OBJECTIVES

This study aims to assess the cost-effectiveness of avelumab compared to doxorubicin in the treatment of previously treated patients with metastatic Merkel cell carcinoma (mMCC) in Portugal.

METHODS

The cost-effectiveness analysis was based on a partitioned-survival model using data from the JAVELIN Merkel 200 trial and observational data. Parametric functions were chosen to extrapolate overall survival, progression-free survival, and time on treatment according to goodness of fit criteria. Utility weights, stratified according to time-to-death, were estimated applying the EQ-5D-5L Portuguese value set to the respective patient-reported outcomes from the JAVELIN Merkel 200 trial. Disutilities due to adverse events were obtained from the literature. Portuguese-specific disease management resource use was based on expert opinion and Portuguese diagnosis related group (DRG) microdata. National legislation and official drug cost databases were the main sources for unit costs. The analysis was conducted from a payers’ perspective, assuming a lifetime horizon and a 5% discount rate for costs and effects. Deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of results.

RESULTS

Avelumab increases average life expectancy by 3.62 undiscounted life years (LY) enabling a discounted gain of 2.66 LY or 2.32 quality adjusted life years (QALY). Economic analysis shows that the higher cost of the avelumab option is mainly due to higher treatment costs. The estimated incremental cost-effectiveness ratios are 35,057€/QALY and 30,576€/LY. Deterministic sensitivity analyses show that results are robust to most scenarios but sensitive to parametric extrapolation options, discount rate and time horizon.

CONCLUSIONS

As the first licensed treatment in this indication, avelumab may be considered a cost-effective option, taking into consideration the rarity of the disease and the usually accepted thresholds in Portugal. The cost-effectiveness model of avelumab in the treatment of mMCC after prior chemotherapy was considered valid to support a reimbursement decision in the Portuguese setting.