Budget Impact Analysis of Fam-Trastuzumab-Deruxtecan as a Second Line in Patients With HER2-Positive Metastatic Breast Cancer in Oman

OBJECTIVES: Despite advancements, breast cancer remains a major global health and financial challenge. Trastuzumab-based therapies, particularly Fam-Trastuzumab-Deruxtecan (T-DXd), have shown superior outcomes, leading to its recommendation as a preferred second-line treatment. However, its high cost necessitates a budget impact analysis (BIA) to evaluate financial feasibility. This study assesses the 1-year budget impact of replacing Trastuzumab Emtansine (TDM1) with T-DXd for HER2+ metastatic breast cancer in an Omani cancer center. METHODS: A static BIA model was built based on National Institute for Health and Care Excellence template with adaptation as required. The model time horizon was 1 year then projected over another 2 years, using 2022 as the baseline year, adopting Omani healthcare-payer perspective. The analysis considered 2 scenarios: (1) TDM1 as the current formulary drug and (2) T-DXd is introduced instead of TDM1, assuming that treatment share would be 100%. One-way sensitivity analysis is performed to assess the model's robustness. RESULTS: The BIA demonstrated that replacing TDM1 with T-DXd for the eligible patients would lead to increase in the budget expenditure. Over a 3-year period, considering the provided assumptions and input data, the cumulative excess amount to €5 909 481.67. The primary contributing factors are the drug acquisition cost and the median treatment duration. The sensitivity analysis results suggest the model is robust to changes in adverse drug reaction costs, unlike changes in treatment duration and drug cost. CONCLUSIONS: Although T-DXd improves clinical outcomes, its adoption as a second-line treatment in Oman poses a substantial financial burden, necessitating careful budget planning to ensure long-term affordability.