Efficacy and safety of filgotinib in combination with methotrexate in Japanese patients with active rheumatoid arthritis who have an inadequate response to methotrexate: Subpopulation analyses of 24-week data of a global phase 3 study (FINCH 1).

OBJECTIVES: Evaluate the efficacy and safety of the Janus kinase-1 inhibitor filgotinib in Japanese patients with rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX). METHODS: Data from 147 Japanese patients in FINCH 1, a 52-week global Phase 3 study, were analysed up to 24 weeks. Patients received once-daily filgotinib 200 or 100 mg, biweekly adalimumab, or placebo, all with stable background MTX. RESULTS: In the Japanese population, American College of Rheumatology 20% response rates at Week 12 (primary endpoint) were 77.5%, 65.9%, 53.6%, and 36.8% for filgotinib 200 mg, filgotinib 100 mg, adalimumab, and placebo. Proportions of patients achieving Disease Activity Score with 28 joints <2.6 at Week 24: filgotinib 200 mg, 65.0%; filgotinib 100 mg, 51.2%; adalimumab, 42.9%; and placebo, 5.3%. Incidence rates of serious infections: filgotinib 200 mg, 2.5%; filgotinib 100 mg, 0%; adalimumab, 10.7%; and placebo, 5.3%. Treatment-emergent laboratory abnormalities Grade ≥3 occurred in five (12.5%) filgotinib 200 mg, three (7.3%) filgotinib 100 mg, one (3.6%) adalimumab, and no placebo patients. No deaths were reported among Japanese patients. CONCLUSIONS: Filgotinib once daily combined with MTX was effective and generally safe and well tolerated up to Week 24 in Japanese patients with RA and inadequate response to MTX.