OBJECTIVES: A cost-utility analysis was performed, from the Greek Healthcare Payer perspective, of Pembrolizumab versus watchful waiting. Watchful waiting is the Standard of Care for adjuvant melanoma patients, according to the Hellenic Society of Medical Oncology. The incidence of melanoma doubles every 8 years globally, and exceeds 5.000 patients over a period of 5 years in Greece, classifying it as the 19^th most fatal cancer type. The use of immune-oncology drugs shows new potential to change the paradigm of cancer treatment and improve quality of life and survival outcomes for patients.

METHODS: A Markov state-transition model was employed to depict time patients spent between the mutually exclusive states of Recurrence Free Survival, Distant Metastasis Free Survival, Locoregional Recurrence and Death. The model calculated direct resource acquisition costs. Drug administration, resource use and utilization, adverse events costs, subsequent treatment costs and terminal care costs, were incorporated in the analysis using national Greek insurance values. Indirect costs were not included. Patient Utility was calculated based on patient’s level data from KN-054 clinical trial, utilizing the EuroQol EQ-5D-3L instrument. Costs and QALY’s were calculated over a horizon of 46 years. Discounting followed NICE recommendations at 3.5% for both costs and outcomes.

RESULTS: Pembrolizumab showed an ICER of 15,186€ per QALY gained. It yielded 10.01 LY’s compared to 6.50 LY’s on the comparator arm, translated to 8.00 QALY’s and 5.08 QALY’s respectively. At a 30,000€ Willingness to Pay threshold, pembolizumab has a probability of 76.1% being cost-effective with the average ICER within the analysis being 15.816 €.

CONCLUSIONS: Pembrolizumab appears to be a cost-effective treatment. It constitutes a significant step towards a potential cure in the adjuvant setting providing an attractive therapeutic solution in both survival and costs for adults with Stage III melanoma and lymph node involvement who have undergone complete resection.