- If entering the study on concomitant Methotrexate (MTX), leflunomide, Sulfasalazine (SSZ), and/or hydroxychloroquine, participant must be on a stable dose of MTX (<= 25 mg/week) and/or SSZ (<= 3 g/day) and/or hydroxychloroquine (<= 400 mg/day) or leflunomide (<= 20 mg/day) for at least 28 days prior to the Baseline Visit. A combination of up to two background conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) is allowed except the combination of MTX and leflunomide.