Dose increase beyond labelled dose of biologics is associated with incremental pharmacy costs: results from a real-world study in the UK.

Background: There is limited evidence regarding biologics dosing patterns and its costs among psoriasis patients in the United Kingdom (UK). Objective: This retrospective study assessed biologics dose increase beyond labelled dose and associated UK pharmacy costs in moderate to severe psoriasis patients. Methods: Adult psoriasis patients on biologic prescription for ≥12 continuous months between January 2010 and March 2015 with their diagnosis recorded in the UK Hospital Treatment Insights Database within one month of such prescription were included. The proportion of patients receiving ≥30% higher the average daily maintenance dose as per the UK product label, and associated 12-month costs were reported. Results: The study included 362 patients, receiving adalimumab (48%), etanercept (17%), ustekinumab (12%), and infliximab (23%). Beyond labelled dose increase was noted in 14% adalimumab, 20% etanercept, 18% ustekinumab and 28% infliximab patients with an associated mean annual extra cost per patient of £7936, £5912, £2422 and £2275, respectively. Conclusion: Dose increase beyond labelled dose of biologics was commonly observed in moderate to severe psoriasis in the UK and resulted in substantial annual incremental pharmacy costs.