Baseline characteristics of and early outcomes in the first 200 patients with rheumatoid arthritis treated with filgotinib in a prospective observational study

Abstract Background/Aims Filgotinib (FIL) is a preferential Janus kinase 1 inhibitor, approved in Europe for the treatment of Rheumatoid arthritis (RA). A phase 4 European study of FIL (FILOSOPHY; NCT04871919) in patients with RA is ongoing. We report baseline characteristics and 1-month efficacy data from the first 200 patients. Methods The prospective, observational study will enroll approximately 1500 patients aged ≥18 years with moderate-severe active RA, prescribed FIL for the first time in accordance with the product label. We report baseline demographics, disease characteristics, comorbidities, prior treatments, reasons for starting FIL, and mean change from baseline (CFB) in pain severity (measured using a 10-cm visual analog scale [VAS]) and Functional Assessment of Chronic Illness Therapy (FACIT)-fatigue score (range 0-52) via electronic PRO data collection at Week 1 and Month 1, and mean CFB in Clinical Disease Activity Index (CDAI; range 0-76) score at Month 1. The proportion of patients with clinically meaningful CFB in FACIT-fatigue (increase of ≥ 4) and VAS pain (reduction of ≥ 10) from Week 1 to Month 1 was reported. Patients included in analysis were enrolled May 2021-February 2022. Results 206 patients were enrolled from Germany (n = 134), UK (n = 40), Netherlands (n = 27), Belgium (n = 4), and Italy (n = 1); nearly 75% were female, mean (standard deviation [SD]) age 56.8 (10.6) years, and mean (SD) RA duration 10.0 (9.5) years. Approximately 40% of treated patients had comorbidities, most common: hypertension (28.3%), dyslipidemia (9.1%), type 2 diabetes mellitus (5.3%). FIL was started due to inadequate response (43.3%), loss of response (40.6%), or intolerance (non-allergic) to previous treatment (5.9%), or for other reasons (10.2%). Of treated patients, 167 (89.3%) received FIL 200 mg and 20 (10.7%) received FIL 100 mg (study drug information was pending for 19 patients). FIL monotherapy was taken by 55.6% of patients (19.3% with glucocorticoids), while 37.4% received FIL in combination with MTX (13.4% with glucocorticoids). Mean (SD) and median (range) daily dose of oral glucocorticoids at baseline was 7.5 (6.0) mg and 5.0 (1.0-30.0) mg. At Week 1 and Month 1, respectively, mean (SD) CFB in FACIT-fatigue score was 3.7 (6.9) and 6.8 (8.6), and mean (SD) CFB in VAS pain score was -11.9 (18.0) and -22.2 (27.8). At Month 1, mean (SD) CFB in CDAI score was -13.7 (17.1). Conclusion These are the first international real-world data to be reported from a cohort of RA patients treated with FIL. At baseline, patients generally had moderate disease activity. Initial interim data indicate rapid improvements in disease measures with FIL treatment (given as combination therapy or monotherapy, with/without glucocorticoids), which could be observed as early as Week 1 for VAS pain and FACIT-fatigue scores. Long-term follow-up is needed to further evaluate effectiveness and safety. Disclosure J. Galloway: Other; AbbVie, AstraZeneca, Biogen, Celgene, Galapagos, Gilead, Janssen, Medicago, Lilly, Novartis, Novavax, Pfizer, Roche, UCB. K. Bevers: None. P. Verschueren: Other; AbbVie, Celltrion, Eli Lilly, Galapagos, Gilead, Nordic Pharma, Pfizer, Roularta, Sidekick Health. R. Caporali: Other; AbbVie, Celltrion, Fresenius-Kabi, Galapagos, Janssen, Pfizer, Roche, UCB, Eli Lilly, Gilead, Sanofi. S. Romero Yuste: Other; Pfizer, Lilly, AbbVie, Biogen, Sanofi. J. Avouac: Other; Galapagos, AbbVie, Lilly, Pfizer, Bristol Myers Squibb, Novartis, Fresenius-Kabi, Sanofi, Sandoz, Nordic Pharma, Biogen, Medac, Janssen, Roche-Chugai. E. Gvozdenovic: Other; Galapagos. K. Harris: Other; Galapagos. M. Zignani: Other; Galapagos. G. Burmester: Other; AbbVie, Galapagos, Lilly, MSD, Pfizer, Roche, UCB, Janssen, Gilead Sciences, Inc.