OBJECTIVES: The aim of this study was to assess the cost-effectiveness of nivolumab versus ‘watch and wait’ as an adjuvant treatment for melanoma in adults with involvement of lymph nodes or metastatic disease, after having undergone complete resection in Belgium.

METHODS: A partitioned survival de novo global cost-effectiveness model was adapted to the Belgian setting. The analysis took a health-care payer perspective, over a life time horizon. Nivolumab was compared with observation (watch and wait), as per local clinical practice.

The efficacy of nivolumab and observation on recurrence free survival (RFS) was informed by an indirect treatment comparison based on patient-level data from CheckMate 238 (24-month cut-off data) and CA184-029 trials, as both include ipilimumab as comparator. An RFS/overall survival (OS) correlation equation supported by published literature allowed to model OS.

The market share of systemic anticancer subsequent therapies was based on local data. Drug acquisition, administration, monitoring, subsequent therapy, adverse events and end-of life costs were obtained from published sources. Utility values based on Belgian EQ-5D tariffs were obtained from CheckMate 238 collected data. An annual discount rate of 3% was used for costs, while an annual discount rate of 1.5% was used for outcomes. Input parameters’ uncertainty was tested in sensitivity analyses. Results were reported in terms of incremental cost-utility ratio (ICUR).

RESULTS: An incremental QALY of 4.44 and incremental costs of €64,331 were estimated with nivolumab in the base case, resulting in an ICUR of €14,504 per QALY gained compared with observation. Nivolumab has approximately 59.0%, 83.9% and 97.4%% probability of being cost-effective at a willingness to pay threshold of €18,000, €24,000 and €40,000 respectively.

CONCLUSIONS: Nivolumab is considered to be a cost-effective strategy for the adjuvant treatment of melanoma in Belgium.