(B-302) Treatment associated serious infection in patients with moderate to severe psoriasis: A cohort study from UK and Ireland

Background: Systemic treatments for psoriasis could increase the risk of serious infection due to their immunomodulatory properties.

Objectives: Our aim was to assess the serious infection risk associated with systemic treatments for psoriasis.

Methods: Adults with moderate-to-severe psoriasis from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR) who received at least one of the biologics, apremilast or conventional nonbiologics (acitretin, ciclosporin and methotrexate) for 6 months or more were included in this cohort study. Infliximab and certolizumab were not included due to differences in treatment cohorts. Patients were followed up from the initiation of treatment until the first serious infection episode, treatment switch/withdrawal, death or last available follow-up date. Infections resulting in hospitalisation, administration of intravenous antibiotics or death were classified as serious. Incidence rates (IR) of serious infection per 1000 person years and corresponding confidence intervals were calculated using R 4.3.2.

Results: A total of 18,231 patients undergoing 38,422 treatment episodes were analysed. Patients were predominantly male (n=21,864 (56.90%)) with a mean age of 46±13.60 years, mean BMI of 31.20±9.60 kg/m2 and a median treatment duration of 1.62 (IQR 3.55) years. Ustekinumab had significantly longer median treatment duration of more than 4 (IQR 1.83, 6.73) years and more patients in the ixekizumab (42.60%) group had concomitant psoriatic arthritis. Overall, 3023 first serious infection episodes were recorded and the incidence rate per 1000 person years of the overall population was 28.54 (95% CI 27.54, 29.58). The incidence rate was lowest for risankizumab (IR 21.51; 95% CI 15.63, 28.87) and highest for apremilast (IR 50.67; 95% CI 39.27, 64.35). Incidence rates of other TNF-α inhibitors were 26.75 (25.03, 28.56) for adalimumab and 29.56 (25.39, 34.22) for etanercept; IL-17 inhibitors were 32.99 (29.45, 36.84) for secukinumab, 27.05 (12.37, 51.35) for bimekizumab, 29.82 (19.48, 43.69) for brodalumab and 30.38 (24.33, 37.47) for ixekizumab; IL-23 inhibitors were 22.79 (18.07, 28.37) for guselkumab, and 24.29 (12.12, 43.46) for tildrakizumab. The IL-12/23 inhibitor ustekinumab had an incidence rate of 25.24 (23.35, 27.24) and conventional nonbiologics 33.74 (31.19, 36.44).

Conclusions: In this analysis, we observed low serious infection incidence across different treatment groups. The Cox proportional hazards analysis with propensity scores and inverse probability treatment weighting (IPTW) to account for potential confounders would provide further insights into the relative risk of serious infection.