First-Line Durvalumab in Addition to Etoposide and Platinum for Extensive-Stage Small Cell Lung Cancer: A US-Based Cost-Effectiveness Analysis

Background The latest published CASPIAN trial demonstrated that adding durvalumab to etoposide and platinum (EP) improved survival dramatically for patients with extensive-stage small cell lung cancer (ES-SCLC). Considering the high cost of durvalumab, this study evaluated the cost-effectiveness of durvalumab plus EP (DEP) in the first-line setting for treatment-naive patients with ES-SCLC from the U.S. payer perspective. Materials and Methods We developed a three-state Markov model to simulate the disease course and source consumption of ES-SCLC over a lifetime horizon. Pseudo-individual patient-level data were generated from digitized Kaplan-Meier curves. Direct medical costs, including drug and administration costs, disease management and adverse events treatment fees, best supportive care and terminal care costs were obtained from sources including the Centers for Medicare and Medicaid Services, Healthcare Cost and Utilization Project, and relevant literature. Health state utility values were derived from published literature. Main outcomes considered were total costs, life-years (LYs), quality-adjusted LYs (QALYs), and incremental cost-effectiveness ratio (ICER). All costs were adjusted for inflation to reflect 2019 U.S. dollars. The willingness-to-pay threshold was set as $150,000/QALY. One-way and probabilistic sensitivity analyses were used to explore the uncertainty of model assumptions. Results Compared with EP, DEP was projected to increase life expectancy by 0.86 LYs (1.73 vs. 0.87) and 0.44 QALYs (0.93 vs. 0.49). The incremental treatment cost was $95,907, and the corresponding ICER was $216,953/QALY. The result was most sensitive to the variation of durvalumab acquisition cost. Probabilistic sensitivity analysis revealed that the probability of DEP over EP regimen to be cost-effective was 9.4% at a willingness-to-pay threshold of $150,000/QALY. In the case of reducing the price of durvalumab by 30.7%, DEP was more cost-effective than EP. Conclusion From the perspective of the U.S. payer, adding durvalumab to EP is estimated to be not cost-effective compared with EP alone for patients with untreated ES-SCLC. Implications for Practice The information provided by this analysis serves as a reference for decision makers. Lowering the price of durvalumab would be a potential measure to improve the economics of durvalumab plus etoposide and platinum (DEP), and the inclusion of durvalumab in the Medicare pharmacopeia can make DEP more economically available. This result may also guide physicians and patients to choose a more economical treatment; alternatively, patients who are able to afford the high costs would be more actively recommended to use DEP.