Efficacy and Safety Study of Abatacept Subcutaneous Plus Methotrexate in Inducing Remission in Adults With Very Early Rheumatoid Arthritis

Adjusted Mean Change From Baseline in Disease Activity Score 28 Based on C-reactive Protein (DAS28-CRP) at Months 6, 12, and 18

TP=treatment period; WP=withdrawal period. The DAS 28-CRP is a measure of disease activity in rheumatoid arthritis (RA) that assesses the 28 joints RA commonly affects; the score includes the number of tender and swollen joints (out of 28), CRP level (a measure of inflammation in the blood), and the patient's global assessment of health (ranging from very good to very bad). DAS-CRP scores range from 0 to 10, with higher values indicating greater disease activity. Individual measures are fed into a complex mathematical formula to produce the overall DAS (a score greater than 5.1 implies active disease; less than 3.2, well controlled disease; and less than 2.6, remission.)

Time frame: Baseline to Month 18

Percentage of Participants Who Achieved Remission by Criteria of the Simplified Disease Activity Index (SDAI) at Months 12 and 18

TP=treatment period; WP=withdrawal period. SDAI-defined remission= ≤3.3. The SDAI is the simple linear sum of 5 outcome parameters: tender joint count (TJC) and swollen joint count (SJC) (based on a 28-joint assessment); patient's and physician's global assessments of disease activity (assessed on 0-10 cm visual analog scale, on which higher scores=greater affection due to disease activity); and C-reactive protein level (mg/dL). SDAI total score=0-86. SDAI \<=3.3 indicates disease remission, \>3.4 to 11=low disease activity, \>11 to 26=moderate disease activity, and \>26=high disease activity. TJC is assessed and recorded at each visit, with no swelling=0, swelling=1. SJC is assessed through identification of joints that are painful under pressure or to passive motion. TJC is recorded on the joint assessment form at each visit, with no tenderness =0, tenderness = 1. Higher score indicates greater affection due to disease activity.

Time frame: Randomization to Month 18

Adjusted Mean Change From Baseline in Scores on Simplified Disease Activity Index (SDAI) Over Time

TP=treatment period; WP=withdrawal period. The SDAI is the simple linear sum of 5 outcome parameters: swollen joint count (SJC) and tender joint count (TJC) (based on a 28-joint assessment); patient's and physician's global assessments of disease activity (assessed on 0-10 cm visual analog scale, on which higher scores=greater affection due to disease activity); and C-reactive protein level (mg/dL). SDAI total score=0-86. SJC is assessed and recorded at each visit, with no swelling=0, swelling=1 (higher score indicates greater swelling). TJC is assessed at each visit through identification of joints that are painful under pressure or to passive motion, with no tenderness=0, tenderness=1 (higher score indicates greater affection due to disease activity)..

Time frame: Randomization to Month 18

Percentage of Participants Achieving a Health Assessment Questionnaire (HAQ) Response Over Time

HAQ response defined as a reduction of at least 0.3 units from baseline in score on the Health Assessment Questionnaire Disability Index (HAQ-DI), which assesses patients' functional ability by rating their abilities over the previous week. The HAQ-DI includes at least 2 questions from each of 8 categories: dressing and grooming, hygiene, arising, reach, eating, grip, walking, and common daily activities. Patients rate difficulty performing specific tasks: 0=without difficulty, 1=with some difficulty, 2=with much difficulty, and 3=unable to do. The sum of the categories score (the highest scored item in the category) is divided by the number of categories answered, yielding a score from 0-3. When aids, devices, or help is indicated by the patient, the score for the category item is raised from a 0 or a 1 to a 2, but if the patient's highest score for a subcategory is a 3, it stays a 3.

Time frame: Randomization to Month 24

Adjusted Mean Change From Baseline in Health Assessment Questionnaire Disability Index (HAQ-DI) Over Time

The Health Assessment Questionnaire Disability Index (HAQ-DI) assesses patients' functional ability by rating their abilities over the previous week. The HAQ-DI includes at least 2 questions from each of 8 categories: dressing and grooming, hygiene, arising, reach, eating, grip, walking, and common daily activities. Patients rate difficulty performing specific tasks: 0=without difficulty, 1=with some difficulty, 2=with much difficulty, and 3=unable to do. The sum of the categories score (the highest scored item in the category) is divided by the number of categories answered, yielding a score from 0-3. When aids, devices, or help is indicated by the patient, the score for the category item is raised from a 0 or a 1 to a 2, but if the patient's highest score for a subcategory is a 3, it stays a 3.

Time frame: Randomization to Month 18

Adjusted Mean Change From Baseline at Months 6, 12, and 18 in Physical Component Summary (PCS) and Mental Component Summary (MCS) Scores of Short Form-36 (SF-36)

TP=treatment period; WP=withdrawal period. The SF-36 is a 36-item self-administered questionnaire developed to assess health-related quality of life (QOL) and comprises 8 domains, including 4 physical (physical health, bodily pain, physical functioning and physical role limitations) and 4 mental (mental health, vitality, social functioning, and emotional role limitation) subscales. Responses are used to derive physical and mental component summary scores, ranging from 0 to 100, with higher scores indicating better QOL (0=Poorest Health; 100=Best Health). Mean change from baseline=postbaseline value-baseline value; a higher value signifies improvement.

Time frame: Randomization to Months 6, 12, and 18

Adjusted Mean Change From Baseline Over Time in Findings on Magnetic Resonance Imaging (MRI)

TP=treatment period; WP=withdrawal period. Change from Baseline=Postbaseline-baseline value. MRI was used to assess joint damage progression at Months 6, 12, and 18. If \>20% of joints with a missing score for a parameter (erosion, osteitis, and synovitis), the MRI score of each parameter was considered missing. If ≤20% of joints had a missing score for a parameter, the MRI score for that parameter from the missing joints was carried forward from the previous MRI assessment, or carried backward from the next MRI assessment, if missing score occurred at baseline. MRI total score ranged from 0 (best outcome) to 4 (worst outcome). A gadolinium-enhanced MRI of the dominant hand-wrist was performed on all randomized patients at 5 points. The hand/wrist assessed to have more synovitis was selected initially and used for all subsequent evaluations. The MRI examination was standardized to ensure sufficient image quality for the evaluation of radiographic progression of rheumatoid arthritis.

Time frame: Randomization to Month 18

Number of Participants With Death as Outcome, Serious Adverse Events (SAEs), Related SAEs, Discontinuations Due to SAEs, Related Adverse Events (AEs), and Discontinuations Due to AEs During the Treatment Period

AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization. Related=having certain, probable, possible, or unknown relationship to study drug.

Time frame: Day 1 to up to 56 days following the last dosing day (Day 365); all deaths during study period, including those that occurred >56 days after last dose in Treatment Period

Adverse Events (AEs) of Interest During the Treatment Period

AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization. Related=having certain, probable, possible, or unknown relationship to study drug. AEs of special interest are events potentially associated with the drug or disease under study.

Time frame: Day 1 to 56 days following last dosing day (Day 365)

Number of Participants With Results on Hematology and Clinical Laboratory Tests Meeting the Criteria for Marked Abnormality During Treatment Period

Lower limit of normal (LLN); Upper limit of normal (ULN); Pretreatment (preRX). Criteria for marked abnormality: Platelet count (\*10\^9 c/µL) \<0.67\*LLN or \>1.5\*ULN, or if preRX\<LLN, use 0.5\*preRX and \<100,000/mm\^3; potassium, serum (mEq) \<0.9\*LLN or \>1.1\*ULN, or if preRX \<LLN, use \<0.9\*preRX or \>ULN if preRX\>ULN, use \>1.1\*preRX or \<LLN; blood urea nitrogen (mg/dL) \>2\*preRX; creatinine (mg/dL) \>1.5\*preRX; ALT (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; AST (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; ALP (U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; G-glutamyl transferase U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; glucose, fasting (mg/dL) \<0.8\*LLN or \>1.5\*ULN, or if preRX\<LLN use \<0.8\*preRX or \>ULN if preRX \>ULN, use \>2.0\*preRX or OR \<LLN; glucose, serum (mg/dL) \<65 or \>220; uric acid (mg/dL)\>1.5\*ULN, or if preRX, use \>2\*preRX; albumin (g/dL) \<0.9\*LLN, or if preRX\<LLN, use \<0.75\*preRX; hemoglobin (g/dL)\>3 decrease from preRX; hematocrit (%) \< 0.75\*preRX.

Time frame: Day 1 up to 56 days following the last dosing day in the Treatment Period (Day 365)

Percentage of Participants With Remission by Disease Activity Score 28 Based on C-reactive Protein (DAS28-CRP) Criteria Over Time During Withdrawal Period- Treated Participants in Remission at Month 12

WP=withdrawal period. Remission defined as DAS28-CRP\<2.6. The DAS 28-CRP is a measure of disease activity in rheumatoid arthritis (RA) and assesses the 28 joints RA commonly affects; the score includes the number of tender and swollen joints (out of 28), CRP level (a measure of inflammation in the blood), and the patient's global assessment of health (ranging from very good to very bad). DAS-CRP scores range from 0 to 10, with higher values indicating greater disease activity. Individual measures are fed into a complex mathematical formula to produce the overall DAS (a score greater than 5.1 implies active disease; less than 3.2, well controlled disease; and less than 2.6, remission.). Percentage= number of participants with remission divided by number of participants who were analyzed (all treated participants who were in remission at end of treatment period and entered the Withdrawal Period)

Time frame: End of Treatment Period (Month 12) to End of Withdrawal Period (Month 24)

Percentage of Participants Who Achieved Remission by Criteria of the Simplified Disease Activity Index (SDAI) Over Time in Treatment Period and Withdrawal Period

TP=treatment period; WP=withdrawal period. SDAI-defined remission= ≤3.3. The SDAI is the simple linear sum of 5 outcome parameters: tender joint count (TJC) and swollen joint count (SJC) (based on a 28-joint assessment); patient's and physician's global assessments of disease activity (assessed on 0-10 cm visual analog scale, on which higher scores=greater affection due to disease activity); and C-reactive protein level (mg/dL). SDAI total score=0-86. SDAI \<=3.3 indicates disease remission, \>3.4 to 11=low disease activity, \>11 to 26=moderate disease activity, and \>26=high disease activity. TJC is assessed and recorded at each visit, with no swelling=0, swelling=1. SJC is assessed through identification of joints that are painful under pressure or to passive motion. TJC is recorded on the joint assessment form at each visit, with no tenderness =0, tenderness = 1. Higher score indicates greater affection due to disease activity. Percent=number with remission/number evaluated (ITT)

Time frame: Randomization to Month 24

Number of Participants With Death as Outcome, Serious Adverse Events (SAEs) and Discontinuations Due to AEs During the Full Study (All Periods)

AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization. Includes data up to last active dose date +56 days if the participant discontinued the Treatment Period or did not enter the Withdrawal Period, up to the day of discontinuation in the Withdrawal Period for participants discontinuing the Withdrawal Period without entering the Re-exposure Period (RP), up to Day 729 visit (Month 24) for participants who complete the Withdrawal Period, and up to 56 days post last active dose in Re-exposure Period for participants entering the Re-exposure Period.

Time frame: Day 1 to 56 days post last dose in the study, up to Month 30

Adverse Events (AEs) of Interest During the Withdrawal Period

AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization. AEs of special interest are events potentially associated with the drug or disease under study. Includes events with an onset date on or after 57 days post last dosing day (active abatacept or active MTX whichever is the later) in the Treatment Period and up to end of Withdrawal Period. Treatment groups represent treatment received during the Treatment Period.

Time frame: Last dose in TP + 57 days, up to Month 24

Adverse Events (AEs) of Interest During the Re-exposure Period

AE=any new unfavorable symptom, sign, or disease or worsening of a preexisting condition that may not have a causal relationship with treatment. SAE=a medical event that at any dose results in death, persistent or significant disability/incapacity, or drug dependency/abuse; is life-threatening, an important medical event, or a congenital anomaly/birth defect; or requires or prolongs hospitalization. AEs of special interest are events potentially associated with the drug or disease under study. Includes data up to 56 days post the last dosing day (active abatacept or active MTX, whichever is the later) in the Re-exposure Period. Treatment groups represent Treatment received during Treatment Period.

Time frame: First dose in Re-exposure period up to last dose of Re-exposure Period + 56 days

Number of Participants With Results on Hematology and Clinical Laboratory Tests Meeting the Criteria for Marked Abnormality in Withdrawal Period

LLN=lower limit of normal; ULN=upper limit of normal; preRX=pretreatment. Criteria for marked abnormality on laboratory test results: Platelet count (\*10\^9 c/µL) \<0.67\*LLN or \>1.5\*ULN, or if preRX\<LLN, use 0.5\*preRX and \<100,000/mm\^3; potassium, serum (mEq) \<0.9\*LLN or \>1.1\*ULN, or if preRX \<LLN, use \<0.9\*preRX or \>ULN if preRX\>ULN, use \>1.1\*preRX or \<LLN; blood urea nitrogen (mg/dL) \>2\*preRX; creatinine (mg/dL) \>1.5\*preRX; ALT (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; AST (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; ALP (U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; G-glutamyl transferase (GGT) (U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; glucose, fasting (mg/dL) \<0.8\*LLN or \>1.5\*ULN, or if preRX\<LLN use \<0.8\*preRX or \>ULN if preRX \>ULN, use \>2.0\*preRX or OR \<LLN; glucose, serum (mg/dL) \<65 or \>220; uric acid (mg/dL)\>1.5\*ULN, or if preRX, use \>2\*preRX; albumin (g/dL) \<0.9\*LLN, or if preRX\<LLN, use \<0.75\*preRX; hemoglobin (g/dL)\>3 decrease from preRX; hematocrit (%) \< 0.75\*preRX.

Time frame: Last dose in TP + 57 days, up to Month 24

Number of Participants With Results on Hematology and Clinical Laboratory Tests Meeting the Criteria for Marked Abnormality in Re-exposure Period

LLN=lower limit of normal; ULN=upper limit of normal; preRX=pretreatment. Criteria for marked abnormality on laboratory test results: Platelet count (\*10\^9 c/µL) \<0.67\*LLN or \>1.5\*ULN, or if preRX\<LLN, use 0.5\*preRX and \<100,000/mm\^3; potassium, serum (mEq) \<0.9\*LLN or \>1.1\*ULN, or if preRX \<LLN, use \<0.9\*preRX or \>ULN if preRX\>ULN, use \>1.1\*preRX or \<LLN; blood urea nitrogen (mg/dL) \>2\*preRX; creatinine (mg/dL) \>1.5\*preRX; ALT (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; AST (U/L) \>3\*ULN, or if preRX\>ULN, use \>4\*preRX; ALP (U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; G-glutamyl transferase U/L) \>2\*ULN, or if preRX\>ULN, use \>3\*preRX; glucose, fasting (mg/dL) \<0.8\*LLN or \>1.5\*ULN, or if preRX\<LLN use \<0.8\*preRX or \>ULN if preRX \>ULN, use \>2.0\*preRX or OR \<LLN; glucose, serum (mg/dL) \<65 or \>220; uric acid (mg/dL)\>1.5\*ULN, or if preRX, use \>2\*preRX; albumin (g/dL) \<0.9\*LLN, or if preRX\<LLN, use \<0.75\*preRX; hemoglobin (g/dL)\>3 decrease from preRX; hematocrit (%) \< 0.75\*preRX.

Time frame: Start of re-exposure period to 56 days post last dose, up to Month 30