Ensuring Sustainability in Pharmaceutical Care: A Retrospective Analysis of Administrative Databases on the Utilization, Costs, and Switching Patterns of Biological Therapies in the Agency for Health Protection of the Metropolitan Area of Milan

<b>Background</b>: Biosimilars represent a fundamental advancement in global healthcare, offering significant cost containment while maintaining both therapeutic efficacy and safety in the management of chronic diseases. The cost savings generated by adopting biosimilars could be reinvested to foster innovation in the healthcare sector and enhance patient access to advanced therapies. <b>Methods</b>: A comprehensive analysis was conducted within an Italian healthcare organization which, through its hospital network, serves over 3.5 million individuals. Usage patterns, expenditure, and patient coverage for the principal biosimilar agents across various therapeutic areas were examined. Data were extracted from institutional registries, and a year-over-year comparison from 2022 to 2024 was performed to evaluate trends in consumption, biosimilar adoption among treatment-naïve patients, incurred costs, potential and actual savings, as well as therapeutic switching profiles. <b>Results</b>: The analysis revealed a marked shift towards biosimilar formulations for the majority of the evaluated biological agents between 2022 and 2024. However, for certain active substances, a reduced market penetration of biosimilars was observed, and critical issues persist that will necessitate future interventions. <b>Conclusions</b>: The results demonstrate a consistent upward trajectory in biosimilar adoption, underscoring significant progress toward their integration into routine clinical practice-a transition that has generated substantial savings over the three-year period considered. Assuming a complete transition to biosimilars, the cumulative potential savings over the three-year period would amount to EUR 7,172,372.99 in 2022, EUR 6,209,289.05 in 2023, and EUR 23,536,824.05 in 2024. This trend aligns with strategic objectives to enhance the sustainability of the Italian National Health Service (SSN) through optimized resource allocation and improved patient access.