Cost Effectiveness and Budget Impact of Nivolumab Plus Ipilimumab Versus Platinum Plus Pemetrexed (with and Without Bevacizumab) in Patients with Unresectable Malignant Pleural Mesothelioma in Switzerland

BACKGROUND: Malignant pleural mesotheliomas (MPMs) are aggressive and often unresectable. In the past, chemotherapy was the standard for palliative treatment. However, immunotherapy with nivolumab+ipilimumab has recently received marketing approval. OBJECTIVES: This study evaluated the cost effectiveness of nivolumab+ipilimumab versus pemetrexed+platinum (with/without bevacizumab) for Swiss patients with unresectable MPM, overall and by histological subtype. METHODS: We developed a three-state Markov cohort model with a cycle length of 1 month, a 30-year time horizon, and a discount rate of 3% per year for costs and benefits. The model included the updated survival and treatment-dependent utility results from the Checkmate-743 and MAPS registration trials. A Swiss statutory health insurance perspective was considered with unit costs for 2022 from publicly available and real-world sources. We assumed a willingness-to-pay (WTP) threshold of CHF100,000/QALY. Model robustness was explored in sensitivity and scenario analyses. RESULTS: Compared with chemotherapy, nivolumab+ipilimumab incurred additional costs of CHF109,115 and 0.57 additional quality-adjusted life-years (QALYs), yielding an incremental cost-effectiveness ratio (ICER) of CHF192,585/QALY (i.e. USD201,829/QALY) gained. Relative to their 2022 list price, nivolumab+ipilimumab may be cost effective if priced at 48% across all histologies. Assuming cisplatin-based instead of carboplatin-based chemotherapy reduced the ICER to CHF158,911/QALY (i.e. USD166,539/QALY). For the non-epithelioid subtype, nivolumab+ipilimumab was cost effective compared with chemotherapy (ICER of CHF97,894/QALY, i.e. USD102,593/QALY). Chemotherapy+bevacizumab was often a dominated strategy or would require a bevacizumab cost reduction to 28%. CONCLUSIONS: Our model projected nivolumab+ipilimumab to be cost effective for the non-epithelioid subtype but not for all histologies. Substantial discounts for nivolumab+ipilimumab would be necessary to achieve cost effectiveness for all histologies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40273-023-01305-3.