OBJECTIVES: This study aims to assess the cost-effectiveness of pembrolizumab for high-risk, early-stage, triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery in Greece.

METHODS: A markov cohort model with four health states (event-free, locoregional-recurrence, distant-metastasis, and death) was adapted from a Greek payer perspective over a 50-year time horizon. Utility values, efficacy and safety data applied in the model were derived from the KEYNOTE-522.Primary outcomes were quality-adjusted life-years (QALYs), life years (LY), total costs and incremental cost-effectiveness ratios (ICER)s per QALY gained. Both costs and health outcomes were discounted at 3.0% per annum. Deterministic sensitivity analyses (DSA) were conducted to identify the input parameters’ impact on ICER and a probabilistic sensitivity analysis (PSA) to account for collective parameter’s uncertainty. Pembrolizumab plus paclitaxel plus carboplatin (PpC), followed by pembrolizumab plus doxorubicin / epirubicin plus cyclophosphamide (Dp/EpC) as neoadjuvant treatment, followed by Surgery; followed by radiation treatment plus pembrolizumab in the adjuvant setting was compared to PpC followed by Dp/EpC as neoadjuvant treatment, followed by Surgery; followed by placebo plus radiation treatment.

RESULTS: The total cost of the Pembrolizumab regimen estimated at €162,314 whilst the costs in the comparator arm were €107,767. The Pembrolizumab regimen yielded 17.75 QALYs and the comparator regimen 14.39 QALYs. The Pembrolizumab combination was more effective than the comparator with 2.62 more QALYs gained and 3.37 more LYs gained. The incremental analysis showed an ICER of €20,830 per QALY gained versus the comparator. The DSA indicated that the most influential parameters did not significantly change the analysis results. PSA confirmed the deterministic analysis results.

CONCLUSIONS: This economic evaluation indicates that the Pembrolizumab regimen examined in this analysis is a cost-effective option (under the 52,770€/QALY threshold) in the neo-adjuvant and adjuvant setting for TNBC in Greece.