Reasons for withdrawal
Measure	Double-Blind (DB) Abatacept 10 mg/kg + Methotrexate (MTX) Participants in the DB study received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Abatacept 2 mg/kg + Methotrexate Participants in the DB study received a weight-tiered dose of 2 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Placebo + Methotrexate Participants in the DB study received a placebo that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Double-Blind Period Adverse Event	5	9	11	0
Double-Blind Period Death	0	1	0	0
Double-Blind Period Lost to Follow-up	1	2	0	0
Double-Blind Period Other Reason	1	0	1	0
Double-Blind Period Lack of Efficacy	13	17	30	0
Double-Blind Period Withdrawal by Subject	5	2	6	0
Open-Label Period Death	0	0	0	7
Open-Label Period Adverse Event	0	0	0	46
Open-Label Period Lack of Efficacy	0	0	0	26
Open-Label Period Lost to Follow-up	0	0	0	3
Open-Label Period Withdrawal by Subject	0	0	0	31
Open-Label Period Administrative Reason By Sponsor	0	0	0	9
Open-Label Period Other Reasons	0	0	0	15

Baseline Characteristics

Abatacept With Methotrexate- Phase IIB

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Double-Blind (DB) Abatacept 10 mg/kg + Methotrexate (MTX) n=115 Participants Participants in the DB study received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Abatacept 2 mg/kg + Methotrexate n=105 Participants Participants in the DB study received a weight-tiered dose of 2 mg/kg of abatacept that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Double-Blind (DB) Placebo + Methotrexate n=119 Participants Participants in the DB study received a placebo that was administered monthly by an intravenous (IV) plus methotrexate (MTX).Participants were maintained on a stable dose of MTX (10-30 mg/wk) during Days 1 to 180 of the DB period; adjustments in corticosteroids (maximum 10 mg/day) and MTX (maximum 30 mg/wk) were permitted (as well as addition of either hydroxychloroquine, sulfasalazine, gold or azathioprine) during Days 181 to 360 of the DB period.	Total n=339 Participants Total of all reporting groups
Age Continuous	55.8 years STANDARD_DEVIATION 12.5 • n=5 Participants	54.4 years STANDARD_DEVIATION 11.3 • n=7 Participants	54.7 years STANDARD_DEVIATION 12.0 • n=5 Participants	55.0 years STANDARD_DEVIATION 11.9 • n=4 Participants
Sex: Female, Male Female	86 Participants n=5 Participants	66 Participants n=7 Participants	79 Participants n=5 Participants	231 Participants n=4 Participants
Sex: Female, Male Male	29 Participants n=5 Participants	39 Participants n=7 Participants	40 Participants n=5 Participants	108 Participants n=4 Participants
Race/Ethnicity, Customized White	100 Participants n=5 Participants	91 Participants n=7 Participants	104 Participants n=5 Participants	295 Participants n=4 Participants
Race/Ethnicity, Customized Black	6 Participants n=5 Participants	0 Participants n=7 Participants	3 Participants n=5 Participants	9 Participants n=4 Participants
Race/Ethnicity, Customized Other	9 Participants n=5 Participants	14 Participants n=7 Participants	12 Participants n=5 Participants	35 Participants n=4 Participants
Weight	77.8 Kg STANDARD_DEVIATION 18.6 • n=5 Participants	78.7 Kg STANDARD_DEVIATION 21.4 • n=7 Participants	79.9 Kg STANDARD_DEVIATION 17.6 • n=5 Participants	78.8 Kg STANDARD_DEVIATION 19.2 • n=4 Participants
Rheumatoid Factor Status Negative	14 Participants n=5 Participants	15 Participants n=7 Participants	27 Participants n=5 Participants	56 Participants n=4 Participants
Rheumatoid Factor Status Positive	99 Participants n=5 Participants	90 Participants n=7 Participants	90 Participants n=5 Participants	279 Participants n=4 Participants
Number of Tender Joints	30.8 Joints STANDARD_DEVIATION 12.2 • n=5 Participants	28.2 Joints STANDARD_DEVIATION 12.0 • n=7 Participants	29.2 Joints STANDARD_DEVIATION 13.0 • n=5 Participants	29.4 Joints STANDARD_DEVIATION 12.4 • n=4 Participants
Number of Swollen Joints	21.3 Joints STANDARD_DEVIATION 8.4 • n=5 Participants	20.2 Joints STANDARD_DEVIATION 8.9 • n=7 Participants	21.8 Joints STANDARD_DEVIATION 8.8 • n=5 Participants	21.1 Joints STANDARD_DEVIATION 8.7 • n=4 Participants
C-Reactive Protein (CRP) Serum Level	2.9 mg/dL STANDARD_DEVIATION 2.8 • n=5 Participants	3.2 mg/dL STANDARD_DEVIATION 2.5 • n=7 Participants	3.2 mg/dL STANDARD_DEVIATION 3.2 • n=5 Participants	3.1 mg/dL STANDARD_DEVIATION 2.9 • n=4 Participants
Duration of Participant Rheumatoid Arthritis (RA)	9.7 Years STANDARD_DEVIATION 9.8 • n=5 Participants	9.7 Years STANDARD_DEVIATION 8.1 • n=7 Participants	8.9 Years STANDARD_DEVIATION 8.3 • n=5 Participants	9.4 Years STANDARD_DEVIATION 8.8 • n=4 Participants

PRIMARY outcome

Timeframe: Day 180

Population: Intent-to-treat population. Participants who discontinued the study due to lack of efficacy (ie, worsening rheumatoid arthritis) were considered ACR 20 nonresponders at all subsequent time points. For all subjects who discontinued for other reasons, their last ACR 20 response was carried forward.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Responders to American College of Rheumatology 20% Improvement Criteria (ACR 20) at Day 180 of the Double-Blind (DB) Period	44 Participants	42 Participants	70 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3,060

Population: All treated participants.

The number of participants receiving concomitant rheumatoid arthritis treatment with disease modifying rheumatic drugs and/or biologics.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Adalimumab	1 Participants	0 Participants	0 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Etanercept	1 Participants	0 Participants	0 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Methotrexate	68 Participants	67 Participants	84 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Corticosteroids (oral and/or injectable)	57 Participants	56 Participants	72 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Nonsteroidal antiinfllammatory drugs	63 Participants	64 Participants	78 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Azanthioprine	0 Participants	1 Participants	1 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Chloroquine	1 Participants	1 Participants	0 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Cyclosporine	1 Participants	0 Participants	2 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Gold Sodium Thiomalate	1 Participants	0 Participants	0 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Hydroxychloroquine	3 Participants	2 Participants	2 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Leflunamide	0 Participants	1 Participants	2 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Sulfasalazine	0 Participants	1 Participants	0 Participants	—
Participants Receiving Concomitant Disease Modifying Rheumatic Drugs and Biologics in Open-Label (OL) Period Infliximab	1 Participants	0 Participants	2 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

AE=any new untoward medical occurrence or worsening of a pre-existing medical condition which does not necessarily have a causal relationship with 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. Related AE/SAE=Certain,Probable,Possible,or Missing relationship to drug.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=219 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period AEs	—	—	211 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period Related AEs	—	—	144 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period Discontinued Due to AEs	—	—	44 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period SAEs	—	—	117 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period Related SAEs	—	—	37 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period Discontinued Due to SAEs	—	—	33 Participants	—
Number of Participants Experiencing Adverse Events (AEs) and Serious Adverse Events (SAEs) in OL Period Deaths	—	—	8 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

AEs were defined as 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 were those which may be associated with the use of immunomodulatory agents or infusion of therapeutic proteins. Acute infusional AEs were defined as those that occurred within 1 hour after the start of the infusion. Peri-Infusional AEs were defined as those that occurred within 24 hours after the start of the infusion.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=219 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With AEs of Special Interest in OL Period Infections/Infestations	—	—	179 Participants	—
Number of Participants With AEs of Special Interest in OL Period Malignant Neoplasms	—	—	20 Participants	—
Number of Participants With AEs of Special Interest in OL Period Autoimmune Disorders	—	—	20 Participants	—
Number of Participants With AEs of Special Interest in OL Period Acute Infusional AEs	—	—	20 Participants	—
Number of Participants With AEs of Special Interest in OL Period Peri-Infusional AEs	—	—	47 Participants	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720,1080, 1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in DB study. n=the number of participants with measurements for that time point.

Time-matched baseline (Day 0) values and post-baseline values were presented for each post-baseline visit and represent only that cohort of participants with measurements available at that post-baseline assessment. Mean Change from Baseline data for these cohorts are presented in Outcome Measure 6.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Baseline Serum Immunoglobulin A (IgA) Over Time in OL Period Baseline for Day 360 cohort (n=74, 59, 60)	341.54 mg/dL Standard Deviation 148.48	264.22 mg/dL Standard Deviation 133.90	308.09 mg/dL Standard Deviation 152.27	—
Baseline Serum Immunoglobulin A (IgA) Over Time in OL Period Baseline for Day 720 cohort (n=71, 53, 53)	338.58 mg/dL Standard Deviation 151.76	256.64 mg/dL Standard Deviation 132.78	290.25 mg/dL Standard Deviation 146.27	—
Baseline Serum Immunoglobulin A (IgA) Over Time in OL Period Baseline for Day 1080 cohort (n=59, 45, 45)	321.02 mg/dL Standard Deviation 153.81	266.89 mg/dL Standard Deviation 143.48	287.27 mg/dL Standard Deviation 140.22	—
Baseline Serum Immunoglobulin A (IgA) Over Time in OL Period Baseline for Day 1440 cohort (n=54, 37, 37)	327.27 mg/dL Standard Deviation 162.13	250.11 mg/dL Standard Deviation 127.88	287.09 mg/dL Standard Deviation 136.50	—
Baseline Serum Immunoglobulin A (IgA) Over Time in OL Period Baseline for Day 1800 cohort (n=50, 38, 34)	327.34 mg/dL Standard Deviation 163.27	244.71 mg/dL Standard Deviation 118.03	292.78 mg/dL Standard Deviation 146.91	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Blood samples for immunoglobulin assessments were obtained to determine change from baseline in serum IgA. Baseline data for these time-matched cohorts are presented in Outcome Measure 5.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in IgA Over Time in OL Period Change from BL at Day 360 (n=74, 59, 60)	-25.66 mg/dL Standard Error 7.83	5.00 mg/dL Standard Error 6.72	-38.24 mg/dL Standard Error 5.95	—
Mean Change From Baseline (BL) in IgA Over Time in OL Period Change from BL at Day 720 (n=71, 53, 53)	-45.06 mg/dL Standard Error 9.27	-20.89 mg/dL Standard Error 7.73	-28.20 mg/dL Standard Error 8.61	—
Mean Change From Baseline (BL) in IgA Over Time in OL Period Change from BL at Day 1080 (n=59, 45, 45)	-52.87 mg/dL Standard Error 12.86	-15.87 mg/dL Standard Error 11.18	-33.10 mg/dL Standard Error 13.08	—
Mean Change From Baseline (BL) in IgA Over Time in OL Period Change from BL at Day 1440 (n=54, 37, 37)	-52.49 mg/dL Standard Error 16.32	-4.41 mg/dL Standard Error 12.28	-30.52 mg/dL Standard Error 9.75	—
Mean Change From Baseline (BL) in IgA Over Time in OL Period Change from BL at Day 1800 (n=50, 38, 34)	-65.95 mg/dL Standard Error 16.26	-25.68 mg/dL Standard Error 12.18	-20.06 mg/dL Standard Error 26.97	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440 and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Time-matched baseline (Day 0) values and post-baseline vales were presented for each post-baseline visit and represent only that cohort of participants with measurements available at that post-baseline assessment. Mean Change from Baseline data for these cohorts are presented in Outcome Measure 8.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Baseline Immunoglobulin G (IgG) Over Time in OL Period Baseline for Day 360 cohort (n=75, 59, 60)	1086.05 mg/dL Standard Deviation 263.41	1079.00 mg/dL Standard Deviation 345.72	1130.31 mg/dL Standard Deviation 295.28	—
Baseline Immunoglobulin G (IgG) Over Time in OL Period Baseline for Day 720 cohort (n=72, 53, 53)	1093.23 mg/dL Standard Deviation 318.24	1076.40 mg/dL Standard Deviation 333.08	1138.58 mg/dL Standard Deviation 303.24	—
Baseline Immunoglobulin G (IgG) Over Time in OL Period Baseline for Day 1080 cohort (n=60, 45, 45)	1053.91 mg/dL Standard Deviation 264.53	1136.27 mg/dL Standard Deviation 372.58	1145.15 mg/dL Standard Deviation 305.51	—
Baseline Immunoglobulin G (IgG) Over Time in OL Period Baseline for Day 1440 cohort (n=55, 37, 37)	1095.49 mg/dL Standard Deviation 261.86	1135.43 mg/dL Standard Deviation 381.72	1154.58 mg/dL Standard Deviation 315.00	—
Baseline Immunoglobulin G (IgG) Over Time in OL Period Baseline for Day 1800 cohort (n=51, 38, 34)	1092.76 mg/dL Standard Deviation 260.85	1137.21 mg/dL Standard Deviation 368.39	1152.63 mg/dL Standard Deviation 305.01	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Blood samples for immunoglobulin assessments were obtained to determine change from baseline in serum IgG. Baseline data for these cohorts are presented in Outcome Measure 7.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in IgG Over Time in OL Period Change from BL at Day 360 (n=75, 59, 60)	-110.71 mg/dL Standard Error 21.46	-15.12 mg/dL Standard Error 21.71	-181.92 mg/dL Standard Error 19.78	—
Mean Change From Baseline (BL) in IgG Over Time in OL Period Change from BL at Day 720 (n=72, 53, 53)	-168.55 mg/dL Standard Error 31.82	-137.06 mg/dL Standard Error 31.62	-183.04 mg/dL Standard Error 28.58	—
Mean Change From Baseline (BL) in IgG Over Time in OL Period Change from BL at Day 1080 (n=60, 45, 45)	-229.91 mg/dL Standard Error 26.75	-150.40 mg/dL Standard Error 33.97	-199.58 mg/dL Standard Error 33.68	—
Mean Change From Baseline (BL) in IgG Over Time in OL Period Change from BL at Day 1440 (n=55, 37, 37)	-279.14 mg/dL Standard Error 33.43	-147.46 mg/dL Standard Error 45.84	-228.11 mg/dL Standard Error 28.90	—
Mean Change From Baseline (BL) in IgG Over Time in OL Period Change from BL at Day 1800 (n=51, 38, 34)	-206.21 mg/dL Standard Error 39.10	-187.94 mg/dL Standard Error 44.40	-217.43 mg/dL Standard Error 39.52	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720,1080,1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Baseline Immunoglobulin M (IgM) Over Time in OL Period Baseline for Day 360 cohort (n=74, 59, 60)	134.29 mg/dL Standard Deviation 66.81	125.10 mg/dL Standard Deviation 52.12	147.76 mg/dL Standard Deviation 76.05	—
Baseline Immunoglobulin M (IgM) Over Time in OL Period Baseline for Day 720 cohort (n=71, 53, 53)	137.79 mg/dL Standard Deviation 69.93	123.25 mg/dL Standard Deviation 52.79	147.76 mg/dL Standard Deviation 76.31	—
Baseline Immunoglobulin M (IgM) Over Time in OL Period Baseline for Day 1080 cohort (n=59, 45, 45)	127.36 mg/dL Standard Deviation 68.06	129.04 mg/dL Standard Deviation 54.79	144.75 mg/dL Standard Deviation 78.89	—
Baseline Immunoglobulin M (IgM) Over Time in OL Period Baseline for Day 1440 cohort (n=54, 37, 37)	136.22 mg/dL Standard Deviation 70.90	133.51 mg/dL Standard Deviation 58.04	141.69 mg/dL Standard Deviation 77.90	—
Baseline Immunoglobulin M (IgM) Over Time in OL Period Baseline for Day 1800 cohort (n=45, 33, 32)	124.15 mg/dL Standard Deviation 67.07	124.63 mg/dL Standard Deviation 58.69	133.22 mg/dL Standard Deviation 61.79	—

PRIMARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the double-blind (DB) study. n = the number of participants with measurements for that time point.

Blood samples for immunoglobulin assessments were obtained to determine change from baseline in serum IgM. Baseline data for these time-matched cohorts are presented in Outcome Measure 9.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in IgM in OL Period Change from BL at Day 360 (n=74, 59, 60)	3.22 mg/dL Standard Error 4.36	11.17 mg/dL Standard Error 3.89	-5.81 mg/dL Standard Error 3.49	—
Mean Change From Baseline (BL) in IgM in OL Period Change from BL at Day 720 (n=71, 53, 53)	0.11 mg/dL Standard Error 4.76	6.45 mg/dL Standard Error 6.11	12.68 mg/dL Standard Error 7.32	—
Mean Change From Baseline (BL) in IgM in OL Period Change from BL at Day 1080 (n=59, 45, 45)	1.93 mg/dL Standard Error 6.61	27.93 mg/dL Standard Error 11.62	0.37 mg/dL Standard Error 6.69	—
Mean Change From Baseline (BL) in IgM in OL Period Change from BL at Day 1440 (n=54, 37, 37)	0.68 mg/dL Standard Error 8.99	14.46 mg/dL Standard Error 9.52	2.52 mg/dL Standard Error 7.07	—
Mean Change From Baseline (BL) in IgM in OL Period Change from BL at Day 1,800 (n=45, 33, 32)	9.06 mg/dL Standard Error 7.55	6.72 mg/dL Standard Error 8.80	7.84 mg/dL Standard Error 6.89	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=217 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Hemoglobin (> 13.0 grams/dL; n=216)	—	—	21 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Hematocrit (< 35%; n=216)	—	—	11 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Platelet Count (<145*10^9 cells/L; n=214)	—	—	1 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Platelet Count (>400*10^9 cells/L; n=214)	—	—	1 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Leukocytes (<3.60 *10^3 cells/µL; n=216)	—	—	12 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Leukocytes (>10.30*10^3 cells/µL; n=216)	—	—	49 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Neutrophils + Bands (<2.0*10^3 c/uL; n=217)	—	—	1 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period Low Absolute Lymphocytes(<1.0*10^3cells/µL; n=217)	—	—	48 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Absolute Lymphocytes(>3.5*10^3cells/µL;n=217)	—	—	0 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Absolute Monocytes (>720*10^3cells/µL; n=217)	—	—	0 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Absolute Basophils(>0.2*10^3 cells/µL; n=217)	—	—	1 Participants	—
Number of Participants With Hematology Values Meeting Marked Abnormality Criteria in OL Period High Absolute Eosinophils(>0.4*10^3cells/µL;n=217)	—	—	21 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=217 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Alkaline Phosphatase (>117 IU/L)	—	—	1 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Aspartate Aminotransferase (>38 IU/L)	—	—	6 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Alanine Aminotransferase (>30 IU/L)	—	—	5 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High G-Glutamyl Transferase (>61 IU/L)	—	—	20 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Total Bilirubin (>1.1 mg/dL)	—	—	0 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Blood Urea Nitrogen (>21.3 mg/dL)	—	—	14 Participants	—
Number of Participants With Liver and Kidney Function Values Meeting Marked Abnormality Criteria in OL Period High Creatinine (>1.30 mg/dL)	—	—	13 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=217 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period Low Serum Sodium (<135 mEq/L; n=217)	—	—	4 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period High Serum Sodium (>145 mEq/L; n=217)	—	—	10 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period Low Serum Potassium (<3.5 mEq/L; n=217)	—	—	8 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period High Serum Potassium (>5.0 mEq/L; n=217)	—	—	10 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period Low Serum Chloride (<97 mEq/L; n=217)	—	—	8 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period High Serum Chloride (>106 mEq/L; n=217)	—	—	3 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period Low Total Calcium (<8.6 mg/dL; n=217)	—	—	0 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period High Total Calcium (>10.2 mg/dL; n=217)	—	—	3 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period Low Inorganic Phosphorus (<2.7 mg/dL; n=217)	—	—	5 Participants	—
Number of Participants With Electrolyte Values Meeting Marked Abnormality Criteria in OL Period High Inorganic Phosphorus (> 4.5 mg/dL; n=217)	—	—	11 Participants	—

PRIMARY outcome

Timeframe: Day 360 to Day 3060

Population: All treated OL participants.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=217 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period Low Serum Glucose (< 70 mg/dL; n=217)	—	—	33 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Serum Glucose (> 110 mg/dL; n=217)	—	—	30 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period Low Fasting Serum Glucose (< 70 mg/dL; n=1)	—	—	0 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Fasting Serum Glucose (> 110 mg/dL; n=1)	—	—	0 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period Low Total Protein (< 6.2 grams/dL; n=217)	—	—	12 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Total Protein (>8.3 grams/dL; n=217)	—	—	1 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period Low Albumin (<3.5 grams/dL; n=217)	—	—	7 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Uric Acid (>7.6 mg/dL; n=217)	—	—	2 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Urine Protein (> trace; n=217)	—	—	29 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Urine Glucose (> trace; n=217)	—	—	32 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Urine Blood (> trace; n=217)	—	—	47 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Urine White Blood Cell Count (> trace; n=162)	—	—	74 Participants	—
Number of Participants With Glucose, Protein, Metabolites, and Urinalysis Values Meeting Marked Abnormality Criteria in OL Period High Urine Red Blood Cell Count (> trace; n=162)	—	—	51 Participants	—

SECONDARY outcome

Timeframe: Days 15, 30, 60, 90, 120, 150,180, 240, 300, and 360

Population: Participants who received at least 1 infusion of study medication

ACR 20 response requires a participant to have a 20% reduction in the number of swollen and tender joints, and a reduction of 20% in three of the following five parameters: physician global assessment of disease, participant global assessment of disease, participant assessment of pain, C-reactive protein or erythrocyte sedimentation rate, and degree of disability in HAQ score. A participant achieved a sustained ACR 20 response if the participant had ACR 20 observed for at least 2 consecutive study visits.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 20 Responders in DB Period Day 15	9 Participants	24 Participants	30 Participants	—
Number of ACR 20 Responders in DB Period Day 30	22 Participants	36 Participants	48 Participants	—
Number of ACR 20 Responders in DB Period Day 60	35 Participants	41 Participants	65 Participants	—
Number of ACR 20 Responders in DB Period Day 90	40 Participants	42 Participants	62 Participants	—
Number of ACR 20 Responders in DB Period Day 120	47 Participants	45 Participants	71 Participants	—
Number of ACR 20 Responders in DB Period Day 150	46 Participants	42 Participants	67 Participants	—
Number of ACR 20 Responders in DB Period Day 180	44 Participants	42 Participants	70 Participants	—
Number of ACR 20 Responders in DB Period Day 240	43 Participants	42 Participants	72 Participants	—
Number of ACR 20 Responders in DB Period Day 300	41 Participants	41 Participants	73 Participants	—
Number of ACR 20 Responders in DB Period Day 360	44 Participants	43 Participants	72 Participants	—

SECONDARY outcome

Timeframe: Day 15; Day 30; Day 60; Day 90; Day 120; Day 150; Day 180; Day 240; Day 300; Day 360

Population: Participants who received at least 1 infusion of study medication

ACR 50 response requires a participant to have a 50% reduction in the number of swollen and tender joints, and a reduction of 50% in three of the following five parameters: physician global assessment of disease, participant global assessment of disease, participant assessment of pain, C-reactive protein or erythrocyte sedimentation rate, and degree of disability in HAQ score. A participant achieved a sustained ACR 50 response if the participant had ACR 50 observed for at least 2 consecutive study visits.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 50 Responders in DB Period Day 15	0 Participants	3 Participants	2 Participants	—
Number of ACR 50 Responders in DB Period Day 30	4 Participants	7 Participants	16 Participants	—
Number of ACR 50 Responders in DB Period Day 60	14 Participants	18 Participants	25 Participants	—
Number of ACR 50 Responders in DB Period Day 90	18 Participants	15 Participants	28 Participants	—
Number of ACR 50 Responders in DB Period Day 120	18 Participants	18 Participants	38 Participants	—
Number of ACR 50 Responders in DB Period Day 150	18 Participants	19 Participants	42 Participants	—
Number of ACR 50 Responders in DB Period Day 180	24 Participants	14 Participants	42 Participants	—
Number of ACR 50 Responders in DB Period Day 240	22 Participants	24 Participants	41 Participants	—
Number of ACR 50 Responders in DB Period Day 300	23 Participants	18 Participants	45 Participants	—
Number of ACR 50 Responders in DB Period Day 360	24 Participants	24 Participants	48 Participants	—

SECONDARY outcome

Timeframe: Day 15; Day 30; Day 60; Day 90; Day 120; Day 150; Day 180; Day 240; Day 300; Day 360

Population: Participants who received at least 1 infusion of study medication

ACR 70 response requires a participant to have a 70% reduction in the number of swollen and tender joints, and a reduction of 70% in three of the following five parameters: physician global assessment of disease, participant global assessment of disease, participant assessment of pain, C-reactive protein or erythrocyte sedimentation rate, and degree of disability in HAQ score. A participant achieved a sustained ACR 70 response if the participant had ACR 70 observed for at least 2 consecutive study visits.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 70 Responders in DB Period Day 15	0 Participants	0 Participants	0 Participants	—
Number of ACR 70 Responders in DB Period Day 30	3 Participants	0 Participants	4 Participants	—
Number of ACR 70 Responders in DB Period Day 60	4 Participants	0 Participants	10 Participants	—
Number of ACR 70 Responders in DB Period Day 90	5 Participants	1 Participants	10 Participants	—
Number of ACR 70 Responders in DB Period Day 120	6 Participants	4 Participants	15 Participants	—
Number of ACR 70 Responders in DB Period Day 150	6 Participants	4 Participants	16 Participants	—
Number of ACR 70 Responders in DB Period Day 180	11 Participants	2 Participants	19 Participants	—
Number of ACR 70 Responders in DB Period Day 240	9 Participants	6 Participants	21 Participants	—
Number of ACR 70 Responders in DB Period Day 300	11 Participants	3 Participants	27 Participants	—
Number of ACR 70 Responders in DB Period Day 360	13 Participants	9 Participants	24 Participants	—

SECONDARY outcome

Timeframe: Day 15; Day 30; Day 60; Day 90; Day 120; Day 150; Day 180; Day 240; Day 300; Day 360

Population: Participants who received at least 1 infusion of study medication

The ACR-N is calculated for each participant by taking the lowest percentage improvement in (1) swollen joint count or (2) tender joint count or (3) the median of the remaining 5 components of the ACR response (participant's assessment of disease activity; participant's global assessment of pain; physician's assessment of disease activity; participant's assessment of physical function; an acute phase reactant value - CRP). Negative numbers indicate worsening.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
ACR Numeric Values (ACR-N) Day 300 (n=114, 105, 119)	21.82 units on a scale Standard Deviation 27.99	18.69 units on a scale Standard Deviation 23.53	39.69 units on a scale Standard Deviation 31.08	—
ACR Numeric Values (ACR-N) Day 15 (n=113, 104, 118)	5.26 units on a scale Standard Deviation 10.37	9.07 units on a scale Standard Deviation 14.76	11.09 units on a scale Standard Deviation 15.53	—
ACR Numeric Values (ACR-N) Day 30 (n=115, 104, 117)	12.06 units on a scale Standard Deviation 18.11	13.20 units on a scale Standard Deviation 17.85	20.45 units on a scale Standard Deviation 23.41	—
ACR Numeric Values (ACR-N) Day 60 (n=114, 105, 119)	17.69 units on a scale Standard Deviation 22.83	17.09 units on a scale Standard Deviation 20.90	28.85 units on a scale Standard Deviation 26.78	—
ACR Numeric Values (ACR-N) Day 90 (n=115, 105, 118)	21.12 units on a scale Standard Deviation 26.10	16.93 units on a scale Standard Deviation 21.61	29.03 units on a scale Standard Deviation 27.38	—
ACR Numeric Values (ACR-N) Day 120 (n=114, 105, 115)	22.87 units on a scale Standard Deviation 26.10	19.26 units on a scale Standard Deviation 23.70	33.80 units on a scale Standard Deviation 29.35	—
ACR Numeric Values (ACR-N) Day 150 (n=114, 103, 118)	22.69 units on a scale Standard Deviation 24.15	19.37 units on a scale Standard Deviation 24.74	36.34 units on a scale Standard Deviation 30.29	—
ACR Numeric Values (ACR-N) Day 180 (n=114, 104, 118)	24.67 units on a scale Standard Deviation 29.03	17.29 units on a scale Standard Deviation 22.02	37.65 units on a scale Standard Deviation 30.39	—
ACR Numeric Values (ACR-N) Day 240 (n=115, 104, 119)	23.49 units on a scale Standard Deviation 27.51	20.71 units on a scale Standard Deviation 25.97	38.34 units on a scale Standard Deviation 31.49	—
ACR Numeric Values (ACR-N) Day 360 (n=115, 105, 119)	24.55 units on a scale Standard Deviation 29.37	20.49 units on a scale Standard Deviation 26.14	40.87 units on a scale Standard Deviation 31.69	—

SECONDARY outcome

Timeframe: Baseline and Day 180; Baseline and Day 360

The AUC for ACR-N is the measure of the area under the curve of the mean change from baseline in ACR-N. The trapezoidal rule was used to compute the AUC. The ACR-N AUC was compared between the two abatacept treatment groups and the placebo group using an analysis of variance (ANOVA) for 6- and 12-month data (Day 180 and Day 360). This allowed for the assessment of subject response throughout the study. See Measure Description in Outcome Measure 18 for a definition of ACR-N.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
ACR-N Area Under The Curve (AUC) on Day 180 and Day 360 Day 180	3242.54 percentage*days Standard Error 332.7	2889.07 percentage*days Standard Error 312.5	5021.70 percentage*days Standard Error 317.9	—
ACR-N Area Under The Curve (AUC) on Day 180 and Day 360 Day 360	7447.87 percentage*days Standard Error 744.8	6393.49 percentage*days Standard Error 699.6	12035.1 percentage*days Standard Error 711.7	—

SECONDARY outcome

Timeframe: Baseline, Day 180

Population: Number of Participants Analyzed = Participants who received at least 1 infusion of study medication; n = subset of participants who had given measurement at both time points.

Percentage change = 100\*(Baseline value - value at specific visit) / Baseline value. The American College of Rheumatology (ACR) response criteria, based on a core set of variables which includes a tender joint count, a swollen joint count, patient-reported pain scale (Subject Assessment of Physical Function \[SAPF\]), patient and physician global assessments of disease activity (Subject Global Assessment \[SGA\] and Physician Global Assessment \[PGA\]), patient assessment of functional ability, and an acute phase reactant (C-Reactive Protein \[CRP\])

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 Tender Joints (n=114, 104, 118)	43.2 percentage change Standard Error 4.1	31.9 percentage change Standard Error 5.0	59.8 percentage change Standard Error 3.6	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 Swollen Joints (n=114, 104, 118)	45.3 percentage change Standard Error 4.1	33.5 percentage change Standard Error 4.3	55.3 percentage change Standard Error 3.5	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 Pain (n=109, 102, 118)	22.1 percentage change Standard Error 5.8	8.2 percentage change Standard Error 7.0	46.2 percentage change Standard Error 4.1	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 SAPF (n=107, 98, 110)	21.6 percentage change Standard Error 6.5	13.7 percentage change Standard Error 5.5	41.2 percentage change Standard Error 4.6	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 Subject Global Assessment (n=111, 103, 118)	9.1 percentage change Standard Error 10.4	17.5 percentage change Standard Error 4.1	40.8 percentage change Standard Error 4.7	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 Physician Global Assessment (n=111, 103, 116)	38.7 percentage change Standard Error 4.4	25.1 percentage change Standard Error 3.5	51.9 percentage change Standard Error 3.4	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 180 C-Reactive Protein (n=108, 98, 114)	16.4 percentage change Standard Error 7.0	-23.4 percentage change Standard Error 11.0	31.8 percentage change Standard Error 6.3	—

SECONDARY outcome

Timeframe: Baseline, Day 360

Population: Number of Participants Analyzed = Participants who received at least 1 infusion of study medication; n = subset of participants who had given measurement at both time points.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 Tender Joints (n=114, 104, 118)	43.6 percentage change Standard Error 4.3	30.0 percentage change Standard Error 5.3	66.4 percentage change Standard Error 3.8	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 Swollen Joints (n=114, 104, 118)	46.4 percentage change Standard Error 4.5	36.2 percentage change Standard Error 4.4	59.7 percentage change Standard Error 3.7	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 Pain (n=109, 102, 118)	26.2 percentage change Standard Error 5.9	65.2 percentage change Standard Error 12.6	44.9 percentage change Standard Error 4.7	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 SAPF (n=107, 98, 110)	22.9 percentage change Standard Error 5.0	10.3 percentage change Standard Error 5.9	42.3 percentage change Standard Error 4.3	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 Subject Global Assessment (n=111, 103, 118)	16.0 percentage change Standard Error 8.9	2.0 percentage change Standard Error 19.1	41.0 percentage change Standard Error 5.1	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 Physician Global Assessment (n=111, 103, 116)	37.9 percentage change Standard Error 4.2	24.1 percentage change Standard Error 3.8	53.5 percentage change Standard Error 3.4	—
Individual Components of ACR Criteria--Mean Percentage Change From Baseline at Day 360 C-Reactive Protein (n=108, 98, 114)	11.0 percentage change Standard Error 9.5	-31.3 percentage change Standard Error 12.6	27.6 percentage change Standard Error 9.9	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

SF-36 measures health-related quality of life across multiple disease states. It has 36 questions with 8 subscale scores and 2 summary scores: PCS=physical functioning, role-physical, bodily pain, and general health; MCS=vitality, social functioning, role-emotional, and mental health. Scoring is done for both subscores and summary scores. For both, 0=worst score (or quality of life) and 100=best score.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Changes From Baseline in the Short Form 36 (SF-36) Physical and Mental Health Component Summary Scores (PCS and MCS) at Day 180 and Day 360 PCS, Mean Change at Day 180 (n=115, 104, 119)	4.6 units on a scale Standard Error 0.7	3.0 units on a scale Standard Error 0.6	8.3 units on a scale Standard Error 0.9	—
Mean Changes From Baseline in the Short Form 36 (SF-36) Physical and Mental Health Component Summary Scores (PCS and MCS) at Day 180 and Day 360 MCS, Mean Change at Day 180 (n=115, 104, 119)	2.7 units on a scale Standard Error 1.2	3.2 units on a scale Standard Error 1.0	5.0 units on a scale Standard Error 1.0	—
Mean Changes From Baseline in the Short Form 36 (SF-36) Physical and Mental Health Component Summary Scores (PCS and MCS) at Day 180 and Day 360 PCS, Mean Change at Day 360 (n=115, 104, 119)	3.5 units on a scale Standard Error 1.1	3.0 units on a scale Standard Error 0.9	5.7 units on a scale Standard Error 1.0	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

A shortened version of the Health Assessment Questionnaire (HAQ), which uses only 8 instead of the 20 original items and is used to assess motor performance in everyday activities, such as dressing, turning a faucet on/off, and getting in and out of a car. Percent change from baseline = (baseline - post baseline value) / baseline value x 100.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Adjusted Mean Percent Changes From Baseline in the Modified Health Assessment Questionnaire (mHAQ) at Day 180 and Day 360 Mean Percentage Change at Day 180 (n=107, 98, 110)	21.41 Percentage of Change on mHAQ scale Standard Error 5.67	13.73 Percentage of Change on mHAQ scale Standard Error 5.35	41.39 Percentage of Change on mHAQ scale Standard Error 5.43	—
Adjusted Mean Percent Changes From Baseline in the Modified Health Assessment Questionnaire (mHAQ) at Day 180 and Day 360 Mean PercentageChange at Day 360 (n=109, 100, 111)	22.74 Percentage of Change on mHAQ scale Standard Error 5.27	10.26 Percentage of Change on mHAQ scale Standard Error 5.00	42.49 Percentage of Change on mHAQ scale Standard Error 5.05	—

SECONDARY outcome

Timeframe: Day 180, Day 360

Population: All treated participants

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With At Least One New Active Joint (Tender Joints and Swollen Joints) at Day 180 and Day 360 New Tender Joints(s) at Day 180	65 participants	70 participants	47 participants	—
Number of Participants With At Least One New Active Joint (Tender Joints and Swollen Joints) at Day 180 and Day 360 New Swollen Joints(s) at Day 180	59 participants	75 participants	55 participants	—
Number of Participants With At Least One New Active Joint (Tender Joints and Swollen Joints) at Day 180 and Day 360 New Tender Joints(s) at Day 360	62 participants	69 participants	33 participants	—
Number of Participants With At Least One New Active Joint (Tender Joints and Swollen Joints) at Day 180 and Day 360 New Swollen Joints(s) at Day 360	59 participants	69 participants	45 participants	—

SECONDARY outcome

Timeframe: From the start of study through the end of the double-blind period (at 12 months)

Population: All treated participants

AE: any new untoward medical occurrence/worsening of pre-existing medical condition, whether or not related to study drug. SAE: any AE that resulted in death; was life threatening; resulted in persistent/significant disability/incapacity; resulted in/prolonged an existing in-patient hospitalization; was a congenital anomaly/birth defect; or was an overdose. Participants who discontinued the study due to any AEs were recorded. Related events include those that were considered by the investigator to be certain, probable, or possibly related to study drug.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period Deaths	1 Participants	0 Participants	0 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period SAEs	19 Participants	19 Participants	14 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period Discontinuations due to SAEs	6 Participants	3 Participants	3 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period Related SAEs	5 Participants	2 Participants	2 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period Discontinuations due to AEs	10 Participants	11 Participants	6 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period AEs	104 Participants	112 Participants	104 Participants	—
Participants Who Experienced Death, Adverse Events (AEs), Serious AEs (SAEs), and Discontinuations During the Double-Blind Period Related AEs	50 Participants	58 Participants	56 Participants	—

SECONDARY outcome

Timeframe: From the start of study up to 60 days post the end of the 12-month double-blind period

Population: Number of Participants Analyzed=All treated participants. n=number of participants evaluated for given measurement.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Blood Chemistry Values During Double-Blind Therapy High Alanine Aminotransferase (ALT)	1 Participants	2 Participants	0 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Blood Chemistry Values During Double-Blind Therapy High Aspartate Aminotransferase (AST)	1 Participants	0 Participants	0 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Blood Chemistry Values During Double-Blind Therapy High Creatinine	3 Participants	4 Participants	4 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Blood Chemistry Values During Double-Blind Therapy Low Potassium	3 Participants	1 Participants	2 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Blood Chemistry Values During Double-Blind Therapy High Potassium	3 Participants	4 Participants	1 Participants	—

SECONDARY outcome

Timeframe: From the start of study up to 60 days post the end of the 12-month double-blind period

Population: Number of Participants Analyzed=All treated participants. n=number of participants evaluated for given measurement.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy Low Hemoglobin (n=115, 104, 119)	0 Participants	3 Participants	1 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy Low Platelets (n=114, 104, 119)	0 Participants	0 Participants	0 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy High Platelets (n=114, 104, 119)	0 Participants	0 Participants	0 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy Low Leukocytes (n=115, 104, 119)	0 Participants	0 Participants	0 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy High Leukocytes (n=115, 104, 119)	6 Participants	14 Participants	12 Participants	—
Participants With Laboratory Abnormalities Meeting the Marked Abnormality Criteria for Selected Hematologic Values During Double-Blind Therapy Low Neutrophils (n=115, 105, 119)	1 Participants	0 Participants	0 Participants	—

SECONDARY outcome

Timeframe: Day 1 to Day 360 (Double-Blind Period), Day 361 to Day 3060 (Open-Label Period)

Population: Treated Participants

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) n=219 Participants Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants Who Discontinued Due to Lack of Efficacy in the DB and OL Periods	16 participants	28 participants	12 participants	26 participants

SECONDARY outcome

Timeframe: Baseline, Days 30, 90, 180, 270, 360

Population: Number of Participants Analyzed=treated participants; n=number of participants with both baseline and post-baseline measurements at timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Baseline for Day 30 Cohort (n=110, 100)	8861.8 titers Standard Deviation 9282.06	—	9151.8 titers Standard Deviation 10692.68	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Day 30 (n=110, 100)	8561.7 titers Standard Deviation 9323.91	—	8361.5 titers Standard Deviation 9931.79	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Baseline for Day 90 Cohort (n=110, 99)	8930.2 titers Standard Deviation 9002.57	—	9052.8 titers Standard Deviation 10392.26	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Day 90 (n=110, 99)	7497.8 titers Standard Deviation 7356.42	—	6842.3 titers Standard Deviation 7659.01	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Baseline for Day 180 Cohort (n=102, 90)	8689.3 titers Standard Deviation 8626.90	—	8853.6 titers Standard Deviation 10330.92	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Day 180 (n=102, 90)	7016.5 titers Standard Deviation 6945.59	—	5967.3 titers Standard Deviation 6535.57	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Baseline for Day 270 Cohort (n=94, 73)	11976.7 titers Standard Deviation 13679.48	—	13149.7 titers Standard Deviation 14850.07	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Day 270 (n=94, 73)	9725.9 titers Standard Deviation 11337.20	—	8027.5 titers Standard Deviation 8863.47	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Baseline for Day 360 Cohort (n=83, 74)	11712.4 titers Standard Deviation 12971.16	—	13287.8 titers Standard Deviation 15024.78	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies With Immunoglobulin (IG) Region Day 360 (n=83, 74)	10284.1 titers Standard Deviation 12175.48	—	8675.1 titers Standard Deviation 10038.76	—

SECONDARY outcome

Timeframe: Baseline, Days 30, 90, 180, 270, 360

Population: Number of Participants Analyzed=treated participants; n=number of participants with both baseline and post-baseline measurements at timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Baseline for Day 30 Cohort (n=110, 101)	11.7 titers Standard Deviation 4.79	—	12.6 titers Standard Deviation 9.59	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Day 30 (n=110, 101)	12.0 titers Standard Deviation 5.58	—	12.5 titers Standard Deviation 9.38	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Baseline for Day 90 Cohort (n=110, 99)	11.6 titers Standard Deviation 4.69	—	12.5 titers Standard Deviation 9.42	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Day 90 (n=110, 99)	11.4 titers Standard Deviation 3.96	—	12.0 titers Standard Deviation 8.31	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Baseline for Day 180 Cohort (n=102, 90)	11.6 titers Standard Deviation 4.76	—	12.6 titers Standard Deviation 9.91	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Day 180 (n=102, 90)	11.7 titers Standard Deviation 5.01	—	12.1 titers Standard Deviation 8.66	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Baseline for Day 270 Cohort (n=95, 73)	12.1 titers Standard Deviation 5.22	—	13.4 titers Standard Deviation 10.51	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Day 270 (n=95, 73)	11.7 titers Standard Deviation 4.42	—	12.5 titers Standard Deviation 8.70	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Baseline for Day 360 Cohort (n=84, 76)	12.2 titers Standard Deviation 5.77	—	13.6 titers Standard Deviation 11.03	—
Immunogenicity Data: Anti-CTLA4Ig Antibodies Without IG Region Day 360 (n=84, 76)	11.6 titers Standard Deviation 4.42	—	12.9 titers Standard Deviation 9.79	—

SECONDARY outcome

Timeframe: Baseline, Days 30, 90, 180, 270, 360

Population: Number of Participants Analyzed=treated participants; n=number of participants with both baseline and post-baseline measurements at timepoint.

Number of participants with ratio of VA/PRE \<=3, \<3 to \<=9, and \>9. Ratios greater than 9 are incidences of Anti-CTLA4Ig sero-conversion.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 30, ratio <=3 (n=110, 100)	100 participants	—	109 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 30, ratio <3 to <=9 (n=110, 100)	0 participants	—	1 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 30, ratio >9 (n=110, 100)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 90, ratio <=3 (n=110, 99)	99 participants	—	110 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 90, ratio <3 to <=9 (n=110, 99)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 90, ratio >9 (n=110, 99)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 180, ratio <=3 (n=102, 90)	90 participants	—	101 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 180, ratio <3 to <=9 (n=102, 90)	0 participants	—	1 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 180, ratio >9 (n=102, 90)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 270, ratio <=3 (n=94, 73)	73 participants	—	94 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 270, ratio <3 to <=9 (n=94, 73)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 270, ratio >9 (n=94, 73)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 360, ratio <=3 (n=83, 74)	72 participants	—	81 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 360, ratio <3 to <=9 (n=83, 74)	2 participants	—	2 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion (Anti-CTLA4Ig Antibodies With IG Region) Day 360, ratio >9 (n=83, 74)	0 participants	—	0 participants	—

SECONDARY outcome

Timeframe: Baseline, Days 30, 90, 180, 270, 360

Population: Number of Participants Analyzed=treated participants; n=number of participants with both baseline and post-baseline measurements at timepoint.

Number of participants with ratio of VA/PRE \<=3, \<3 to \<=9, and \>9. Ratios greater than 9 are incidences of Anti-CTLA4Ig sero-conversion.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 30, ratio <=3 (n=110, 101)	99 participants	—	108 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 30, ratio <3 to <=9 (n=110, 101)	2 participants	—	1 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 30, ratio >9 (n=110, 101)	0 participants	—	1 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 90, ratio <=3 (n=110, 99)	99 participants	—	110 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 90, ratio <3 to <=9 (n=110, 99)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 90, ratio >9 (n=110, 99)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 180, ratio <=3 (n=102, 90)	89 participants	—	101 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 180, ratio <3 to <=9 (n=102, 90)	0 participants	—	1 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 180, ratio >9 (n=102, 90)	1 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 270, ratio <=3 (n=95, 73)	73 participants	—	95 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 270, ratio <3 to <=9 (n=95, 73)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 270, ratio >9 (n=95, 73)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 360, ratio <=3 (n=84, 76)	76 participants	—	84 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 360, ratio <3 to <=9 (n=84, 76)	0 participants	—	0 participants	—
Immunogenicity Data: Categories of Post Baseline Value to Baseline Value (VA/PRE) Ratios and Number of Participants With Sero-conversion(Anti-CTLA4Ig Antibodies Without IG Region) Day 360, ratio >9 (n=84, 76)	0 participants	—	0 participants	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in Rheumatoid Factor at Day 180 and Day 360 Mean Change at Day 180 (n=95, 84, 74)	-28.1 IU/mL Interval -52.1 to -4.1	-0.6 IU/mL Interval -31.7 to 30.4	-104.3 IU/mL Interval -151.5 to 57.0	—
Pharmacodynamic Measure: Mean Changes From Baseline in Rheumatoid Factor at Day 180 and Day 360 Mean Change at Day 360 (n=69, 54, 57)	-23.6 IU/mL Interval -56.8 to 9.7	20.9 IU/mL Interval -11.3 to 53.1	-118.3 IU/mL Interval -175.2 to -61.4	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in Interleukin-6 at Day 180 and Day 360 Mean Change at Day 180 (n=85, 74, 68)	-16.1 pg/mL Interval -24.2 to -8.0	1.3 pg/mL Interval -7.9 to 10.5	-20.5 pg/mL Interval -27.8 to -13.2	—
Pharmacodynamic Measure: Mean Changes From Baseline in Interleukin-6 at Day 180 and Day 360 Mean Change at Day 360 (n=56, 47, 47)	-12.7 pg/mL Interval -22.5 to -2.9	-0.6 pg/mL Interval -8.1 to 6.9	-20.9 pg/mL Interval -31.6 to -10.2	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in Plasma Soluble Interleukin-2 Receptor (sIL-2R) at Day 180 and Day 360 Mean Change at Day 180 (n=94, 84, 76)	-135.5 pg/mL Interval -241.5 to -29.5	43.6 pg/mL Interval -71.2 to 158.4	-315.9 pg/mL Interval -418.5 to -213.3	—
Pharmacodynamic Measure: Mean Changes From Baseline in Plasma Soluble Interleukin-2 Receptor (sIL-2R) at Day 180 and Day 360 Mean Change at Day 360 (n=68, 55, 54)	40.4 pg/mL Interval -71.5 to 152.3	196.8 pg/mL Interval 24.3 to 369.4	-194.3 pg/mL Interval -305.7 to -83.0	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in E-Selectin at Day 180 and Day 360 Mean Change at Day 360 (n=75, 67, 61)	0.6 ng/mL Interval -6.0 to 9.0	2.0 ng/mL Interval -4.9 to 9.0	-10.9 ng/mL Interval -15.7 to -6.1	—
Pharmacodynamic Measure: Mean Changes From Baseline in E-Selectin at Day 180 and Day 360 Mean Change at Day 180 (n=88, 80, 71)	0.5 ng/mL Interval -6.0 to 7.0	-0.7 ng/mL Interval -6.9 to 5.5	-8.3 ng/mL Interval -13.2 to -3.4	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in Soluble Inter-Cellular Adhesion Molecule 1 (sICAM-1) at Day 180 and Day 360 Mean Change at Day 180 (n=94, 82, 75)	-6.2 ng/mL Interval -27.5 to 15.1	1.1 ng/mL Interval -31.9 to 34.1	-40.6 ng/mL Interval -58.5 to -22.8	—
Pharmacodynamic Measure: Mean Changes From Baseline in Soluble Inter-Cellular Adhesion Molecule 1 (sICAM-1) at Day 180 and Day 360 Mean Change at Day 360 (n=77, 67, 63)	-13.6 ng/mL Interval -36.3 to 9.0	0.7 ng/mL Interval -27.6 to 28.9	-55.2 ng/mL Interval -74.8 to -35.5	—

SECONDARY outcome

Timeframe: Baseline, Day 180, Day 360

Population: Number of Participants Analyzed=total number of participants in each treatment group. n=number of treated Participants with measurement at baseline and given timepoint.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=105 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=119 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=115 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Pharmacodynamic Measure: Mean Changes From Baseline in Tumor Necrosis Factor (TNF)-Alpha at Day 180 and Day 360 Mean Change at Day 180 (n=83, 74, 68)	-1.2 ng/mL Interval -4.3 to 1.9	-3.6 ng/mL Interval -8.0 to 0.7	-3.7 ng/mL Interval -8.7 to 1.3	—
Pharmacodynamic Measure: Mean Changes From Baseline in Tumor Necrosis Factor (TNF)-Alpha at Day 180 and Day 360 Mean Change at Day 360 (n=61, 48, 49)	1.1 ng/mL Interval -1.3 to 3.4	-0.3 ng/mL Interval -3.2 to 2.7	-3.0 ng/mL Interval -8.7 to 2.7	—

SECONDARY outcome

Timeframe: Days 360, 450, 540, 630, 720, 810, 900, 1080, 1350, 1440, 1530, 1620, 1710, 1800, 1980, 2160, 2340, 2520, 2700, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the double-blind (DB) study. N = number of participants analyzed and n = the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 20 Responders in OL Period Day 360 (n=84, 68, 67)	40 Participants	37 Participants	64 Participants	—
Number of ACR 20 Responders in OL Period Day 450 (n=83, 67, 66)	45 Participants	46 Participants	56 Participants	—
Number of ACR 20 Responders in OL Period Day 540 (n=82, 65, 59)	45 Participants	45 Participants	61 Participants	—
Number of ACR 20 Responders in OL Period Day 630 (n=79, 63, 59)	44 Participants	44 Participants	60 Participants	—
Number of ACR 20 Responders in OL Period Day 720 (n=75, 59, 56)	39 Participants	43 Participants	58 Participants	—
Number of ACR 20 Responders in OL Period Day 810 (n=73, 56, 54)	41 Participants	44 Participants	49 Participants	—
Number of ACR 20 Responders in OL Period Day 900 (n=69, 53, 51)	42 Participants	42 Participants	56 Participants	—
Number of ACR 20 Responders in OL Period Day 990 (n=66, 52, 51)	39 Participants	40 Participants	52 Participants	—
Number of ACR 20 Responders in OL Period Day 1080 (n=66, 50, 49)	39 Participants	35 Participants	48 Participants	—
Number of ACR 20 Responders in OL Period Day 1170 (n=65, 50, 49)	35 Participants	36 Participants	46 Participants	—
Number of ACR 20 Responders in OL Period Day 1260 (n=64, 49, 46)	41 Participants	39 Participants	48 Participants	—
Number of ACR 20 Responders in OL Period Day 1350 (n=62, 48, 44)	30 Participants	37 Participants	46 Participants	—
Number of ACR 20 Responders in OL Period Day 440 (n=61, 47, 44)	38 Participants	37 Participants	43 Participants	—
Number of ACR 20 Responders in OL Period Day 1530 (n=60, 46, 43)	35 Participants	29 Participants	45 Participants	—
Number of ACR 20 Responders in OL Period Day 1620 (n=58, 45, 43)	35 Participants	38 Participants	44 Participants	—
Number of ACR 20 Responders in OL Period Day 1710 (n=58, 45, 42)	34 Participants	38 Participants	37 Participants	—
Number of ACR 20 Responders in OL Period Day 1800 (n=56, 44, 42)	32 Participants	38 Participants	44 Participants	—
Number of ACR 20 Responders in OL Period Day 1980 (n=53, 44, 40)	34 Participants	28 Participants	37 Participants	—
Number of ACR 20 Responders in OL Period Day 2160 (n=49, 42, 38)	33 Participants	32 Participants	39 Participants	—
Number of ACR 20 Responders in OL Period Day 2340 (n=47, 36, 36)	27 Participants	28 Participants	35 Participants	—
Number of ACR 20 Responders in OL Period Day 2520 (n=43, 37, 33)	30 Participants	28 Participants	31 Participants	—
Number of ACR 20 Responders in OL Period Day 2700 (n=37, 34, 34)	26 Participants	23 Participants	33 Participants	—
Number of ACR 20 Responders in OL Period Day 2880 (n=36, 31, 32)	28 Participants	27 Participants	28 Participants	—
Number of ACR 20 Responders in OL Period Day 3060 (n=18, 18, 17)	13 Participants	14 Participants	13 Participants	—

SECONDARY outcome

Timeframe: Days 360, 450, 540, 630, 720, 810, 900, 1080, 1350, 1440, 1530, 1620, 1710, 1800, 1980, 2160, 2340, 2520, 2700, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. N=number of participants analyzed; n=the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 50 Responders in the OL Period Day 1,260 (n=64, 49, 46)	24 Participants	28 Participants	33 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,350 (n=62, 48, 44)	24 Participants	28 Participants	28 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,440 (n=61, 47, 44)	33 Participants	24 Participants	25 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,530 (n=60, 46, 43)	28 Participants	26 Participants	33 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,620 (n=58, 45, 43)	27 Participants	26 Participants	29 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,710 (n=58, 45, 42)	27 Participants	25 Participants	23 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,800 (n=56, 44, 42)	28 Participants	28 Participants	34 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,980 (n=53, 44, 40)	26 Participants	22 Participants	31 Participants	—
Number of ACR 50 Responders in the OL Period Day 2,160 (n=49, 42, 38)	30 Participants	25 Participants	25 Participants	—
Number of ACR 50 Responders in the OL Period Day 2,340 (n=47, 36, 36)	15 Participants	21 Participants	24 Participants	—
Number of ACR 50 Responders in the OL Period Day 2,520 (n=43, 37, 33)	23 Participants	21 Participants	25 Participants	—
Number of ACR 50 Responders in the OL Period Day 2,700 (n=37, 34, 34)	19 Participants	17 Participants	23 Participants	—
Number of ACR 50 Responders in the OL Period Day 2,880 (n=36, 31, 32)	18 Participants	19 Participants	23 Participants	—
Number of ACR 50 Responders in the OL Period Day 3,060 (n=18, 18, 17)	10 Participants	9 Participants	8 Participants	—
Number of ACR 50 Responders in the OL Period Day 360 (n=84, 68, 67)	23 Participants	21 Participants	44 Participants	—
Number of ACR 50 Responders in the OL Period Day 450 (n=83, 67, 66)	30 Participants	30 Participants	41 Participants	—
Number of ACR 50 Responders in the OL Period Day 540 (n=82, 65, 59)	28 Participants	31 Participants	38 Participants	—
Number of ACR 50 Responders in the OL Period Day 630 (n=79, 63, 59)	27 Participants	31 Participants	38 Participants	—
Number of ACR 50 Responders in the OL Period Day 720 (n=75, 59, 56)	29 Participants	34 Participants	43 Participants	—
Number of ACR 50 Responders in the OL Period Day 810 (n=73, 56, 54)	23 Participants	30 Participants	42 Participants	—
Number of ACR 50 Responders in the OL Period Day 900 (n=69, 53, 51)	34 Participants	29 Participants	40 Participants	—
Number of ACR 50 Responders in the OL Period Day 990 (n=66, 52, 51)	28 Participants	31 Participants	40 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,080 (n=66, 50, 49)	24 Participants	29 Participants	35 Participants	—
Number of ACR 50 Responders in the OL Period Day 1,170 (n=65, 50, 49)	27 Participants	29 Participants	36 Participants	—

SECONDARY outcome

Timeframe: Days 360, 450, 540, 630, 720, 810, 900, 1080, 1350, 1440, 1530, 1620, 1710, 1800, 1980, 2160, 2340, 2520, 2700, 2880, and 3060

ACR 70 response requires a participant to have a 70% reduction in the number of swollen and tender joints, and a reduction of 70% in 3 of the following 5 parameters: physician global assessment of disease, participant global assessment of disease, participant assessment of pain, C-reactive protein or erythrocyte sedimentation rate, and degree of disability in HAQ score. A participant achieved a sustained ACR 70 response if the participant had ACR 70 observed for at least 2 consecutive study visits.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of ACR 70 Responders in the OL Period Day 1980 (n=53, 44, 40)	16 Participants	10 Participants	25 Participants	—
Number of ACR 70 Responders in the OL Period Day 2160 (n=49, 42, 38)	18 Participants	11 Participants	23 Participants	—
Number of ACR 70 Responders in the OL Period Day 360 (n=84, 68, 67)	13 Participants	9 Participants	24 Participants	—
Number of ACR 70 Responders in the OL Period Day 450 (n=83, 67, 66)	14 Participants	12 Participants	21 Participants	—
Number of ACR 70 Responders in the OL Period Day 540 (n=82, 65, 59)	15 Participants	12 Participants	28 Participants	—
Number of ACR 70 Responders in the OL Period Day 630 (n=79, 63, 59)	17 Participants	15 Participants	25 Participants	—
Number of ACR 70 Responders in the OL Period Day 720 (n=75, 59, 56)	18 Participants	16 Participants	22 Participants	—
Number of ACR 70 Responders in the OL Period Day 810 (n=73, 56, 54)	14 Participants	11 Participants	20 Participants	—
Number of ACR 70 Responders in the OL Period Day 900 (n=69, 53, 51)	16 Participants	15 Participants	19 Participants	—
Number of ACR 70 Responders in the OL Period Day 990 (n=66, 52, 51)	17 Participants	17 Participants	23 Participants	—
Number of ACR 70 Responders in the OL Period Day 1080 (n=66, 50, 49)	18 Participants	16 Participants	21 Participants	—
Number of ACR 70 Responders in the OL Period Day 1170 (n=65, 50, 49)	16 Participants	17 Participants	23 Participants	—
Number of ACR 70 Responders in the OL Period Day 1260 (n=64, 49, 46)	12 Participants	20 Participants	20 Participants	—
Number of ACR 70 Responders in the OL Period Day 1350 (n=62, 48, 44)	13 Participants	13 Participants	18 Participants	—
Number of ACR 70 Responders in the OL Period Day 1440 (n=61, 47, 44)	16 Participants	15 Participants	19 Participants	—
Number of ACR 70 Responders in the OL Period Day 1530 (n=60, 46, 43)	16 Participants	13 Participants	22 Participants	—
Number of ACR 70 Responders in the OL Period Day 1620 (n=58, 45, 43)	15 Participants	16 Participants	21 Participants	—
Number of ACR 70 Responders in the OL Period Day 1710 (n=58, 45, 42)	18 Participants	12 Participants	15 Participants	—
Number of ACR 70 Responders in the OL Period Day 1800 (n=56, 44, 42)	17 Participants	15 Participants	21 Participants	—
Number of ACR 70 Responders in the OL Period Day 2340 (n=47, 36, 36)	11 Participants	14 Participants	19 Participants	—
Number of ACR 70 Responders in the OL Period Day 2520 (n=43, 37, 33)	16 Participants	11 Participants	19 Participants	—
Number of ACR 70 Responders in the OL Period Day 2700 (n=37, 34, 34)	12 Participants	12 Participants	20 Participants	—
Number of ACR 70 Responders in the OL Period Day 2880 (n=36, 31, 32)	10 Participants	12 Participants	17 Participants	—
Number of ACR 70 Responders in the OL Period Day 3060 (n=18, 18, 17)	6 Participants	7 Participants	6 Participants	—

SECONDARY outcome

Timeframe: Days 360, 720,1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. N =number of participants analyzed; n=the number of participants with measurements for that time point.

The mHAQ is a self-administered questionnaire composed of 20 questions that assess physical functions in 8 domains: dressing, arising, eating, walking, hygiene, reach, grip, and common activities. The answers are graded on a 4-point scale: 0=without any difficulty, 1=with some difficulty, 2=with much difficulty, and 3=unable to do. The HAQ disease index is a weighted sum of the scale scores, with a higher score indicating poorer function. A clinically meaningful improvement was defined as a reduction from baseline in mHAQ score of at least 0.30 units.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 360 (n=84, 68, 67)	30 Participants	23 Participants	46 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 720 (n=75, 59, 56)	34 Participants	21 Participants	39 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 1080 (n=66, 50, 49)	28 Participants	28 Participants	34 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 1440 (n=61, 47, 44)	26 Participants	20 Participants	31 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 1800 (n=56, 44, 42)	27 Participants	20 Participants	29 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 2160 (n=49, 42, 38)	24 Participants	15 Participants	26 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 2520 (n=43, 37, 33)	21 Participants	17 Participants	23 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 2880 (n=36, 31, 32)	21 Participants	14 Participants	18 Participants	—
Number of Participants With a Clinically Meaningful Improvement on the Modified Health Assessment Questionnaire (mHAQ) in OL Period Day 3060 (n=18, 18, 17)	8 Participants	5 Participants	8 Participants	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720,1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Serum evaluations were carried out to determine participant baseline rheumatoid factor serum concentration. Time-matched baseline(Day 0) values and post-baseline vales were presented for each post-baseline visit and represent only that cohort of participants with measurements available at that post-baseline assessment.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 360 cohort (n=80, 62, 65)	219.24 IU/mL Standard Deviation 262.55	233.57 IU/mL Standard Deviation 299.75	291.98 IU/mL Standard Deviation 374.41	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 720 cohort (n=69, 57, 54)	217.21 IU/mL Standard Deviation 267.03	227.81 IU/mL Standard Deviation 308.53	256.12 IU/mL Standard Deviation 361.74	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 1080 cohort (n=64, 49, 47)	172.00 IU/mL Standard Deviation 204.63	203.94 IU/mL Standard Deviation 250.44	233.95 IU/mL Standard Deviation 346.73	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 1440 cohort (n=57, 41, 41)	165.39 IU/mL Standard Deviation 173.31	215.71 IU/mL Standard Deviation 258.60	243.32 IU/mL Standard Deviation 363.86	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 1800 cohort (n=51, 41, 40)	175.41 IU/mL Standard Deviation 206.37	205.33 IU/mL Standard Deviation 254.25	165.39 IU/mL Standard Deviation 152.94	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 2160 (n=43, 34, 30)	181.91 IU/mL Standard Deviation 216.48	194.17 IU/mL Standard Deviation 254.30	185.74 IU/mL Standard Deviation 173.26	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 2520 (n=23, 24, 22)	158.42 IU/mL Standard Deviation 210.74	269.55 IU/mL Standard Deviation 309.15	175.13 IU/mL Standard Deviation 156.99	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 2880 (n=15, 16, 13)	197.63 IU/mL Standard Deviation 251.82	366.38 IU/mL Standard Deviation 362.39	159.93 IU/mL Standard Deviation 123.69	—
Baseline Level of Serum Rheumatoid Factor Over Time in OL Period Baseline for Day 3060 (n=7, 9, 5)	223.44 IU/mL Standard Deviation 316.59	232.60 IU/mL Standard Deviation 202.38	214.29 IU/mL Standard Deviation 120.00	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720,1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Serum evaluations were carried out to determine participant change from baseline in rheumatoid factor serum concentration. Mean change from baseline = value at post-baseline OL time point-value and baseline OL time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 360 (n=80, 62, 65)	-21.71 IU/mL Standard Error 14.50	7.77 IU/mL Standard Error 21.05	-72.78 IU/mL Standard Error 39.69	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 720 (n=69, 57, 54)	-40.23 IU/mL Standard Error 23.05	-48.37 IU/mL Standard Error 48.47	37.51 IU/mL Standard Error 76.03	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 1080 (n=64, 49, 47)	-34.78 IU/mL Standard Error 24.22	-0.04 IU/mL Standard Error 38.15	8.53 IU/mL Standard Error 66.71	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 1440 (n=57, 41, 41)	-15.68 IU/mL Standard Error 32.26	1.54 IU/mL Standard Error 49.24	43.81 IU/mL Standard Error 97.15	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 1800 (n=51, 41, 40)	10.95 IU/mL Standard Error 41.17	-49.83 IU/mL Standard Error 40.58	30.29 IU/mL Standard Error 30.78	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 2160 (n=43, 34, 30)	-26.29 IU/mL Standard Error 35.06	-65.50 IU/mL Standard Error 51.49	-8.44 IU/mL Standard Error 45.19	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 2520 (n=23, 24, 22)	-54.92 IU/mL Standard Error 41.93	-50.05 IU/mL Standard Error 70.38	87.61 IU/mL Standard Error 99.50	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 2880 (n=15, 16, 13)	-102.06 IU/mL Standard Error 64.62	46.54 IU/mL Standard Error 193.55	28.47 IU/mL Standard Error 45.91	—
Mean Change From Baseline in Serum Rheumatoid Factor Level Over Time in OL Period Change at Day 3060 (n=7, 9, 5)	-89.00 IU/mL Standard Error 109.53	118.40 IU/mL Standard Error 252.72	-45.14 IU/mL Standard Error 88.72	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720,1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Serum evaluations were carried out to determine participant serum levels of sIL2-r at baseline. Time-matched baseline (Day 0) values and post-baseline vales were presented for each post-baseline visit and represent only that cohort of participants with measurements available at that post-baseline assessment.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Soluble Serum Interleukin-2 Receptor Level (sIL2-r) Over Time in OL Period Baseline for Day 360 cohort (n=69, 57, 58)	1365.40 pg/mL Standard Deviation 524.90	1480.93 pg/mL Standard Deviation 713.88	1424.86 pg/mL Standard Deviation 790.75	—
Mean Baseline Soluble Serum Interleukin-2 Receptor Level (sIL2-r) Over Time in OL Period Baseline for Day 720 cohort (n=66, 53, 49)	1351.15 pg/mL Standard Deviation 497.64	1437.24 pg/mL Standard Deviation 730.73	1419.82 pg/mL Standard Deviation 721.00	—
Mean Baseline Soluble Serum Interleukin-2 Receptor Level (sIL2-r) Over Time in OL Period Baseline for Day 1080 cohort (n=57, 47, 44)	1341.51 pg/mL Standard Deviation 520.06	1392.09 pg/mL Standard Deviation 678.85	1413.28 pg/mL Standard Deviation 760.39	—
Mean Baseline Soluble Serum Interleukin-2 Receptor Level (sIL2-r) Over Time in OL Period Baseline for Day 1440 cohort (n=47, 36, 31)	1323.14 pg/mL Standard Deviation 538.82	1409.71 pg/mL Standard Deviation 687.86	1418.64 pg/mL Standard Deviation 806.85	—
Mean Baseline Soluble Serum Interleukin-2 Receptor Level (sIL2-r) Over Time in OL Period Baseline for Day 1800 cohort (n=27, 13, 17)	1160.15 pg/mL Standard Deviation 444.37	1476.06 pg/mL Standard Deviation 590.14	1252.04 pg/mL Standard Deviation 572.14	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, and 1800

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Serum evaluations were carried out to determine participant serum levels of sIL2-r. Mean change from baseline=value at post-baseline OL time point-value and baseline OL time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline in sIL2-r Over Time in OL Period Change at Day 1440 (n=47, 36, 31)	-392.08 pg/mL Standard Error 81.78	-394.45 pg/mL Standard Error 123.99	-421.57 pg/mL Standard Error 98.79	—
Mean Change From Baseline in sIL2-r Over Time in OL Period Change at Day 360 (n=69, 57, 58)	44.05 pg/mL Standard Error 60.80	207.40 pg/mL Standard Error 91.17	-200.62 pg/mL Standard Error 56.43	—
Mean Change From Baseline in sIL2-r Over Time in OL Period Change at Day 720 (n=66, 53, 49)	-209.19 pg/mL Standard Error 60.08	-213.22 pg/mL Standard Error 83.64	-323.26 pg/mL Standard Error 83.71	—
Mean Change From Baseline in sIL2-r Over Time in OL Period Change at Day 1080 (n=57, 47, 44)	-44.98 pg/mL Standard Error 95.04	-156.20 pg/mL Standard Error 69.04	-158.93 pg/mL Standard Error 96.60	—
Mean Change From Baseline in sIL2-r Over Time in OL Period Change at Day 1800 (n=27, 13, 17)	-84.77 pg/mL Standard Error 61.61	-247.12 pg/mL Standard Error 128.65	-249.81 pg/mL Standard Error 123.30	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080,1440,1800, 2160, 2520, 2880, 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Serum evaluations were carried out to evaluate participant serum CRP concentrations at baseline. Time-matched BL (Day 0) values and post-BL vales were presented for each post-BL visit and represent only that cohort of participants with measurements available at that post-BL assessment.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 360 cohort (n=78, 65, 65)	3.02 mg/dL Standard Deviation 2.36	2.61 mg/dL Standard Deviation 2.20	2.90 mg/dL Standard Deviation 2.25	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 720 cohort (n=68, 54, 53)	3.16 mg/dL Standard Deviation 2.60	2.60 mg/dL Standard Deviation 2.03	2.64 mg/dL Standard Deviation 2.03	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 1080 cohort (n=61, 50, 47)	3.06 mg/dL Standard Deviation 2.63	2.52 mg/dL Standard Deviation 2.06	2.58 mg/dL Standard Deviation 1.99	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 1440 cohort (n=56, 46, 41)	3.11 mg/dL Standard Deviation 2.71	2.62 mg/dL Standard Deviation 2.16	2.65 mg/dL Standard Deviation 2.02	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 1800 cohort (n=52, 41, 41)	3.10 mg/dL Standard Deviation 2.75	2.64 mg/dL Standard Deviation 2.15	2.40 mg/dL Standard Deviation 1.73	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 2160 cohort (n=43, 34, 33)	2.91 mg/dL Standard Deviation 2.77	2.80 mg/dL Standard Deviation 2.36	2.34 mg/dL Standard Deviation 1.66	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 2520 cohort (n=36, 35, 32)	3.02 mg/dL Standard Deviation 2.79	2.86 mg/dL Standard Deviation 2.35	2.46 mg/dL Standard Deviation 1.70	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 2880 cohort (n=27, 26, 27)	2.95 mg/dL Standard Deviation 3.00	3.08 mg/dL Standard Deviation 2.49	2.14 mg/dL Standard Deviation 1.42	—
Mean Baseline Serum C-Reactive Protein Level Over Time in OL Period Baseline for Day 3060 cohort (n=14, 10, 8)	2.99 mg/dL Standard Deviation 3.07	2.72 mg/dL Standard Deviation 1.30	1.93 mg/dL Standard Deviation 1.12	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Serum evaluations were carried out to evaluate participant concentrations of serum C reactive protein. Mean change from baseline=value at post-baseline OL time point-value and baseline OL time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 360 (n=78, 65, 65)	-1.13 mg/dL Standard Error 0.33	-0.08 mg/dL Standard Error 0.38	-1.38 mg/dL Standard Error 0.29	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 720 (n=68, 54, 53)	-2.08 mg/dL Standard Error 0.38	-1.26 mg/dL Standard Error 0.28	-1.46 mg/dL Standard Error 0.25	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 1080 (n=61, 50, 47)	-1.93 mg/dL Standard Error 0.38	-1.20 mg/dL Standard Error 0.35	-0.96 mg/dL Standard Error 0.44	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 1440 (n=56, 46, 41)	-1.91 mg/dL Standard Error 0.37	-1.21 mg/dL Standard Error 0.44	-1.56 mg/dL Standard Error 0.33	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 1800 (n=52, 41, 41)	-1.33 mg/dL Standard Error 0.83	-1.72 mg/dL Standard Error 0.35	-1.53 mg/dL Standard Error 0.25	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 2160 (n=43, 34, 33)	-2.11 mg/dL Standard Error 0.46	-2.04 mg/dL Standard Error 0.42	-1.33 mg/dL Standard Error 0.37	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 2520 (n=36, 35, 32)	-2.29 mg/dL Standard Error 0.48	-2.01 mg/dL Standard Error 0.40	-1.45 mg/dL Standard Error 0.39	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 2880 (n=27, 26, 27)	-2.16 mg/dL Standard Error 0.61	-2.25 mg/dL Standard Error 0.49	-1.47 mg/dL Standard Error 0.34	—
Mean Change From Baseline in Level of C Reactive Protein Over Time in OL Period Change at Day 3060 (n=14, 10, 8)	-2.10 mg/dL Standard Error 1.00	-1.73 mg/dL Standard Error 0.50	-1.06 mg/dL Standard Error 0.36	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

SF-36 = PCS \& MCS \& 8 individual indices (physical function, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, \& mental health). Subscales were scored using norm-based methods that standardized scores to a mean of 50 \& a standard deviation of 10 in the general population. Scores range from 0 to 100, with a higher score indicating better quality of life. Time-matched BL \& post-BL values are presented for each post-BL visit \& represent only that cohort with measurements available at that assessment. Change from BL data are presented in Outcome Measure 50.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 360 cohort (n=84, 66, 64)	31.03 Units on a Scale Standard Deviation 8.87	32.57 Units on a Scale Standard Deviation 7.94	30.90 Units on a Scale Standard Deviation 8.14	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 720 cohort (n=73, 55, 53)	30.83 Units on a Scale Standard Deviation 8.03	32.48 Units on a Scale Standard Deviation 7.14	31.44 Units on a Scale Standard Deviation 8.35	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 1080 cohort (n=63, 50, 49)	31.73 Units on a Scale Standard Deviation 8.63	32.38 Units on a Scale Standard Deviation 7.08	31.56 Units on a Scale Standard Deviation 8.14	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 1440 cohort (n=59, 46, 44)	31.80 Units on a Scale Standard Deviation 8.84	32.20 Units on a Scale Standard Deviation 7.44	31.46 Units on a Scale Standard Deviation 8.31	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	32.02 Units on a Scale Standard Deviation 8.91	32.36 Units on a Scale Standard Deviation 7.57	32.19 Units on a Scale Standard Deviation 8.72	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	32.25 Units on a Scale Standard Deviation 9.07	32.29 Units on a Scale Standard Deviation 7.70	32.15 Units on a Scale Standard Deviation 8.72	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	32.75 Units on a Scale Standard Deviation 9.20	32.54 Units on a Scale Standard Deviation 7.39	31.93 Units on a Scale Standard Deviation 9.50	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	33.65 Units on a Scale Standard Deviation 8.66	32.66 Units on a Scale Standard Deviation 7.81	32.63 Units on a Scale Standard Deviation 8.71	—
Mean Baseline Physical Component Summary (PCS) of the Short-Form 36 (SF-36) Over Time in OL Period Baseline for Day 3060 cohort (n=17, 17, 16)	33.88 Units on a Scale Standard Deviation 9.12	33.40 Units on a Scale Standard Deviation 9.52	36.81 Units on a Scale Standard Deviation 7.68	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

The SF-36 consists of 2 summaries, the PCS and the MCS, and 8 individual indexes. The MCS addresses 4 of the 8 individual indices: vitality, social functioning, role-emotional, and mental health. The scores range from 0 to 100, with a higher score indicating better quality of life. Mean change from baseline=value at post-baseline OL time point-value and baseline OL time point. Baseline data for these time-matched cohorts are presented in Outcome Measure 49.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 3060 (n=17, 17, 16)	5.70 Units on a Scale Standard Error 1.98	9.06 Units on a Scale Standard Error 2.35	8.55 Units on a Scale Standard Error 2.74	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 360 (n=84, 66, 64)	7.13 Units on a Scale Standard Error 0.99	4.53 Units on a Scale Standard Error 1.04	9.66 Units on a Scale Standard Error 1.05	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 720 (n=73, 55, 53)	8.48 Units on a Scale Standard Error 1.25	8.30 Units on a Scale Standard Error 1.10	9.15 Units on a Scale Standard Error 1.17	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 1080 (n=63, 50, 49)	8.14 Units on a Scale Standard Error 1.36	9.28 Units on a Scale Standard Error 1.29	9.28 Units on a Scale Standard Error 1.22	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 1440 (n=59, 46, 44)	9.53 Units on a Scale Standard Error 1.28	9.50 Units on a Scale Standard Error 1.29	8.18 Units on a Scale Standard Error 1.33	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 1800 (n=54, 43, 42)	7.60 Units on a Scale Standard Error 1.25	9.18 Units on a Scale Standard Error 1.20	9.30 Units on a Scale Standard Error 1.49	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 2160 (n=45, 36, 35)	10.61 Units on a Scale Standard Error 1.44	8.86 Units on a Scale Standard Error 1.65	9.51 Units on a Scale Standard Error 1.72	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 2520 (n=38, 35, 33)	8.26 Units on a Scale Standard Error 1.58	7.92 Units on a Scale Standard Error 1.80	10.12 Units on a Scale Standard Error 1.88	—
Mean Change From Baseline (BL) in the Physical Component Summary (PCS) of the SF-36 Over Time in OL Period Change from BL on Day 2880 (n=33, 30, 31)	7.51 Units on a Scale Standard Error 1.35	9.19 Units on a Scale Standard Error 1.64	10.97 Units on a Scale Standard Error 1.96	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

SF-36=PCS, MCS, \& 8 individual indices. MCS addresses 4 of the 8 indices: vitality, social functioning, role-emotional, \& mental health. Subscales were scored using norm-based methods that standardized the scores to a mean of 50 \& a standard deviation of 10 in the general population. Scores range from 0 to 100, with a higher score indicating better quality of life. Time-matched baseline (Day 0) values \& post-baseline (BL) values are presented for each post-BL visit \& represent only that cohort with measurements available at that post-BL assessment. See Outcome Measure 51 for Change from BL.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline (Day 0) for Day 360 cohort (n=84, 66, 64)	42.10 Units on a Scale Standard Deviation 13.08	44.44 Units on a Scale Standard Deviation 12.36	46.27 Units on a Scale Standard Deviation 12.13	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline (Day 0) for Day 720 cohort (n=73,55, 53)	41.82 Units on a Scale Standard Deviation 13.10	44.74 Units on a Scale Standard Deviation 12.62	46.17 Units on a Scale Standard Deviation 12.24	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=63, 50, 49)	42.10 Units on a Scale Standard Deviation 12.82	44.53 Units on a Scale Standard Deviation 12.52	45.45 Units on a Scale Standard Deviation 11.76	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=59, 46, 44)	42.48 Units on a Scale Standard Deviation 13.06	44.66 Units on a Scale Standard Deviation 12.74	45.32 Units on a Scale Standard Deviation 11.38	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	41.87 Units on a Scale Standard Deviation 12.99	44.68 Units on a Scale Standard Deviation 12.85	45.07 Units on a Scale Standard Deviation 11.31	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	42.09 Units on a Scale Standard Deviation 12.96	43.89 Units on a Scale Standard Deviation 12.36	45.57 Units on a Scale Standard Deviation 11.45	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	42.53 Units on a Scale Standard Deviation 13.34	44.51 Units on a Scale Standard Deviation 12.09	46.35 Units on a Scale Standard Deviation 12.07	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	40.74 Units on a Scale Standard Deviation 12.02	43.51 Units on a Scale Standard Deviation 11.20	45.48 Units on a Scale Standard Deviation 11.45	—
Mean Baseline Mental Component Summary (MCS) of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=17, 17, 16)	40.94 Units on a Scale Standard Deviation 13.47	45.14 Units on a Scale Standard Deviation 12.42	46.24 Units on a Scale Standard Deviation 13.26	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 450, 540, 630, 720, 810, 900, 1080, 1350, 1440, 1530, 1620, 1710, 1800, 1980, 2160, 2340, 2520, 2700, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	6.97 Units on a Scale Standard Error 1.69	3.87 Units on a Scale Standard Error 2.18	5.00 Units on a Scale Standard Error 1.92	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 66, 64)	6.03 Units on a Scale Standard Error 1.32	2.53 Units on a Scale Standard Error 1.34	6.05 Units on a Scale Standard Error 1.19	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73,55, 53)	6.02 Units on a Scale Standard Error 1.49	4.17 Units on a Scale Standard Error 1.57	4.59 Units on a Scale Standard Error 1.29	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=63, 50, 49)	4.87 Units on a Scale Standard Error 1.44	5.52 Units on a Scale Standard Error 1.78	4.01 Units on a Scale Standard Error 1.23	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=59, 46, 44)	6.68 Units on a Scale Standard Error 1.34	4.76 Units on a Scale Standard Error 2.12	4.67 Units on a Scale Standard Error 1.31	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	4.59 Units on a Scale Standard Error 1.66	2.26 Units on a Scale Standard Error 1.71	5.32 Units on a Scale Standard Error 1.38	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 36, 35)	5.95 Units on a Scale Standard Error 1.46	4.55 Units on a Scale Standard Error 2.19	6.22 Units on a Scale Standard Error 1.47	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 35, 33)	7.34 Units on a Scale Standard Error 1.75	4.44 Units on a Scale Standard Error 2.26	2.81 Units on a Scale Standard Error 1.85	—
Mean Change From Baseline (BL) in the MCS of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=17, 17, 16)	5.51 Units on a Scale Standard Error 2.88	1.91 Units on a Scale Standard Error 3.26	4.81 Units on a Scale Standard Error 2.90	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 66)	30.18 Units on a Scale Standard Deviation 10.23	30.80 Units on a Scale Standard Deviation 9.48	29.84 Units on a Scale Standard Deviation 9.57	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 56, 53)	30.58 Units on a Scale Standard Deviation 9.99	30.79 Units on a Scale Standard Deviation 9.10	30.39 Units on a Scale Standard Deviation 9.63	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=64, 50, 49)	31.21 Units on a Scale Standard Deviation 10.35	30.95 Units on a Scale Standard Deviation 8.95	30.27 Units on a Scale Standard Deviation 9.38	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=60, 46, 44)	31.50 Units on a Scale Standard Deviation 10.12	31.26 Units on a Scale Standard Deviation 9.15	30.47 Units on a Scale Standard Deviation 9.43	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	31.81 Units on a Scale Standard Deviation 10.45	31.48 Units on a Scale Standard Deviation 9.08	30.96 Units on a Scale Standard Deviation 9.74	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 37, 35)	32.24 Units on a Scale Standard Deviation 10.42	31.56 Units on a Scale Standard Deviation 9.51	31.41 Units on a Scale Standard Deviation 10.16	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	32.79 Units on a Scale Standard Deviation 10.26	32.04 Units on a Scale Standard Deviation 8.95	31.47 Units on a Scale Standard Deviation 10.64	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	33.56 Units on a Scale Standard Deviation 10.07	32.18 Units on a Scale Standard Deviation 9.32	31.77 Units on a Scale Standard Deviation 10.62	—
Mean Baseline (BL) Physical Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=18, 18, 16)	33.92 Units on a Scale Standard Deviation 9.55	32.37 Units on a Scale Standard Deviation 10.37	34.97 Units on a Scale Standard Deviation 9.74	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

SF-36=2 summaries (PCS \& MCS) \& 8 individual indices including physical function, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, \& mental health. All subscales were scored using norm-based methods that standardized the scores to a mean of 50 \& a standard deviation of 10 in the general population. The scores range from 0 to 100, with a higher score indicating better quality of life. Mean change from BL = value at post-BL OL time point-value and BL OL time point. Baseline data for these time-matched cohorts are presented in Outcome Measure 53.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	6.53 Units on a Scale Standard Error 0.99	3.31 Units on a Scale Standard Error 0.92	8.58 Units on a Scale Standard Error 1.11	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	7.50 Units on a Scale Standard Error 1.32	7.30 Units on a Scale Standard Error 1.15	8.36 Units on a Scale Standard Error 1.16	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=64, 50, 49)	6.22 Units on a Scale Standard Error 1.49	7.62 Units on a Scale Standard Error 1.08	8.36 Units on a Scale Standard Error 1.32	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=60, 46, 44)	7.19 Units on a Scale Standard Error 1.48	7.58 Units on a Scale Standard Error 1.22	7.91 Units on a Scale Standard Error 1.48	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	5.48 Units on a Scale Standard Error 1.45	6.16 Units on a Scale Standard Error 1.33	8.39 Units on a Scale Standard Error 1.60	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 37, 35)	8.28 Units on a Scale Standard Error 1.53	5.46 Units on a Scale Standard Error 1.32	9.24 Units on a Scale Standard Error 1.74	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 35, 33)	6.58 Units on a Scale Standard Error 1.74	5.87 Units on a Scale Standard Error 1.64	7.92 Units on a Scale Standard Error 2.02	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	5.90 Units on a Scale Standard Error 1.63	6.63 Units on a Scale Standard Error 1.49	9.93 Units on a Scale Standard Error 2.09	—
Mean Change From Baseline (BL) in the Physical Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=18, 18, 16)	4.29 Units on a Scale Standard Error 1.91	6.16 Units on a Scale Standard Error 2.01	6.21 Units on a Scale Standard Error 2.87	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 66, 66)	31.70 Units on a Scale Standard Deviation 7.77	34.17 Units on a Scale Standard Deviation 8.82	33.68 Units on a Scale Standard Deviation 9.66	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 56, 53)	31.49 Units on a Scale Standard Deviation 7.51	33.69 Units on a Scale Standard Deviation 8.78	34.06 Units on a Scale Standard Deviation 10.09	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=64, 50, 49)	32.20 Units on a Scale Standard Deviation 7.96	33.58 Units on a Scale Standard Deviation 8.42	34.36 Units on a Scale Standard Deviation 10.22	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=60, 46, 44)	32.57 Units on a Scale Standard Deviation 8.20	33.10 Units on a Scale Standard Deviation 7.98	33.97 Units on a Scale Standard Deviation 9.90	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	32.39 Units on a Scale Standard Deviation 8.31	33.01 Units on a Scale Standard Deviation 8.01	33.85 Units on a Scale Standard Deviation 9.79	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	33.26 Units on a Scale Standard Deviation 8.85	32.80 Units on a Scale Standard Deviation 7.63	33.61 Units on a Scale Standard Deviation 9.61	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	33.41 Units on a Scale Standard Deviation 8.93	33.95 Units on a Scale Standard Deviation 8.68	33.72 Units on a Scale Standard Deviation 9.85	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	33.38 Units on a Scale Standard Deviation 8.45	33.43 Units on a Scale Standard Deviation 7.90	33.74 Units on a Scale Standard Deviation 9.60	—
Mean Baseline Role-Physical Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=17, 18, 16)	34.63 Units on a Scale Standard Deviation 8.57	35.47 Units on a Scale Standard Deviation 9.82	37.52 Units on a Scale Standard Deviation 11.71	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 66, 66)	6.97 Units on a Scale Standard Error 1.22	5.68 Units on a Scale Standard Error 1.51	10.10 Units on a Scale Standard Error 1.32	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	9.60 Units on a Scale Standard Error 1.49	9.03 Units on a Scale Standard Error 1.55	9.69 Units on a Scale Standard Error 1.51	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=64, 50, 49)	8.06 Units on a Scale Standard Error 1.69	12.12 Units on a Scale Standard Error 1.86	8.73 Units on a Scale Standard Error 1.63	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=60, 46, 44)	10.30 Units on a Scale Standard Error 1.66	11.89 Units on a Scale Standard Error 1.76	7.78 Units on a Scale Standard Error 1.69	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	7.57 Units on a Scale Standard Error 1.50	11.11 Units on a Scale Standard Error 1.74	9.95 Units on a Scale Standard Error 1.85	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 36, 35)	10.41 Units on a Scale Standard Error 1.92	11.65 Units on a Scale Standard Error 2.14	10.37 Units on a Scale Standard Error 1.86	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 35, 33)	9.50 Units on a Scale Standard Error 1.94	9.43 Units on a Scale Standard Error 2.57	9.49 Units on a Scale Standard Error 2.20	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	7.31 Units on a Scale Standard Error 1.84	10.95 Units on a Scale Standard Error 2.32	11.79 Units on a Scale Standard Error 2.32	—
Mean Change From Baseline (BL) in the Role-Physical Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=17, 18, 16)	4.32 Units on a Scale Standard Error 2.63	10.61 Units on a Scale Standard Error 3.48	11.65 Units on a Scale Standard Error 3.53	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 66)	33.82 Units on a Scale Standard Deviation 7.69	36.39 Units on a Scale Standard Deviation 7.98	35.91 Units on a Scale Standard Deviation 8.52	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 56, 53)	34.23 Units on a Scale Standard Deviation 7.63	35.93 Units on a Scale Standard Deviation 7.35	36.10 Units on a Scale Standard Deviation 8.76	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baselinefor Day 1080 cohort (n=64, 50, 49)	34.57 Units on a Scale Standard Deviation 7.84	36.04 Units on a Scale Standard Deviation 7.48	36.06 Units on a Scale Standard Deviation 8.73	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=60, 46, 44)	34.56 Units on a Scale Standard Deviation 7.99	35.42 Units on a Scale Standard Deviation 7.37	35.28 Units on a Scale Standard Deviation 8.59	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	34.57 Units on a Scale Standard Deviation 8.23	35.54 Units on a Scale Standard Deviation 7.27	36.22 Units on a Scale Standard Deviation 8.94	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	34.50 Units on a Scale Standard Deviation 8.27	35.59 Units on a Scale Standard Deviation 7.65	35.57 Units on a Scale Standard Deviation 9.35	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	35.29 Units on a Scale Standard Deviation 8.32	35.32 Units on a Scale Standard Deviation 7.73	35.35 Units on a Scale Standard Deviation 9.49	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	35.76 Units on a Scale Standard Deviation 8.27	35.29 Units on a Scale Standard Deviation 8.03	35.12 Units on a Scale Standard Deviation 9.68	—
Mean Baseline Bodily Pain Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=17, 18, 16)	35.75 Units on a Scale Standard Deviation 7.82	37.72 Units on a Scale Standard Deviation 8.69	38.83 Units on a Scale Standard Deviation 9.60	—

SECONDARY outcome

Timeframe: BL (Day 0); Day 360; Day 720; Day 1,080; Day 1,440; Day 1,800; Day 2,160; Day 2,520; Day 2,880; Day 3,060

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	9.26 Units on a Scale Standard Error 1.07	4.12 Units on a Scale Standard Error 1.13	10.35 Units on a Scale Standard Error 1.14	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	9.40 Units on a Scale Standard Error 1.33	9.17 Units on a Scale Standard Error 1.42	8.84 Units on a Scale Standard Error 1.36	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 1,080 (n=64, 50, 49)	9.67 Units on a Scale Standard Error 1.55	9.48 Units on a Scale Standard Error 1.59	9.02 Units on a Scale Standard Error 1.35	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 1,440 (n=60, 46, 44)	11.38 Units on a Scale Standard Error 1.59	10.86 Units on a Scale Standard Error 1.61	9.54 Units on a Scale Standard Error 1.37	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 1,800 (n=54, 43, 42)	8.73 Units on a Scale Standard Error 1.62	10.03 Units on a Scale Standard Error 1.64	9.08 Units on a Scale Standard Error 1.50	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 2,160 (n=45, 36, 35)	12.11 Units on a Scale Standard Error 1.66	10.83 Units on a Scale Standard Error 1.74	10.27 Units on a Scale Standard Error 1.83	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 2,520 (n=38, 35, 33)	10.55 Units on a Scale Standard Error 1.61	10.11 Units on a Scale Standard Error 1.76	10.97 Units on a Scale Standard Error 1.90	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 2,880 (n=33, 30, 31)	10.08 Units on a Scale Standard Error 1.66	10.86 Units on a Scale Standard Error 1.86	11.68 Units on a Scale Standard Error 1.99	—
Mean Change From BL in the Bodily Pain Domain of the SF-36 Over Time in OL Period Change from BL at Day 3,060 (n=17, 18, 16)	6.45 Units on a Scale Standard Error 2.85	10.52 Units on a Scale Standard Error 3.15	9.28 Units on a Scale Standard Error 3.77	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 360 cohort (n=84, 67, 66)	35.87 Units on a Scale Standard Deviation 9.23	37.45 Units on a Scale Standard Deviation 9.01	37.11 Units on a Scale Standard Deviation 9.23	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 720 cohort (n=73, 56, 53)	35.61 Units on a Scale Standard Deviation 8.96	38.06 Units on a Scale Standard Deviation 8.26	37.36 Units on a Scale Standard Deviation 9.30	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 1,080 cohort (n=64, 50, 49)	35.78 Units on a Scale Standard Deviation 9.13	37.45 Units on a Scale Standard Deviation 8.37	37.55 Units on a Scale Standard Deviation 9.38	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 1,440 cohort (n=60, 46, 44)	35.67 Units on a Scale Standard Deviation 8.88	37.64 Units on a Scale Standard Deviation 8.60	37.41 Units on a Scale Standard Deviation 9.12	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 1,800 cohort (n=54, 43, 42)	35.60 Units on a Scale Standard Deviation 8.98	37.78 Units on a Scale Standard Deviation 8.59	38.08 Units on a Scale Standard Deviation 9.75	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 2,160 cohort (n=45, 37, 35)	35.69 Units on a Scale Standard Deviation 8.85	36.93 Units on a Scale Standard Deviation 8.65	38.81 Units on a Scale Standard Deviation 9.94	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 2,520 cohort (n=38, 36, 33)	36.17 Units on a Scale Standard Deviation 9.40	36.98 Units on a Scale Standard Deviation 8.50	39.25 Units on a Scale Standard Deviation 10.40	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 2,880 cohort (n=33, 30, 31)	35.39 Units on a Scale Standard Deviation 8.54	36.57 Units on a Scale Standard Deviation 8.54	40.09 Units on a Scale Standard Deviation 10.49	—
Mean BL General Health Domain of the SF-36 Over Time in OL Period BL (Day 0) for Day 3,060 cohort (n=18, 18, 16)	33.88 Units on a Scale Standard Deviation 8.58	36.84 Units on a Scale Standard Deviation 9.18	41.37 Units on a Scale Standard Deviation 11.49	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n=the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	6.08 Units on a Scale Standard Error 1.05	3.48 Units on a Scale Standard Error 0.71	6.98 Units on a Scale Standard Error 0.90	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	5.99 Units on a Scale Standard Error 1.24	5.09 Units on a Scale Standard Error 0.96	5.96 Units on a Scale Standard Error 1.06	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=64, 50, 49)	6.27 Units on a Scale Standard Error 1.07	5.63 Units on a Scale Standard Error 1.05	6.18 Units on a Scale Standard Error 1.12	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=60, 46, 44)	8.01 Units on a Scale Standard Error 0.91	4.80 Units on a Scale Standard Error 1.17	5.84 Units on a Scale Standard Error 1.12	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	6.87 Units on a Scale Standard Error 1.26	3.97 Units on a Scale Standard Error 1.25	6.52 Units on a Scale Standard Error 1.25	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 37, 35)	8.73 Units on a Scale Standard Error 1.30	5.38 Units on a Scale Standard Error 1.56	5.27 Units on a Scale Standard Error 1.40	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 36, 33)	6.51 Units on a Scale Standard Error 1.21	5.38 Units on a Scale Standard Error 1.43	6.42 Units on a Scale Standard Error 1.85	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	8.67 Units on a Scale Standard Error 1.45	5.61 Units on a Scale Standard Error 1.30	6.37 Units on a Scale Standard Error 2.05	—
Mean Change From Baseline (BL) in the General Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=18, 18, 16)	6.82 Units on a Scale Standard Error 2.21	3.88 Units on a Scale Standard Error 1.46	5.09 Units on a Scale Standard Error 2.73	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n = the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 66)	40.68 Units on a Scale Standard Deviation 8.84	42.49 Units on a Scale Standard Deviation 9.81	41.17 Units on a Scale Standard Deviation 8.29	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 55, 53)	41.22 Units on a Scale Standard Deviation 8.25	43.25 Units on a Scale Standard Deviation 9.84	41.15 Units on a Scale Standard Deviation 8.29	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=63, 50, 49)	41.72 Units on a Scale Standard Deviation 8.56	42.58 Units on a Scale Standard Deviation 9.81	40.65 Units on a Scale Standard Deviation 8.24	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=59, 46, 44)	41.85 Units on a Scale Standard Deviation 8.81	43.08 Units on a Scale Standard Deviation 9.81	40.84 Units on a Scale Standard Deviation 8.17	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	41.40 Units on a Scale Standard Deviation 8.72	43.42 Units on a Scale Standard Deviation 9.83	41.09 Units on a Scale Standard Deviation 8.27	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 37, 35)	40.93 Units on a Scale Standard Deviation 8.65	42.77 Units on a Scale Standard Deviation 10.04	41.66 Units on a Scale Standard Deviation 8.59	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 36, 33)	41.43 Units on a Scale Standard Deviation 9.26	42.74 Units on a Scale Standard Deviation 9.64	41.66 Units on a Scale Standard Deviation 9.03	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	40.22 Units on a Scale Standard Deviation 8.22	42.34 Units on a Scale Standard Deviation 9.57	42.12 Units on a Scale Standard Deviation 8.80	—
Mean Baseline Vitality Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=18, 17, 16)	41.12 Units on a Scale Standard Deviation 7.29	42.40 Units on a Scale Standard Deviation 9.20	44.06 Units on a Scale Standard Deviation 8.66	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 37, 35)	7.10 Units on a Scale Standard Error 1.18	4.60 Units on a Scale Standard Error 1.96	8.15 Units on a Scale Standard Error 1.53	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	6.33 Units on a Scale Standard Error 1.14	3.49 Units on a Scale Standard Error 1.70	7.44 Units on a Scale Standard Error 1.41	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	4.91 Units on a Scale Standard Error 1.03	1.86 Units on a Scale Standard Error 1.04	8.50 Units on a Scale Standard Error 1.02	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 55, 53)	6.20 Units on a Scale Standard Error 1.27	4.69 Units on a Scale Standard Error 1.20	7.77 Units on a Scale Standard Error 1.01	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=63, 50, 49)	6.30 Units on a Scale Standard Error 1.16	6.46 Units on a Scale Standard Error 1.23	7.73 Units on a Scale Standard Error 1.18	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=59, 46, 44)	7.61 Units on a Scale Standard Error 1.23	4.73 Units on a Scale Standard Error 1.62	6.00 Units on a Scale Standard Error 1.25	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 36, 33)	6.86 Units on a Scale Standard Error 1.21	3.82 Units on a Scale Standard Error 2.03	6.64 Units on a Scale Standard Error 1.98	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	7.10 Units on a Scale Standard Error 1.34	4.76 Units on a Scale Standard Error 1.70	6.65 Units on a Scale Standard Error 1.86	—
Mean Change From Baseline (BL) in the Vitality Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=18, 17, 16)	6.68 Units on a Scale Standard Error 2.21	3.99 Units on a Scale Standard Error 2.34	4.60 Units on a Scale Standard Error 3.02	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n =the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 66)	34.45 Units on a Scale Standard Deviation 10.52	38.14 Units on a Scale Standard Deviation 10.91	38.59 Units on a Scale Standard Deviation 10.99	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 56, 53)	35.04 Units on a Scale Standard Deviation 9.81	39.11 Units on a Scale Standard Deviation 10.74	39.37 Units on a Scale Standard Deviation 11.13	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=64, 50, 49)	34.77 Units on a Scale Standard Deviation 9.22	39.08 Units on a Scale Standard Deviation 10.71	38.99 Units on a Scale Standard Deviation 11.04	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=60, 46, 44)	35.19 Units on a Scale Standard Deviation 9.36	38.88 Units on a Scale Standard Deviation 11.05	38.77 Units on a Scale Standard Deviation 11.04	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	34.92 Units on a Scale Standard Deviation 9.54	39.04 Units on a Scale Standard Deviation 11.03	38.84 Units on a Scale Standard Deviation 11.52	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	35.42 Units on a Scale Standard Deviation 9.54	38.06 Units on a Scale Standard Deviation 10.97	39.16 Units on a Scale Standard Deviation 11.45	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	35.11 Units on a Scale Standard Deviation 9.85	38.88 Units on a Scale Standard Deviation 10.93	39.42 Units on a Scale Standard Deviation 11.82	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	36.33 Units on a Scale Standard Deviation 8.80	38.40 Units on a Scale Standard Deviation 10.75	39.54 Units on a Scale Standard Deviation 12.14	—
Mean Baseline Social Functioning Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=17, 18, 16)	36.33 Units on a Scale Standard Deviation 8.78	38.82 Units on a Scale Standard Deviation 12.52	42.77 Units on a Scale Standard Deviation 11.66	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n = the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	8.02 Units on a Scale Standard Error 1.11	4.44 Units on a Scale Standard Error 1.12	8.47 Units on a Scale Standard Error 1.25	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	8.43 Units on a Scale Standard Error 1.35	6.86 Units on a Scale Standard Error 1.28	6.62 Units on a Scale Standard Error 1.39	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=64, 50, 49)	8.25 Units on a Scale Standard Error 1.05	7.87 Units on a Scale Standard Error 1.38	5.94 Units on a Scale Standard Error 1.20	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=60, 46, 44)	9.56 Units on a Scale Standard Error 1.39	8.02 Units on a Scale Standard Error 1.82	6.24 Units on a Scale Standard Error 1.51	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	6.69 Units on a Scale Standard Error 1.56	6.59 Units on a Scale Standard Error 1.86	8.65 Units on a Scale Standard Error 1.49	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 36, 35)	9.95 Units on a Scale Standard Error 1.29	7.13 Units on a Scale Standard Error 2.08	9.53 Units on a Scale Standard Error 1.58	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 35, 33)	10.70 Units on a Scale Standard Error 1.40	5.76 Units on a Scale Standard Error 2.19	5.00 Units on a Scale Standard Error 2.24	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	6.69 Units on a Scale Standard Error 1.70	5.25 Units on a Scale Standard Error 1.93	7.90 Units on a Scale Standard Error 1.99	—
Mean Change From Baseline (BL) in the Social Functioning Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=17, 18, 16)	6.03 Units on a Scale Standard Error 2.23	4.07 Units on a Scale Standard Error 3.03	6.07 Units on a Scale Standard Error 2.98	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 64)	36.63 Units on a Scale Standard Deviation 14.30	38.88 Units on a Scale Standard Deviation 14.28	40.29 Units on a Scale Standard Deviation 14.09	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 56, 53)	36.15 Units on a Scale Standard Deviation 14.08	38.84 Units on a Scale Standard Deviation 14.68	40.19 Units on a Scale Standard Deviation 14.04	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=64, 50, 49)	37.01 Units on a Scale Standard Deviation 14.09	39.43 Units on a Scale Standard Deviation 14.76	39.21 Units on a Scale Standard Deviation 13.92	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=60, 46, 44)	37.48 Units on a Scale Standard Deviation 14.02	39.30 Units on a Scale Standard Deviation 14.81	38.84 Units on a Scale Standard Deviation 13.90	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	36.97 Units on a Scale Standard Deviation 14.19	39.29 Units on a Scale Standard Deviation 14.76	38.76 Units on a Scale Standard Deviation 13.97	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 36, 35)	37.78 Units on a Scale Standard Deviation 14.02	39.09 Units on a Scale Standard Deviation 14.97	38.72 Units on a Scale Standard Deviation 14.29	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 2520 cohort (n=38, 35, 33)	37.88 Units on a Scale Standard Deviation 14.21	40.34 Units on a Scale Standard Deviation 14.67	39.54 Units on a Scale Standard Deviation 14.85	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	36.73 Units on a Scale Standard Deviation 14.29	39.37 Units on a Scale Standard Deviation 14.62	38.10 Units on a Scale Standard Deviation 14.62	—
Mean Baseline Role-Emotional Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=17, 18, 16)	37.78 Units on a Scale Standard Deviation 14.45	44.15 Units on a Scale Standard Deviation 14.12	40.47 Units on a Scale Standard Deviation 14.93	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n = the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 64)	7.55 Units on a Scale Standard Error 2.05	3.79 Units on a Scale Standard Error 1.94	8.03 Units on a Scale Standard Error 1.58	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 56, 53)	8.28 Units on a Scale Standard Error 2.29	6.36 Units on a Scale Standard Error 1.97	6.93 Units on a Scale Standard Error 1.68	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=64, 50, 49)	4.64 Units on a Scale Standard Error 2.24	7.95 Units on a Scale Standard Error 2.27	5.76 Units on a Scale Standard Error 1.88	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=60, 46, 44)	8.24 Units on a Scale Standard Error 2.31	7.18 Units on a Scale Standard Error 2.56	6.67 Units on a Scale Standard Error 1.86	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	4.16 Units on a Scale Standard Error 2.48	4.51 Units on a Scale Standard Error 2.19	7.41 Units on a Scale Standard Error 2.04	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 36, 35)	7.61 Units on a Scale Standard Error 2.40	6.47 Units on a Scale Standard Error 2.87	7.84 Units on a Scale Standard Error 2.16	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 35, 33)	8.43 Units on a Scale Standard Error 2.92	5.75 Units on a Scale Standard Error 2.64	5.82 Units on a Scale Standard Error 2.34	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	8.78 Units on a Scale Standard Error 2.32	4.76 Units on a Scale Standard Error 3.04	8.94 Units on a Scale Standard Error 2.72	—
Mean Change From Baseline (BL) in the Role-Emotional Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=17, 18, 16)	5.85 Units on a Scale Standard Error 3.92	0.66 Units on a Scale Standard Error 4.66	9.92 Units on a Scale Standard Error 4.09	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Population: All treated OL participants. Participants were grouped according to the treatment they received in the DB study. n = the number of participants with measurements for that time point.

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 360 cohort (n=84, 67, 66)	41.29 Units on a Scale Standard Deviation 12.28	42.35 Units on a Scale Standard Deviation 11.62	44.66 Units on a Scale Standard Deviation 11.94	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 720 cohort (n=73, 55, 53)	40.49 Units on a Scale Standard Deviation 12.72	41.99 Units on a Scale Standard Deviation 11.58	44.53 Units on a Scale Standard Deviation 12.19	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 1080 cohort (n=63, 50, 49)	40.81 Units on a Scale Standard Deviation 12.66	41.44 Units on a Scale Standard Deviation 11.55	44.13 Units on a Scale Standard Deviation 11.82	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 1440 cohort (n=59, 46, 44)	41.11 Units on a Scale Standard Deviation 12.61	41.60 Units on a Scale Standard Deviation 11.77	44.24 Units on a Scale Standard Deviation 11.09	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 1800 cohort (n=54, 43, 42)	40.78 Units on a Scale Standard Deviation 12.39	41.50 Units on a Scale Standard Deviation 11.78	44.13 Units on a Scale Standard Deviation 11.14	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 2160 cohort (n=45, 37, 35)	40.50 Units on a Scale Standard Deviation 12.17	40.89 Units on a Scale Standard Deviation 11.05	44.79 Units on a Scale Standard Deviation 11.18	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baselinefor Day 2520 cohort (n=38, 36, 33)	42.05 Units on a Scale Standard Deviation 12.54	41.06 Units on a Scale Standard Deviation 11.44	45.54 Units on a Scale Standard Deviation 11.10	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 2880 cohort (n=33, 30, 31)	39.77 Units on a Scale Standard Deviation 10.76	40.24 Units on a Scale Standard Deviation 10.92	44.87 Units on a Scale Standard Deviation 9.92	—
Mean Baseline Mental Health Domain of the SF-36 Over Time in OL Period Baseline for Day 3060 cohort (n=18, 17, 16)	39.49 Units on a Scale Standard Deviation 11.62	40.18 Units on a Scale Standard Deviation 12.07	44.89 Units on a Scale Standard Deviation 11.85	—

SECONDARY outcome

Timeframe: Baseline (Day 0) and Days 360, 720, 1080, 1440, 1800, 2160, 2520, 2880, and 3060

Outcome measures

Outcome measures
Measure	OL Abatacept: Original 2 mg/kg n=68 Participants Participants in the DBperiod received a weight-tiered dose of 2 mg/kg of abatacept administered monthly by IV infusion over approximately weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original Placebo n=67 Participants Participants in the DB period received a placebo administered monthly by IV infusion over approximately 30 minutes. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	OL Abatacept: Original 10 mg /kg n=84 Participants Participants in the DB period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by IV infusion over approximately 30 minutes. Participants weighing \<60 kg received abatacept 500 mg, participants weighing ≥60 kg and ≤100 kg received abatacept 750 mg, and participants \>100 kg received abatacept 1 g. Participants in the present study received an OL weight-tiered dose of abatacept 10 mg/kg.	Open-Label (OL) Abatacept (10 mg / kg) Following a 5-month interim (where the placebo group was split into 2mg/kg abatacept or placebo and participants in 2 original abatacept continued at same dose), participants who enrolled in OL period received a weight-tiered dose of 10 mg/kg of abatacept that was administered monthly by an intravenous (IV) infusion over approximately 30 minutes. Participants weighing \< 60 kg received abatacept 500 mg, participants weighing ≥ 60 kg and ≤ 100 kg received abatacept 750 mg, and participants \> 100 kg received abatacept 1 g.
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 3060 (n=18, 17, 16)	4.68 Units on a Scale Standard Error 2.59	6.99 Units on a Scale Standard Error 2.68	2.65 Units on a Scale Standard Error 2.35	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 360 (n=84, 67, 66)	5.74 Units on a Scale Standard Error 1.14	2.60 Units on a Scale Standard Error 1.13	5.41 Units on a Scale Standard Error 1.10	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 720 (n=73, 55, 53)	5.49 Units on a Scale Standard Error 1.29	4.59 Units on a Scale Standard Error 1.50	4.22 Units on a Scale Standard Error 1.18	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1080 (n=63, 50, 49)	5.41 Units on a Scale Standard Error 1.48	5.54 Units on a Scale Standard Error 1.59	4.62 Units on a Scale Standard Error 1.03	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1440 (n=59, 46, 44)	5.96 Units on a Scale Standard Error 1.24	5.59 Units on a Scale Standard Error 1.93	4.81 Units on a Scale Standard Error 1.14	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 1800 (n=54, 43, 42)	5.44 Units on a Scale Standard Error 1.45	3.15 Units on a Scale Standard Error 1.80	4.47 Units on a Scale Standard Error 1.34	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2160 (n=45, 37, 35)	5.96 Units on a Scale Standard Error 1.26	5.29 Units on a Scale Standard Error 1.94	5.82 Units on a Scale Standard Error 1.33	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2520 (n=38, 36, 33)	6.06 Units on a Scale Standard Error 1.50	6.33 Units on a Scale Standard Error 1.94	3.15 Units on a Scale Standard Error 1.92	—
Mean Change From Baseline (BL) in the Mental Health Domain of the SF-36 Over Time in OL Period Change from BL at Day 2880 (n=33, 30, 31)	6.30 Units on a Scale Standard Error 1.60	6.78 Units on a Scale Standard Error 1.98	4.96 Units on a Scale Standard Error 1.71	—

Adverse Events

Aba 10mg/kg+MTX

Serious events: 17 serious events

Other events: 96 other events

Deaths: 0 deaths

Aba 2mg/kg+MTX

Serious events: 19 serious events

Other events: 98 other events

Deaths: 0 deaths

Abatacept (LT)

Serious events: 117 serious events

Other events: 200 other events

Deaths: 0 deaths

Placebo+MTX

Serious events: 21 serious events

Other events: 108 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Aba 10mg/kg+MTX n=115 participants at risk	Aba 2mg/kg+MTX n=105 participants at risk	Abatacept (LT) n=219 participants at risk	Placebo+MTX n=119 participants at risk
Nervous system disorders CEREBRAL ARTERY EMBOLISM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Eye disorders IRITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Investigations ARTHROSCOPY	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Investigations SLEEP STUDY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Investigations INVESTIGATION	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Investigations VASCULAR TEST	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Investigations ARTERIOGRAM CORONARY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Investigations HAEMOGLOBIN DECREASED	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders TACHYCARDIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders PERICARDITIS	0.00% 0/115	0.95% 1/105	0.91% 2/219	0.00% 0/119
Cardiac disorders ANGINA PECTORIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.84% 1/119
Cardiac disorders ANGINA UNSTABLE	0.87% 1/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders CARDIAC ANEURYSM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders PLEUROPERICARDITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders ATRIAL FIBRILLATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders PERICARDIAL EFFUSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders MYOCARDIAL INFARCTION	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.84% 1/119
Cardiac disorders ACUTE CORONARY SYNDROME	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders CARDIOPULMONARY FAILURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders CORONARY ARTERY DISEASE	0.87% 1/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Cardiac disorders LEFT VENTRICULAR FAILURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders AORTIC VALVE INCOMPETENCE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders CARDIAC FAILURE CONGESTIVE	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.84% 1/119
Cardiac disorders ACUTE MYOCARDIAL INFARCTION	0.87% 1/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Cardiac disorders SUPRAVENTRICULAR TACHYCARDIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.84% 1/119
Cardiac disorders ATRIOVENTRICULAR BLOCK COMPLETE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders EMBOLISM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders HAEMATOMA	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Vascular disorders THROMBOSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders HYPERTENSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders AORTIC ANEURYSM	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Vascular disorders DEEP VEIN THROMBOSIS	0.00% 0/115	0.00% 0/105	1.8% 4/219	0.00% 0/119
Vascular disorders AORTIC ANEURYSM RUPTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders THROMBOPHLEBITIS SUPERFICIAL	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders SUPERIOR VENA CAVAL OCCLUSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Vascular disorders PERIPHERAL ARTERIAL OCCLUSIVE DISEASE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Social circumstances JOINT PROSTHESIS USER	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Psychiatric disorders ANXIETY	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Psychiatric disorders MAJOR DEPRESSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Psychiatric disorders MENTAL STATUS CHANGES	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Hepatobiliary disorders BILIARY COLIC	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Hepatobiliary disorders CHOLELITHIASIS	0.87% 1/115	0.00% 0/105	1.8% 4/219	0.00% 0/119
Hepatobiliary disorders CHOLECYSTITIS ACUTE	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Immune system disorders POLYARTERITIS NODOSA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders SYNCOPE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders SCIATICA	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Nervous system disorders DIZZINESS	0.00% 0/115	0.95% 1/105	0.46% 1/219	0.00% 0/119
Nervous system disorders CONVULSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders HYPOAESTHESIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders RADICULOPATHY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders RADICULAR PAIN	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders PARTIAL SEIZURES	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders MULTIPLE SCLEROSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders SPINAL CORD COMPRESSION	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Nervous system disorders CEREBROVASCULAR ACCIDENT	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Nervous system disorders TRANSIENT GLOBAL AMNESIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Nervous system disorders CEREBELLAR ARTERY THROMBOSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders COLITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders VOMITING	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.84% 1/119
Gastrointestinal disorders HAEMORRHOIDS	0.00% 0/115	0.95% 1/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders GASTRIC ULCER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders ABDOMINAL MASS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Gastrointestinal disorders ABDOMINAL PAIN	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Gastrointestinal disorders DUODENAL ULCER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders INGUINAL HERNIA	0.00% 0/115	0.95% 1/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders UMBILICAL HERNIA	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Gastrointestinal disorders PANCREATITIS ACUTE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders RECTAL HAEMORRHAGE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders HERNIAL EVENTRATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders ABDOMINAL DISTENSION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders OESOPHAGEAL STENOSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders PANCREATITIS CHRONIC	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders MALLORY-WEISS SYNDROME	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders GASTROINTESTINAL DISORDER	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Gastrointestinal disorders RETROPERITONEAL HAEMATOMA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Gastrointestinal disorders DUODENAL ULCER HAEMORRHAGE	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Gastrointestinal disorders UMBILICAL HERNIA, OBSTRUCTIVE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Ear and labyrinth disorders VERTIGO	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations SEPSIS	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Infections and infestations ABSCESS	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Infections and infestations CYSTITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations VIRAEMIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations PNEUMONIA	0.00% 0/115	0.00% 0/105	3.7% 8/219	0.84% 1/119
Infections and infestations SINUSITIS	0.00% 0/115	0.95% 1/105	0.46% 1/219	0.00% 0/119
Infections and infestations BRONCHITIS	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Infections and infestations CELLULITIS	0.00% 0/115	0.95% 1/105	0.46% 1/219	0.00% 0/119
Infections and infestations ERYSIPELAS	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Infections and infestations OSTEOMYELITIS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Infections and infestations DIVERTICULITIS	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Infections and infestations OTITIS EXTERNA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations PYELONEPHRITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations TOOTH INFECTION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations BRONCHOPNEUMONIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations AMOEBIC DYSENTERY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations ESCHERICHIA SEPSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations ARTHRITIS BACTERIAL	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Infections and infestations ARTHRITIS INFECTIVE	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Infections and infestations INFECTED SKIN ULCER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations LOCALISED INFECTION	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Infections and infestations EYE INFECTION FUNGAL	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations PNEUMONIA HAEMOPHILUS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations ABDOMINAL WALL ABSCESS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations PERICARDITIS INFECTIVE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations INTERVERTEBRAL DISCITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations URINARY TRACT INFECTION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations BACTERIAL PYELONEPHRITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations DEVICE RELATED INFECTION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Infections and infestations POST PROCEDURAL INFECTION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Renal and urinary disorders PROTEINURIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Renal and urinary disorders RENAL FAILURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Renal and urinary disorders RENAL IMPAIRMENT	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures ANGIOPLASTY	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Surgical and medical procedures ARTHRODESIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures POLYPECTOMY	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Surgical and medical procedures SYNOVECTOMY	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.84% 1/119
Surgical and medical procedures CYST REMOVAL	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Surgical and medical procedures TENDON GRAFT	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Surgical and medical procedures STERILISATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures FOOT OPERATION	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Surgical and medical procedures KNEE OPERATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures BUNION OPERATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures HIP ARTHROPLASTY	0.87% 1/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Surgical and medical procedures KNEE ARTHROPLASTY	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.84% 1/119
Surgical and medical procedures JOINT ARTHROPLASTY	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Surgical and medical procedures CHOLESTEATOMA REMOVAL	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Surgical and medical procedures CORONARY ARTERY BYPASS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Surgical and medical procedures MITRAL VALVE REPLACEMENT	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Metabolism and nutrition disorders GOUT	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Metabolism and nutrition disorders DEHYDRATION	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Metabolism and nutrition disorders DIABETIC FOOT	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Metabolism and nutrition disorders HYPERNATRAEMIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Metabolism and nutrition disorders DIABETES MELLITUS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Metabolism and nutrition disorders HYPOPHOSPHATAEMIA	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Metabolism and nutrition disorders METABOLIC ACIDOSIS	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Metabolism and nutrition disorders DIABETIC KETOACIDOSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Metabolism and nutrition disorders TYPE 2 DIABETES MELLITUS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Metabolism and nutrition disorders DIABETES MELLITUS INADEQUATE CONTROL	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Blood and lymphatic system disorders ANAEMIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Blood and lymphatic system disorders LEUKOPENIA	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Blood and lymphatic system disorders LEUKOCYTOSIS	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Blood and lymphatic system disorders LYMPHOID TISSUE HYPERPLASIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Skin and subcutaneous tissue disorders RASH	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Skin and subcutaneous tissue disorders PSORIASIS	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Reproductive system and breast disorders MENORRHAGIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Reproductive system and breast disorders EPIDIDYMITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Reproductive system and breast disorders MENOMETRORRHAGIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Reproductive system and breast disorders SCROTAL SWELLING	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Reproductive system and breast disorders VAGINAL HAEMORRHAGE	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Injury, poisoning and procedural complications WOUND	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications OVERDOSE	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Injury, poisoning and procedural complications LIMB INJURY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications HIP FRACTURE	0.00% 0/115	0.00% 0/105	1.8% 4/219	0.84% 1/119
Injury, poisoning and procedural complications FEMUR FRACTURE	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Injury, poisoning and procedural complications MUSCLE RUPTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications TENDON RUPTURE	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Injury, poisoning and procedural complications WRIST FRACTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications DEVICE BREAKAGE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications PELVIC FRACTURE	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Injury, poisoning and procedural complications PROCEDURAL PAIN	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Injury, poisoning and procedural complications RADIUS FRACTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications SPINAL FRACTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications FRACTURED SACRUM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications JOINT DISLOCATION	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Injury, poisoning and procedural complications MULTIPLE FRACTURES	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications BURNS SECOND DEGREE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications PUBIC RAMI FRACTURE	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Injury, poisoning and procedural complications FEMORAL NECK FRACTURE	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Injury, poisoning and procedural complications ROAD TRAFFIC ACCIDENT	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications DISLOCATION OF VERTEBRA	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Injury, poisoning and procedural complications ABDOMINAL WOUND DEHISCENCE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications MEDICAL DEVICE COMPLICATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications POST PROCEDURAL HAEMORRHAGE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications POST PROCEDURAL COMPLICATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Injury, poisoning and procedural complications DISLOCATION OF JOINT PROSTHESIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders BURSITIS	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Musculoskeletal and connective tissue disorders ARTHRITIS	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Musculoskeletal and connective tissue disorders BACK PAIN	0.00% 0/115	0.00% 0/105	1.8% 4/219	0.00% 0/119
Musculoskeletal and connective tissue disorders SYNOVITIS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Musculoskeletal and connective tissue disorders ARTHRALGIA	0.00% 0/115	0.00% 0/105	2.7% 6/219	0.00% 0/119
Musculoskeletal and connective tissue disorders GROIN PAIN	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders ARTHROPATHY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders TENOSYNOVITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders FOOT DEFORMITY	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Musculoskeletal and connective tissue disorders JOINT SWELLING	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders LIMB DEFORMITY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders OSTEOARTHRITIS	0.00% 0/115	0.00% 0/105	3.2% 7/219	0.00% 0/119
Musculoskeletal and connective tissue disorders TENDON DISORDER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders FINGER DEFORMITY	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders JOINT DESTRUCTION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders MUSCULAR WEAKNESS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders PAIN IN EXTREMITY	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Musculoskeletal and connective tissue disorders RHEUMATOID NODULE	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Musculoskeletal and connective tissue disorders MUSCULOSKELETAL PAIN	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders RHEUMATOID ARTHRITIS	0.00% 0/115	0.95% 1/105	8.2% 18/219	1.7% 2/119
Musculoskeletal and connective tissue disorders OSTEOPOROTIC FRACTURE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders ROTATOR CUFF SYNDROME	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.84% 1/119
Musculoskeletal and connective tissue disorders MUSCULOSKELETAL DISORDER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Musculoskeletal and connective tissue disorders INTERVERTEBRAL DISC PROTRUSION	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Musculoskeletal and connective tissue disorders INTERVERTEBRAL DISC DEGENERATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders COUGH	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders ASTHMA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.84% 1/119
Respiratory, thoracic and mediastinal disorders DYSPNOEA	0.87% 1/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders PLEURISY	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders HAEMOPTYSIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders PNEUMONITIS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders LUNG DISORDER	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders PLEURAL EFFUSION	0.00% 0/115	0.95% 1/105	1.4% 3/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders THROAT TIGHTNESS	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders PULMONARY EMBOLISM	0.87% 1/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders PULMONARY FIBROSIS	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders RESPIRATORY DISTRESS	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Respiratory, thoracic and mediastinal disorders CHRONIC OBSTRUCTIVE PULMONARY DISEASE	0.00% 0/115	0.00% 0/105	0.91% 2/219	0.00% 0/119
General disorders DEATH	0.00% 0/115	0.95% 1/105	0.00% 0/219	0.00% 0/119
General disorders HERNIA	0.87% 1/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
General disorders PYREXIA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
General disorders CHEST PAIN	0.87% 1/115	3.8% 4/105	0.91% 2/219	0.00% 0/119
General disorders SUDDEN DEATH	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
General disorders CHEST DISCOMFORT	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
General disorders IMPAIRED HEALING	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
General disorders GENERAL PHYSICAL HEALTH DETERIORATION	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BREAST CANCER	0.00% 0/115	0.00% 0/105	1.4% 3/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) LUNG NEOPLASM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BLADDER CANCER	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) OVARIAN CANCER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BOWEN'S DISEASE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) PROSTATE CANCER	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) NEOPLASM PROSTATE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) ENDOMETRIAL CANCER	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) MALIGNANT MELANOMA	0.00% 0/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) LIGHT CHAIN DISEASE	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) LUNG ADENOCARCINOMA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BASAL CELL CARCINOMA	0.87% 1/115	0.00% 0/105	2.3% 5/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) LUNG CANCER METASTATIC	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) LUNG NEOPLASM MALIGNANT	0.87% 1/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) SQUAMOUS CELL CARCINOMA	0.00% 0/115	0.00% 0/105	1.8% 4/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BENIGN SALIVARY GLAND NEOPLASM	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) SQUAMOUS CELL CARCINOMA OF SKIN	0.87% 1/115	0.00% 0/105	0.00% 0/219	0.84% 1/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BLADDER TRANSITIONAL CELL CARCINOMA	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119
Neoplasms benign, malignant and unspecified (incl cysts and polyps) SMALL CELL LUNG CANCER STAGE UNSPECIFIED	0.00% 0/115	0.00% 0/105	0.46% 1/219	0.00% 0/119

Other adverse events

Other adverse events
Measure	Aba 10mg/kg+MTX n=115 participants at risk	Aba 2mg/kg+MTX n=105 participants at risk	Abatacept (LT) n=219 participants at risk	Placebo+MTX n=119 participants at risk
Eye disorders CATARACT	0.87% 1/115	0.95% 1/105	8.7% 19/219	2.5% 3/119
Eye disorders CONJUNCTIVITIS	2.6% 3/115	1.9% 2/105	8.2% 18/219	1.7% 2/119
Investigations ALANINE AMINOTRANSFERASE INCREASED	0.87% 1/115	3.8% 4/105	5.9% 13/219	3.4% 4/119
Vascular disorders HYPERTENSION	7.0% 8/115	11.4% 12/105	20.5% 45/219	7.6% 9/119
Psychiatric disorders ANXIETY	2.6% 3/115	0.95% 1/105	10.5% 23/219	2.5% 3/119
Psychiatric disorders INSOMNIA	4.3% 5/115	2.9% 3/105	7.8% 17/219	3.4% 4/119
Psychiatric disorders DEPRESSION	2.6% 3/115	2.9% 3/105	13.7% 30/219	7.6% 9/119
Nervous system disorders HEADACHE	13.9% 16/115	16.2% 17/105	19.6% 43/219	16.0% 19/119
Nervous system disorders SCIATICA	0.87% 1/115	0.00% 0/105	9.1% 20/219	0.00% 0/119
Nervous system disorders DIZZINESS	5.2% 6/115	4.8% 5/105	14.6% 32/219	2.5% 3/119
Nervous system disorders PARAESTHESIA	1.7% 2/115	0.95% 1/105	6.8% 15/219	3.4% 4/119
Nervous system disorders HYPOAESTHESIA	1.7% 2/115	3.8% 4/105	5.9% 13/219	0.84% 1/119
Gastrointestinal disorders NAUSEA	13.9% 16/115	11.4% 12/105	12.8% 28/219	14.3% 17/119
Gastrointestinal disorders VOMITING	3.5% 4/115	3.8% 4/105	8.2% 18/219	7.6% 9/119
Gastrointestinal disorders DIARRHOEA	12.2% 14/115	10.5% 11/105	18.3% 40/219	7.6% 9/119
Gastrointestinal disorders DYSPEPSIA	6.1% 7/115	11.4% 12/105	14.2% 31/219	5.9% 7/119
Gastrointestinal disorders CONSTIPATION	3.5% 4/115	4.8% 5/105	9.1% 20/219	0.00% 0/119
Gastrointestinal disorders ABDOMINAL PAIN	6.1% 7/115	6.7% 7/105	7.3% 16/219	4.2% 5/119
Gastrointestinal disorders MOUTH ULCERATION	0.87% 1/115	0.95% 1/105	3.2% 7/219	5.9% 7/119
Gastrointestinal disorders ABDOMINAL DISCOMFORT	2.6% 3/115	0.00% 0/105	7.8% 17/219	1.7% 2/119
Gastrointestinal disorders ABDOMINAL PAIN UPPER	1.7% 2/115	2.9% 3/105	9.6% 21/219	2.5% 3/119
Gastrointestinal disorders GASTROOESOPHAGEAL REFLUX DISEASE	0.87% 1/115	0.95% 1/105	5.0% 11/219	2.5% 3/119
Ear and labyrinth disorders VERTIGO	1.7% 2/115	0.95% 1/105	6.4% 14/219	1.7% 2/119
Infections and infestations RHINITIS	1.7% 2/115	0.95% 1/105	8.7% 19/219	0.00% 0/119
Infections and infestations INFLUENZA	4.3% 5/115	2.9% 3/105	10.5% 23/219	5.0% 6/119
Infections and infestations SINUSITIS	4.3% 5/115	6.7% 7/105	22.8% 50/219	8.4% 10/119
Infections and infestations BRONCHITIS	7.8% 9/115	6.7% 7/105	23.3% 51/219	4.2% 5/119
Infections and infestations PHARYNGITIS	2.6% 3/115	1.9% 2/105	9.1% 20/219	2.5% 3/119
Infections and infestations HERPES ZOSTER	2.6% 3/115	1.9% 2/105	11.4% 25/219	0.00% 0/119
Infections and infestations TOOTH ABSCESS	1.7% 2/115	1.9% 2/105	5.0% 11/219	2.5% 3/119
Infections and infestations GASTROENTERITIS	2.6% 3/115	1.9% 2/105	11.9% 26/219	1.7% 2/119
Infections and infestations NASOPHARYNGITIS	14.8% 17/115	18.1% 19/105	34.7% 76/219	9.2% 11/119
Infections and infestations FUNGAL INFECTION	1.7% 2/115	2.9% 3/105	5.5% 12/219	2.5% 3/119
Infections and infestations LOCALISED INFECTION	0.00% 0/115	0.95% 1/105	5.0% 11/219	0.84% 1/119
Infections and infestations URINARY TRACT INFECTION	2.6% 3/115	1.9% 2/105	21.9% 48/219	2.5% 3/119
Infections and infestations LOWER RESPIRATORY TRACT INFECTION	2.6% 3/115	0.95% 1/105	8.2% 18/219	0.84% 1/119
Infections and infestations UPPER RESPIRATORY TRACT INFECTION	11.3% 13/115	9.5% 10/105	26.5% 58/219	7.6% 9/119
Renal and urinary disorders HAEMATURIA	0.00% 0/115	0.95% 1/105	5.9% 13/219	0.00% 0/119
Metabolism and nutrition disorders HYPERCHOLESTEROLAEMIA	0.00% 0/115	0.00% 0/105	5.9% 13/219	0.00% 0/119
Skin and subcutaneous tissue disorders RASH	5.2% 6/115	3.8% 4/105	14.2% 31/219	5.0% 6/119
Skin and subcutaneous tissue disorders ECZEMA	0.87% 1/115	0.95% 1/105	5.9% 13/219	0.00% 0/119
Skin and subcutaneous tissue disorders ERYTHEMA	0.87% 1/115	0.00% 0/105	5.5% 12/219	0.00% 0/119
Skin and subcutaneous tissue disorders PRURITUS	2.6% 3/115	0.95% 1/105	5.0% 11/219	1.7% 2/119
Skin and subcutaneous tissue disorders SKIN LESION	0.00% 0/115	0.95% 1/105	5.0% 11/219	2.5% 3/119
Injury, poisoning and procedural complications FALL	1.7% 2/115	0.00% 0/105	7.3% 16/219	1.7% 2/119
Injury, poisoning and procedural complications CONTUSION	1.7% 2/115	1.9% 2/105	6.8% 15/219	0.84% 1/119
Musculoskeletal and connective tissue disorders BURSITIS	2.6% 3/115	1.9% 2/105	7.8% 17/219	0.84% 1/119
Musculoskeletal and connective tissue disorders ARTHRITIS	3.5% 4/115	2.9% 3/105	3.7% 8/219	5.9% 7/119
Musculoskeletal and connective tissue disorders BACK PAIN	8.7% 10/115	8.6% 9/105	29.7% 65/219	7.6% 9/119
Musculoskeletal and connective tissue disorders NECK PAIN	2.6% 3/115	1.9% 2/105	9.6% 21/219	0.00% 0/119
Musculoskeletal and connective tissue disorders ARTHRALGIA	3.5% 4/115	9.5% 10/105	13.7% 30/219	9.2% 11/119
Musculoskeletal and connective tissue disorders TENDONITIS	0.00% 0/115	2.9% 3/105	7.3% 16/219	0.84% 1/119
Musculoskeletal and connective tissue disorders MUSCLE SPASMS	0.87% 1/115	1.9% 2/105	5.0% 11/219	0.00% 0/119
Musculoskeletal and connective tissue disorders PAIN IN EXTREMITY	0.87% 1/115	2.9% 3/105	8.7% 19/219	3.4% 4/119
Musculoskeletal and connective tissue disorders MUSCULOSKELETAL PAIN	0.00% 0/115	5.7% 6/105	6.8% 15/219	3.4% 4/119
Musculoskeletal and connective tissue disorders RHEUMATOID ARTHRITIS	30.4% 35/115	47.6% 50/105	45.7% 100/219	46.2% 55/119
Respiratory, thoracic and mediastinal disorders COUGH	13.9% 16/115	9.5% 10/105	23.7% 52/219	12.6% 15/119
Respiratory, thoracic and mediastinal disorders DYSPNOEA	2.6% 3/115	2.9% 3/105	7.8% 17/219	5.9% 7/119
Respiratory, thoracic and mediastinal disorders NASAL CONGESTION	1.7% 2/115	0.95% 1/105	5.9% 13/219	1.7% 2/119
Respiratory, thoracic and mediastinal disorders OROPHARYNGEAL PAIN	6.1% 7/115	3.8% 4/105	12.8% 28/219	7.6% 9/119
General disorders FATIGUE	6.1% 7/115	8.6% 9/105	11.9% 26/219	12.6% 15/119
General disorders PYREXIA	2.6% 3/115	0.95% 1/105	5.9% 13/219	0.84% 1/119
General disorders CHEST PAIN	1.7% 2/115	2.9% 3/105	6.4% 14/219	0.84% 1/119
General disorders OEDEMA PERIPHERAL	3.5% 4/115	2.9% 3/105	13.2% 29/219	4.2% 5/119
General disorders INFLUENZA LIKE ILLNESS	0.87% 1/115	1.9% 2/105	5.5% 12/219	1.7% 2/119

Additional Information

BMS Study Director

Bristol-Myers Squibb

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Bristol-Myers Squibb Co. agreements with investigators vary; constant is our right to embargo communications regarding trial results prior to public release for a period ≤60 days from submittal for review. We will not prohibit investigators from publishing, but will prohibit the disclosure of previously undisclosed confidential information other than study results, and request postponement of single-center publications until after disclosure of the clinical trial's primary publication.
Publication restrictions are in place

Restriction type: OTHER