Cost-effectiveness of Pembrolizumab in Combination with Chemotherapy Versus Chemotherapy and Pembrolizumab Monotherapy in the First-line Treatment of Squamous Non-small-cell Lung Cancer in the US

To describe the cost-effectiveness of pembrolizumab plus chemotherapy (carboplatin and paclitaxel or nab-paclitaxel; P + C) in metastatic, squamous, non-small-cell lung cancer (NSCLC) patients in the US. A model comparing P + C versus C alone is developed utilizing partitioned survival analysis. Primary clinical efficacy, treatment utilization, health utility and safety data are derived from the KEYNOTE-407 trial and projected over 20 years. Costs for drugs and non-drug disease management are also incorporated. Additionally, the cost-effectiveness of P + C vs. pembrolizumab monotherapy (P) is evaluated via an indirect treatment comparison, for patient subgroups with PD-L1 Tumor Proportion Score (TPS) ≥ 50% and 1-49%. Overall, P + C is projected to increase life expectancy by 1.95 years vs. C (3.86 versus 1.91). The resultant ICER is $86,293/QALY. In patients with PD-L1 ≥ 50%, 1-49% and <1 the corresponding incremental cost-effectiveness ratios (ICERs) are $99,777/QALY, $85,986/QALY and $87,507/QALY, respectively. Versus P, in the PD-L1 ≥ 50% subgroup, P + C appears cost saving; however, this result should be interpreted with caution as there is considerable uncertainty in the relative efficacy of these comparators. Across all eligible patients, the addition of pembrolizumab to chemotherapy is projected to approximately double life expectancy, yielding an extension to a point not previously seen in metastatic squamous NSCLC. Overall, and within all relevant PD-L1 subgroups, use of P + C yields an ICER below $100,000/QALY, and can be a cost-effective first-line treatment for eligible metastatic squamous NSCLC patients for whom chemotherapy is currently administered. In the PD-L1 ≥ 50% subgroup, additional follow-up within trials of pembrolizumab plus chemotherapy and pembrolizumab monotherapy are needed to better define cost-effectiveness between these comparators.