Risk of common infections among individuals with psoriasis in Sweden: A nationwide cohort study comparing secukinumab to ustekinumab

Purpose: To determine risk of respiratory tract infections, urinary tract infections and candidiasis in secukinumab users compared to ustekinumab users among individuals with psoriasis in Sweden.

Methods: This was a Swedish population-based register-linked new-user cohort study on individuals with psoriasis and psoriasis arthritis treated with secukinumab (2015-2017) and ustekinumab (2009-2017). Ever-never exposure definition was used, that is, each individual's follow-up time was attributed to the drug they were first exposed to. Risk of severe respiratory and urinary tract infections and candidiasis (diagnosis codes from out-patient specialist visits and in-patient hospitalisations) and respiratory and urinary tract infections treated in primary care (proxied by dispensation of antibiotics) was determined by adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox regression. We also give crude incidence rates and rate ratios.

Results: In total, 1955 new users of secukinumab (n = 848) and ustekinumab (n = 1107) were identified. There was a slightly increased risk of respiratory and urinary tract infections treated in primary care among secukinumab users compared to ustekinumab users (HR: 1.22, 95% CI: 1.03-1.43). Non-significant differences in estimated risk of severe respiratory and urinary tract infections (HR: 0.96, 95% CI: 0.57-1.61) and candidiasis (HR: 1.80, 95% CI: 0.84-3.84) treated in the hospital setting were observed.

Conclusion: We observed a slightly increased risk of respiratory and urinary tract infections treated in primary care among secukinumab users compared to ustekinumab users. Larger studies with longer follow-up are needed to draw conclusions on relative safety.