AB0886 EVALUATION OF FACTORS ASSOCIATED WITH EARLY VERSUS LATE Ts/bdmards INITIATION IN SPONDYLOARTHRITIS PATIENTS. AN ANALYSIS OF THE REGISPONSER AND REGISPON-3 REGISTRIES

Background: Biological and targeted-synthetic therapy has revolutionized the management of spondyloarthritis (SpA) improving the quality of life of the patients. Early identification of the factors that delay the start of biological treatment could allow us to improve the overall management of the SpA patients. To our knowledge, no studies have evaluated the factors associated with early versus late start of biological therapy in SpA patients. Objectives: a) To study the evolution of the ts/bDMARDs initiation in SpA patients over time regarding the onset of symptoms; b) To evaluate the factors associated with early or late initiation of ts/bDMARDs in SpA patients. Methods: Longitudinal and multicentre study where patients with SpA from REGISPONSER (assessed in 2004) were re-evaluated 17 years later (2021-2022), resulting in the REGISPON-3 study. REGISPONSER dataset has been combined with the REGISPON-3 data obtaining two visits separated by 17 years. Firstly, among patients who have started ts/bDMARDs at any time, we performed a Kaplan-Meier curve to calculate the cumulative probability of initiating biologics since the onset of symptoms and their median of years. Secondly, patients were divided into early versus late ts/bDMARDs initiation according to that median. Finally, we conducted a univariate and a multivariate logistic regression to evaluate the clinical and sociodemographic characteristics associated with early versus late start of therapy. Results: A total of 381 patients were re-evaluated in REGISPON-3. Among these, a total of 189 (49.6%) patients diagnosed with SpA had started biological treatment at some point since the onset of symptoms (REGISPONSER and REGISPON-3). Figure 1 shows the cumulative probability of starting ts/bDMARDs from any point among patients who have started these treatments during the course of their disease. The median number of years that patients started ts/bDMARDs therapy since symptom onset was 21 years, so patients were divided into early and late initiation (<21 and ≥21 years since symptom onset, respectively). Table 1 shows the univariate analysis of the clinical and sociodemographic characteristics of the patients according to the early or late initiation of ts/bDMARDs. Psoriasis and IBD were associated with an early initiation of ts/bDMARDs while positive HLA-B27, axial symptoms and a greater diagnosis delay were associated with a late initiation. Multivariate analysis showed that factors associated with late initiation of ts/bDMARDs were a longer diagnosis delay [1.324 (95% CI 1.197 to 1.467)], while IBD [0.044 (95% CI 0.005 to 0.371)] was associated with an early initiation. Conclusion: ts/bDMARDs initiation can occur at any time during the course of the disease. A greater diagnosis delay contributes to a later start of ts/bDMARDs while the appearance of extramusculoskeletal manifestations such as IBD are related to an early start of treatment. REFERENCES: NIL. Table 1. Description of the clinical and sociodemographic characteristics of the patients according to the early or late start of the biological treatment IBD: inflammatory bowel disease, csDMARDS: conventional synthetic disease-modifying antirheumatic drugs; CRP: C Reactive Protein. Acknowledgements: NIL. Disclosure of Interests: None declared.