A Study to Compare the Response to Treatment With Abatacept vs Adalimumab, on Background Methotrexate, in Adults With Early, Seropositive, and Shared Epitope-positive Rheumatoid Arthritis and an Inadequate Response to Methotrexate

A Randomized, Head-to-head, Single-blind Study to Compare the Response to Treatment With Subcutaneous Abatacept vs Adalimumab, on Background Methotrexate, in Adults With Early, Seropositive Rheumatoid Arthritis Who Have Shared Epitope HLA Class II Risk Alleles and Have an Inadequate Response to Methotrexate

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04909801

Enrollment

338

Registered

2021-06-02

Start date

2021-09-15

Completion date

2027-09-01

Last updated

2025-02-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Rheumatoid Arthritis

Keywords

Abatacept, Adalimumab, BMS-188667, Humira®, Methotrexate, Orencia®, Rheumatoid Arthritis

Brief summary

The purpose of this study is to evaluate the superiority in efficacy of abatacept compared with adalimumab, on background methotrexate, in adults with early, seropositive, and shared epitope-positive rheumatoid arthritis and an inadequate methotrexate response.

Interventions

DRUGAbatacept

Abatacept SC (125 mg) once weekly

DRUGAdalimumab

Adalimumab SC (40 mg) once every 2 weeks

DRUGMethotrexate

Methotrexate oral/parenteral maximum tolerated dose (minimum 15 mg and maximum 25 mg weekly)

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Early rheumatoid arthritis (RA), defined as symptoms of RA that started ≤ 12 months prior to screening and satisfied the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2010 criteria for the classification of RA at some point during the 12-month period * Naïve to any targeted (biologic or nonbiologic) disease-modifying antirheumatic drugs (DMARDs), conventional synthetic DMARDs other than methotrexate (MTX), or investigational therapies for RA * Treated with MTX for at least 12 weeks, with a stable dose of oral or parenteral MTX for at least 4 weeks prior to randomization * Anti-cyclic citrullinated peptide-2 (Anti-CCP-2) test that is \> 3× the upper limit of normal and are positive for rheumatoid factor (RF) according to central lab testing during screening * At least a Disease Activity Score 28-joint count calculated using C-reactive protein (DAS28-CRP) ≥ 3.2 at screening * At least 3 tender and at least 3 swollen joints at screening and at randomization

Exclusion criteria

* Women who are breastfeeding * Autoimmune disease other than RA (e.g., psoriasis, systemic lupus erythematosus \[SLE\], vasculitis, seronegative spondyloarthritis, inflammatory bowel disease, Sjogren's syndrome) or currently active fibromyalgia * History of or current inflammatory joint disease other than RA (e.g., psoriatic arthritis, gout, reactive arthritis, Lyme disease) * At risk for tuberculosis * Recent acute infection * History of chronic or recurrent bacterial infection (e.g., chronic pyelonephritis, osteomyelitis, bronchiectasis) * History of infection of a joint prosthesis or artificial joint * History of systemic fungal infections (such as histoplasmosis, blastomycosis, or coccidiomycosis) * History of primary immunodeficiency * Current clinical findings or a history of a demyelinating disorder * 5 or more joints cannot be assessed for tenderness or swelling Other protocol-defined inclusion/

Design outcomes

Primary

Measure	Time frame	Description
Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	Baseline, week 24	The ACR 50 definition of improvement is a 50% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 50% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.

Secondary

Measure	Time frame	Description
Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	Baseline, week 24	The ACR 50 definition of improvement is a 50% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 50% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) at Week 24	Week 24	CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.
Adjusted Mean Change From Baseline in SE+ Participant-Reported Pain Visual Analog Scale (VAS) at Week 24	Baseline, week 24	Participant-reported pain by a 0-100mm visual analog scale; higher score indicates more pain. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 20 definition of improvement is a 20% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 20% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 50 definition of improvement is a 50% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 50% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 70 definition of improvement is a 70% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 70% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29, 57, 85, 113, 141, 169	DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\sqrt(TJC28) + 0.28\sqrt(SJC28) + 0.36\ln(CRP+1) + 0.014\GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.
Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29, 57, 85, 113, 141, 169	CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.
Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29, 57, 85, 113, 141, 169	SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL.
Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 20 definition of improvement is a 20% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 20% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 50 definition of improvement is a 50% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 50% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Baseline, day 29, 57, 85, 113, 141, 169	The ACR 70 definition of improvement is a 70% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 70% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.
Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29, 57, 85, 113, 141, 169	DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\sqrt(TJC28) + 0.28\sqrt(SJC28) + 0.36\ln(CRP+1) + 0.014\GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.
Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29, 57, 85, 113, 141, 169	CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.
Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29, 57, 85, 113, 141, 169	SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL.
Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. Remission was defined as DAS28-CRP \< 2.6. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\sqrt(TJC28) + 0.28\sqrt(SJC28) + 0.36\ln(CRP+1) + 0.014\GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) at Week 24	Week 24	DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\sqrt(TJC28) + 0.28\sqrt(SJC28) + 0.36\ln(CRP+1) + 0.014\GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.
Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. Remission was defined as SDAI =\< 3.3. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	6\) Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI). For the eight disability categories (Dressing/grooming, arising, eating, walking, hygiene, reach, grip, and activities), there is an aids or devices variables to record the type of assistance. If aids or devices and/or assistance from another person are checked for a category, the score is set to 2 (much difficulty), if the original score is 0 (no difficulty) or 1 (some difficulty). HAQ-DI is then calculated by summing the adjusted categories scores and dividing by the number of categories answered (increasing scores for the 8 disability categories questionnaire indicate increasing level of difficulty with 0 being the lowest score without any difficulty and 3 being the highest score unable to do. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. Remission was defined as DAS28-CRP \< 2.6. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\sqrt(TJC28) + 0.28\sqrt(SJC28) + 0.36\ln(CRP+1) + 0.014\GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI remission was defined as =\<2.8. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. Remission was defined as SDAI =\< 3.3. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	6\) Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI). For the eight disability categories (Dressing/grooming, arising, eating, walking, hygiene, reach, grip, and activities), there is an aids or devices variables to record the type of assistance. If aids or devices and/or assistance from another person are checked for a category, the score is set to 2 (much difficulty), if the original score is 0 (no difficulty) or 1 (some difficulty). HAQ-DI is then calculated by summing the adjusted categories scores and dividing by the number of categories answered (increasing scores for the 8 disability categories questionnaire indicate increasing level of difficulty with 0 being the lowest score without any difficulty and 3 being the highest score unable to do. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Baseline, day 29, 57, 85, 113, 141, 169	1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Up to week 24	SF-36 is a generic 36-item questionnaire measuring health-related quality of life, which covers 8 health dimensions within 2 components. The physical component summary (PCS) consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. Participants self-report on items in a subscale that have between 2-6 choices per item using Likert-type responses (e.g. none of the time, some of the time). Summations of item scores of the same subscale give the subscale scores, which are transformed into a range from 0 to 100, with a higher score indicating better quality of life. The 8 subscales will be scored using norm-based methods that have standardized the T-scores to a mean of 50 and a standard deviation of 10 in the general population.
Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Up to week 24	SF-36 is a generic 36-item questionnaire measuring health-related quality of life, which covers 8 health dimensions within 2 components. The physical component summary (PCS) consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. Participants self-report on items in a subscale that have between 2-6 choices per item using Likert-type responses (e.g. none of the time, some of the time). Summations of item scores of the same subscale give the subscale scores, which are transformed into a range from 0 to 100, with a higher score indicating better quality of life. The 8 subscales will be scored using norm-based methods that have standardized the T-scores to a mean of 50 and a standard deviation of 10 in the general population.
Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for SE+ Participants	Up to week 24	The SF-36 v2.0, which covers 8 health dimensions within 2 components. The physical component summary (PCS) of the SF-36 consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) of the SF-36 consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. The scores range from 0 to 100, with a higher score indicating better quality of life. The 2 summary scores (PCS and MCS) will be calculated by taking a weighted linear combination of the 8 individual subscales. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for All Participants	Up to week 24	The SF-36 v2.0, which covers 8 health dimensions within 2 components. The physical component summary (PCS) of the SF-36 consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) of the SF-36 consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. The scores range from 0 to 100, with a higher score indicating better quality of life. The 2 summary scores (PCS and MCS) will be calculated by taking a weighted linear combination of the 8 individual subscales. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.
Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Baseline, day 29, 57, 85, 113, 141, 169	CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI remission was defined as =\<2.8. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Countries

Argentina, Australia, Czechia, France, Germany, Italy, Japan, Mexico, Poland, Spain, Switzerland, Taiwan, United Kingdom, United States

Participant flow

Pre-assignment details

338 participants were treated during the single-blind treatment. 321 of the participants who completed the single-blind treatment continued to be treated in the open-label.

Participants by arm

Arm	Count
Abatacept Participants self-administered Abatacept 125 mg subcutaneous injection weekly up to and including Week 103 (Day 722) with background stable methotrexate therapy	169
Adalimumab, Then Abatacept (OLE Period) Participants self-administered Adalimumab 40 mg subcutaneous injection once every 2 weeks up to and including Week 22 (Day 155) with background stable methotrexate therapy. Those participants who entered the OL phase then took 125 mg Abatacept, which was self-administered subcutaneous weekly up to and including Week 103 (Day 722)	169
Total	338

Withdrawals & dropouts

Period	Reason	FG000	FG001
Overall Study	Adverse Event	1	2
Overall Study	Lack of Efficacy	2	1
Overall Study	other reasons	1	1
Overall Study	Participant request to discontinue study treatment	1	2
Overall Study	Withdrawal by Subject	2	1

Baseline characteristics

Characteristic	Total	Abatacept	Adalimumab, Then Abatacept (OLE Period)
Age, Continuous	48.4 Years STANDARD_DEVIATION 13.59	49.3 Years STANDARD_DEVIATION 13.71	47.4 Years STANDARD_DEVIATION 13.43
Race (NIH/OMB) American Indian or Alaska Native	18 Participants	9 Participants	9 Participants
Race (NIH/OMB) Asian	40 Participants	17 Participants	23 Participants
Race (NIH/OMB) Black or African American	5 Participants	4 Participants	1 Participants
Race (NIH/OMB) More than one race	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Unknown or Not Reported	40 Participants	17 Participants	23 Participants
Race (NIH/OMB) White	235 Participants	122 Participants	113 Participants
Sex: Female, Male Female	268 Participants	130 Participants	138 Participants
Sex: Female, Male Male	70 Participants	39 Participants	31 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 169	0 / 169
other Total, other adverse events	34 / 169	41 / 169
serious Total, serious adverse events	4 / 169	6 / 169

Outcome results

Primary

Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24

The ACR 50 definition of improvement is a 50% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 50% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.

Time frame: Baseline, week 24

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at week 24 or discontinuation due to any reason before week 24 are considered non-responders

Arm	Measure	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	59.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	60.3 Percentage of participants

p-value: 0.902695% CI: [0.6, 1.6]Regression, Logistic

Secondary

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for All Participants

The SF-36 v2.0, which covers 8 health dimensions within 2 components. The physical component summary (PCS) of the SF-36 consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) of the SF-36 consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. The scores range from 0 to 100, with a higher score indicating better quality of life. The 2 summary scores (PCS and MCS) will be calculated by taking a weighted linear combination of the 8 individual subscales. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Time frame: Up to week 24

Secondary

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for SE+ Participants

Time frame: Up to week 24

Secondary

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants

SF-36 is a generic 36-item questionnaire measuring health-related quality of life, which covers 8 health dimensions within 2 components. The physical component summary (PCS) consists of these 4 subscales: Physical functioning, Role-physical, Bodily pain, General health. The mental component summary (MCS) consists of these 4 subscales: Vitality, Social functioning, Role-emotional, Mental health. Participants self-report on items in a subscale that have between 2-6 choices per item using Likert-type responses (e.g. none of the time, some of the time). Summations of item scores of the same subscale give the subscale scores, which are transformed into a range from 0 to 100, with a higher score indicating better quality of life. The 8 subscales will be scored using norm-based methods that have standardized the T-scores to a mean of 50 and a standard deviation of 10 in the general population.

Time frame: Up to week 24

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Physical Functioning	9.2 T-score	Standard Error 0.813
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Role-Physical	9.1 T-score	Standard Error 0.809
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Bodily Pain	14.2 T-score	Standard Error 0.863
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: General Health	8.1 T-score	Standard Error 0.779
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Vitality	10.0 T-score	Standard Error 0.878
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Social Functioning	9.6 T-score	Standard Error 0.828
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Role-Emotional	9.0 T-score	Standard Error 0.921
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Mental Health	8.9 T-score	Standard Error 0.799
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Physical Component Summary	10.2 T-score	Standard Error 0.738
Abatacept	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Mental Component Summary	8.4 T-score	Standard Error 0.818
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Mental Health	7.1 T-score	Standard Error 0.795
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Physical Functioning	9.8 T-score	Standard Error 0.817
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Social Functioning	9.4 T-score	Standard Error 0.824
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Role-Physical	8.9 T-score	Standard Error 0.805
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Mental Component Summary	7.3 T-score	Standard Error 0.814
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Bodily Pain	12.0 T-score	Standard Error 0.859
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Role-Emotional	9.1 T-score	Standard Error 0.917
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: General Health	6.5 T-score	Standard Error 0.783
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Physical Component Summary	9.6 T-score	Standard Error 0.735
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants	Day 169: Vitality	8.4 T-score	Standard Error 0.874

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants

1. Tender joint count (standard 68 joint count) 2. Swollen joint count (standard 66 joint count) 3. Participant global assessment of pain (a 0-100mm visual analog scale with 100 mm being the worst pain) 4. Participant global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the highest disease activity) 5. Physician global assessment of disease activity (a 0-100mm visual analog scale with 100 mm being the worst case) 6. Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI) (increasing scores for the 8 disability categories indicate increasing level of difficulty). HAQDI is calculated by summing the adjusted categories scores and dividing by the number of categories answered 7. C-reactive protein (increasing levels indicate increasing level of disease) Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 29: Total Tender Joint Count	-8.1 Joints count	Standard Error 0.529
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 29: Total Swollen Joint Count	-6.1 Joints count	Standard Error 0.374
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 57: Total Tender Joint Count	-11.3 Joints count	Standard Error 0.549
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 57: Total Swollen Joint Count	-8.7 Joints count	Standard Error 0.322
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 85: Total Tender Joint Count	-12.7 Joints count	Standard Error 0.507
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 85: Total Swollen Joint Count	-9.3 Joints count	Standard Error 0.289
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 113: Total Tender Joint Count	-14.4 Joints count	Standard Error 0.411
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 113: Total Swollen Joint Count	-10.1 Joints count	Standard Error 0.255
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 141: Total Tender Joint Count	-14.8 Joints count	Standard Error 0.417
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 141: Total Swollen Joint Count	-10.6 Joints count	Standard Error 0.259
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 169: Total Tender Joint Count	-14.5 Joints count	Standard Error 0.474
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 169: Total Swollen Joint Count	-10.2 Joints count	Standard Error 0.311
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 169: Total Tender Joint Count	-13.8 Joints count	Standard Error 0.468
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 29: Total Tender Joint Count	-8.2 Joints count	Standard Error 0.527
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 113: Total Tender Joint Count	-13.9 Joints count	Standard Error 0.41
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 29: Total Swollen Joint Count	-6.6 Joints count	Standard Error 0.372
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 141: Total Swollen Joint Count	-9.9 Joints count	Standard Error 0.257
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 57: Total Tender Joint Count	-11.1 Joints count	Standard Error 0.545
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 113: Total Swollen Joint Count	-9.8 Joints count	Standard Error 0.254
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 57: Total Swollen Joint Count	-8.7 Joints count	Standard Error 0.319
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 169: Total Swollen Joint Count	-9.8 Joints count	Standard Error 0.307
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 85: Total Tender Joint Count	-12.4 Joints count	Standard Error 0.506
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 141: Total Tender Joint Count	-13.8 Joints count	Standard Error 0.414
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants	Day 85: Total Swollen Joint Count	-9.4 Joints count	Standard Error 0.289

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 29: Total Tender Joint Count	-9.1 Joints count	Standard Error 0.58
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 29: Total Swollen Joint Count	-6.2 Joints count	Standard Error 0.422
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 57: Total Tender Joint Count	-11.9 Joints count	Standard Error 0.608
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 57: Total Swollen Joint Count	-8.6 Joints count	Standard Error 0.378
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 85: Total Tender Joint Count	-13.5 Joints count	Standard Error 0.608
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 85: Total Swollen Joint Count	-9.5 Joints count	Standard Error 0.352
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 113: Total Tender Joint Count	-14.5 Joints count	Standard Error 0.516
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 113: Total Swollen Joint Count	-10.1 Joints count	Standard Error 0.321
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 141: Total Tender Joint Count	-14.8 Joints count	Standard Error 0.499
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 141: Total Swollen Joint Count	-10.4 Joints count	Standard Error 0.321
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 169: Total Tender Joint Count	-14.7 Joints count	Standard Error 0.58
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 169: Total Swollen Joint Count	-10.2 Joints count	Standard Error 0.397
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 169: Total Tender Joint Count	-13.8 Joints count	Standard Error 0.583
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 29: Total Tender Joint Count	-8.6 Joints count	Standard Error 0.58
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 113: Total Tender Joint Count	-13.8 Joints count	Standard Error 0.526
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 29: Total Swollen Joint Count	-6.7 Joints count	Standard Error 0.422
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 141: Total Swollen Joint Count	-9.8 Joints count	Standard Error 0.325
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 57: Total Tender Joint Count	-11.6 Joints count	Standard Error 0.621
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 113: Total Swollen Joint Count	-9.8 Joints count	Standard Error 0.326
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 57: Total Swollen Joint Count	-8.8 Joints count	Standard Error 0.386
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 169: Total Swollen Joint Count	-9.7 Joints count	Standard Error 0.399
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 85: Total Tender Joint Count	-12.7 Joints count	Standard Error 0.618
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 141: Total Tender Joint Count	-13.9 Joints count	Standard Error 0.506
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants	Day 85: Total Swollen Joint Count	-9.4 Joints count	Standard Error 0.358

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Participants Global Assess Disease Activity (mm)	-19.4 score on a scale	Standard Error 1.865
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Physician Global Assess Disease Activity (mm)	-24.4 score on a scale	Standard Error 1.613
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Participants Assessment of Pain (mm)	-19.2 score on a scale	Standard Error 1.872
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Participants Global Assess Disease Activity (mm)	-27.3 score on a scale	Standard Error 1.888
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Physician Global Assess Disease Activity (mm)	-35.7 score on a scale	Standard Error 1.583
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Participants Assessment of Pain (mm)	-25.9 score on a scale	Standard Error 1.957
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Participants Global Assess Disease Activity (mm)	-32.8 score on a scale	Standard Error 1.874
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Physician Global Assess Disease Activity (mm)	-40.1 score on a scale	Standard Error 1.459
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Participants Assessment of Pain (mm)	-32.1 score on a scale	Standard Error 1.939
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Participants Global Assess Disease Activity (mm)	-37.7 score on a scale	Standard Error 1.787
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Physician Global Assess Disease Activity (mm)	-46.8 score on a scale	Standard Error 1.216
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Participants Assessment of Pain (mm)	-36.6 score on a scale	Standard Error 1.883
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Participants Global Assess Disease Activity (mm)	-38.4 score on a scale	Standard Error 1.866
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Physician Global Assess Disease Activity (mm)	-48.5 score on a scale	Standard Error 1.258
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Participants Assessment of Pain (mm)	-38.7 score on a scale	Standard Error 1.858
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Participants Global Assess Disease Activity (mm)	-39.1 score on a scale	Standard Error 1.842
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Physician Global Assess Disease Activity (mm)	-47.7 score on a scale	Standard Error 1.32
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Participants Assessment of Pain (mm)	-39.5 score on a scale	Standard Error 1.895
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Physician Global Assess Disease Activity (mm)	-45.2 score on a scale	Standard Error 1.221
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Participants Global Assess Disease Activity (mm)	-20.6 score on a scale	Standard Error 1.868
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Participants Global Assess Disease Activity (mm)	-34.8 score on a scale	Standard Error 1.78
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Physician Global Assess Disease Activity (mm)	-27.7 score on a scale	Standard Error 1.612
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Participants Assessment of Pain (mm)	-37.0 score on a scale	Standard Error 1.864
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 29: Participants Assessment of Pain (mm)	-22.7 score on a scale	Standard Error 1.863
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Physician Global Assess Disease Activity (mm)	-44.9 score on a scale	Standard Error 1.218
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Participants Global Assess Disease Activity (mm)	-28.3 score on a scale	Standard Error 1.893
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Participants Assessment of Pain (mm)	-35.4 score on a scale	Standard Error 1.83
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Physician Global Assess Disease Activity (mm)	-36.7 score on a scale	Standard Error 1.579
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 113: Participants Assessment of Pain (mm)	-33.9 score on a scale	Standard Error 1.871
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 57: Participants Assessment of Pain (mm)	-28.7 score on a scale	Standard Error 1.954
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Physician Global Assess Disease Activity (mm)	-46.2 score on a scale	Standard Error 1.296
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Participants Global Assess Disease Activity (mm)	-32.8 score on a scale	Standard Error 1.884
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 141: Participants Global Assess Disease Activity (mm)	-34.1 score on a scale	Standard Error 1.856
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Physician Global Assess Disease Activity (mm)	-41.2 score on a scale	Standard Error 1.459
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 169: Participants Global Assess Disease Activity (mm)	-36.6 score on a scale	Standard Error 1.827
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants	Day 85: Participants Assessment of Pain (mm)	-33.7 score on a scale	Standard Error 1.923

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Participants Global Assess Disease Activity (mm)	-20.0 score on a scale	Standard Error 2.23
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Physician Global Assess Disease Activity (mm)	-26.8 score on a scale	Standard Error 1.896
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Participants Assessment of Pain (mm)	-19.5 score on a scale	Standard Error 2.219
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Participants Global Assess Disease Activity (mm)	-25.7 score on a scale	Standard Error 2.205
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Physician Global Assess Disease Activity (mm)	-37.7 score on a scale	Standard Error 1.782
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Participants Global Assess Disease Activity (mm)	-37.7 score on a scale	Standard Error 2.124
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Physician Global Assess Disease Activity (mm)	-47.6 score on a scale	Standard Error 1.462
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Participants Assessment of Pain (mm)	-37.0 score on a scale	Standard Error 2.207
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Participants Global Assess Disease Activity (mm)	-38.8 score on a scale	Standard Error 2.243
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Physician Global Assess Disease Activity (mm)	-48.9 score on a scale	Standard Error 1.498
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Participants Assessment of Pain (mm)	-39.0 score on a scale	Standard Error 2.212
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Participants Global Assess Disease Activity (mm)	-39.6 score on a scale	Standard Error 2.237
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Physician Global Assess Disease Activity (mm)	-48.0 score on a scale	Standard Error 1.683
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Participants Assessment of Pain (mm)	-40.9 score on a scale	Standard Error 2.256
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Participants Assessment of Pain (mm)	-24.8 score on a scale	Standard Error 2.305
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Participants Global Assess Disease Activity (mm)	-33.4 score on a scale	Standard Error 2.239
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Physician Global Assess Disease Activity (mm)	-43.8 score on a scale	Standard Error 1.66
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Participants Assessment of Pain (mm)	-33.1 score on a scale	Standard Error 2.321
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Participants Global Assess Disease Activity (mm)	-35.0 score on a scale	Standard Error 2.274
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Participants Global Assess Disease Activity (mm)	-21.4 score on a scale	Standard Error 2.23
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Physician Global Assess Disease Activity (mm)	-42.2 score on a scale	Standard Error 1.675
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Physician Global Assess Disease Activity (mm)	-27.1 score on a scale	Standard Error 1.87
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Physician Global Assess Disease Activity (mm)	-45.7 score on a scale	Standard Error 1.491
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 29: Participants Assessment of Pain (mm)	-23.6 score on a scale	Standard Error 2.229
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Participants Assessment of Pain (mm)	-37.7 score on a scale	Standard Error 2.288
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Participants Global Assess Disease Activity (mm)	-28.4 score on a scale	Standard Error 2.276
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 141: Participants Assessment of Pain (mm)	-38.3 score on a scale	Standard Error 2.223
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Physician Global Assess Disease Activity (mm)	-37.6 score on a scale	Standard Error 1.806
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Participants Assessment of Pain (mm)	-33.3 score on a scale	Standard Error 2.363
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 85: Participants Global Assess Disease Activity (mm)	-32.9 score on a scale	Standard Error 2.302
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Participants Global Assess Disease Activity (mm)	-35.7 score on a scale	Standard Error 2.162
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Participants Global Assess Disease Activity (mm)	-36.0 score on a scale	Standard Error 2.278
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Physician Global Assess Disease Activity (mm)	-45.8 score on a scale	Standard Error 1.482
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 57: Participants Assessment of Pain (mm)	-29.1 score on a scale	Standard Error 2.358
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 113: Participants Assessment of Pain (mm)	-34.3 score on a scale	Standard Error 2.237
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants	Day 169: Physician Global Assess Disease Activity (mm)	-45.9 score on a scale	Standard Error 1.683

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants

6\) Participant assessment of physical function Health Assessment Questionnaire Disability Index (HAQ-DI). For the eight disability categories (Dressing/grooming, arising, eating, walking, hygiene, reach, grip, and activities), there is an aids or devices variables to record the type of assistance. If aids or devices and/or assistance from another person are checked for a category, the score is set to 2 (much difficulty), if the original score is 0 (no difficulty) or 1 (some difficulty). HAQ-DI is then calculated by summing the adjusted categories scores and dividing by the number of categories answered (increasing scores for the 8 disability categories questionnaire indicate increasing level of difficulty with 0 being the lowest score without any difficulty and 3 being the highest score unable to do. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline=Post-baseline - Baseline value.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 29: Disability Index	-0.4 score on a scale	Standard Error 0.04
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 57: Disability Index	-0.6 score on a scale	Standard Error 0.042
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 85: Disability Index	-0.7 score on a scale	Standard Error 0.043
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 113: Disability Index	-0.7 score on a scale	Standard Error 0.041
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 141: Disability Index	-0.8 score on a scale	Standard Error 0.04
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 169: Disability Index	-0.8 score on a scale	Standard Error 0.042
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 141: Disability Index	-0.7 score on a scale	Standard Error 0.04
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 29: Disability Index	-0.5 score on a scale	Standard Error 0.04
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 113: Disability Index	-0.7 score on a scale	Standard Error 0.041
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 57: Disability Index	-0.6 score on a scale	Standard Error 0.042
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 169: Disability Index	-0.8 score on a scale	Standard Error 0.042
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants	Day 85: Disability Index	-0.6 score on a scale	Standard Error 0.043

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 29: Disability Index	-0.4 score on a scale	Standard Error 0.047
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 57: Disability Index	-0.6 score on a scale	Standard Error 0.049
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 85: Disability Index	-0.8 score on a scale	Standard Error 0.05
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 113: Disability Index	-0.8 score on a scale	Standard Error 0.047
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 141: Disability Index	-0.9 score on a scale	Standard Error 0.046
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 169: Disability Index	-0.9 score on a scale	Standard Error 0.049
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 141: Disability Index	-0.8 score on a scale	Standard Error 0.046
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 29: Disability Index	-0.5 score on a scale	Standard Error 0.047
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 113: Disability Index	-0.7 score on a scale	Standard Error 0.048
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 57: Disability Index	-0.6 score on a scale	Standard Error 0.05
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 169: Disability Index	-0.8 score on a scale	Standard Error 0.05
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants	Day 85: Disability Index	-0.7 score on a scale	Standard Error 0.051

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 29: C Reactive Protein (mg/L)	-1.4 mg/L	Standard Error 1.52
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 57: C Reactive Protein (mg/L)	-5.7 mg/L	Standard Error 0.635
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 85: C Reactive Protein (mg/L)	-5.4 mg/L	Standard Error 0.719
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 113: C Reactive Protein (mg/L)	-5.7 mg/L	Standard Error 0.704
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 141: C Reactive Protein (mg/L)	-5.9 mg/L	Standard Error 0.778
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 169: C Reactive Protein (mg/L)	-6.2 mg/L	Standard Error 0.912
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 141: C Reactive Protein (mg/L)	-5.5 mg/L	Standard Error 0.774
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 29: C Reactive Protein (mg/L)	-6.8 mg/L	Standard Error 1.514
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 113: C Reactive Protein (mg/L)	-5.8 mg/L	Standard Error 0.702
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 57: C Reactive Protein (mg/L)	-6.4 mg/L	Standard Error 0.635
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 169: C Reactive Protein (mg/L)	-5.0 mg/L	Standard Error 0.9
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants	Day 85: C Reactive Protein (mg/L)	-6.6 mg/L	Standard Error 0.717

Secondary

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 29: C Reactive Protein (mg/L)	-1.4 mg/L	Standard Error 1.986
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 57: C Reactive Protein (mg/L)	-6.1 mg/L	Standard Error 0.818
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 85: C Reactive Protein (mg/L)	-6.7 mg/L	Standard Error 0.745
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 113: C Reactive Protein (mg/L)	-7.5 mg/L	Standard Error 0.701
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 141: C Reactive Protein (mg/L)	-7.9 mg/L	Standard Error 0.724
Abatacept	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 169: C Reactive Protein (mg/L)	-6.6 mg/L	Standard Error 1.083
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 141: C Reactive Protein (mg/L)	-7.6 mg/L	Standard Error 0.733
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 29: C Reactive Protein (mg/L)	-8.1 mg/L	Standard Error 1.995
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 113: C Reactive Protein (mg/L)	-7.3 mg/L	Standard Error 0.713
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 57: C Reactive Protein (mg/L)	-7.4 mg/L	Standard Error 0.845
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 169: C Reactive Protein (mg/L)	-5.4 mg/L	Standard Error 1.098
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants	Day 85: C Reactive Protein (mg/L)	-8.6 mg/L	Standard Error 0.759

Secondary

Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants

CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI remission was defined as =\<2.8. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 29	-14.6 score on a scale	Standard Error 0.818
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 57	-20.9 score on a scale	Standard Error 0.786
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 85	-23.5 score on a scale	Standard Error 0.763
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 113	-26.6 score on a scale	Standard Error 0.644
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 141	-27.1 score on a scale	Standard Error 0.647
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 169	-26.7 score on a scale	Standard Error 0.763
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 141	-25.2 score on a scale	Standard Error 0.631
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 29	-15.9 score on a scale	Standard Error 0.823
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 113	-25.4 score on a scale	Standard Error 0.646
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 57	-21.6 score on a scale	Standard Error 0.784
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 169	-25.4 score on a scale	Standard Error 0.749
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants	Day 85	-23.5 score on a scale	Standard Error 0.769

Comparison: Day 29p-value: 0.231995% CI: [-0.9, 3.5]longitudinal

Comparison: Day 57p-value: 0.557295% CI: [-1.5, 2.7]longitudinal

Comparison: Day 85p-value: 0.936695% CI: [-2, 2.1]longitudinal

Comparison: Day 113p-value: 0.150895% CI: [-3.5, 1]longitudinal

Comparison: Day 141p-value: 0.030395% CI: [-3.6, -0.2]longitudinal

Comparison: Day 169p-value: 0.233395% CI: [-3.3, 0.8]longitudinal

Secondary

Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 29	-15.5 score on a scale	Standard Error 0.972
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 57	-21.3 score on a scale	Standard Error 0.928
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 85	-24.6 score on a scale	Standard Error 0.928
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 113	-26.8 score on a scale	Standard Error 0.798
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 141	-27.3 score on a scale	Standard Error 0.783
Abatacept	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 169	-26.9 score on a scale	Standard Error 0.959
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 141	-25.6 score on a scale	Standard Error 0.78
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 29	-15.9 score on a scale	Standard Error 0.955
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 113	-25.6 score on a scale	Standard Error 0.808
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 57	-21.9 score on a scale	Standard Error 0.949
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 169	-25.5 score on a scale	Standard Error 0.959
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants	Day 85	-23.7 score on a scale	Standard Error 0.945

Comparison: Day 29p-value: 0.785295% CI: [-2.3, 3.1]longitudinal

Comparison: Day 57p-value: 0.633695% CI: [-2, 3.3]longitudinal

Comparison: Day 85p-value: 0.487995% CI: [-3.5, 1.7]longitudinal

Comparison: Day 113p-value: 0.281295% CI: [-3.5, 1]longitudinal

Comparison: Day 141p-value: 0.120595% CI: [-3.9, 0.5]longitudinal

Comparison: Day 169p-value: 0.300195% CI: [-4.1, 1.3]longitudinal

Secondary

Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants

DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. Remission was defined as DAS28-CRP \< 2.6. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\*sqrt(TJC28) + 0.28\*sqrt(SJC28) + 0.36\*ln(CRP+1) + 0.014\*GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 29	-1.2 score on a scale	Standard Error 0.084
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 57	-1.9 score on a scale	Standard Error 0.089
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 85	-2.2 score on a scale	Standard Error 0.091
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 113	-2.6 score on a scale	Standard Error 0.084
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 141	-2.7 score on a scale	Standard Error 0.085
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 169	-2.6 score on a scale	Standard Error 0.094
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 141	-2.5 score on a scale	Standard Error 0.085
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 29	-1.5 score on a scale	Standard Error 0.084
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 113	-2.6 score on a scale	Standard Error 0.084
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 57	-2.1 score on a scale	Standard Error 0.089
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 169	-2.6 score on a scale	Standard Error 0.093
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants	Day 85	-2.4 score on a scale	Standard Error 0.091

Comparison: Day 29p-value: 0.009995% CI: [0.1, 0.5]longitudinal

Comparison: Day 57p-value: 0.151995% CI: [-0.1, 0.4]longitudinal

Comparison: Day 85p-value: 0.250595% CI: [-0.1, 0.4]longitudinal

Comparison: Day 113p-value: 0.524895% CI: [-0.3, 0.2]longitudinal

Comparison: Day 141p-value: 0.177895% CI: [-0.3, 0.2]longitudinal

Comparison: Day 169p-value: 0.85195% CI: [-0.3, 0.2]longitudinal

Secondary

Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 29	-1.3 score on a scale	Standard Error 0.099
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 57	-2.0 score on a scale	Standard Error 0.104
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 85	-2.3 score on a scale	Standard Error 0.109
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 113	-2.7 score on a scale	Standard Error 0.099
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 141	-2.7 score on a scale	Standard Error 0.101
Abatacept	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 169	-2.6 score on a scale	Standard Error 0.114
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 141	-2.6 score on a scale	Standard Error 0.102
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 29	-1.6 score on a scale	Standard Error 0.099
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 113	-2.6 score on a scale	Standard Error 0.101
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 57	-2.1 score on a scale	Standard Error 0.109
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 169	-2.6 score on a scale	Standard Error 0.116
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants	Day 85	-2.4 score on a scale	Standard Error 0.112

Comparison: Day 29p-value: 0.097795% CI: [0, 0.5]longitudinal

Comparison: Day 57p-value: 0.288995% CI: [-0.1, 0.5]longitudinal

Comparison: Day 85p-value: 0.767695% CI: [-0.3, 0.4]longitudinal

Comparison: Day 113p-value: 0.615795% CI: [-0.3, 0.2]longitudinal

Comparison: Day 141p-value: 0.390495% CI: [-0.4, 0.2]longitudinal

Comparison: Day 169p-value: 0.835995% CI: [-0.4, 0.3]longitudinal

Secondary

Adjusted Mean Change From Baseline in SE+ Participant-Reported Pain Visual Analog Scale (VAS) at Week 24

Participant-reported pain by a 0-100mm visual analog scale; higher score indicates more pain. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Time frame: Baseline, week 24

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements

Arm	Measure	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in SE+ Participant-Reported Pain Visual Analog Scale (VAS) at Week 24	-40.9 Score on a scale	Standard Error 2.256
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SE+ Participant-Reported Pain Visual Analog Scale (VAS) at Week 24	-37.7 Score on a scale	Standard Error 2.288

Secondary

Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants

Time frame: Up to week 24

Population: All treated participants with both baseline and post-baseline measurements

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Physical Functioning	8.9 T-score	Standard Error 0.706
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Role-Physical	8.6 T-score	Standard Error 0.681
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Bodily Pain	13.5 T-score	Standard Error 0.719
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: General Health	7.9 T-score	Standard Error 0.652
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Vitality	9.4 T-score	Standard Error 0.74
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Social Functioning	8.9 T-score	Standard Error 0.701
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Role-Emotional	8.4 T-score	Standard Error 0.773
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Mental Health	8.0 T-score	Standard Error 0.712
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Physical Component Summary	9.9 T-score	Standard Error 0.619
Abatacept	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Mental Component Summary	7.6 T-score	Standard Error 0.718
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Mental Health	7.6 T-score	Standard Error 0.7
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Physical Functioning	9.4 T-score	Standard Error 0.697
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Social Functioning	9.8 T-score	Standard Error 0.69
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Role-Physical	8.7 T-score	Standard Error 0.669
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Mental Component Summary	7.7 T-score	Standard Error 0.705
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Bodily Pain	11.7 T-score	Standard Error 0.706
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Role-Emotional	8.8 T-score	Standard Error 0.759
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: General Health	6.7 T-score	Standard Error 0.644
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Physical Component Summary	9.2 T-score	Standard Error 0.608
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants	Day 169: Vitality	8.8 T-score	Standard Error 0.725

Secondary

Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants

SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. Remission was defined as SDAI =\< 3.3. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL. Baseline value is the last assessment taken prior to first dose of single-blind study medication. Change from Baseline = Post-baseline - Baseline value.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 29	-14.7 Score on a scale	Standard Error 0.843
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 57	-21.5 Score on a scale	Standard Error 0.788
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 85	-24.0 Score on a scale	Standard Error 0.769
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 113	-27.2 Score on a scale	Standard Error 0.648
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 141	-27.7 Score on a scale	Standard Error 0.661
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 169	-27.3 Score on a scale	Standard Error 0.787
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 141	-25.8 Score on a scale	Standard Error 0.647
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 29	-16.6 Score on a scale	Standard Error 0.849
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 113	-26.0 Score on a scale	Standard Error 0.649
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 57	-22.1 Score on a scale	Standard Error 0.789
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 169	-26.0 Score on a scale	Standard Error 0.771
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants	Day 85	-24.2 Score on a scale	Standard Error 0.775

Comparison: Day 29p-value: 0.093895% CI: [-0.3, 4.2]longitudinal

Comparison: Day 57p-value: 0.605395% CI: [-1.6, 2.7]longitudinal

Comparison: Day 85p-value: 0.85795% CI: [-1.9, 2.3]longitudinal

Comparison: Day 113p-value: 0.159295% CI: [-3, 0.5]longitudinal

Comparison: Day 141p-value: 0.031995% CI: [-3.7, -0.2]longitudinal

Comparison: Day 169p-value: 0.205995% CI: [-3.4, 0.7]longitudinal

Secondary

Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline with both baseline and post-baseline measurements. Non-responders are not included

Arm	Measure	Group	Value (MEAN)	Dispersion
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 29	-15.6 score on a scale	Standard Error 1.008
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 57	-21.9 score on a scale	Standard Error 0.931
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 85	-25.3 score on a scale	Standard Error 0.935
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 113	-27.5 score on a scale	Standard Error 0.797
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 141	-28.1 score on a scale	Standard Error 0.791
Abatacept	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 169	-27.6 score on a scale	Standard Error 0.978
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 141	-26.4 score on a scale	Standard Error 0.787
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 29	-16.7 score on a scale	Standard Error 0.99
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 113	-26.3 score on a scale	Standard Error 0.807
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 57	-22.5 score on a scale	Standard Error 0.962
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 169	-26.1 score on a scale	Standard Error 0.983
Adalimumab, Then Abatacept (OLE Period)	Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants	Day 85	-24.6 score on a scale	Standard Error 0.953

Comparison: Day 29p-value: 0.410795% CI: [-1.6, 4]longitudinal

Comparison: Day 57p-value: 0.682495% CI: [-2.1, 3.2]longitudinal

Comparison: Day 85p-value: 0.579395% CI: [-3.4, 1.9]longitudinal

Comparison: Day 113p-value: 0.288395% CI: [-4.2, 1.2]longitudinal

Comparison: Day 141p-value: 0.128595% CI: [-3.9, 0.5]longitudinal

Comparison: Day 169p-value: 0.281595% CI: [-4.2, 1.2]longitudinal

Secondary

Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time

CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29	7.7 Percentage of participants
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 57	15.4 Percentage of participants
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 85	24.9 Percentage of participants
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 113	31.4 Percentage of participants
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 141	34.3 Percentage of participants
Abatacept	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 169	33.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 141	29.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29	6.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 113	29.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 57	14.2 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 169	32.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 85	20.7 Percentage of participants

Comparison: Day 29p-value: 0.656595% CI: [0.5, 2.9]Regression, Logistic

Comparison: Day 57p-value: 0.70195% CI: [0.6, 2.1]Regression, Logistic

Comparison: Day 85p-value: 0.368395% CI: [0.8, 2.1]Regression, Logistic

Comparison: Day 113p-value: 0.637295% CI: [0.7, 1.8]Regression, Logistic

Comparison: Day 141p-value: 0.292295% CI: [0.8, 2]Regression, Logistic

Comparison: Day 169p-value: 0.817895% CI: [0.7, 1.7]Regression, Logistic

Secondary

Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time

DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\*sqrt(TJC28) + 0.28\*sqrt(SJC28) + 0.36\*ln(CRP+1) + 0.014\*GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29	10.7 Percentage of participants
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 57	27.2 Percentage of participants
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 85	37.3 Percentage of participants
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 113	49.7 Percentage of participants
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 141	54.4 Percentage of participants
Abatacept	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 169	46.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 141	51.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29	16.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 113	54.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 57	33.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 169	50.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 85	40.8 Percentage of participants

Comparison: Day 29p-value: 0.107895% CI: [0.3, 1.1]Regression, Logistic

Comparison: Day 57p-value: 0.185595% CI: [0.4, 1.2]Regression, Logistic

Comparison: Day 85p-value: 0.522395% CI: [0.6, 1.4]Regression, Logistic

Comparison: Day 113p-value: 0.407895% CI: [0.5, 1.3]Regression, Logistic

Comparison: Day 141p-value: 0.523895% CI: [0.7, 1.8]Regression, Logistic

Comparison: Day 169p-value: 0.47495% CI: [0.5, 1.3]Regression, Logistic

Secondary

Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time

SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29	7.7 Percentage of participants
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 57	14.8 Percentage of participants
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 85	23.1 Percentage of participants
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 113	33.1 Percentage of participants
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 141	35.5 Percentage of participants
Abatacept	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 169	34.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 141	28.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29	7.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 113	28.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 57	16.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 169	31.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 85	20.7 Percentage of participants

Comparison: Day 29p-value: 0.959995% CI: [0.4, 2.2]Regression, Logistic

Comparison: Day 57p-value: 0.789995% CI: [0.5, 1.7]Regression, Logistic

Comparison: Day 85p-value: 0.630595% CI: [0.7, 1.9]Regression, Logistic

Comparison: Day 113p-value: 0.349195% CI: [0.8, 2]Regression, Logistic

Comparison: Day 141p-value: 0.491695% CI: [0.7, 1.9]Regression, Logistic

Comparison: Day 169p-value: 0.569795% CI: [0.7, 1.8]Regression, Logistic

Secondary

Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time

The ACR 20 definition of improvement is a 20% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 20% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 29	46.7 Percentage of participants
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 57	66.3 Percentage of participants
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 85	72.8 Percentage of participants
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 113	85.2 Percentage of participants
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 141	84.0 Percentage of participants
Abatacept	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 169	77.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 141	79.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 29	52.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 113	79.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 57	68.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 169	76.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 85	76.3 Percentage of participants

Comparison: Day 29p-value: 0.311795% CI: [0.5, 1.2]Regression, Logistic

Comparison: Day 57p-value: 0.61295% CI: [0.6, 1.4]Regression, Logistic

Comparison: Day 85p-value: 0.433995% CI: [0.5, 1.3]Regression, Logistic

Comparison: Day 113p-value: 0.196395% CI: [0.8, 2.6]Regression, Logistic

Comparison: Day 141p-value: 0.327595% CI: [0.8, 2.3]Regression, Logistic

Comparison: Day 169p-value: 0.911395% CI: [0.6, 1.7]Regression, Logistic

Secondary

Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24

Time frame: Baseline, week 24

Population: All treated participants

Arm	Measure	Value (NUMBER)
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	59.2 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24	63.9 Percentage of participants

p-value: 0.353495% CI: [0.5, 1.3]Regression, Logistic

Secondary

Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 29	20.1 Percentage of participants
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 57	38.5 Percentage of participants
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 85	52.7 Percentage of participants
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 113	60.4 Percentage of participants
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 141	61.5 Percentage of participants
Abatacept	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 169	59.2 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 141	58.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 29	27.2 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 113	59.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 57	41.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 169	63.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 85	53.3 Percentage of participants

Comparison: Day 29p-value: 0.124795% CI: [0.4, 1.1]Regression, Logistic

Comparison: Day 57p-value: 0.565695% CI: [0.6, 1.4]Regression, Logistic

Comparison: Day 85p-value: 0.89795% CI: [0.6, 1.5]Regression, Logistic

Comparison: Day 113p-value: 0.917595% CI: [0.7, 1.6]Regression, Logistic

Comparison: Day 141p-value: 0.599695% CI: [0.7, 1.7]Regression, Logistic

Comparison: Day 169p-value: 0.353495% CI: [0.5, 1.3]Regression, Logistic

Secondary

Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time

The ACR 70 definition of improvement is a 70% improvement over baseline in tender and swollen joint counts (#1 and #2) and a 70% improvement in 3 of the 5 remaining core data set measures (Participant global assessment of pain, participant global assessment of disease activity, physician global assessment of disease activity, participant assessment of physical function, and acute phase reactant value). Baseline value is the last assessment taken prior to first dose of single-blind study medication.

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All treated participants. Participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 29	5.9 Percentage of participants
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 57	20.7 Percentage of participants
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 85	30.2 Percentage of participants
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 113	35.5 Percentage of participants
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 141	40.2 Percentage of participants
Abatacept	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 169	39.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 141	40.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 29	10.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 113	33.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 57	23.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 169	45.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 85	32.0 Percentage of participants

Comparison: Day 29p-value: 0.164195% CI: [0.2, 1.3]Regression, Logistic

Comparison: Day 57p-value: 0.590595% CI: [0.5, 1.5]Regression, Logistic

Comparison: Day 85p-value: 0.714695% CI: [0.6, 1.5]Regression, Logistic

Comparison: Day 113p-value: 0.741695% CI: [0.7, 1.7]Regression, Logistic

Comparison: Day 141p-value: 0.902695% CI: [0.6, 1.5]Regression, Logistic

Comparison: Day 169p-value: 0.260595% CI: [0.5, 1.2]Regression, Logistic

Secondary

Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) at Week 24

CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.

Time frame: Week 24

Arm	Measure	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) at Week 24	33.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) at Week 24	35.3 Percentage of participants

p-value: 0.61495% CI: [0.5, 1.5]Regression, Logistic

Secondary

Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time

CDAI is a simple linear sum of the following four components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm). CDAI scores range from 2-76; higher scores indicate more active disease. CDAI is calculated using the following formula: TJC + SJC + PGA + MDGA where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, and MDGA = physician global assessment on a visual analog scale 0-10 cm.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29	9.4 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 57	17.1 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 85	26.5 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 113	29.1 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 141	34.2 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 169	33.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 141	30.2 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 29	6.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 113	32.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 57	13.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 169	35.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time	Day 85	19.8 Percentage of participants

Comparison: Day 29p-value: 0.415295% CI: [0.6, 4.1]Regression, Logistic

Comparison: Day 57p-value: 0.591795% CI: [0.6, 2.5]Regression, Logistic

Comparison: Day 85p-value: 0.334895% CI: [0.7, 2.6]Regression, Logistic

Comparison: Day 113p-value: 0.395995% CI: [0.4, 1.4]Regression, Logistic

Comparison: Day 141p-value: 0.622595% CI: [0.7, 2]Regression, Logistic

Comparison: Day 169p-value: 0.61495% CI: [0.5, 1.5]Regression, Logistic

Secondary

Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) at Week 24

DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\*sqrt(TJC28) + 0.28\*sqrt(SJC28) + 0.36\*ln(CRP+1) + 0.014\*GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.

Time frame: Week 24

Arm	Measure	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) at Week 24	44.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) at Week 24	46.6 Percentage of participants

p-value: 0.582495% CI: [0.5, 1.5]Regression, Logistic

Secondary

Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time

DAS28-CRP is a continuous variable which is a composite of 4 variables: the number of tender joints out of a pre-specified 28 joints, the number of swollen joints out of a pre-specified 28 joints, C-reactive protein in mg/L (CRP) and participant assessment of disease activity measure on a visual analogue scale (VAS) of 100mm. DAS28-CRP scores range from 0 to 10; higher scores indicate more active disease. DAS28-CRP is calculated using the following formula: DAS28-CRP(4) = 0.56\*sqrt(TJC28) + 0.28\*sqrt(SJC28) + 0.36\*ln(CRP+1) + 0.014\*GH + 0.96 where t28 = number of painful joints from 28 joints, sw28 = number of swollen joints from 28 joints, CRP = c-reactive protein in mg/L, and GH = general health or patient's global assessment of disease activity on a 100 mm VAS.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29	12.8 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 57	30.8 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 85	41.0 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 113	49.6 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 141	54.7 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 169	44.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 141	52.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 29	16.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 113	52.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 57	32.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 169	46.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time	Day 85	40.5 Percentage of participants

Comparison: Day 29p-value: 0.3295% CI: [0.3, 1.4]Regression, Logistic

Comparison: Day 57p-value: 0.499295% CI: [0.5, 1.5]Regression, Logistic

Comparison: Day 85p-value: 0.896395% CI: [0.6, 1.7]Regression, Logistic

Comparison: Day 113p-value: 0.454495% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 141p-value: 0.898595% CI: [0.6, 1.8]Regression, Logistic

Comparison: Day 169p-value: 0.582495% CI: [0.5, 1.5]Regression, Logistic

Secondary

Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time

SDAI is a simple linear sum of the following five components: Tender joint counts out of 28 joints, Swollen joint counts out of 28 joints, Participant global assessment of disease activity (0-10cm), Physicians global assessment of disease activity (0-10cm), high-sensitivity C-reactive protein (hsCRP mg/dL). SDAI total scores range from 0-86; higher scores indicate more active disease. SDAI is calculated using the following formula: TJC + SJC + PGA + MDGA + CRP where TJC = number of painful joints from 28 joints, SJC = number of swollen joints from 28 joints, PGA = patient global assessment on a visual analog scale 0-10 cm, MDGA = physician global assessment on a visual analog scale 0-10 cm, and CRP = c-reactive protein in mg/dL.

Time frame: Day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29	9.4 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 57	17.1 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 85	24.8 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 113	31.6 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 141	35.9 Percentage of participants
Abatacept	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 169	33.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 141	32.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 29	7.8 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 113	31.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 57	14.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 169	34.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time	Day 85	19.8 Percentage of participants

Comparison: Day 29p-value: 0.808495% CI: [0.4, 2.9]Regression, Logistic

Comparison: Day 57p-value: 0.74795% CI: [0.5, 2.3]Regression, Logistic

Comparison: Day 85p-value: 0.523395% CI: [0.7, 2.3]Regression, Logistic

Comparison: Day 113p-value: 0.729595% CI: [0.5, 1.6]Regression, Logistic

Comparison: Day 141p-value: 0.762195% CI: [0.6, 1.9]Regression, Logistic

Comparison: Day 169p-value: 0.686195% CI: [0.5, 1.6]Regression, Logistic

Secondary

Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 29	47.0 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 57	66.7 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 85	74.4 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 113	85.5 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 141	82.9 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 169	76.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 141	79.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 29	51.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 113	76.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 57	71.6 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 169	75.9 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time	Day 85	75.9 Percentage of participants

Comparison: Day 29p-value: 0.499695% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 57p-value: 0.44995% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 85p-value: 0.80995% CI: [0.5, 1.7]Regression, Logistic

Comparison: Day 113p-value: 0.073995% CI: [0.9, 3.6]Regression, Logistic

Comparison: Day 141p-value: 0.420195% CI: [0.7, 2.6]Regression, Logistic

Comparison: Day 169p-value: 0.792895% CI: [0.6, 2]Regression, Logistic

Secondary

Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 29	20.5 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 57	38.5 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 85	54.7 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 113	60.7 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 141	60.7 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 169	59.0 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 141	60.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 29	26.7 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 113	59.5 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 57	43.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 169	60.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time	Day 85	54.3 Percentage of participants

Comparison: Day 29p-value: 0.270195% CI: [0.4, 1.3]Regression, Logistic

Comparison: Day 57p-value: 0.486395% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 85p-value: 0.951395% CI: [0.6, 1.7]Regression, Logistic

Comparison: Day 113p-value: 0.853695% CI: [0.6, 1.8]Regression, Logistic

Comparison: Day 141p-value: 0.922395% CI: [0.6, 1.7]Regression, Logistic

Comparison: Day 169p-value: 0.902695% CI: [0.6, 1.6]Regression, Logistic

Secondary

Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time

Time frame: Baseline, day 29, 57, 85, 113, 141, 169

Population: All participants that are shared epitope-positive (SE+) at baseline. SE+ participants with missing data at each timepoint are considered non-responders

Arm	Measure	Group	Value (NUMBER)
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 57	17.9 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 113	35.0 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 29	6.8 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 141	40.2 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 85	30.8 Percentage of participants
Abatacept	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 169	39.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 85	35.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 29	10.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 57	24.1 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 169	47.4 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 113	35.3 Percentage of participants
Adalimumab, Then Abatacept (OLE Period)	Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time	Day 141	44.0 Percentage of participants

Comparison: Day 29p-value: 0.341195% CI: [0.2, 1.6]Regression, Logistic

Comparison: Day 57p-value: 0.254695% CI: [0.4, 1.3]Regression, Logistic

Comparison: Day 85p-value: 0.455895% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 113p-value: 0.954495% CI: [0.6, 1.7]Regression, Logistic

Comparison: Day 141p-value: 0.54595% CI: [0.5, 1.4]Regression, Logistic

Comparison: Day 169p-value: 0.222795% CI: [0.4, 1.2]Regression, Logistic

Source: ClinicalTrials.gov · Data processed: Jul 11, 2026

A Study to Compare the Response to Treatment With Abatacept vs Adalimumab, on Background Methotrexate, in Adults With Early, Seropositive, and Shared Epitope-positive Rheumatoid Arthritis and an Inadequate Response to Methotrexate

Conditions

Keywords

Brief summary

Related papers

Interventions

Sponsors

Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Pre-assignment details

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for All Participants

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) at Week 104 for SE+ Participants

Adjusted Mean Change From Baseline in 36-item Short Form Survey (SF-36) Over Time for SE+ Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for All Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 1-2 Over Time for SE+ Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for All Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 3-5 Over Time for SE+ Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for All Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 6 Over Time for SE+ Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for All Participants

Adjusted Mean Change From Baseline in American College of Rheumatology (ACR) Core Components 7 Over Time for SE+ Participants

Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for All Participants

Adjusted Mean Change From Baseline in Clinical Disease Activity Index (CDAI) Over Time for SE+ Participants

Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for All Participants

Adjusted Mean Change From Baseline in Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein (DAS28-CRP) Over Time for SE+ Participants

Adjusted Mean Change From Baseline in SE+ Participant-Reported Pain Visual Analog Scale (VAS) at Week 24

Adjusted Mean Change From Baseline in SF-36 Over Time for All Participants

Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for All Participants

Adjusted Mean Change From Baseline in Simple Disease Activity Index (SDAI) Over Time for SE+ Participants

Percentage of Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time

Percentage of Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time

Percentage of Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time

Percentage of Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time

Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response at Week 24

Percentage of Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time

Percentage of Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time

Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) at Week 24

Percentage of SE+ Participants Achieving Clinical Disease Activity Index Remission (CDAI <= 2.8) Over Time

Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) at Week 24

Percentage of SE+ Participants Achieving Disease Activity Score 28 Joint Count Calculated Using C Reactive Protein Remission (DAS28-CRP < 2.6) Over Time

Percentage of SE+ Participants Achieving Simple Disease Activity Index Remission (SDAI <= 3.3) Over Time

Percentage of SE+ Participants Meeting 20% Improvement in American College of Rheumatology Criteria (ACR20) Response Over Time

Percentage of SE+ Participants Meeting 50% Improvement in American College of Rheumatology Criteria (ACR50) Response Over Time

Percentage of SE+ Participants Meeting 70% Improvement in American College of Rheumatology Criteria (ACR70) Response Over Time