OP0149 RADIOGRAPHIC PROGRESSION FROM NON-RADIOGRAPHIC TO RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS: RESULTS FROM A 5-YEAR MULTICOUNTRY PROSPECTIVE OBSERVATIONAL STUDY

Background Patients (pts) with axial spondyloarthritis (axSpA) are classified into radiographic axSpA (r-axSpA) and non-radiographic (nr-axSpA) based on the presence or absence of sacroiliitis. Approximately 20% to 80% newly diagnosed pts have nr-axSpA 8% 40% progress r-axSpA over next 2 10 years. Objectives To evaluate progression from 5 years in a prospective multicentre cohort. Methods PROOF was global, real-world, prospective, observational study conducted rheumatology clinical practices 29 countries across 6 different geographic regions. 1 The enrolled adults chronic back pain for ≥3 months onset before 45 age. This analysis included who also fulfilled Assessment SpondyloArthritis international Society (ASAS) classification criteria axSpA. Study visits occurred at baseline (BL) yearly thereafter. Baseline follow-up radiographs sacroiliac joints (SIJ) were evaluated initial diagnosis independently by central readers according modified New York criteria. In case disagreement (nr- r-axSpA), images adjudicated third reader. Radiographic Kaplan-Meier analysis. Cox proportional hazards regression analyses time conducted. For model 1, ‘imaging arm vs arm’ used as an independent variable, 2, ‘active inflammation magnetic resonance imaging highly suggestive sacroiliitis associated SpA’ used. Further, potential predictive factors models age, gender, duration, number SpA parameters, smoking status, CRP, good response NSAIDs, HLA-B27 current use NSAIDs TNF inhibitors. Results Among 2633 pts, 2165 (82%) ASAS these, 1612 (74%) having (1050 [65%]) (562 [35%]) reading. majority (77%) due positive findings (plus ≥1 feature) 23% arm. A total 246 had SIJ radiograph this these any observed 40 (16%) Mean 2.4 (ranging 0.9 5.1 years) descriptive (Kaplan-Meier curve shown Figure 1). analysis, male gender (hazard ratio [HR]: 3.16 [95% CI: 1.22–8.17]; P =0.0174), fulfilment (HR: 6.64 [1.37–32.25]; =0.0188), 4.66 [1.23–17.71]; =0.0237), significantly (Figure positivity showed significant association 3.99 [1.10–14.49]; =0.0353; Conclusion study, 16% progressed within mean disease Predictors well positivity. References [1]Poddubnyy D. et al , Rheumatology (Oxford ). 2021; doi: 10.1093/rheumatology/keab901 Disclosure Interests Denis Poddubnyy Speakers bureau: AbbVie, Bristol Myers Squibb, Eli Lilly, MSD, Novartis, Pfizer, UCB, Consultant of: Biocad, Gilead, GlaxoSmithKline, Samsung Bioepis, Grant/research support from: Joachim Sieper Janssen, Merck, Roche, Servet Akar Santiago Muñoz-Fernández BMS, Galapagos, UCB., Hildrun Haibel Sobi, Boehringer, Torsten Diekhoff Paid instructor for: Canon MS, Mikhail Protopopov: None declared, Elisabeth Altmaier Fabiana Ganz Shareholder Owns AbbVie stock options., Employee Robert Inman Amgen, Sandoz, Janssen