ABSTRACT: Importance: In the open-label phase III POSEIDON randomized clinical trial (RCT), a limited course of tremelimumab plus durvalumab and chemotherapy (T + D + CT) indicated in the first-line treatment of metastatic non-small cell lung cancer (mNSCLC), progression-free survival, and overall survival (OS) were substantially improved without significant additional tolerance burden compared to chemotherapy (CT). However, given the high cost of T + D + CT, its value needs to be evaluated in terms of both potency and cost. Objective: To evaluate the cost-effectiveness of T + D + CT versus CT in individuals with previously untreated mNSCLC from a U.S. payer perspective. Design, setting, and participants: A three-state Markov model was adopted to weigh the lifetime costs and effectiveness of T + D + CT versus CT for the treatment of first-line mNSCLC, according to the results of the POSEIDON phase III RCT involving 675 individuals with mNSCLC. Individuals were simulated to undergo either T + D + CT for up to four 21-day cycles, followed by durvalumab once every 4 weeks until disease progression or unacceptable toxic effects and one additional tremelimumab dose, or CT for up to six 21-day cycles (with or without pemetrexed maintenance; all groups) in the analysis. Main outcomes and measures: Lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were evaluated with a willingness-to-pay (WTP) threshold of $ 100,000 to $ 150,000 per QALY. The uncertainty of the model was investigated using univariate and probabilistic sensitivity analysis. Results: T + D + CT produced additional 0.36 QALYs with additional costs of $ 217,694, compared to CT, giving rise to ICERs of $ 608,667.86/QALY. The univariate sensitivity analysis demonstrated that the outcomes were most sensitive to the cost of durvalumab. Other variables with a large or moderate influence were the utility of progression-free survival state, utility of progressive disease state, and cost of tremelimumab. Probability sensitivity analysis revealed that T + D + CT had a 0% probability of cost-effectiveness in individuals with mNSCLC at a willingness-to-pay threshold of $ 100,000 to $ 150,000 per QALY. Conclusion and relevance: In this model, T + D + CT was estimated to be less cost-effective than CT for patients with mNSCLC at a WTP threshold of $ 100,000 to $ 150,000 per QALY in the United States. When new combination therapies with remarkable effect become pivotal in the first-line treatment, the price reduction of durvalumab and tremelimumab may be necessary to achieve cost-effectiveness in future possible context.
