Tremelimumab and durvalumab with chemotherapy in first-line treatment for metastatic non-small cell lung cancer: a US-based cost-effectiveness analysis.

Background: While the tremelimumab plus durvalumab combined with chemotherapy (T + D + CT) has shown promise in treating epidermal growth factor receptor/anaplastic lymphoma kinase (EGFR/ALK) wild-type metastatic non-small cell lung cancer (mNSCLC), particularly in patients with low or no programmed cell death ligand 1 (PD-L1) expression, the economic implications of its high cost remain poorly understood. This study fills a critical gap in knowledge by evaluating the cost-effectiveness of T + D + CT from a US health care perspective, offering valuable insights for clinical and policy decision-making. Methods: A 10-year Markov model was crafted to track the disease progression, survival, and treatment-related toxicities of a patient cohort with EGFR/ALK wild-type mNSCLC. Transition probabilities were derived from the POSEIDON trial, while health state utilities were obtained from the literature. Cost data, including drug acquisition and administration, subsequent anticancer therapies, and adverse event management were estimated using the Centers for Medicare and Medicaid Services and the Healthcare Cost and Utilization Project databases, with additional costs sourced from current literature. All cost and effectiveness measures were discounted at an annual rate of 3%. The model's robustness was assessed through deterministic sensitivity analysis (DSA), probabilistic sensitivity analysis (PSA), and scenario analysis. Results: T + D + CT compared to chemotherapy alone yielded incremental cost-effectiveness ratios (ICERs) of $370,208 to $691,960 per quality-adjusted life-year (QALY) gained, exceeding the standard willingness-to-pay (WTP) threshold of $100,000 to $150,000 per QALY. Against durvalumab plus chemotherapy, T + D + CT was only cost-effective in all subgroups. DSA results for patients with PD-L1 expression <1% showed that the ICER for first-line T + D + CT remained above the WTP threshold range, even with substantial changes to model inputs. PSA revealed a higher likelihood of T + D + CT being cost-effective as WTP thresholds increased. Scenario analysis confirmed the study's primary findings, with the exception of a scenario where durvalumab was offered at no cost. Conclusions: The findings suggests that T + D + CT may not be a cost-effectiveness first-line treatment for EGFR/ALK wild-type mNSCLC in the US, given its high ICERs and limited cost-effectiveness in the majority of PD-L1 expression subgroups.