OBJECTIVES: To evaluate the cost-effectiveness of fixed-dose combination NIVO+RELA versus NIVO monotherapy as first-line (1L) treatment for advanced melanoma in the population of the Netherlands with PDL-1 <1% from a societal perspective.

METHODS: A 3-state partitioned-survival model was developed using efficacy, safety, and utility data from the Phase III RELATIVITY-47 trial with a minimum follow-up of 8.7 months for overall survival (OS). OS and progression-free survival (PFS) were extrapolated over a 40-year time horizon using parametric models for both treatment arms using within trial analysis. All costs were Netherlands-specific (2023 Euros) with an annual discount rate of 4% for costs and 1.5% for outcomes. In addition to medical costs, costs for transportation, informal care and productivity loss were applied to capture the full societal benefit of treatment. Outcomes were quality-adjusted life years (QALYs), total cost, and incremental cost-utility ratios (ICUR). Sensitivity analyses were conducted to assess the model’s robustness.

RESULTS: Mean QALYs were 7.72 for NIVO+RELA and 6.22 for NIVO yielding an incremental benefit of 1.50 QALYs for NIVO+RELA. Total costs for NIVO+RELA were €231,435 and €163,186 for NIVO, with incremental costs of €68,249 for NIVO+RELA. The ICUR was €43,802/QALY. PSA results were stable with 1000 iterations. NIVO+RELA remained cost-effective in scenario analyses, indicating model results were robust to alternative assumptions.

CONCLUSIONS: In conclusion, our study presents compelling modeling evidence supporting the cost-effectiveness of NIVO+RELA as a valuable addition to the first-line treatment options for advanced melanoma in PD-L1 < 1% patients in the Netherlands. With an ICUR of €42,734/QALY, our findings indicate that this combination therapy falls well below the unofficial cost-effectiveness threshold of €80,000/QALY. Nevertheless, it is important to interpret these results with caution due to absence of details surrounding the confidential prices for NIVO, where national financial arrangements are currently in place.