OP0140 BIOLOGIC REFRACTORY DISEASE IN AXIAL SPONDYLOARTHRITIS - DEFINITION, PREVALENCE AND PATIENT CHARACTERISTICS. A COLLABORATION BETWEEN FIVE NORDIC BIOLOGIC REGISTRIES

• Published in: Annals of the Rheumatic Diseases
• Main Authors: DI Giuseppe, D., Lindström, U., Aaltonen, K., Relas, H., Aarrestad Provan, S., Gudbjornsson, B., Hetland, M. L., Askling, J., Schjødt Jørgensen, T., Dreyer, L., Nordström, D., Michelsen, B., Geirsson, A. J., Jacobsson, L. T. H., Glintborg, B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMJ 2021
• Subjects: General Biochemistry, Genetics and Molecular Biology; Immunology; Immunology and Allergy; Rheumatology; Norway; Iceland
• Online Access: http://dx.doi.org/10.1136/annrheumdis-2021-eular.630; https://syndication.highwire.org/content/doi/10.1136/annrheumdis-2021-eular.630

Background: In clinical practice, some patients with axial spondyloarthritis (axSpA) fail several consecutive biological treatments (bDMARDs). How this group of ”refractory” patients should best be defined, how common they are, and what their characteristics are, is poorly understood. Objectives: To explore the point prevalence of bDMARD refractory disease in axSpA over time, according to different definitions, and to describe the characteristics of refractory vs. not-refractory patients upon start of their first bDMARD. Methods: Observational prospective cohort study. Patients with axSpA (ankylosing spondylitis/non-radiographic axial SpA) starting a first bDMARD 2009-2018 were identified in biologic registries in Denmark, Sweden, Finland, Norway and Iceland. Clinical characteristics and treatments were retrieved, and data were pooled for analysis. Refractory disease was defined based on the number of different bDMARD treatments started in individual patients: mild (≥3 bDMARDs), moderate (≥4), and strict (5 or more). Restart of same bDMARD with another bDMARD in between counted as separate courses whereas switch from originator to corresponding biosimilar was ignored. Proportions of patients fulfilling each definition of refractory disease at 2 and 5 years after the start of 1st bDMARD were calculated. Point-prevalence per calendar-year was calculated as the number of patients with refractory disease at the end of each year, divided by the total number of patients ever having starting a first bDMARD before that time-point, and who were still alive and resident in the country. Results: The point prevalence of refractory axSpA increased with calendar-time (Figure). Among 12,037 included axSpA patients (64% male), the point-prevalence of bDMARD refractory disease in 2018 was 16%/7%/3% according to mild/moderate/strict definitions (Table). Table 1. Biologic refractory axSpA according to three definitions A. Baseline characteristics upon start 1st bDMARD Refractory definition Overall cohort MILD MODERATE STRICT N ...