Objective. Autoantibodies against CD74 (anti-CD74) are associated with ankylosing spondylitis (AS). The present multicenter study, the International Spondyloarthritis Autoantibody (InterSpA) trial, was undertaken to compare the sensitivity and specificity of anti-CD74 and HLA-B27 in identifying patients with nonradiographic axial spondyloarthritis (axSpA).Methods. Patients ages 18-45 years with inflammatory back pain of ≤2 years' duration and a clinical suspicion of axSpA were recruited. HLA-B27 genotyping and magnetic resonance imaging of sacroiliac joints were performed in all patients. One hundred forty-nine patients with chronic inflammatory back pain (IBP) not caused by axSpA served as controls, and additional controls included 50 AS patients and 100 blood donors whose specimens were analyzed.Results. One hundred patients with inflammatory back pain received a diagnosis of nonradiographic axSpA from the investigators and fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criteria. The mean age was 29 years, and the mean symptom duration was 12.5 months. The sensitivity of IgA anti-CD74 and IgG anti-CD74 for identifying the 100 axSpA patients was 47% and 17%, respectively. The specificity of both IgA anti-CD74 and IgG anti-CD74 was 95.3%. The sensitivity of HLA-B27 was 81%. The positive likelihood ratios were 10.0 (IgA anti-CD74), 3.6 (IgG anti-CD74), and 8.1 (HLA-B27). Assuming a 5% pretest probability of axSpA in chronic back pain patients, the posttest probability, after consideration of the respective positive test results, was 33.3% for IgA anti-CD74, 15.3% for IgG anti-CD74, and 28.8% for HLA-B27. A combination of IgA anti-CD74 and HLA-B27 results in a posttest probability of 80.2%.Conclusion. IgA anti-CD74 may be a useful tool for identifying axSpA. The diagnostic value of the test in daily practice requires further confirmation.

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)

BackgroundThere is a higher prevalence of obesity in patients (pts) with psoriatic disease1. The German non-interventional study AQUILA provides real-world data on the influence of body mass index (BMI) of pts with psoriatic arthritis (PsA) on therapeutic effectiveness and safety under treatment with secukinumab, a fully human monoclonal antibody that selectively inhibits IL-17A.ObjectivesThe aims of this interim analysis are to describe selected baseline (BL) demographics and to evaluate secukinumab treatment outcomes on disease activity and impact of disease on health and to report safety profile depending on the BMI of PsA pts.MethodsAQUILA is an ongoing, multi-center study including up to 3000 pts with active PsA or ankylosing spondylitis. Pts were observed from BL up to week (w) 52. Real-world data were assessed prospectively and analyzed as observed. Data were collected on Psoriatic Arthritis Impact of Disease-12 items (PsAID-12 score) and Patient’s Global Assessment (PGA). For calculation of proportion of pts that experienced (serious) adverse events ((S)AEs), all PsA pts were included that received at least one dose of secukinumab. This interim analysis focuses on BMI subgroups ≤25 kg/m2 (normal weight), >25 to ≤30 kg/m2 (overweight) and >30 kg/m2 (obese) in PsA pts.ResultsAt BL, BMI data were available for 1228 PsA pts: 26.5% (n=325) normal weight, 35.0% (n=430) overweight and 38.5% (n=473) obese PsA pts. Proportion of men was lower in normal weight and obese PsA pts. As BMI increased, so did age and comorbidities/extraarticular manifestations (EAMs; Table 1); e.g. percentage of PsA pts with heart-related disease increased from 5.2% in normal weight to 9.3% in obese PsA pts.Table 1.Overview of baseline characteristics in PsA pts depending on BMIDemographicsBMI ≤25 kg/m2(N=325)BMI >25 to ≤30 kg/m2(N=430)BMI >30 kg/m2(N=473)Male*105 (32.3)219 (50.9)188 (39.7)Age, years**49.5 (±12.7)53.2 (±11.0)54.1 (±10.6)PsAID**4.7 (2.4)4.9 (2.2)5.4 (2.0)PGA**4.8 (2.6)5.4 (2.4)5.5 (2.4)Comorbidities/EAMs* Heart-related disease17 (5.2)29 (6.7)44 (9.3) Coronary heart disease10 (3.1)25 (5.8)35 (7.4) Stroke1 (0.3)9 (2.1)11 (2.3) Heart insufficiency9 (2.8)15 (3.5)15 (3.2) Uveitis5 (1.5)6 (1.4)10 (2.1) Depression137 (53.5)190 (55.2)231 (58.5)*variables are given as n (%); **variables given as mean (SD)Mean PsAID at BL was similar for all BMI subgroups (≤25: 4.7; >25-≤30: 4.9; >30: 5.4; Figure 1A). Mean improvement from BL to w52 was 1.9 (40.4%) for normal weight, 1.8 (36.7%) for overweight, and 1.7 (31.5%) for obese PsA pts.Figure 1.Impact of disease and PGA in PsA pts stratified by BMI.Note: p-values are of exploratory nature. Wilcoxon tests were used to show significant subroup differences.Mean PGA developed in a similar way over time with lowest scores for normal weight and highest scores for obese PsA pts (Figure 1B). Mean improvement from BL to w52 was 2.0 (41.6%) for normal weight, 2.2 (40.7%) for overweight, and 1.8 (32.7%) for obese PsA pts.The occurrence of AEs/SAEs with or without suspected relationship to secukinumab was most frequent in overweight and obese PsA pts. For example, the percentage of SAEs in normal weight PsA pts was 21.6%, in overweight 26.3% and in obese 25.9%. There were no unexpected safety signals in either subgroup. One male obese PsA patient died. Cause of death was not reported, however, treating physician did not suspect a causal relationship to secukinumab.ConclusionIn a real-world setting, secukinumab improved impact of disease and patient´s global assessment of disease activity in all BMI subgroups of PsA pts. However, normal weight PsA pts had numerically better PsAID and PGA scores than obese PsA pts. Altogether, real-world data of this interim analysis show that secukinumab is an effective treatment with a favorable safety profile up to 52 weeks in PsA pts in all BMI subgroups.References[1]Queiro, R., Lorenzo, A., Tejón, P., Coto, P. & Pardo, E. Medicine (Baltimore) 98, e16400 (2019).Disclosure of InterestsUta Kiltz Consultant of: AbbVie, Amgen, Biogen, Chugai, Eli Lilly, Gilead, GSK, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche, UCB, Grant/research support from: AbbVie, Amgen, Biogen, Chugai, Eli Lilly, Gilead, GSK, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche, UCB, Jan Brandt-Juergens Consultant of: Abbvie, Affibody, BMS, Gilead, Janssen, Lilly, Medac, MSD, Novartis, Pfizer, Roche, Sanofi-Aventis, UCB, Peter Kästner Consultant of: Chugai, Novartis, Elke Riechers Consultant of: AbbVie, Chugai, Novartis, UCB, Grant/research support from: AbbVie, Chugai, Novartis, UCB, Pfizer, Daniel Peterlik Employee of: Novartis, Christina Budden Employee of: Novartis, Hans-Peter Tony Consultant of: AbbVie, Astra-Zeneca, BMS, Chugai, Janssen, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi