Cost-effectiveness of neoadjuvant and adjuvant novel cancer therapies in stage II-III non-small cell lung cancer in Sri Lanka.

Newer cancer treatments, such as small molecule tyrosine kinase inhibitors and monoclonal antibodies that restore anti-tumour immunity, lead to improved survival when delivered as adjuvant or neoadjuvant treatments with surgery or chemoradiotherapy for early and locally advanced non-small cell lung cancer (NSCLC). However, these novel drugs are costly, posing a funding challenge for most health systems. A Markov modelling-based cost-utility analysis was conducted to determine its cost-effectiveness in Sri Lanka from a health system perspective. A decision-analytic model was developed to evaluate the incremental costs and quality-adjusted life-years (QALYs) associated with treating patients diagnosed with stage II-III NSCLC for the following treatments: adjuvant osimertinib following surgery and after curative chemoradiotherapy, adjuvant alectinib after surgery, neoadjuvant nivolumab prior to surgery, adjuvant pembrolizumab and atezolizumab after surgery, perioperative durvalumab and pembrolizumab and consolidation durvalumab after chemoradiotherapy. The study employed 1-month simulation cycles over a lifetime. Sex-specific analyses were conducted and parameter uncertainty was addressed using probabilistic analysis. A willingness-to-pay threshold of US$6700 per QALY was applied. A 5-year budget impact analysis was performed for therapies identified as cost-effective. At the primary threshold, adjuvant osimertinib after surgery and after curative chemoradiotherapy, adjuvant alectinib after surgery and neoadjuvant nivolumab were cost-effective in both males and females. However, conclusions were sensitive to lower opportunity-cost-informed thresholds. At US$3000 per QALY, only osimertinib-based strategies remained robustly cost-effective. Other therapies were not cost-effective at current prices and would require substantial price reductions. The 5-year cumulative budget impact of adopting cost-effective therapies under full implementation was approximately US$11.8 million. Using a common modelling approach and Sri Lanka-specific costing assumptions, we present comparative cost-effectiveness results across multiple novel perioperative, adjuvant and neoadjuvant strategies for stage II-III NSCLC. These findings are intended to support prioritisation of which therapies could be considered first for public funding and to indicate the price reductions required for other agents to represent value for money.