Presentation (CTI)

OBJECTIVES: The aim of this study is to evaluate the cost-effectiveness of the combination of neoadjuvant and adjuvant pembrolizumab use with the standard of care (SOC) for patients with resectable locally advanced (LA) head and neck squamous cell carcinoma (HNSCC) with PD-L1, Combined Positive Score (CPS) equal or above 1 compared to the standard of care (radiotherapy for high-risk patients combined with cisplatin) in Greece.
METHODS: Markov model with four health states (event-free, local or salvageable recurrence, progressed disease and death) was developed in Microsoft Excel. A payer’s perspective and a lifetime horizon of 40 years were used. Clinical data, safety profile and quality of life data were drawn from the KEYNOTE-689 clinical trial. Outcomes were patients’ life years gained (LYG), quality-adjusted life years (QALYs), total costs and incremental cost-effectiveness ratio (ICER) per LYG and per QALY. Costs and outcomes were discounted at 3.0% per annum. Α one-way sensitivity analysis (OWSA) was undertaken to examine the most influential parameters on the results and a probabilistic sensitivity analysis (PSA) was conducted to account for uncertainty in the model.
RESULTS: The model showed that, over a lifetime horizon, perioperative pembrolizumab in combination with the SoC resulted in 73,026 € additional costs compared to the SoC, while it extended LY by 1.75 and increased QALY's by 1.33 . The ICER was estimated to be 27,350€ per LYG and 35,936€ per QALY, which is below the national cost effectiveness threshold for Greece (64,926€/QALY)(WHO 3x GDP per capita). OWSA indicated that the model's most influential parameters included a shorter time horizon, using alternative transition probabilities and using a 0% discount rate. PSA was cost-effective in 88.7% of the 1,000 iterations, which indicates our analysis is robust.
CONCLUSIONS: Perioperative pembrolizumab plus SOC was demonstrated to be a cost-effective treatment option for LA HNSCC patients with PD-L1 CPS ≥1 in Greece.