OBJECTIVES. To evaluate prevalence of patients with axSpA diagnosis and their treatment patterns and drug utilization in real-world settings.

METHODS. This observational study was performed using administrative databases of selected Italian settings and included patients with axSpA diagnosis identified by ICD-9-CM or exemption code. A cross-sectional analysis was performed for years 2016-2018 to evaluate treatment patterns. Patients prescribed drugs indicated for axSpA were defined “treated”, otherwise “untreated”. A longitudinal analysis was conducted to investigate biological disease-modifying antirheumatic drugs (bDMARDs) utilization among axSpA patients receiving their first bDMARD (index-therapy) during years 2014 and 2017. Follow-up was from index-therapy prescription date to end of data availability. Switch was defined when bDMARDs administered during follow-up were different than index-therapy. Treatment discontinuation was defined as absence of bDMARDs prescriptions during last trimester of follow-up.

RESULTS. In the sample analysed, AxSpA prevalence was 0.076% (0.088% in adult population). Cross-sectional analysis: patients with axSpA diagnosis were 5,942 in 2016, 6,554 in 2017, 7,146 in 2018. Proportion of untreated patients was 34.1% (2016), 36.6% (2017) and 51.5% (2018), that of bDMARDs-treated patients was 21.4% (2016), 22.0% (2017), 16.9% (2018). In 2016 the only class of biologic prescribed was anti-TNF; in 2017 bDMARDs-treated patients started receiving anti-IL-17A agents (7.9% in 2017, 12.9% in 2018). Longitudinal analysis: in 2014, of 349 patients included, 9.5% switched therapy; 13.8% discontinued their bDMARDs treatment after a mean time of 84.9±72.7 days. In 2017, 262 patients were considered: 12.2% switched therapy and 27.1% had a treatment discontinuation after a mean time of 107.0±81.9 days.

CONCLUSIONS. In this real-world study, we provided axSpA prevalence in an unselected Italian population under clinical practice settings. Preliminary results showed significant proportions of untreated patients. In 2017, around one-fourth of patients receiving first bDMARD discontinued their treatment. Our findings suggest an unmet therapeutic need exists for axSpA patients.