Background/Aims: Filgotinib (FIL) is an oral, potent, selective Janus kinase 1 (JAK1) inhibitor. FINCH 1 (NCT02889796) assessed FIL efficacy, safety and patient reported outcome (PRO) data in patients (pts) with rheumatoid arthritis (RA) with an inadequate response to methotrexate (MTX-IR). We report data through week 52 (W52) of the FINCH 1 study. Primary outcome results at week (W)12 and W24 were previously reported.

Methods: This global, phase 3, double-blind, active- and placebo (PBO)-controlled study randomised MTX-IR pts with active RA on a background of stable MTX 3:3:2:3 to oral FIL 200 mg or FIL 100 mg once daily, subcutaneous adalimumab (ADA) 40 mg every 2W, or PBO up to W52; pts receiving PBO at W24 were re-randomised to FIL 100 or 200 mg. Efficacy was assessed using clinical, radiographic, and pt-reported outcomes; W52 comparisons were not adjusted for multiplicity, and nominal p-values are reported. Safety endpoints included types and rates of adverse events (AEs) and laboratory abnormalities. PRO assessment included the HAQ-DI and VAS pain scale, SF-36, and FACIT-Fatigue questionnaire. Change from baseline (CFB) at various time points was assessed up to W52 for each treatment group.

Results: Of 1,755 treated pts, 1,417 received study drug through W52. FIL efficacy was sustained through W52 with DAS28(CRP) <2.6 remission rates of 54%, 43%, and 46% of pts receiving FIL 200 and 100 mg and ADA, respectively, (nominal p for FIL 200 vs ADA = 0.024) (Table 1). FIL safety profile through W52 was consistent with W24 data. AEs of interest were infrequent and balanced among treatments. As early as W2, through W24, pts receiving either dose of FIL experienced nominally significantly greater (p < 0.001) CFB in HAQ-DI and VAS pain scale than those receiving PBO. These improvements were sustained up to W52. In general, CFB for HAQ-DI, VAS pain scale, and FACIT-Fatigue observed for the FIL groups was higher or comparable to ADA through W52 (Table 1).

Conclusion: Through W52, both FIL 200 and 100 mg showed sustained efficacy, rapid and sustained improvement in patient QoL based on clinical and pt-reported outcomes and were well tolerated in MTX-IR pts with RA.