BACKGROUND

The phase III KEYNOTE-604 study confirmed the benefit of pembrolizumab combined with chemotherapy in the first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC). Taken into account the clinical benefits of pembrolizumab and its high cost, this study aimed to assess the cost-effectiveness of adding pembrolizumab to standard first-line etoposide-platinum (EP) for patients with ES-SCLC from the US payer perspective.

METHODS

A Markov model was developed to compare the cost and quality-adjusted life-year (QALY) of pembrolizumab plus EP and placebo plus EP over a 10-year time horizon. Clinical efficacy and safety data were pooled from the KEYNOTE-604 trial. Utilities were obtained from published resources. Costs were mainly collected from Medicare in 2020. Sensitivity analyses were performed to examine the robustness of our model.

RESULTS

Adding pembrolizumab to standard first-line EP resulted in the better effectiveness than EP chemotherapy alone for ES-SCLC by 0.22 QALYs. Pembrolizumab plus EP was dominated economically by placebo plus EP, leading to an incremental cost-effectiveness ratio (ICER) of $334,373/ QALY. Deterministic sensitivity analyses indicated that the uncertainty in model parameters exerted no substantial effect on our results. Probability sensitivity analysis indicated that probabilities for pembrolizumab plus EP being cost-effective within a wide range of willingness to pay were modest.

CONCLUSION

From the US payer perspective, the first-line treatment for ES-SCLC with pembrolizumab plus EP was not cost-effective compared with placebo plus EP. Although pembrolizumab combination chemotherapy was beneficial to the survival of ES-SCLC, price reduction may be the necessary to improve its cost-effectiveness.