Atezolizumab monotherapy as first-line treatment for non-small cell lung cancer ineligible for treatment with a platinum-containing regimen (IPSOS): a cost-effectiveness analysis in the USA.

Objective: This study explores the cost-effectiveness of atezolizumab monotherapy compared with chemotherapy as first-line treatment for stage IIIB or IV non-small cell lung cancer (IIIB/IV-NSCLC) ineligible for platinum-based chemotherapy from a US payer perspective.

Design: This is based on the IPSOS clinical trial. We conducted a comprehensive assessment of the cost-effectiveness of atezolizumab monotherapy versus single-agent chemotherapy over a 15-year duration. Employing a robust Markov model incorporating data from 453 patients, we calculated total costs, life-years (LYs), quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER) at a willingness-to-pay (WTP) threshold of $150 000 per QALY. We performed one-way, two-way and probabilistic sensitivity analyses to validate our model.

Setting: The US payer perspective.

Participants: A cohort with NSCLC ineligible for treatment with a platinum-containing regimen from IPSOS clinical trial.

Interventions: Atezolizumab monotherapy versus chemotherapy.

Primary outcome measure: Cost, QALYs, LYs and ICER.

Result: Chemotherapy resulted in an average survival of 0.930 QALYs (1.528 LYs) per patient at an average cost of $67 579. Atezolizumab treatment provided an additional 0.309 QALYs but incurred an extra cost of $66 472, leading to an ICER of $215 069 per QALY compared with chemotherapy. The cost of atezolizumab had the most significant impact on the model outcomes. Probabilistic sensitivity analysis showed that atezolizumab had a 30.2% probability of being considered cost-effective at a WTP threshold of $150 000 per QALY in the USA. These results remained consistent across various scenarios and sensitivity analyses employing both deterministic and probabilistic approaches.

Conclusion: The current price of atezolizumab renders it an unlikely cost-effective treatment option for patients with IIIB/IV-NSCLC from the payer's perspective in the USA. To achieve cost-effectiveness, substantial discounts are necessary.

Trial registration number: The IMpower-110, an open-label, randomised, phase 3 clinical trial (NCT02409342). The IPSOS clinical trial (NCT03191786).