Cost Effectiveness of Pembrolizumab vs. Standard-of-Care Chemotherapy as First-Line Treatment for Metastatic NSCLC that Expresses High Levels of PD-L1 in the United States

Objectives: Our objectives were to evaluate the cost effectiveness of pembrolizumab compared with standard-of-care (SoC) platinum-based chemotherapy as first-line treatment in patients with metastatic non-small-cell lung cancer (NSCLC) that expresses high levels of programmed death ligand-1 (PD-L1) [tumour proportion score (TPS) ≥50%], from a US third-party public healthcare payer perspective. Methods: We conducted a partitioned-survival model with a cycle length of 1 week and a base-case time horizon of 20 years. Parametric models were fitted to Kaplan–Meier estimates of time on treatment, progression-free survival and overall survival from the KEYNOTE-024 randomized clinical trial (patients aged ≥18 years with stage IV NSCLC, TPS ≥50%, without epidermal growth factor receptor (EGFR)-activating mutations or anaplastic lymphoma kinase (ALK) translocations who received no prior systemic chemotherapy) and validated with long-term registry data. Quality-adjusted life-years (QALYs) were calculated based on EuroQoL-5 Dimensions (EQ-5D) utility data collected in the trial. Costs ($US, year 2016 values) for drug acquisition/administration, adverse events and clinical management were included. Costs and outcomes were discounted at 3% per year. A series of deterministic and probabilistic sensitivity analyses were performed to test the robustness of the results. Results: In the base-case scenario, pembrolizumab resulted in an expected gain of 1.31 life-years (LYs) and 1.05 QALYs and an incremental cost of $US102,439 compared with SoC. The incremental cost per QALY gain was $US97,621/QALY and the incremental cost per LY gain was $US78,344/LY. Conclusions: Pembrolizumab is projected to be a cost-effective option compared with SoC platinum-based chemotherapy as first-line treatment in adults with metastatic NSCLC expressing high levels of PD-L1.