Cost-Utility Analysis of Adjuvant Olaparib for Germline BRCA1/2-Mutated, High-Risk HER2-Negative Early Breast Cancer in Spain

Objective Here we estimate the cost-effectiveness of olaparib in the Spanish National Health Service (SNHS) as adjuvant treatment of early germline mutations in the BRCA1/2 genes (gBRCAm) HER2-negative (HER2neg) breast cancer (BC) with high risk of recurrence. Methods A semi-Markov model was adapted to the Spanish healthcare setting, using the perspective of the SNHS, and a lifetime horizon. Two scenarios were compared: receiving olaparib versus standard of care (SoC) treatment. The model comprised five health states and included the clinical results of the OlympiA trial, along with the direct healthcare costs associated with the use of early BC and subsequent treatment resources (€2023). A discount rate of 3% was applied for future cost and quality-of-life outcomes. A probabilistic sensitivity analysis (PSA) was carried out. Results The introduction of olaparib as adjuvant treatment for patients with early gBRCAm HER2neg BC with high risk of recurrence could involve an incremental cost of €44,273 and €50,164, with an improvement of 1.14 and 1.28 quality-adjusted life years (QALYs) for hormone receptor-positive (HR+) and triple-negative (TN) patients, respectively. Therefore, adjuvant olaparib could be cost-effective for early gBRCAm HER2neg BC, with an incremental cost-effectiveness ratio of €38,839/QALY and €39,084/QALY for HR+ and TN patients, respectively. The results from the PSA showed that 75.7% and 82.2% of the simulations fell below the €60,000/QALY threshold. Conclusions Olaparib as adjuvant treatment could be cost-effective in gBRCAm patients with early HER2neg BC in Spain.