Objectives: To assess the budgetary impact of introducing bimekizumab, as a treatment option for adult patients with active Psoriatic Arthritis (PsA), previously treated with conventional disease-modifying antirheumatic drugs (DMARDs) in Greece, alongside currently available biologic therapies, Janus kinase inhibitors, and apremilast.

Methods: A budget impact model was adapted from a public-payer perspective to project the financial implications of including bimekizumab in the PsA treatment landscape over five-years (2025-2029). The model integrated epidemiological data of Greek PsA patients, market share scenarios with and without bimekizumab, efficacy inputs (treatment response measured by American College of Rheumatology [ACR50] and surrogate data for Health assessment questionnaire disability index [HAQ-DI] changes), based on BE-COMPLETE and BE-OPTIMAL trials, a published network meta-analysis of published clinical trials (excluding HAQ-DI data), and direct reimbursement costs for each treatment. Market share projections were based on pharmaceutical company estimations. All unit costs were considered based on the year of the analysis (€,2023). Epidemiological data were sourced from officially published studies and local clinical expert opinions. The measured outcomes were incremental cost and total budgetary impact, evaluating the respective budget expenditures with and without bimekizumab in the Greek PsA market.

Results: The eligible population ranged from 7,858 in the first year to 8,242 patients in the fifth year, with the number of patients treated with bimekizumab in the new market scenario estimated to increase from 51 in 2025 to 597 in 2029. Adding bimekizumab to the Greek PsA market resulted in an average total budget impact of €169/patient per year. Over the five-year horizon, the inclusion of bimekizumab led to an increase in public expenditures, with an average annual total budget impact of €1,372,979.

Conclusions: Based on this budget impact analysis, the introduction of bimekizumab to the PsA market in Greece is expected to have a minimal budgetary impact.