Background:Secukinumab (SEC), a fully human monoclonal antibody that selectively inhibits interleukin 17A, is approved for treatment of patients with ankylosing spondylitis (AS). However, there is lack of real-world evidence on SEC treatment outcomes, disease activity, physical functioning and on its retention, especially in anti-tumor necrosis factor (anti-TNF) naïve patients and patients pretreated with different anti-TNFs in medical history.1Objectives:The aim of this interim analysis is to evaluate SEC treatment outcomes on disease activity, physical functioning and retention rates in AS patients stratified by number of anti-TNFs (naive, 1 or ≥2) in medical history.Methods:AQUILA is an ongoing, multi-center, non-interventional study. AS and psoriatic arthritis patients treated with SEC in daily practice are enrolled and observed from baseline (BL, d0 or d1 of study start) up to week 52 according to clinical routine. Real-world effectiveness of SEC was assessed prospectively and analyzed as observed. Here, we report interim results of SEC effectiveness on different treatment outcomes in AS patients by means of validated questionnaires such as patient´s global assessment (PGA), Bath Ankylosing Disease Activity Index (BASDAI), and Assessment of Spondyloarthritis Health Index (ASAS-HI). In addition, retention rates (time from study inclusion until premature SEC treatment discontinuation) were assessed through Kaplan-Meier plots. This interim analysis focuses onanti-TNF naïveand AS patients treated with1 anti-TNFor≥2 anti-TNFsin medical history. Wilcoxon tests were conducted to show significant differences between the subgroups.Results:At BL, 311 AS patients were included; 72 (23.2%) of them received SEC already for more than 1 day up to more than 6 months before BL. Most AS patients were anti-TNF-experienced (71.1%): 82 (26.4%) and 139 (44.7%) AS patients had 1 or ≥2 prior anti-TNF treatments, respectively. BL scores for PGA, BASDAI and ASAS-HI were similar between the different anti-TNF subgroups. Constant improvement was shown in all parameters from BL up to week 52, irrespective of prior anti-TNF treatment (PGA-anti-TNF naïve: 5.9 to 3.5, PGA-1 anti-TNF:6.1 to 4.2 and PGA-≥2 anti-TNFs:6.7 to 5.1; BASDAI-anti-TNF naïve: 5.3 to 3.4, BASDAI-1 anti-TNF:5.5 to 3.7 and BASDAI-≥2 anti-TNFs:5.7 to 4.7). However, overall better improvement was observed inanti-TNF naïvepatients, as seen by the example of ASAS-HI (Fig. 1). Between 30% and 40% of patients prematurely discontinued SEC treatment in the subgroups1 anti-TNFand≥2 anti-TNFs, respectively, while only about 20% did so in theanti-TNF naïveAS patients (Fig. 2).Conclusion:SEC has shown to improve disease activity, physical functioning and QoL in anti-TNF-naïve and pretreated AS patients in a real-world setting. The benefits of SEC were numerically more distinct in anti-TNF-naïve patients. Moreover, SEC demonstrated high retention rate, particularly in anti-TNF-naïve patients, thereby confirming previously reported real-world data on SEC from EuroSpA research collaboration network.2References:[1]Glintborg B, et al, Ann Rheum Dis 2013;72:1149-55; 2. Michelsen B, et al, Arthritis Rheumatol 2019:71(suppl10) #1822Disclosure of Interests:Uta Kiltz Grant/research support from: AbbVie, Amgen, Biogen, Novartis, Pfizer, Consultant of: AbbVie, Biocad, Eli Lilly and Company, Grünenthal, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, MSD, Novartis, Pfizer, Roche, UCB, Jan Brandt-Juergens: None declared, Peter Kästner Consultant of: Chugai, Novartis, Elke Riechers Grant/research support from: AbbVie, Chugai, Lilly, Janssen, Novartis, Pfizer, Roche, UCB, Consultant of: AbbVie, Chugai, Novartis, UCB, Daniel Peterlik Employee of: Novartis Pharma GmbH, Hans-Peter Tony Consultant of: AbbVie, Astra-Zeneca, BMS, Chugai, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, SanofiFigure 1.Change of health in AS patients treated with SEC stratified by anti-TNF pretreatmentFigure 2.SEC treatment retention depending on anti-TNF pretreatment (Kaplan-Meier plot)