Persistence to Biologic Therapy among Patients with Spondyloarthritis: An Observational Study using the OPAL Dataset.

Objective To describe the treatment response and persistence to biologic DMARD (bDMARD) therapy in patients with ankylosing spondylitis (AS) in a real-world Australian cohort. Methods This was a retrospective, non-interventional cohort study that extracted data for patients with AS from the Optimising Patient outcomes in Australian rheumatology (OPAL) dataset for the period Aug-2006 to Sep-2019. Patients were classified as either bDMARD initiators if they commenced a bDMARD during the sampling window, or bDMARD naive if they did not. Results were summarised descriptively. Treatment persistence was calculated using Kaplan-Meier methods. Differences in treatment persistence were explored using log-rank tests. Results 5048 patients with AS were identified. 2597 patients initiated bDMARDs and 2451 remained bDMARD naive throughout the study window. Treatment with first, second and third line bDMARDs significantly reduced disease activity. Median persistence on first line bDMARDs was 96 months (95% CI 85 to 109), declining to 19 months (95% CI 16 to 22) in second line, and 14 months (95% CI 11 to 18) in third line therapy. Median persistence was longest for the golimumab treated group in all lines of therapy and shortest for the etanercept group. Differences in persistence rates according to the time-period that bDMARDs were prescribed (pre-and post-2012) were also seen for etanercept and adalimumab. Conclusion In this cohort all bDMARDs effectively reduced disease activity. Patients remained on their first bDMARD longer than subsequent agents. Median persistence was longest for the golimumab treated group in all lines of therapy and shortest for the etanercept group.