One-Year Treatment Outcomes of Secukinumab Versus Tumor Necrosis Factor Inhibitors in Spondyloarthritis: Results From Five Nordic Biologic Registries Including More Than 10,000 Treatment Courses

Objective: To describe baseline characteristics and to compare treatment effectiveness of secukinumab versus tumor necrosis factor inhibitors (TNFi) in patients with spondyloarthritis (SpA) using adalimumab as the main comparator. Methods: This was an observational, prospective cohort study. Patients with SpA (clinical ankylosing spondylitis, nonradiographic axial SpA, or undifferentiated SpA) starting secukinumab or a TNFi during 2015–2018 were identified from 5 Nordic clinical rheumatology registries. Data on comorbidities and extraarticular manifestations (psoriasis, uveitis, and inflammatory bowel disease) were captured from national registries (data available in 94% of patients) and included in multivariable analyses. We assessed 1-year treatment retention (crude survival curves, adjusted hazard ratios [HR_adj] for treatment discontinuation) and 6-month response rates (Ankylosing Spondylitis Disease Activity Score [ASDAS] score <2.1, Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] <40 mm, crude/LUNDEX-adjusted, adjusted logistic regression analyses with odds ratios [ORs]) stratified by line of biologic treatment (first, second, and third plus). Results: In total, 10,853 treatment courses (842 secukinumab and 10,011 TNFi, of which 1,977 were adalimumab) were included. The proportions of patients treated with secukinumab during the first, second, and third-plus lines of treatment were 1%, 6%, and 22%, respectively). Extraarticular manifestations varied across treatments, while other baseline characteristics were largely similar. Secukinumab had a 1-year retention comparable to adalimumab as a first or second line of treatment but poorer as a third-plus line of therapy (secukinumab 56% [95% confidence interval (95% CI) 51–61%] versus adalimumab 70% [95% CI 64–75%]; HR_adj 1.43 [95% CI 1.12–1.81]). Across treatment lines, secukinumab had poorer estimates for 6-month response rates than adalimumab, statistically significantly only for the third-plus line (adjusted analyses: ASDAS score <2.1 OR 0.56 [95% CI 0.35–0.90]; BASDAI <40 mm OR 0.62 [95% CI 0.41–0.95]). Treatment outcomes varied across the 5 TNFi. Conclusion: Secukinumab was mainly used in biologics-experienced patients with SpA. Secukinumab and adalimumab performed similarly in patients who had failed a first biologic, although with increasing prior biologic exposure, adalimumab was superior.