Cost-Effectiveness and Net Monetary Benefit of Olaparib Maintenance Therapy Versus No Maintenance Therapy After First-line Platinum-based Chemotherapy in Newly Diagnosed Advanced BRCA1/2-mutated Ovarian Cancer in the Italian National Health Service

Purpose: The aim of this study was to evaluate the cost-effectiveness and net monetary benefit of olaparib maintenance therapy compared with no maintenance therapy after first-line platinum-based chemotherapy in newly diagnosed advanced BRCA1/2-mutated ovarian cancer from the Italian National Health Service (NHS) perspective. Methods: We developed a lifetime Markov model in which a cohort of patients with newly diagnosed advanced BRCA1/2-mutated ovarian cancer was assigned to receive either olaparib maintenance therapy or active surveillance (Italian standard of care) after first-line platinum-based chemotherapy to compare cost-effectiveness and net monetary benefit of the 2 strategies. Data on clinical outcomes were obtained from related clinical trial literature and extrapolated using parametric survival analyses. Data on costs were derived from Italian official sources and relevant real-world studies. The incremental cost-effectiveness ratio (ICER), incremental cost-utility ratio (ICUR), and incremental net monetary benefit (INMB) were computed and compared against an incremental cost per quality-adjusted life-year (QALY) gained of €16,372 willingness-to-pay (WTP) threshold. We used deterministic sensitivity analysis (DSA) and probabilistic sensitivity analysis (PSA) to assess how uncertainty affects results; we also performed scenario analyses to compare results under different pricing settings. Findings: In the base-case scenario, during a 50-year time horizon, the total costs for patients treated with olaparib therapy and active surveillance were €124,359 and €97,043, respectively, and QALYs gained were 7.29 and 4.88, respectively, with an ICER of €9,515 per life-year gained, an ICUR of €11,345 per QALY gained, and an INMB of €12,104. In scenario analyses, considering maximum selling prices for all other drugs, ICUR decreased to €11,311 per QALY and €7,498 per QALY when a 10% and 20% discount, respectively, was applied to the olaparib official price, and the INMB increased to €12,186 and €21,366, respectively. DSA found that the model results were most sensitive to the proportion of patients with relapsing disease in response to platinum-based chemotherapy, time receiving olaparib first-line maintenance treatment, and subsequent treatments price. According to PSAresults, olaparib was associated with a probability of being cost-effective at a €16,372 per QALY WTP threshold ranging from 70% to 100% in the scenarios examined. Implications: Our analysis indicates that olaparib maintenance therapy may deliver a significant health benefit with a contained upfront cost during a 50-year time horizon, from the Italian NHS perspective, providing value in a setting with curative intent