Dose-finding Study of GLPG0634 as add-on to Methotrexate in Active Rheumatoid Arthritis Participants (DARWIN1)

Percentage of Participants Achieving an ACR20 Response at Week 24

ACR20 response was defined as: 1) ≥ 20% improvement from baseline in SJC66, and 2) ≥ 20% improvement from baseline in TJC68, and 3) ≥ 20% improvement from baseline in at least 3 of the following 5 items: 1. Pain VAS (taken from the HAQ-DI), 2. Patient's Global Assessment of Disease Activity VAS, 3. Physician's Global Assessment of Disease Activity VAS, 4. Total HAQ-DI score, and 5. CRP. Non-responder imputation was used.

Time frame: Week 24

Percentage of Participants Achieving an ACR50 Response at Weeks 1, 2, 4, 8, 12, and 24

ACR50 response was defined as: 1) ≥ 50% improvement from baseline in SJC66, and 2) ≥ 50% improvement from baseline in TJC68, and 3) ≥ 50% improvement from baseline in at least 3 of the following 5 items: 1. Pain VAS (taken from the HAQ-DI) 2. Patient's Global Assessment of Disease Activity VAS 3. Physician's Global Assessment of Disease Activity VAS 4. Total HAQ-DI score 5. CRP. Non-responder imputation was used.

Time frame: Weeks 1, 2, 4, 8, 12, and 24

Percentage of Participants Achieving an ACR70 Response at Weeks 1, 2, 4, 8, 12, and 24

ACR70 response: 1) ≥ 70% improvement from baseline in SJC66, and 2) ≥ 70% improvement from baseline in TJC68, and 3) ≥ 70% improvement from baseline in at least 3 of the following 5 items: 1. Pain VAS (taken from the HAQ-DI), 2. Patient's Global Assessment of Disease Activity VAS, 3. Physician's Global Assessment of Disease Activity VAS, 4. Total HAQ-DI score, and 5. CRP. Non-responder imputation was used.

Time frame: Weeks 1, 2, 4, 8, 12, and 24

ACR N% Improvement (ACR-N) Response at Weeks 1, 2, 4, 8, 12, and 24

The ACR-N is the smallest percentage improvement in swollen and tender joints and the median of the remaining 5 core parameters, and is expected to be more sensitive to change than the ACR20, ACR50 or ACR70. It is a number varying between 0 and 100, with higher numbers indicating less severity of symptoms. Last observation carried forward (LOCF) algorithm was used (ie, to impute a missing value, the last preceding nonmissing value was used).

Time frame: Weeks 1, 2, 4, 8, 12, and 24

Percentage of Participants With Disease Activity Score 28 Joints Corrected for CRP (DAS28 (CRP)) European League Against Rheumatism (EULAR) Response at Weeks 1, 2, 4, 8, 12, and 24

DAS28 (CRP) was categorized into EULAR response categories (none, moderate, good) as follows: None = Actual DAS28 (CRP) ≤ 3.2, \> 3.2 to ≤ 5.1, or \> 5.1 AND Improvement in DAS28 (CRP) from baseline ≤ 6.0 or \> 0.6 to ≤ 1.2; Moderate = Actual DAS28 (CRP) ≤ 3.2 AND Improvement in DAS28 (CRP) from baseline \> 0.6 to ≤ 1.2, Actual DAS28 (CRP) \> 3.2 to ≤ 5.1 or \> 5.1 AND Improvement in DAS28 (CRP) from baseline \> 1.2, or Actual DAS28 (CRP) \> 3.2 to ≤ 5.1 AND Improvement in DAS28 (CRP) from baseline \> 0.6 to ≤ 1.2; Good = Actual DAS28 (CRP) ≤ 3.2 AND Improvement in DAS28 (CRP) from baseline \> 1.2. LOCF algorithm was used.

Time frame: Weeks 1, 2, 4, 8, 12, and 24

Percentage of Participants Achieving ACR/EULAR Remission at Weeks 2, 4, 8, 12, and 24

A participant's disease activity status can be defined as being in remission when scores on the TJC28, SJC28, CRP (actual value in mg/dL) and Patient Global Assessment of Disease Activity (cm) are all ≤ 1. Non-responder imputation was used.

Time frame: Weeks 2, 4, 8, 12, and 24

Change From Baseline in Simplified Disease Activity Index (SDAI) at Weeks 1, 2, 4, 8, 12, and 24

The SDAI is the numerical sum of 5 outcome parameters: TJC28, SJC28, Patient Global Assessment of Disease Activity (in cm), Physician's Global Assessment of Disease Activity (in cm), and CRP (mg/dL). The SDAI was categorized as follows: • High disease activity: SDAI \> 26 • Moderate disease activity: 11 to 26 • Low disease activity: 3.3 to 11 • Remission: ≤ 3.3. LOCF algorithm was used. The SDAI total score ranges from 0 to approximately 86.

Time frame: Baseline and Weeks 1, 2, 4, 8, 12, and 24

Change From Baseline in Clinical Disease Activity Index (CDAI) at Weeks 1, 2, 4, 8, 12, and 24

The CDAI is the SDAI modified to exclude CRP and is the sum of the 4 outcome parameters: TJC28, SJC28, Patient Global Assessment of Disease Activity (in cm), and Physician's Global Assessment of Disease Activity (in cm). The CDAI was be categorized as follows: • High disease activity: \> 22 • Moderate disease activity: 10 to 22 • Mild disease activity: 2.8 to 10 • Remission: ≤ 2.8. LOCF algorithm was used. The CDAI total score ranges from 0 to approximately 76.

Time frame: Baseline and Weeks 1, 2, 4, 8, 12, and 24

Change From Baseline in Quality of Life Using the Functional Assessment of Chronic Illness Therapy (FACIT) at Weeks 4, 12, and 24

FACIT-Fatigue scale is a 13-item questionnaire, each scored on a 5-point scale: 0 (Not at all) to 4 (Very much). The larger the participant's response to the questions (with the exception of 2 negatively stated that are scored reversely), the greater the fatigue. The sum of all responses resulted in the FACIT-Fatigue score for a total possible score of 0 (worse score) to 52 (better score), with a higher score indicating a better quality of life. LOCF algorithm was used.

Time frame: Baseline and Weeks 4, 12, and 24

Change From Baseline in Quality of Life Using the Short Form-36 (SF-36) Scores at Weeks 4, 12, and 24

The SF-36 is a 36-item questionnaire measuring 8 domains (physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health). Each domain score ranges from 0 (worst) to 100 (best), with higher scores reflecting better health-related functional status. Two summary scale scores were computed based on weighted combinations of the 8 domain scores: the Physical Component Summary (PCS) and the Mental Component Summary (MCS). LOCF algorithm was used.

Time frame: Baseline and Weeks 4, 12, and 24