Trial Outcomes & Findings for A Phase III Study of Abatacept in Patients With Rheumatoid Arthritis and an Inadequate Response to Methotrexate (NCT NCT00409838)

NCT ID: NCT00409838

Last Updated: 2013-08-08

Results Overview

The ACR 20 is based on 20% improvement (compared with baseline values) in tender and swollen joint counts and on 20% improvement in 3 of the remaining 5 core set measures (participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function) and 1 acute phase reactant value.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 113 participants
• Primary outcome timeframe: At Day 169
• Results posted on: 2013-08-08

Participant Flow

Participant milestones

Measure	Abatacept, 10 mg/kg Short-term Period: Participants received a body-weight tiered dose of abatacept approximating 10 mg/kg. Study medication was administered intravenously (IV) on Days 1, 15, and 29 and every 28 days thereafter up to and including Day 141 (6-month treatment). Long-term Period: Participants who completed the Short-term Period received treatment with abatacept, administered IV at a weight-tiered dose approximately 10 mg/kg.	Placebo Placebo was administered IV on Days 1, 15, and 29 and every 28 days thereafter up to and including Day 141 (6-month treatment).
Short-term Period STARTED	56	57
Short-term Period Treated (Baseline) Population	55	57
Short-term Period COMPLETED	53	52
Short-term Period NOT COMPLETED	3	5
Long-term Extension Period STARTED	105	0
Long-term Extension Period COMPLETED	87	0
Long-term Extension Period NOT COMPLETED	18	0

Reasons for withdrawal

Measure	Abatacept, 10 mg/kg Short-term Period: Participants received a body-weight tiered dose of abatacept approximating 10 mg/kg. Study medication was administered intravenously (IV) on Days 1, 15, and 29 and every 28 days thereafter up to and including Day 141 (6-month treatment). Long-term Period: Participants who completed the Short-term Period received treatment with abatacept, administered IV at a weight-tiered dose approximately 10 mg/kg.	Placebo Placebo was administered IV on Days 1, 15, and 29 and every 28 days thereafter up to and including Day 141 (6-month treatment).
Short-term Period Adverse Event	0	1
Short-term Period Lost to Follow-up	0	1
Short-term Period Withdrawal by Subject	2	3
Short-term Period Never Treated	1	0
Long-term Extension Period Adverse Event	10	0
Long-term Extension Period Death	1	0
Long-term Extension Period Lack of Efficacy	2	0
Long-term Extension Period Withdrawal by Subject	3	0
Long-term Extension Period Poor compliance/noncompliance	1	0
Long-term Extension Period Pregnancy	1	0

Baseline Characteristics

A Phase III Study of Abatacept in Patients With Rheumatoid Arthritis and an Inadequate Response to Methotrexate

Baseline characteristics by cohort

Measure	Abatacept n=55 Participants Dosage: 500 mg to 1 g; participants randomized to the abatacept group received a body-weight tiered dose approximating 10 mg/kg. Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).	Placebo n=57 Participants Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).	Total n=112 Participants Total of all reporting groups
Age Continuous	47.2 years STANDARD_DEVIATION 12.2 • n=5 Participants	49.9 years STANDARD_DEVIATION 10.6 • n=7 Participants	48.6 years STANDARD_DEVIATION 11.4 • n=5 Participants
Sex: Female, Male Female	47 Participants n=5 Participants	49 Participants n=7 Participants	96 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	8 Participants n=7 Participants	16 Participants n=5 Participants
weight	56.5 kilograms STANDARD_DEVIATION 9.5 • n=5 Participants	54.2 kilograms STANDARD_DEVIATION 7.5 • n=7 Participants	55.3 kilograms STANDARD_DEVIATION 8.6 • n=5 Participants

PRIMARY outcome

Timeframe: At Day 169

Population: All randomized participants who received study drug.

The ACR 20 is based on 20% improvement (compared with baseline values) in tender and swollen joint counts and on 20% improvement in 3 of the remaining 5 core set measures (participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function) and 1 acute phase reactant value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants Meeting the Criteria of the American College of Rheumatology for 20% Improvement (ACR20)	65.5 percentage of participants	42.1 percentage of participants	—

PRIMARY outcome

Timeframe: Day 169 to up to 56 days post the last dose (Day 1485) in the LTE period

Population: All participants who completed the short-term period and received at least 1 infusion of abatacept during the LTE period

AE=any new untoward medical occurrence or worsening of a preexisting medical condition which does not necessarily have a causal relationship with this treatment. Related AE=relationship of certain, probable, possible, or missing. 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 the development of drug dependency or drug abuse, is an important medical event.

Outcome measures

Measure	Abatacept, 10 mg/kg n=105 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs Deaths	1 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs SAEs	41 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs Related SAEs	10 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs Discontinuations due to SAEs	8 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs AEs	100 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs Related AEs	45 Participants	—	—
Long-term Extension (LTE) (Open-Label) Period: Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuatons Due to SAEs, Adverse Events (AEs), Related AEs, and Discontinuations Due to AEs Discontinuations due to AEs	10 Participants	—	—

SECONDARY outcome

Timeframe: At Day 169

Population: All randomized participants who received study drug.

The ACR defines ACR 50 and ACR70 response as a 50% or 70% improvement (compared with baseline values) in tender and swollen joint counts and 50% or 70% improvement in 3 of the remaining 5 core set measures (patient global assessment of pain, patient global assessment of disease activity, physician global assessment of disease activity, subject assessment of physical function) and 1 acute phase reactant value (C-reactive protein).

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants With American College of Rheumatology (ACR) ACR50 and ACR70 Response at Day 169 ACR 50	32.7 Percentage of participants	15.8 Percentage of participants	—
Percentage of Participants With American College of Rheumatology (ACR) ACR50 and ACR70 Response at Day 169 ACR 70	14.5 Percentage of participants	7.0 Percentage of participants	—

SECONDARY outcome

Timeframe: From Baseline to Day 169

Population: All randomized participants who received study drug and who were evaluable.

The ACR defines improvement in core components as 20%, 50%, or 70% improvement in tender and swollen joint counts and 3 of the remaining core components: patient global assessment of disease activity, physician global assessment of disease activity, patient assessment of pain, patient self-assessed disability (Health Assessment Questionnaire Disability Index [HAQ-DI]), and levels of 1 acute phase reactant (C-reactive protein levels or erythrocyte sedimentation rate.) The HAQ-DI assesses a patient's level of functional ability via 20 questions in 8 categories of functioning; scale=0 (no disability) to 3 (completely disabled); total possible score=24. The higher the score, the greater the disability.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Tender Joints ≥ 20% improvement	81.1 Percentage of participants	76.9 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Tender Joints ≥ 50% improvement	66.0 Percentage of participants	50.0 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Tender Joints ≥ 70% improvement	49.1 Percentage of participants	23.1 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Swollen Joints ≥ 20% improvement	92.5 Percentage of participants	76.9 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Swollen Joints ≥ 50% improvement	77.4 Percentage of participants	57.7 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Swollen Joints ≥ 70% improvement	60.4 Percentage of participants	40.4 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Pain Assessment ≥ 20% improvement	73.6 Percentage of participants	53.9 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Pain Assessment ≥ 50% improvement	47.2 Percentage of participants	23.1 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Pain Assessment ≥ 70% improvement	28.3 Percentage of participants	11.5 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components HAQ-DI ≥ 20% improvement	67.9 Percentage of participants	44.2 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components HAQ-DI ≥ 50% improvement	32.1 Percentage of participants	23.1 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components HAQ-DI ≥ 70% improvement	20.8 Percentage of participants	5.8 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Global Assessment ≥ 20% improvement	66.0 Percentage of participants	53.9 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Global Assessment ≥ 50% improvement	39.6 Percentage of participants	21.2 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Patient Global Assessment ≥ 70% improvement	26.4 Percentage of participants	11.5 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Physician Global Assessment ≥ 20% improvement	86.8 Percentage of participants	71.2 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Physician Global Assessment ≥ 50% improvement	60.4 Percentage of participants	40.4 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components C-reactive Protein ≥ 20% improvement	83.0 Percentage of participants	61.5 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components Physician Global Assessment ≥ 70% improvement	30.2 Percentage of participants	19.2 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components C-reactive Protein ≥ 50% improvement	75.5 Percentage of participants	53.9 Percentage of participants	—
Percentage of Participants With at Least 20%, 50%, or 70% Improvement From Baseline in American College of Rheumatology (ACR) Core Components C-reactive Protein ≥ 70% improvement	64.2 Percentage of participants	28.9 Percentage of participants	—

SECONDARY outcome

Timeframe: From Baseline to Days 169 and 1485

Population: All randomized participants who received study drug and who were evaluable.

Adjusted mean change from baseline. The DAS28 provides a score on a scale from 0 to 10 indicating the current activity of rheumatoid arthritis (>5.1=high disease activity; <3.2=low disease activity; <2.6=remission). CRP or ESR give estimations of DAS28 values on a group level. Change from Baseline=Postbaseline - Baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Disease Activity Scores (DAS) Based on C-reactive Protein (DAS 28 [CRP]) Levels or Erythrocyte Sedimentation Rate (DAS 28[ESR]) Day 169: DAS28 (CRP)	-2.12 Units on a scale Standard Error 0.17	-1.21 Units on a scale Standard Error 0.17	—
Change From Baseline in Disease Activity Scores (DAS) Based on C-reactive Protein (DAS 28 [CRP]) Levels or Erythrocyte Sedimentation Rate (DAS 28[ESR]) Day 169: DAS28 (ESR)	-2.22 Units on a scale Standard Error 0.17	-1.15 Units on a scale Standard Error 0.16	—
Change From Baseline in Disease Activity Scores (DAS) Based on C-reactive Protein (DAS 28 [CRP]) Levels or Erythrocyte Sedimentation Rate (DAS 28[ESR]) Day 1485: DAS28 (CRP) (n=31, 35)	-2.97 Units on a scale Standard Error 0.23	-3.13 Units on a scale Standard Error 0.22	—
Change From Baseline in Disease Activity Scores (DAS) Based on C-reactive Protein (DAS 28 [CRP]) Levels or Erythrocyte Sedimentation Rate (DAS 28[ESR]) Day 1485: DAS28 (ESR) (NA)	NA Units on a scale Standard Error NA Not evaluated	NA Units on a scale Standard Error NA Not evaluated	—

SECONDARY outcome

Timeframe: From Baseline to Day 169

Population: All randomized participants who received study drug

Adjusted mean change from baseline. The HAQ-DI assesses a patient's level of functional ability via 20 questions in 8 categories of functioning. Patients respond on a scale from 0 (no disability) to 3 (completely disabled); total possible score=24. Higher score indicates greater disability. Change from baseline= postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score HAQ Disability Index	-0.53 Units on a scale Standard Error 0.07	-0.24 Units on a scale Standard Error 0.07	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Dressing and Grooming	-0.58 Units on a scale Standard Error 0.09	-0.37 Units on a scale Standard Error 0.09	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Arising	-0.58 Units on a scale Standard Error 0.10	-0.36 Units on a scale Standard Error 0.10	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Eating	-0.52 Units on a scale Standard Error 0.09	-0.13 Units on a scale Standard Error 0.09	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Walking	-0.54 Units on a scale Standard Error 0.10	-0.23 Units on a scale Standard Error 0.10	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Hygiene	-0.37 Units on a scale Standard Error 0.09	-0.21 Units on a scale Standard Error 0.09	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Reaching	-0.34 Units on a scale Standard Error 0.11	-0.11 Units on a scale Standard Error 0.10	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Gripping	-0.67 Units on a scale Standard Error 0.11	-0.36 Units on a scale Standard Error 0.11	—
Change From Baseline to Day 169 in Health Assessment Questionnaire Disability Index (HAQ-DI) Score Activities	-0.56 Units on a scale Standard Error 0.10	-0.25 Units on a scale Standard Error 0.10	—

SECONDARY outcome

Timeframe: From Baseline to Day 169

Population: All randomized participants who received study drug and were evaluable.

Adjusted mean change from baseline. The SF-36 is a 36-item self-administered questionnaire developed to assess health-related quality of life and comprised of 8 domains( including 4 physical and 4 mental subscales) used to derive the physical and mental component summary scores. All subscales were scored using norm-based methods that standardized the scores to a mean of 50 and 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. Change from baseline=postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=54 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=53 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline to Day 169 in Analysis of Short-Form 36 (SF-36) Health Survey Questionnaire Domains Physical Component Summary	6.52 Units on a scale Standard Error 1.05	2.16 Units on a scale Standard Error 1.06	—
Change From Baseline to Day 169 in Analysis of Short-Form 36 (SF-36) Health Survey Questionnaire Domains Mental Component Summary	8.18 Units on a scale Standard Error 1.37	4.36 Units on a scale Standard Error 1.38	—

SECONDARY outcome

Timeframe: Throughout double-blind study period (up to Day 169); table includes data up to 56 days past double-blind period or start of the open-label period, whichever occurred first.

Population: All randomized participants who received study drug.

AE=any new untoward medical occurrence or worsening of a preexisting medical condition that does not necessarily have a causal relationship with this treatment. Related AE=relationship of certain, probable, possible, or missing. 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 the development of drug dependency or drug abuse, is an important medical event.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period Deaths	0 Percentage of participants	1.8 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period SAEs	3.6 Percentage of participants	5.3 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period Related SAEs	0 Percentage of participants	1.8 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period Discontinued due to SAEs	0 Percentage of participants	1.8 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period AEs	70.9 Percentage of participants	70.2 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period Related AEs	12.7 Percentage of participants	15.8 Percentage of participants	—
Percentage of Participants Experiencing Deaths, Serious Adverse Events (SAEs), Adverse Events (AEs), Related SAEs and AEs, and Discontinuations Due to SAEs and AEs During the Double-Blind Period Discontinued due to AEs	0 Percentage of participants	1.8 Percentage of participants	—

SECONDARY outcome

Timeframe: At the end of infusion and 2 to 4 hours after the start of infusion on Day 85, at anytime between Day 92 and 96, and pre-dose on Day 113

Population: Participants with measurement at stated dose level

Steady-state PK parameters following administration of body-weight tiered doses approximating 10 mg/kg. Tmax = the time after administration of a drug when the maximum plasma concentration is reached; when the rate of absorption equals the rate of elimination. T-Half = the biological half-life or elimination half life of a substance is the time it takes for a substance to lose half of its pharmacologic, physiologic, or radiologic activity.

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Abatacept Pharmacokinetic (PK) Parameters: Time to Maximum Concentration (Tmax) and Half-Life of Elimination (T-Half) Tmax	1.385 Hours Standard Deviation 1.0607	1.193 Hours Standard Deviation 0.9956	1.325 Hours Standard Deviation 1.0351
Abatacept Pharmacokinetic (PK) Parameters: Time to Maximum Concentration (Tmax) and Half-Life of Elimination (T-Half) T-Half	183.583 Hours Standard Deviation 35.2606	172.451 Hours Standard Deviation 28.7270	180.078 Hours Standard Deviation 33.4795

SECONDARY outcome

Timeframe: At the end of infusion and 2 to 4 hours after the start of the infusion on Day 85, at anytime between Day 92 and 96, and pre-dose on Day 113

Population: Participants with measurement at stated dose level

Steady-state PK parameters following administration of body-weight tiered doses approximating 10 mg/kg. Maximum Concentration (Cmax)= the maximum plasma concentration of the drug.

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Abatacept Pharmacokinetic (PK) Parameters - Maximum Concentration (Cmax)	241.972 μg/mL Standard Deviation 41.7191	312.591 μg/mL Standard Deviation 63.3026	264.204 μg/mL Standard Deviation 59.0589

SECONDARY outcome

Timeframe: At the end of infusion, 2 to 4 hours after the start of infusion on Day 85, anytime between Day 92 and 96, and predose on Day 113

Population: Participants with measurement at stated dose level

Area Under the Plasma Concentration-Time Curve (AUC), a measure of drug absorption, in a dosing interval of 28 days from Day 85 to Day 113. Steady-state PK parameters following administration of body-weight tiered doses approximating 10 mg/kg.

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Abatacept Pharmacokinetic (PK) Parameters - Area Under the Curve (AUC)	38940.063 μg.h/mL Standard Deviation 9731.0561	48283.479 μg.h/mL Standard Deviation 10283.2572	41881.508 μg.h/mL Standard Deviation 10743.8152

SECONDARY outcome

Timeframe: Day 29, every 28 days until Day 141

Population: Participants with measurement at stated dose level

Steady-state PK parameters following administration of body-weight tiered doses approximating 10 mg/kg. Clearance is a pharmacokinetic parameter that describes how quickly drugs are eliminated, metabolized or distributed throughout the body.

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Abatacept Pharmacokinetic (PK) Parameters: Total Body Clearance (CLT)	0.269 mL/h/kg Standard Deviation 0.0730	0.240 mL/h/kg Standard Deviation 0.0460	0.260 mL/h/kg Standard Deviation 0.0666

SECONDARY outcome

Timeframe: At the end of infusion, 2 to 4 hours after the start of infusion on Day 85, anytime between Day 92 and 96, and predose on Day 113

Population: Participants with measurement at stated dose level

The volume of distribution of drug at steady state (VSS). Steady-state PK parameters following administration of body-weight tiered doses approximating 10 mg/kg.

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Abatacept Pharmacokinetic (PK) Parameters: Volume at Steady State (VSS)	0.064 L/kg Standard Deviation 0.0165	0.055 L/kg Standard Deviation 0.0142	0.061 L/kg Standard Deviation 0.0162

SECONDARY outcome

Timeframe: At the end of infusion and 2 to 4 hours after the start of the infusion on Day 85

Population: Participants with measurement at timepoint

Minimum concentration (Cmin) of Abatacept 500 mg and 750 mg at given time points

Outcome measures

Measure	Abatacept, 10 mg/kg n=37 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=17 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg n=54 Participants
Summary Statistics of Minimum Observed Serum Concentration (Cmin) for Abatacept Day 29	37.76 μg/mL Standard Deviation 10.971	52.19 μg/mL Standard Deviation 19.619	42.30 μg/mL Standard Deviation 15.611
Summary Statistics of Minimum Observed Serum Concentration (Cmin) for Abatacept Day 57	19.96 μg/mL Standard Deviation 11.337	24.42 μg/mL Standard Deviation 7.697	21.31 μg/mL Standard Deviation 10.504
Summary Statistics of Minimum Observed Serum Concentration (Cmin) for Abatacept Day 85	17.45 μg/mL Standard Deviation 7.442	20.83 μg/mL Standard Deviation 10.749	18.52 μg/mL Standard Deviation 8.661
Summary Statistics of Minimum Observed Serum Concentration (Cmin) for Abatacept Day 113	17.51 μg/mL Standard Deviation 6.858	22.06 μg/mL Standard Deviation 9.365	18.94 μg/mL Standard Deviation 7.936

SECONDARY outcome

Timeframe: Day 169

Population: All participants who received study drug (abatacept)

Immunogenicity was determined by measuring adult subject sera for reactivity against the whole Abatacept molecule (CTLA4Ig) and CTLA4-T (CTLA4 without the Ig regions).

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Immunogenicity of Abatacept- Number of Participants With Reactivity Toward CTLA4-IG and CTLA4-T at Day 169 Reactivity toward CTLA4-T	0 participants	—	—
Immunogenicity of Abatacept- Number of Participants With Reactivity Toward CTLA4-IG and CTLA4-T at Day 169 Reactivity toward CTLA4Ig	0 participants	—	—

SECONDARY outcome

Timeframe: From Baseline to Day 169

Population: All randomized participants who received study drug. Participants with baseline and post-baseline measurements were included, not the participants who had only baseline measurements.

Mean change in surrogate marker mean ESR. A surrogate marker is an indirect measurement of effectiveness. Change from Baseline = postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Surrogate Marker Erythrocyte Sedimentation Rate (ESR) at Day 169	-30.0 mm/h Standard Error 2.86	-4.44 mm/h Standard Error 3.87	—

SECONDARY outcome

Timeframe: Baseline, Day 169

Population: All Randomized and Treated Participants. The summary was based on the last observation carried forward (LOCF) procedure. Participants with baseline and post-baseline measurements were included, not the participants who had only baseline measurements.

Mean change in RF. A surrogate marker is an indirect measurement of effectiveness. Mean change from Baseline = postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=55 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=57 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Surrogate Marker Rheumatoid Factor (RF) at Day 169	-54.1 IU/mL Standard Error 20.52	-12.1 IU/mL Standard Error 14.38	—

SECONDARY outcome

Timeframe: Days 169, at 6-month intervals on-treatment, and at Days 28, 56, and 85 after the last infusion of study medication in the LTE period

Population: All participants who during the LTE period, received at least 1 infusion of abatacept and had at least 1 immunogenicity sample collected.

Positive antibody titers were identified by validated enzyme-linked immunosorbent assay results. On-treatment samples were obtained during the LTE period, and posttreatment samples were following the last infusion of study medication.

Outcome measures

Measure	Abatacept, 10 mg/kg n=105 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
LTE Period: Overall Number of Participants With Positive Results of Immunogenicity Samples Overall	14 Participants	—	—
LTE Period: Overall Number of Participants With Positive Results of Immunogenicity Samples On-treatment	9 Participants	—	—
LTE Period: Overall Number of Participants With Positive Results of Immunogenicity Samples Posttreatment	11 Participants	—	—

SECONDARY outcome

Timeframe: Days 15 through 1569

Population: All participants who completed the ST period and received at least 1 infusion of abatacept during the LTE period. n=evaluable participants at that timepoint for that measure.

The ACR 20, ACR50, and ACR70 are based on 20%, 50% and 70% improvement, respectively, (compared with baseline values) in tender and swollen joint counts and on 20%, 50% and 70%, respectively, improvement in 3 of the remaining 5 core set measures (participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function) and 1 acute phase reactant value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 15 ACR20	13.2 Percentage of participants Interval 4.1 to 22.3	11.5 Percentage of participants Interval 2.9 to 20.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 15 ACR50	1.9 Percentage of participants Interval 0.0 to 10.1	3.8 Percentage of participants Interval 0.5 to 13.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 15 ACR70	0 Percentage of participants	0 Percentage of participants	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 29 ACR20	24.5 Percentage of participants Interval 12.9 to 36.1	21.2 Percentage of participants Interval 10.1 to 32.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 29 ACR50	1.9 Percentage of participants Interval 0.0 to 10.0	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 29 ACR70	1.9 Percentage of participants Interval 0.0 to 10.0	3.8 Percentage of participants Interval 0.5 to 13.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 57 ACR20 (n=52, 52)	51.9 Percentage of participants Interval 38.3 to 65.5	23.1 Percentage of participants Interval 11.6 to 34.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 57 ACR50 (n=52, 52)	5.8 Percentage of participants Interval 1.2 to 15.9	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 57 ACR70 (n=52, 52)	1.9 Percentage of participants Interval 0.0 to 10.3	5.8 Percentage of participants Interval 1.2 to 15.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 85 ACR20	58.5 Percentage of participants Interval 45.2 to 71.8	36.5 Percentage of participants Interval 23.5 to 49.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 85 ACR50	17.0 Percentage of participants Interval 6.9 to 27.1	9.6 Percentage of participants Interval 1.6 to 17.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 85 ACR70	5.7 Percentage of participants Interval 1.2 to 15.7	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 113 ACR20	64.2 Percentage of participants Interval 51.2 to 77.1	48.1 Percentage of participants Interval 34.5 to 61.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 113 ACR50	30.2 Percentage of participants Interval 17.8 to 42.5	11.5 Percentage of participants Interval 2.9 to 20.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 113 ACR70	3.8 Percentage of participants Interval 0.5 to 13.0	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 141 ACR20	66.0 Percentage of participants Interval 53.3 to 78.8	53.8 Percentage of participants Interval 40.3 to 67.4	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 141 ACR50	30.2 Percentage of participants Interval 17.8 to 42.5	11.5 Percentage of participants Interval 2.9 to 20.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 141 ACR70	15.1 Percentage of participants Interval 5.5 to 24.7	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 169 ACR20	67.9 Percentage of participants Interval 55.4 to 80.5	46.2 Percentage of participants Interval 32.6 to 59.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 169 ACR50	34.0 Percentage of participants Interval 21.2 to 46.7	17.3 Percentage of participants Interval 7.0 to 27.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 169 ACR70	15.1 Percentage of participants Interval 5.5 to 24.7	7.7 Percentage of participants Interval 2.1 to 18.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 197 ACR20 (n=53, 50)	75.5 Percentage of participants Interval 63.9 to 87.1	60.0 Percentage of participants Interval 46.4 to 73.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 197 ACR50 (n=53, 51)	45.3 Percentage of participants Interval 31.9 to 58.7	37.3 Percentage of participants Interval 24.0 to 50.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 197 ACR70 (n=53, 51)	22.6 Percentage of participants Interval 11.4 to 33.9	11.8 Percentage of participants Interval 2.9 to 20.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 225 ACR20	75.5 Percentage of participants Interval 63.9 to 87.1	65.4 Percentage of participants Interval 52.5 to 78.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 225 ACR50	49.1 Percentage of participants Interval 35.6 to 62.5	32.7 Percentage of participants Interval 19.9 to 45.4	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 225 ACR70	22.6 Percentage of participants Interval 11.4 to 83.9	13.5 Percentage of participants Interval 4.2 to 22.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 253 ACR20 (n=52, 51)	71.2 Percentage of participants Interval 58.8 to 83.5	64.7 Percentage of participants Interval 51.6 to 77.8	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 253 ACR50 (n=52, 51)	44.2 Percentage of participants Interval 30.7 to 57.7	35.3 Percentage of participants Interval 22.2 to 48.4	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 253 ACR70 (n=52, 51)	21.2 Percentage of participants Interval 10.1 to 32.3	13.7 Percentage of participants Interval 4.3 to 23.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 337 ACR20 (n=52, 51)	78.8 Percentage of participants Interval 67.7 to 89.9	62.7 Percentage of participants Interval 49.5 to 76.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 337 ACR50 (n=52, 51)	48.1 Percentage of participants Interval 34.5 to 61.7	43.1 Percentage of participants Interval 29.5 to 56.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 337 ACR70 (n=52, 51)	30.8 Percentage of participants Interval 18.2 to 43.3	17.6 Percentage of participants Interval 7.2 to 28.1	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 421 ACR20 (n=51, 51)	84.3 Percentage of participants Interval 74.3 to 94.3	78.4 Percentage of participants Interval 67.1 to 89.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 421 ACR50 (n=51, 51)	49.0 Percentage of participants Interval 35.3 to 62.7	56.9 Percentage of participants Interval 43.3 to 70.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 421 ACR70 (n=51, 51)	29.4 Percentage of participants Interval 16.9 to 41.9	31.4 Percentage of participants Interval 18.6 to 44.1	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 505 ACR20 (n=50, 51)	88.0 Percentage of participants Interval 79.0 to 97.0	84.3 Percentage of participants Interval 74.3 to 94.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 505 ACR50 (n=50, 51)	62.0 Percentage of participants Interval 48.5 to 75.5	56.9 Percentage of participants Interval 43.3 to 70.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 505 ACR70 (n=50, 51)	40.0 Percentage of participants Interval 26.4 to 53.6	25.5 Percentage of participants Interval 13.5 to 37.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 561 ACR20 (n=50, 50)	88.0 Percentage of participants Interval 79.0 to 97.0	86.0 Percentage of participants Interval 76.4 to 95.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 561 ACR50 (n=50, 50)	64.0 Percentage of participants Interval 50.7 to 77.3	60.0 Percentage of participants Interval 46.4 to 73.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 561 ACR70 (n=50, 50)	38.0 Percentage of participants Interval 24.5 to 51.5	32.0 Percentage of participants Interval 19.1 to 44.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 645 ACR20 (n=50, 50)	86.0 Percentage of participants Interval 76.4 to 95.6	82.0 Percentage of participants Interval 71.4 to 92.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 645 ACR50 (n=50, 50)	54.0 Percentage of participants Interval 40.2 to 67.8	56.0 Percentage of participants Interval 42.2 to 69.8	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 645 ACR70 (n=50, 50)	38.0 Percentage of participants Interval 24.5 to 51.5	34.0 Percentage of participants Interval 20.9 to 47.1	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 729 ACR20 (n=49, 50)	83.7 Percentage of participants Interval 73.3 to 94.0	74.0 Percentage of participants Interval 61.8 to 86.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 729 ACR50 (n=49, 50)	63.3 Percentage of participants Interval 49.8 to 76.8	54.0 Percentage of participants Interval 40.2 to 67.8	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 729 ACR70 (n=49, 50)	34.7 Percentage of participants Interval 21.4 to 48.0	32.0 Percentage of participants Interval 19.1 to 44.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 813 ACR20 (n=48, 49)	91.7 Percentage of participants Interval 83.8 to 99.5	79.6 Percentage of participants Interval 68.3 to 90.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 813 ACR50 (n=48, 49)	58.3 Percentage of participants Interval 44.4 to 72.3	59.2 Percentage of participants Interval 45.4 to 72.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 813 ACR70 (n=48, 49)	41.7 Percentage of participants Interval 27.7 to 55.6	34.7 Percentage of participants Interval 21.4 to 48.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 897 ACR20 (n=46, 49)	80.4 Percentage of participants Interval 69.0 to 91.9	79.6 Percentage of participants Interval 68.3 to 90.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 897 ACR50 (n=46, 49)	56.5 Percentage of participants Interval 42.2 to 70.8	53.1 Percentage of participants Interval 39.1 to 67.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 897 ACR70 (n=46, 49)	39.1 Percentage of participants Interval 25.0 to 53.2	34.7 Percentage of participants Interval 21.4 to 48.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 981 ACR20 (n=44, 48)	84.1 Percentage of participants Interval 73.3 to 94.9	79.2 Percentage of participants Interval 67.7 to 90.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 981 ACR50 (n=44, 48)	61.4 Percentage of participants Interval 47.0 to 75.8	60.4 Percentage of participants Interval 46.6 to 74.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 981 ACR70 (n=43, 48)	34.9 Percentage of participants Interval 20.6 to 49.1	41.7 Percentage of participants Interval 27.7 to 55.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1065 ACR20 (n=45, 48)	80.0 Percentage of participants Interval 68.3 to 91.7	79.2 Percentage of participants Interval 67.7 to 90.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1065 ACR50 (n=45, 48)	64.4 Percentage of participants Interval 50.5 to 78.4	60.4 Percentage of participants Interval 46.6 to 74.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1065 ACR70 (n=45, 48)	42.2 Percentage of participants Interval 27.8 to 56.7	43.8 Percentage of participants Interval 29.7 to 57.8	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1149 ACR20 (n=45, 48)	84.4 Percentage of participants Interval 73.9 to 95.0	75.0 Percentage of participants Interval 62.8 to 87.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1149 ACR50 (n=45, 48)	55.6 Percentage of participants Interval 41.0 to 70.1	62.5 Percentage of participants Interval 48.8 to 76.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1149 ACR70 (n=45, 48)	35.6 Percentage of participants Interval 21.6 to 49.5	43.8 Percentage of participants Interval 29.7 to 57.8	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day1233 ACR20 (n=44, 48)	84.1 Percentage of participants Interval 73.3 to 94.9	79.2 Percentage of participants Interval 67.7 to 90.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day1233 ACR50 (n=44, 48)	63.6 Percentage of participants Interval 49.4 to 77.9	52.1 Percentage of participants Interval 38.0 to 66.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day1233 ACR70 (n=44, 48)	43.2 Percentage of participants Interval 28.5 to 57.8	41.7 Percentage of participants Interval 27.7 to 55.6	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1317 ACR20 (n=44, 47)	90.9 Percentage of participants Interval 82.4 to 99.4	76.6 Percentage of participants Interval 64.5 to 88.7	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1317 ACR50 (n=44, 47)	63.6 Percentage of participants Interval 49.4 to 77.9	53.2 Percentage of participants Interval 38.9 to 67.5	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1317 ACR70 (n=44, 47)	40.9 Percentage of participants Interval 26.4 to 55.4	36.2 Percentage of participants Interval 22.4 to 49.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1401 ACR20 (n=41, 43)	90.2 Percentage of participants Interval 81.2 to 99.3	81.4 Percentage of participants Interval 69.8 to 93.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1401 ACR50 (n=41, 43)	68.3 Percentage of participants Interval 54.0 to 82.5	51.2 Percentage of participants Interval 36.2 to 66.1	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1401 ACR70 (n=41, 43)	39.0 Percentage of participants Interval 24.1 to 54.0	39.5 Percentage of participants Interval 24.9 to 54.1	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1485 ACR20 (n=31, 35)	83.9 Percentage of participants Interval 70.9 to 96.8	85.7 Percentage of participants Interval 74.1 to 97.3	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1485 ACR50 (n=31, 35)	67.7 Percentage of participants Interval 51.3 to 84.2	62.9 Percentage of participants Interval 46.8 to 78.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1485 ACR70 (n=31, 35)	38.7 Percentage of participants Interval 21.6 to 55.9	45.7 Percentage of participants Interval 29.2 to 62.2	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1569 ACR20 (n=20, 18)	100.0 Percentage of participants Interval 100.0 to 100.0	88.9 Percentage of participants Interval 74.4 to 100.0	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1569 ACR50 (n=20, 18)	80.0 Percentage of participants Interval 62.5 to 97.5	72.2 Percentage of participants Interval 51.5 to 92.9	—
Percentage of Participants Achieving ACR20, ACR50, and ACR70 Over Time Day 1569 ACR70 (n=20, 18)	30.0 Percentage of participants Interval 9.9 to 50.1	44.4 Percentage of participants Interval 21.5 to 67.4	—

SECONDARY outcome

Timeframe: At Day 1485

Population: All participants who received study drug and who were evaluable

Improvement is measured by an improved response of at least 0.3 units from baseline on the HAQ-DI score. The HAQ-DI assesses a patient's level of functional ability via 20 questions in 8 categories of functioning. Patients respond on a scale from 0 (no disability) to 3 (completely disabled); total possible score=24. Higher score indicates greater disability. Change from baseline= postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=31 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=35 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants With Physical Function Response as Assessed Using the Health Assessment Questionnaire Disability Index (HAQ-DI)	77.4 Percentage of participants	60.0 Percentage of participants	—

SECONDARY outcome

Timeframe: Day 1485

Population: All participants who received study drug and who were evaluable

The HAQ-DI assesses a patient's level of functional ability via 20 questions in 8 categories of functioning. Patients respond on a scale from 0 (no disability) to 3 (completely disabled); total possible score=24. Higher score indicates greater disability. Change from baseline= postbaseline - baseline value.

Outcome measures

Measure	Abatacept, 10 mg/kg n=31 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=35 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Health Assessment Questionnaire Disability Index (HAQ-DI) Score	-0.76 Units on a scale Standard Error 0.14	-0.53 Units on a scale Standard Error 0.11	—

SECONDARY outcome

Timeframe: At Day 1485

Population: All participants who received study drug and who were evaluable

The SF-36 is a 36-item questionnaire used to measure Quality of Life over 8 physically and emotionally based areas: physical functioning, role limitations due to physical health, role limitations due to emotional problems, energy/fatigue, emotional well-being, social functioning, pain, and general health. Answers to each question correspond to a precoded numeric value. An aggregate percentage score is reached for each of the 8 sections and is based on answers to questions. The mean average is worked out for each section. Scores range from 0% (lowest level of functioning) to 100% (highest level of functioning, with higher score indicated increasing levels of functioning.

Outcome measures

Measure	Abatacept, 10 mg/kg n=31 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=35 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Changes From Baseline in Short-Form 36 (SF-36) Physical and Mental Health Summaries Physical component score	10.34 Units on a scale Standard Error 1.80	8.48 Units on a scale Standard Error 1.57	—
Changes From Baseline in Short-Form 36 (SF-36) Physical and Mental Health Summaries Mental component score	7.93 Units on a scale Standard Error 2.44	7.73 Units on a scale Standard Error 2.34	—

SECONDARY outcome

Timeframe: At Days 169 and 1485

Population: All participants who received study drug and who were evaluable

EULAR defines LDAS as a disease activity score as measured by c-reactive protein (DAS28-CRP) ≤3.2 and remission as DAS28-CRP <2.6

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants With European League Against Rheumatism (EULAR)-Defined Low Disease Activity Score (LDAS) and With EULAR-defined Remission EULAR-defined LDAS (Day 169)	35.8 Percentage of participants	13.5 Percentage of participants	—
Percentage of Participants With European League Against Rheumatism (EULAR)-Defined Low Disease Activity Score (LDAS) and With EULAR-defined Remission EULAR-defined LDAS (Day 1485) (n=31, 35)	61.3 Percentage of participants	68.6 Percentage of participants	—
Percentage of Participants With European League Against Rheumatism (EULAR)-Defined Low Disease Activity Score (LDAS) and With EULAR-defined Remission EULAR-defined remission (Day 169)	24.5 Percentage of participants	9.6 Percentage of participants	—
Percentage of Participants With European League Against Rheumatism (EULAR)-Defined Low Disease Activity Score (LDAS) and With EULAR-defined Remission EULAR-defined remission(Day 1485) (n=31, 35)	35.5 Percentage of participants	54.3 Percentage of participants	—

SECONDARY outcome

Timeframe: At Days 169 and 1569

Population: All participants who received study drug and who were evaluable

The SDAI is the sum of 5 parameters: Tender joint (TJC) and swollen joint(SJC)counts, based on a 28-joint assessment; patient global (PtGA)and physician global assessments (PGA), assessed on 0-10 cm visual analog scale (VAS), on which higher scores=greater affection due to disease activity DA); and C-reactive protein level. SDAI total score=0-86. SDAI <=3.3 indicates disease remission, >3.4 to 11=low DA, >11 to 26=moderate DA, and >26=high DA. SJC is assessed at each visit, with no swelling=0, swelling=1. TJC is assessed through identification of joints painful under pressure or to passive motion at each visit, with no tenderness=0, tenderness=1. Higher score=greater affection due to DA. CDAI is sum of 4 parameters: TJC and SJC (based on a 28-joint assessment), PtGA and PGA (assessed on 0-10 cm VAS; higher scores=greater affection due to disease activity). CDAI total score=0-76. CDAI <=2.8 indicates disease remission, >2.8 to 10=low DA, >10 to 22=moderate DA, and >22=high DA.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Changes From Baseline in the Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI) Scores SDAI score (Day 169)	-22.84 Units on a scale Interval -26.58 to -19.0	-14.07 Units on a scale Interval -17.28 to -10.87	—
Changes From Baseline in the Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI) Scores SDAI score (Day 1569) (n=20, 18)	-29.74 Units on a scale Interval -34.06 to -25.43	-29.20 Units on a scale Interval -33.7 to -24.7	—
Changes From Baseline in the Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI) Scores CDAI score (Day 169)	-20.99 Units on a scale Interval -24.52 to -17.46	-13.49 Units on a scale Interval -16.42 to -10.56	—
Changes From Baseline in the Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI) Scores CDAI score (Day 1569) (n=20, 18)	-27.79 Units on a scale Interval -31.78 to -23.8	-27.34 Units on a scale Interval -31.54 to -23.15	—

SECONDARY outcome

Timeframe: At Days 169, 337, 729, 1149, and 1485

Population: All participants who finished the Short-term period. n=Number of evaluable participants

LDAS is defined as a Disease Activity Score C-reactive protein (DAS28-CRP) level <=3.2. Remission is defined as a DAS28-CRP level <2.6.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission LDAS (Day 169)	35.8 Percentage of participants Interval 22.9 to 48.8	13.5 Percentage of participants Interval 4.2 to 22.7	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission LDAS (Day 337) (n=52, 51)	51.9 Percentage of participants Interval 38.3 to 65.5	35.3 Percentage of participants Interval 22.2 to 48.4	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission LDAS (Day 729) (n=48, 50)	62.5 Percentage of participants Interval 48.8 to 76.2	56.0 Percentage of participants Interval 42.2 to 69.8	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission LDAS (Day 1149) (n=44,48)	63.6 Percentage of participants Interval 49.4 to 77.9	60.4 Percentage of participants Interval 46.6 to 74.3	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission LDAS (Day 1485) (n=31, 35)	61.3 Percentage of participants Interval 44.1 to 78.4	68.6 Percentage of participants Interval 53.2 to 84.0	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission Remission (Day 169)	24.5 Percentage of participants Interval 12.9 to 36.1	9.6 Percentage of participants Interval 1.6 to 17.6	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission Remission (Day 337) (n=52, 51)	34.6 Percentage of participants Interval 21.7 to 47.5	23.5 Percentage of participants Interval 11.9 to 35.2	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission Remission (Day 729) (n=48, 50)	43.8 Percentage of participants Interval 29.7 to 57.8	38.0 Percentage of participants Interval 24.5 to 51.5	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission Remission (Day 1149) (n=44,8)	38.6 Percentage of participants Interval 24.2 to 53.0	50.0 Percentage of participants Interval 35.9 to 64.1	—
Percentage of Participants With Low Disease Activity Score (LDAS) or Who Are in Remission Remission (Day 1485) (n=31, 35)	35.5 Percentage of participants Interval 18.6 to 52.3	54.3 Percentage of participants Interval 37.8 to 70.8	—

SECONDARY outcome

Timeframe: Days 169 to 1569

Population: Participants who completed the Short-term Period. n=Number of evaluable participants.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Levels of C-reactive Protein (CRP) Day 169	-1.85 mg/dL Standard Error 0.29	-0.58 mg/dL Standard Error 0.34	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 197 (n=53, 49)	-1.87 mg/dL Standard Error 0.28	-1.23 mg/dL Standard Error 0.36	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 225	-1.73 mg/dL Standard Error 0.51	-1.62 mg/dL Standard Error 0.32	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 253 (n=52, 51)	-1.91 mg/dL Standard Error 0.31	-1.52 mg/dL Standard Error 0.32	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 337 (n=52, 51)	-1.94 mg/dL Standard Error 0.30	-1.67 mg/dL Standard Error 0.32	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 421 (n=51, 51)	-2.06 mg/dL Standard Error 0.26	-1.77 mg/dL Standard Error 0.33	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 505 (n=50, 51)	-2.10 mg/dL Standard Error 0.28	-1.75 mg/dL Standard Error 0.33	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 561 (n=50, 50)	-2.23 mg/dL Standard Error 0.27	-1.68 mg/dL Standard Error 0.39	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 645 (n=50, 50)	-2.24 mg/dL Standard Error 0.28	-1.88 mg/dL Standard Error 0.34	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 729 (n=49, 50)	-2.29 mg/dL Standard Error 0.28	-1.63 mg/dL Standard Error 0.37	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 813 (n=48, 49)	-2.24 mg/dL Standard Error 0.29	-1.81 mg/dL Standard Error 0.34	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 897 (n=46, 49)	-2.41 mg/dL Standard Error 0.30	-1.76 mg/dL Standard Error 0.35	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 981 (n=44, 48)	-1.99 mg/dL Standard Error 0.33	-1.99 mg/dL Standard Error 0.36	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1065 (n=45, 48)	-2.06 mg/dL Standard Error 0.32	-1.47 mg/dL Standard Error 0.40	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1149 (n=45, 48)	-2.00 mg/dL Standard Error 0.34	-1.86 mg/dL Standard Error 0.36	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1233 (n=44, 48)	-1.96 mg/dL Standard Error 0.33	1.70 mg/dL Standard Error 0.37	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1317 (n=44, 47)	-2.00 mg/dL Standard Error 0.35	-1.81 mg/dL Standard Error 0.40	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1401 (n=41, 43)	-1.93 mg/dL Standard Error 0.33	-1.83 mg/dL Standard Error 0.40	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1485 (n=31, 35)	-1.95 mg/dL Standard Error 0.47	-1.86 mg/dL Standard Error 0.41	—
Change From Baseline in Levels of C-reactive Protein (CRP) Day 1569 (n=20, 18)	-2.43 mg/dL Standard Error 0.43	-1.68 mg/dL Standard Error 0.42	—

SECONDARY outcome

Timeframe: Days 169 to 1569

Population: Participants who completed the Short-term Period. n=Number of evaluable participants.

Outcome measures

Measure	Abatacept, 10 mg/kg n=53 Participants Participants received abatacept in a body-weight tiered dose approximating 10 mg/kg intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Placebo n=52 Participants Participants received placebo IV on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141.	Abatacept 500 mg and 750 mg
Change From Baseline in Erythrocyte Sedimentation Rate Day 897 (n=46, 49)	-34.37 mm/h Standard Error 4.13	-18.22 mm/h Standard Error 4.65	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 169	-30.60 mm/h Standard Error 2.93	-7.12 mm/h Standard Error 3.84	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 197 (n=53, 49)	-28.43 mm/h Standard Error 3.27	-15.14 mm/h Standard Error 3.79	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 225	-27.30 mm/h Standard Error 3.09	-20.27 mm/h Standard Error 3.51	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 253 (n=52, 51)	-27.85 mm/h Standard Error 3.24	-20.78 mm/h Standard Error 3.97	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 337 (n=52, 51)	-28.58 mm/h Standard Error 3.35	-23.86 mm/h Standard Error 3.78	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 421 (n=51, 51)	-28.45 mm/h Standard Error 3.34	-24.94 mm/h Standard Error 3.86	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 505 (n=50, 51)	-31.30 mm/h Standard Error 3.46	-24.69 mm/h Standard Error 4.07	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 561 (n=50, 49)	-29.32 mm/h Standard Error 3.63	-24.90 mm/h Standard Error 4.24	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 645 (n=50, 50)	-28.22 mm/h Standard Error 3.74	-27.38 mm/h Standard Error 4.10	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 729 (n=49, 50)	-32.80 mm/h Standard Error 3.70	-23.04 mm/h Standard Error 3.60	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 813 (n=48, 47)	-31.52 mm/h Standard Error 3.95	-22.91 mm/h Standard Error 4.03	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 981 (n=44, 48)	-33.61 mm/h Standard Error 3.68	-21.54 mm/h Standard Error 4.53	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1065 (n=45, 47)	-31.53 mm/h Standard Error 3.95	-22.09 mm/h Standard Error 4.37	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1149 (n=45, 48)	-31.00 mm/h Standard Error 4.59	-20.29 mm/h Standard Error 4.61	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1233 (n=42, 48)	-30.93 mm/h Standard Error 5.08	-22.10 mm/h Standard Error 4.70	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1317 (n=43, 47)	-33.67 mm/h Standard Error 4.45	-21.89 mm/h Standard Error 4.48	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1401 (n=41, 43)	-32.41 mm/h Standard Error 4.83	-23.88 mm/h Standard Error 4.91	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1485 (n=31, 35)	-33.81 mm/h Standard Error 6.96	-25.69 mm/h Standard Error 5.70	—
Change From Baseline in Erythrocyte Sedimentation Rate Day 1569 (n=20, 18)	-46.80 mm/h Standard Error 6.79	-23.33 mm/h Standard Error 5.85	—

Adverse Events

Abatacept 10 mg/kg

Serious events: 2 serious events

Other events: 27 other events

Deaths: 0 deaths

Placebo

Serious events: 3 serious events

Other events: 26 other events

Deaths: 0 deaths

Serious adverse events

Measure	Abatacept 10 mg/kg n=55 participants at risk 500 mg to 1 g; subjects randomized to the abatacept group received a body-weight tiered dose approximating 10 mg/kg. Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).	Placebo n=57 participants at risk Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).
Endocrine disorders ADRENAL CYST	0.00% 0/55	1.8% 1/57
Infections and infestations SEPSIS	0.00% 0/55	1.8% 1/57
Injury, poisoning and procedural complications ROAD TRAFFIC ACCIDENT	1.8% 1/55	0.00% 0/57
Musculoskeletal and connective tissue disorders PAIN IN EXTREMITY	0.00% 0/55	1.8% 1/57
Musculoskeletal and connective tissue disorders LUMBAR SPINAL STENOSIS	1.8% 1/55	0.00% 0/57
Respiratory, thoracic and mediastinal disorders PNEUMOTHORAX	0.00% 0/55	1.8% 1/57
Respiratory, thoracic and mediastinal disorders INTERSTITIAL LUNG DISEASE	0.00% 0/55	1.8% 1/57

Other adverse events

Measure	Abatacept 10 mg/kg n=55 participants at risk 500 mg to 1 g; subjects randomized to the abatacept group received a body-weight tiered dose approximating 10 mg/kg. Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).	Placebo n=57 participants at risk Study medication was administered intravenously (IV) on Days 1, 15, and 29, and every 28 days thereafter up to and including Day 141 (6 month treatment).
Investigations WEIGHT INCREASED	7.3% 4/55	0.00% 0/57
Nervous system disorders HEADACHE	5.5% 3/55	5.3% 3/57
Gastrointestinal disorders DYSPEPSIA	5.5% 3/55	3.5% 2/57
Gastrointestinal disorders MOUTH ULCERATION	5.5% 3/55	1.8% 1/57
Gastrointestinal disorders EPIGASTRIC DISCOMFORT	5.5% 3/55	1.8% 1/57
Infections and infestations NASOPHARYNGITIS	7.3% 4/55	15.8% 9/57
Infections and infestations URINARY TRACT INFECTION	1.8% 1/55	5.3% 3/57
Infections and infestations UPPER RESPIRATORY TRACT INFECTION	9.1% 5/55	10.5% 6/57
Skin and subcutaneous tissue disorders SWELLING FACE	1.8% 1/55	5.3% 3/57
Musculoskeletal and connective tissue disorders BACK PAIN	5.5% 3/55	3.5% 2/57
Respiratory, thoracic and mediastinal disorders COUGH	10.9% 6/55	5.3% 3/57
Respiratory, thoracic and mediastinal disorders PRODUCTIVE COUGH	5.5% 3/55	0.00% 0/57
General disorders FATIGUE	5.5% 3/55	1.8% 1/57

Additional Information

BMS Study Director

Bristol-Myers Squibb

Email: Clinical.Trials@bms.com

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