Rapid Fire Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

Cost-Effectiveness and Budget Impact of PD-L1–Guided Pembrolizumab Strategies in Advanced Non–Small Cell Lung Cancer (145742)

Srinivas Teppala 1 2 , Juhee Koo 2 , Stephen Clarke 3 , Christine Y Lu 1 2
  1. Kolling Institute, University of Sydney and Northern Sydney Local Health District, St Leonards, NSW, Australia
  2. School of Pharmacy, University of Sydney, Camperdown, NSW, Australia
  3. Department of Medical Oncology, Royal North Shore Hospital, St Leonards, NSW, Australia

Aims: Previous economic assessments of pembrolizumab for advanced non-small cell lung cancer (NSCLC) relied on randomized controlled trial (RCT) data, which may not reflect routine clinical practice. This is the first study from a developed country to evaluate program death ligand -1 (PD-L1)–guided pembrolizumab treatment strategies for advanced non-small cell lung cancer (NSCLC), incorporating pembrolizumab monotherapy for patients with PD-L1 tumour proportion score (TPS) ≥50% and pembrolizumab plus platinum-based chemotherapy for those with PD-L1 TPS <50%, using both RCT and real-world evidence (RWE)-informed data.

Methods: A cost-utility analysis comparing three strategies: (1) Standard of Care (SoC; platinum-chemotherapy); (2) PD-L1-guided pembrolizumab (monotherapy for TPS ≥50%; combination for TPS <50%) using RCT data (KEYNOTE-024 & 189); and (3) RWE model using Australian population-based cohorts. Analyses comparing costs and health outcomes in quality-adjusted life-years (QALYs) were performed from an Australian health payer perspective using semi-Markov modelling over a 5-year time horizon. A budget impact analysis (BIA) was also performed.

Results: Pembrolizumab strategies had incremental costs of AU$94,909 and a gain of 0.225 QALYs, resulting in an incremental cost−effectiveness ratio (ICER) of AU$421,661/QALY in the RCT-based analysis. The ICER for the RWE-informed scenario was AU$1.14million/QALY, driven by smaller incremental health gains (0.065 QALYs). At a willingness−to−pay threshold of AU$75,000/QALY, the probability of cost-effectiveness was <1% in both scenarios. In the BIA, the RWE-informed assessment resulted in a net 5-year cost-saving of AU$29.4 million relative to RCT-based projections, possibly explained by lower survival and reduced treatment-related costs in the RWE scenario.

Conclusion: While pembrolizumab provides clinical benefit, its value for money is low under current study assumptions. The substantial divergence in RCT and RWE-informed ICERs highlights the potential role of real-world data for post-approval reassessment of new medicines.