“…In a 12‐week, phase IIb, randomized, double‐blind, placebo‐controlled study of peficitinib monotherapy (25 mg, 50 mg, 100 mg, and 150 mg) in Japanese patients with moderate‐to‐severe RA (not required to fail to respond to 1 or more conventional synthetic disease‐modifying antirheumatic drugs [csDMARDs]; http://ClinicalTrials.gov identifier NCT01649999), 50 mg, 100 mg, or 150 mg once‐daily doses of peficitinib resulted in statistically significant American College of Rheumatology 20% improvement criteria (ACR20) responses compared with placebo, and had satisfactory tolerability . In a second 12‐week, phase IIb, randomized, double‐blind, parallel‐group, placebo‐controlled, dose‐finding (peficitinib 25 mg, 50 mg, 100 mg, and 150 mg), multicenter study, statistically significant improvements in ACR20 response with peficitinib combined with methotrexate (MTX) were only observed in the peficitinib 50 mg group compared with placebo plus MTX ( P < 0.05) in patients who had an inadequate response to MTX (NCT01554696) .…”