BackgroundFilgotinib (FIL) is a Janus kinase 1 preferential inhibitor for the treatment of moderate to severe rheumatoid arthritis (RA)1. The recommended dose for adults with RA is 200 mg (FIL200); however, a starting dose of 100 mg (FIL100) is recommended for those aged ≥75 years (y) in view of limited clinical experience1. An important consideration is the generally higher incidence of adverse events (AEs) in the elderly due to comorbidities.ObjectivesTo evaluate the efficacy and safety of FIL100 and FIL200 in patients with RA aged ≥75 y.MethodsFINCH 4 (NCT03025308) is an ongoing phase 3 open-label LTE study of FIL100 and FIL200 for RA. Eligible patients completed a prior phase 3 randomized double-blind study of FIL lasting 52 weeks (FINCH 1 or 3) or 24 weeks (FINCH 2). In this post hoc analysis, safety and efficacy were assessed in patients aged ResultsAt LTE Week 48, 52% and 44% of patients aged Figure 1.The exposure-adjusted incidence rate (EAIR) of serious AEs and AEs of special interest (AESI) was generally higher in patients aged ≥75 y than Table 1.Exposure-adjusted incidence rate (95% CI) of AEs at Week 48 as events per 100 years of exposureFIL200FIL100Age, years≥75≥75n=1469n=61n=1136n=63(PYE 2253.9)(PYE 92.2)(PYE 1753.7)(PYE 98.4)With prior FIL exposure, n (%)1142 (77.7)53 (86.9)830 (73.1)33 (52.4)TEAE48.3 (45.5, 51.3)55.3 (42.1, 72.8)48.7 (45.5, 52.1)42.7 (31.6, 57.8)Serious TEAE6.8 (5.8, 8.0)17.4 (10.6, 28.3)7.4 (6.2, 8.7)14.2 (8.4, 24.0)AE leading to premature study discontinuation2.9 (2.3, 3.7)9.8 (5.1, 18.8)3.9 (3.1, 5.0)4.1 (1.5, 10.8)AE leading to death0.5 (0.3, 0.9)3.3 (0.7, 9.5)*0.3 (0.2, 0.8)0.0 (0.0, 3.8)Infections28.8 (26.6, 31.1)29.3 (20.1, 42.7)27.4 (25.0, 29.9)26.4 (18.0, 38.8)Serious infections1.6 (1.2, 2.2)2.2 (0.5, 8.7)1.7 (1.1, 2.4)3.1 (1.0, 9.5)Herpes zoster1.6 (1.2, 2.3)2.2 (0.5, 8.7)1.0 (0.6, 1.6)3.1 (1.0, 9.5)Adjudicated major adverse cardiovascular event0.4 (0.2, 0.7)2.2 (0.5, 8.7)0.5 (0.2, 0.9)1.0 (0.1, 7.2)Venous thrombotic and embolic events0.3 (0.1, 0.6)2.2 (0.5, 8.7)0.2 (0.1, 0.5)1.0 (0.1, 7.2)Malignancy excluding NMSC0.7 (0.4, 1.2)4.3 (1.6, 11.6)0.7 (0.4, 1.2)3.1 (1.0, 9.5)NMSC0.4 (0.2, 0.8)1.1 (0.0, 6.0)0.2 (0.1, 0.6)0.0 (0.0, 3.8)*Cause of death: esophageal carcinoma; cardiovascular; unknown. FIL(100/200), filgotinib (100/200 mg); NMSC, nonmelanoma skin cancer; PYE, patient years of exposure; (TE)AE, (treatment-emergent) adverse eventConclusionIn the ≥75 y group, response rates for key efficacy measures remained stable to Week 48 and were generally higher with FIL200 vs FIL100. The incidence of serious AEs and AESI was higher in those aged ≥75 than References[1]Filgotinib SmPCAcknowledgementsThe FINCH studies were funded by Gilead Sciences (Foster City, CA, United States). We thank the physicians and patients who participated in the studies. Medical writing support was provided by Debbie Sherwood, BSc (Aspire Scientific Ltd, Bollington, UK) and funded by Galapagos NV (Mechelen, Belgium).Disclosure of InterestsDaniel Aletaha Speakers bureau: AbbVie, Amgen, Lilly, Janssen, Merck, Novartis, Pfizer, Roche, and Sandoz, Consultant of: AbbVie, Amgen, Lilly, Janssen, Merck, Novartis, Pfizer, Roche, and Sandoz, Grant/research support from: AbbVie, Amgen, Lilly, Novartis, Roche, SoBi, and Sanofi, Rene Westhovens Speakers bureau: Celltrion, Galapagos, and Gilead, Consultant of: Celltrion, Galapagos, and Gilead, Bernard Combe Speakers bureau: AbbVie, BMS, Celltrion, Eli Lilly, Gilead-Galapagos, Janssen, MSD, Novartis, Pfizer, and Roche-Chugai, Consultant of: AbbVie, Celltrion, Eli Lilly, Gilead-Galapagos, Janssen, and Roche-Chugai, Jacques-Eric Gottenberg Consultant of: AbbVie, BMS, Galapagos, Gilead, Lilly, and Pfizer, Grant/research support from: BMS and Pfizer, Maya H Buch Speakers bureau: AbbVie, Consultant of: AbbVie, Galapagos, Gilead, and Pfizer, Grant/research support from: Gilead and Pfizer, Roberto Caporali Speakers bureau: AbbVie, Amgen, BMS, Celltrion, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Sandoz, and UCB, Consultant of: AbbVie, Amgen, BMS, Celltrion, Fresenius-Kabi, Galapagos, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sandoz, and UCB, José A Gómez-Puerta Speakers bureau: AbbVie, BMS, Galapagos, GSK, Lilly, MSD, Novartis, Pfizer, Roche, and Sanofi, Consultant of: GSK, Roche, and Sanofi, Paul Van Hoek Employee of: Galapagos, Vijay Rajendran Employee of: Galapagos, Pieter-Jan Stiers Shareholder of: Galapagos, Employee of: Galapagos, Thijs Hendrikx Employee of: Galapagos, Gerd Rüdiger Burmester Consultant of: AbbVie, Amgen, BMS, Galapagos, Lilly, MSD, Pfizer, Roche, and Sanofi, Yoshiya Tanaka Speakers bureau: AbbVie, Amgen, Astellas, Astra-Zeneca, Boehringer-Ingelheim, BMS, Chugai, Eisai, Eli Lilly, Gilead, Mitsubishi-Tanabe, and YL Biologics, Consultant of: AbbVie, Ayumi, Daiichi-Sankyo, Eli Lilly, GSK, Sanofi, and Taisho, Grant/research support from: AbbVie, Asahi-Kasei, Boehringer-Ingelheim, Chugai, Corrona, Daiichi-Sankyo, Eisai, Kowa, Mitsubishi-Tanabe, and Takeda