POS0578 REAL-WORLD EFFECTIVENESS OF FILGOTINIB IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED FOR UP TO 2 YEARS IN CLINICAL PRACTICE: INTERIM RESULTS FROM FILOSOPHY AND PARROTFISH

Background: Filgotinib is a Janus kinase 1 preferential inhibitor that has shown efficacy and safety in randomized clinical trials [1-3]. FILOSOPHY (NCT04871919) and PARROTFISH (NCT05323591) are ongoing, prospective, observational Phase 4 studies to assess filgotinib in a real-world setting in Europe. Real-word data from clinical practice provide valuable information beyond that captured by clinical trials. Objectives: To assess the effectiveness of filgotinib in patients with rheumatoid arthritis (RA), based on interim pooled data from FILOSOPHY and PARROTFISH, at up to 24 months, and to determine treatment persistence and adherence at 6 and 12 months, respectively. Methods: FILOSOPHY and PARROTFISH enrolled adult patients with moderate to severe active RA and no prior filgotinib exposure, prescribed filgotinib for the first time (according to the product label and local standard of care). Disease Activity Score in 28 joints using C-reactive protein (DAS28-CRP) (4 components), Clinical Disease Activity Index (CDAI) score and Health Assessment Questionnaire–Disability Index (HAQ-DI) score were assessed at baseline and Month 1, 3, 6, 12, 18 and 24 (up to Month 12 for HAQ-DI). The current analysis assessed these outcomes in four patient subgroups: advanced therapy (AT)-naïve patients, AT-experienced patients, patients treated with filgotinib monotherapy and patients treated with filgotinib in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) for RA. In each subgroup, the proportion of patients to achieve CDAI remission (≤2.8), CDAI low disease activity (LDA; >2.8 to ≤10), DAS28-CRP remission (≤2.6), DAS28-CRP LDA (>2.6 to ≤3.2) and a clinically meaningful change from baseline in HAQ-DI score (reduction of ≥0.22) was assessed. The Kaplan–Meier method was used to estimate the probability of treatment persistence (patients continuing to receive filgotinib) up to 6 months. Treatment adherence (the extent to which patients take their medication) was measured using the 5-item Compliance Questionnaire for Rheumatology (CQR5). Results: This interim analysis includes 1,309 patients treated between May 2021 and January 2024, with a median follow-up of 366 days. At baseline, the median (IQR) age was 56 (49–64) years, and 76.6% of patients were female. 485 (37.1%) patients were AT naïve and 824 (62.9%) were AT experienced. During the study, 553 (42.2%) patients received filgotinib monotherapy, whereas 685 (52.3%) received filgotinib in combination with csDMARDs (treatment data are to be confirmed in 71 [5.4%] patients). 1,196 (91.4%) patients received filgotinib 200 mg and 113 (8.6%) received filgotinib 100 mg. In each subgroup, the proportion of patients to achieve remission or LDA increased from baseline to Month 1, further increasing to Month 24. At Month 24, CDAI remission and LDA were achieved by 35.3% (12/34) and 52.9% (18/34) of patients in the AT-naïve subgroup and by 16.4% (9/55) and 54.5% (30/55) of patients in the AT-experienced subgroup, respectively (Figure 1A). DAS28-CRP remission and LDA were achieved at Month 24 by 67.6% (23/34) and 17.6% (6/34) of patients in the AT-naïve subgroup and by 62.0% (31/50) and 16.0% (8/50) of patients in the AT-experienced subgroup, respectively. In the filgotinib monotherapy subgroup, CDAI remission and LDA were achieved at Month 24 by 36.8% (14/38) and 42.1% (16/38) of patients, and correspondingly by 16.3% (7/43) and 65.1% (28/43) of patients in the combination therapy subgroup (Figure 1B). DAS28-CRP remission and LDA were achieved by 74.3% (26/35) and 14.3% (5/35) of patients in the monotherapy subgroup and by 60.5% (26/43) and 18.6% (8/43) of patients in the combination therapy subgroup, respectively. HAQ-DI results also improved in all patient subgroups. At Month 12, a clinically meaningful change in HAQ-DI score was achieved by 66.7% (14/21) and 65.5% (19/29) of patients in the AT-naïve and AT-experienced subgroups, respectively, and in 47.8% (11/23) and 81.5% (22/27) of patients in the filgotinib monotherapy and combination subgroups, respectively. At the time of the current interim analysis, 329 (25.1%) patients had discontinued filgotinib, with treatment persistence (95% CI) estimated at 84.9% (82.8, 86.8) at Month 6 (Figure 2). The most common reason for discontinuation was lack of efficacy (40.1% [132/329]) and adverse events (38.6% [127/329]). Treatment adherence was high over the study period; at Month 12, 83.9% of patients had >80% adherence according to the CQR5. As previously reported [4], safety data were in line with the available evidence. Conclusion: Interim data from the real-world FILOSOPHY and PARROTFISH studies show early improvements in disease activity from Month 1 (the first postbaseline timepoint at which DAS28-CRP and CDAI score were assessed). Improvements were maintained in all subgroups, with 71%–88% of patients achieving CDAI LDA or remission at Month 24. Between 48–82% of patients experienced a clinically meaningful change in HAQ-DI score at Month 12 across subgroups. Treatment persistence at Month 6 was high (84.9%), and at Month 12, most patients (83.9%) had >80% treatment adherence. These data demonstrate the effectiveness of filgotinib for the treatment of patients with moderate to severe active RA in daily clinical practice. REFERENCES: [1] Combe B, et al. Ann Rheum Dis 2021;80:848–58. [2] Genovese MC, et al. JAMA 2019;322:315–25. [3] Westhovens R, et al. Ann Rheum Dis 2021;80:727–38. [4] Galloway J, et al. Arthritis Rheumatol 2024; 76(suppl 9). Download: Download high-res image (358KB) Download: Download full-size image Download: Download high-res image (216KB) Download: Download full-size image Acknowledgements: We thank the physicians and patients who participated in these studies. The study was funded by Alfasigma S.p.A. (Bologna, Italy). Medical writing support was provided by Debbie Sherwood, BSc, CMPP (Aspire Scientific, Bollington, UK), and funded by Alfasigma S.p.A. Publication coordination was provided by Steve Winter, PhD, and funded by Alfasigma S.p.A. Disclosure of Interests: Patrick Verschueren Speaker's bureau: AbbVie, Galapagos, Lilly, Medicongress and Roularta, Consultant: Alfasigma S.p.A., Boehringer Ingelheim, Citryll, Galapagos, Lilly, Pfizer and Sidekick Health, Grant/research support: Galapagos and Pfizer, Reinhard Bos Speaker's bureau: Galapagos and Janssen, Consultant: AbbVie, Galapagos, Pfizer and UCB, Grant/research support: Galapagos and Sanofi, Gerd R. Burmester Speaker's bureau: AbbVie, BMS, Galapagos, Janssen, Lilly, Novartis, Pfizer, Sanofi and UCB, Consultant: AbbVie, BMS, Galapagos, Janssen, Lilly, Novartis, Pfizer, Sanofi and UCB, Alejandro Escudero-Contreras Consultant: AbbVie, Lilly and Pfizer, Grant/research support: AbbVie, Lilly and Pfizer, Ouafia Bouzid Employee: Alfasigma S.p.A., Thomas P.A. Debray Consultant: Alfasigma S.p.A., Biogen, Daiichi Sankyo, Galapagos and Gilead, Carole Van der Donckt Employee: Alfasigma S.p.A., Neil McKay Speaker's bureau: Alfasigma S.p.A., Consultant: Gilead, Grant/research support: AbbVie, Alfasigma S.p.A., Amgen, Novartis and UCB (all departmental support), Christian Roux Consultant: AbbVie, Alfasigma S.p.A., Galapagos, Novartis, Pfizer and UCB, Grant/research support: Lilly, Roberto F. Caporali Speaker's bureau: AbbVie, Amgen, BMS, Celltrion, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz and UCB, Consultant: AbbVie, Amgen, BMS, Celltrion, Fresenius Kabi, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz and UCB. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.