OPT-In; Optimized Patient Treatment Outcomes in Plaque Psoriasis: A 3-Year State-Transition Treatment-Sequencing Model in the Italian Setting

Introduction: There are several treatment options for plaque psoriasis (PsO), but uncertainty remains around the optimal sequencing of treatments. The aims of this study were to investigate how adopting a best-treatment-first treatment sequence impacts patient outcomes and healthcare systems and to quantify the cost of treatment failure to the healthcare system. Methods: A 3-year state-transition treatment-sequencing model which identifies all possible treatment sequences in PsO was adapted to the Italian healthcare setting. Treatments considered in the model are those with European Medicines Agency marketing authorization and reimbursement in Italy as of December 2022. Italian market share data (2019-2021) and list prices (2022) informed the current prescribed sequences; these sequences were compared against all possible sequences to determine opportunities for improvement. Both the national perspective in Italy as well as the local perspective from seven regions were considered. The cost of treatment failure was informed through a questionnaire circulated to Italian dermatologists. Results: Overall, 1284 possible treatment sequences are possible when four lines of treatment are considered for patients with moderate-to-severe PsO in Italy. Within the estimated range of treatment failures across those sequences (0.97-2.56 per patient over 3 years), current prescribing behavior from the national perspective suggests patients will face 1.44 failures on average; this highlights the potential for improvement. For every treatment failure, the cost borne by the Italian National Healthcare Service (NHS) is €676.80. Overall, prescribing more optimized treatment sequences results in a 22.95% reduction in failures with a 2.27% increase in costs. The regional analyses found similar trends. Conclusions: Results suggest that selecting the most effective treatment sequences for incident patients provides the greatest opportunity to reduce treatment failures and maximize patient outcomes with a modest impact on costs. While regional variations exist, there is room for improvement across the board, which could translate to more efficient local healthcare systems.