A cost-utility analysis of avelumab for metastatic Merkel cell carcinoma in Taiwan

Background: Metastatic Merkel cell carcinoma (mMCC) has traditionally been managed with palliative chemotherapy regimens or best supportive care (BSC). Avelumab, a novel anti-programmed death-ligand 1 (PD-L1) human monoclonal antibody for mMCC treatment, is being studied in the pivotal JAVELIN Merkel 200 trial. Aim: Incorporating trial results, this analysis aimed to evaluate the cost-utility of avelumab in Taiwan. Methods and results: A de novo partitioned-survival model with three key health states related to survival (progression-free disease, progressed disease, and death) was applied in this study. The data of clinical efficacy, safety, and patient utilities were obtained from the JAVELIN Merkel 200 trial, literature review, and Taiwanese clinical expert opinion. Cost-utility analysis was performed, and results were presented as cost per quality-adjusted life year (QALY) gained. For treatment-naïve patients, the incremental cost-effectiveness ratios (ICERs) for avelumab vs BSC and avelumab vs chemotherapy were US$44885.06 and US$42993.06 per QALY gained, respectively. As to treatment-experienced mMCC patients, avelumab was associated with ICERs of US$27243.06 (vs BSC)/US$26557.43 (vs chemotherapy) per QALY gained. All ICERs remained consistently within the willingness-to-pay (WTP) threshold of US$53,333.33 per QALY gained. Conclusion: This study demonstrated avelumab to be a cost-effective treatment option for both treatment-experienced and treatment-naïve mMCC patients with very poor prognosis in Taiwan.