Valutazione economica dei CDK4/6i nel carcinoma mammario metastatico: un modello basato su aderenza e persistenza real-world

Introduction. HR+/HER2-metastatic breast cancer is the most frequent advanced subtype and is commonly treated with CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) plus endocrine therapy. This analysis assessed real-world adherence, persistence and economic impact from the perspective of an Italian Local Health Authority. Materials and methods. A retrospective single-center study was conducted on 38 patients treated between January 2023 and March 2025. Adherence was measured by Proportion of Days Covered (PDC); persistence was assessed over 18 months. A cost-effectiveness analysis was performed, including deterministic and probabilistic sensitivity analyses. Results. All three treatments showed high mean adherence: abemaciclib 0.88±0.05; ribociclib 0.87±0.13; palbociclib 0.86±0.09. By day 548, treatment persistence was 40% for ribociclib, 33.3% for abemaciclib, and 16.7% for palbociclib. The economic analysis identified abemaciclib as the most affordable option (-90% in cost vs. palbociclib), while ribociclib was the most effective in terms of persistence. Both proved dominant over palbociclib. It is also evident that treatment persistence has an economic impact comparable to the drug’s cost, underscoring the importance of interventions aimed at improving long-term persistence. Conclusions. The integration of adherence, persistence, and cost data indicates that abemaciclib and ribociclib are preferable to palbociclib for managing HR+/HER2-metastatic breast cancer. Structured counseling can support adherence and continuity, reducing discontinuations and improving outcomes and sustainability. The research pharmacist plays a crucial role in generating real-world evidence to inform sustainable, context-specific therapeutic decisions.