A cost-effectiveness analysis of consolidation immunotherapy with durvalumab in stage III NSCLC responding to definitive radiochemotherapy in Switzerland.

Abstract Background Consolidation immunotherapy with the programmed death ligand 1 (PD-L1) inhibitor durvalumab improves survival in patients with stage III non-small cell lung cancer (NSCLC) responding to radiochemotherapy. The aim of this study was to assess the cost-effectiveness of durvalumab in Switzerland based on the most recent PACIFIC survival follow-up. Methods We constructed a Markov model based on the 3-year follow-up data of the PACIFIC trial and compared consolidation durvalumab to observation. We used published utility values and assessed costs for treatment strategies from the perspective of the Swiss healthcare payer. Cost-effectiveness was tested both in the intention-to-treat (ITT) population of the PACIFIC trial unselected for PD-L1 tumor expression and in patients with PD-L1 expressing tumors (≥1%). Results In the unselected/PD-L1 positive patients, durvalumab showed an incremental effectiveness of 0.76/1.18 QALY and incremental costs of Swiss Francs (CHF) 67,239/78,177, resulting in ICERs of CHF 88,703/66,131 per QALY gained, respectively. The most influential factors for the ICER were the utility prior to first progression, costs for durvalumab, and the hazard ratio for overall survival under durvalumab versus observation. The cost-effectiveness of durvalumab was better than CHF 100,000 per QALY gained in 75% of the simulations in probabilistic sensitivity analysis. Conclusion Assuming a willingness-to-pay threshold of CHF 100,000 per QALY gained, consolidation durvalumab is likely to be cost-effective both in patients with inoperable stage III NSCLC unselected for PD-L1 status and in patients with PD-L1-expressing tumors in Switzerland.