Cost Effectiveness of Avelumab for Metastatic Merkel Cell Carcinoma

BACKGROUND: Metastatic Merkel cell carcinoma (mMCC) is a rare and aggressive skin cancer. Until recently, there were no licensed treatment options for patients with mMCC, and prognosis was poor. A cost-effectiveness analysis was conducted for avelumab, a newly available treatment option for mMCC, versus standard care (SC), from a UK National Health Service perspective. METHODS: A partitioned survival model was developed to assess the lifetime costs and effects of avelumab versus SC. Data from the JAVELIN Merkel 200 trial (NCT02155647) were used to inform estimates of quality-adjusted life-years (QALYs). Unit costs and associated frequencies of use were informed by published literature and clinical expert opinion. Results were presented as incremental cost-effectiveness ratios (ICERs, i.e. the cost per QALY gained) for treatment-experienced (TE) and treatment-naïve (TN) patients. Uncertainty was explored through a range of sensitivity analyses. RESULTS: Discounting costs and QALYs at 3.5% per annum, avelumab was associated with ICERs of £35,274 (TE)/£39,178 (TN) per QALY gained. Probabilistic sensitivity analysis results demonstrated that avelumab was associated with an 88.3% (TE)/69.3% (TN) probability of being cost effective at a willingness-to-pay threshold for end-of-life treatments of £50,000 per QALY gained. Results were most sensitive to alternative survival extrapolations and dosing assumptions. CONCLUSIONS: The analysis results suggest that avelumab is likely to be a cost-effective treatment option for UK mMCC patients. The results for TN patients are subject to some uncertainty, and a confirmatory analysis will be conducted with more mature data.