Trial Outcomes & Findings for Dose-finding Study of GLPG0634 as add-on to Methotrexate in Active Rheumatoid Arthritis Participants (DARWIN1) (NCT NCT01888874)

Participants were enrolled at study sites in Europe, South America, North America, Australia, and New Zealand. The first participant was screened on 17 July 2013. The last study visit occurred on 14 May 2015.

A total of 1255 participants were screened of which 599 participants were randomized into the study and only 594 participants were treated.

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

The American College of Rheumatology (ACR) response is a measurement of improvement in multiple disease assessment criteria. The ACR20 response is defined as: 1) ≥ 20% improvement from baseline in SJC66, and 2) ≥ 20% improvement from baseline in tender TJC68, and 3) ≥ 20% improvement from baseline in at least 3 of the following 5 items: 1. Pain visual analog scale (VAS) (taken from the Health Assessment Questionnaire - Disability Index \[HAQ-DI\]), 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 (ie, to impute a missing response, the participant was assumed to be a non-responder).

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.