First-line pembrolizumab in PD-L1 positive non-small-cell lung cancer: A cost-effectiveness analysis from the UK health care perspective

Abstract

BackgroundPembrolizumab has shown significant survival benefits in treating chemotherapy-naïve non-small-cell lung cancer patients (NSCLC) with increased level of PD-L1 expression. This analysis aimed to evaluate the cost-effectiveness of pembrolizumab as a first-line treatment for patients with PD-L1 positive NSCLC from the UK health care perspective. MethodsA Markov model with progression-free, progressive disease and death states was developed. Clinical parameters were informed by the KEYNOTE-024 trial. Utility values were sourced from published literature. Cost data including drug acquisition costs, disease management costs, and adverse event costs were derived from British National Formulary and published literature. The model was run until 99% patients died. Both health outcomes and costs were discounted at an annual rate of 3.5%. Deterministic and probabilistic sensitivity analyses were performed to address the uncertainties around model parameters. ResultsIn the base case, pembrolizumab is projected to increase patient’s life expectancy by 1.32 life-years over chemotherapy (2.45 vs. 1.13) and 0.83 QALYs (1.55 vs. 0.71) at an additional cost of £72,465, yielding an incremental cost-effectiveness ratio of £86,913/QALY. When parameters were varied in the deterministic sensitivity analyses, results are most sensitive to duration of median overall survival in both groups. Probability sensitivity analyses showed that using a willingness-to-pay threshold of £50,000 per QALY, the probability of pembrolizumab being cost-effective is 29.4%. ConclusionUsing a willingness-to-pay threshold of £50,000, pembrolizumab is not cost-effective at its current list price and a discount of 50% or more is required for it to be cost-effective comparing to commonly prescribed chemotherapy. Risk-sharing contracts may be helpful in resolving some of the underlying uncertainty associated with the long-term survival and varying extent of patient response.