Serplulimab Plus Chemotherapy vs Chemotherapy for Treatment of US and Chinese Patients with Extensive-Stage Small-Cell Lung Cancer: A Cost-Effectiveness Analysis to Inform Drug Pricing.

Background: Serplulimab is a potential valuable therapy, while patients, physicians, and decision-makers are uncertain about the cost-effectiveness of this novel drug and its corresponding reasonable price. This study aimed to simulate the price at which serplulimab was cost-effective as first-line therapy for United States (US) and Chinese extensive-stage small-cell lung cancer (ES-SCLC) patients.

Methods: In this economic evaluation, a partitioned survival model was constructed from the perspective of US and Chinese payers. Baseline characteristics of patients and critical clinical data were obtained from ASTRUM-005. Costs and utilities were collected from open-access databases and published literature. Cumulative costs (in US dollars), life years, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) were measured and compared. Price simulation was conducted to inform the pricing strategy at the given willingness-to-pay (WTP) threshold. The robustness of the model was assessed via sensitivity analyses and scenario analyses; subgroup analyses were also included.

Results: Base-case analysis indicated that serplulimab ($818.16/100 mg) would be cost-effective in the US at the WTP threshold of $150,000, with improved effectiveness of 0.61 QALYs and an additional cost of $64,918 (ICER $106,757). Serplulimab ($818.16/100 mg, patient assistance program considered) was cost-effective in China, with improved effectiveness of 0.58 QALYs and an increased overall cost of $19,369 (ICER $33,392). The price simulation results indicated that serplulimab was favored in the US when the price was less than $762.11/100 mg and $1261.57/100 mg at the WTP threshold of $100,000 and $150,000, respectively; it was cost-effective at the WTP threshold of $38,184 when the price was less than $373.37/100 mg in China. Sensitivity analyses revealed that the above results were stable. Subgroup analysis results indicated an overall trend for subgroups with better survival advantages to have a higher probability of cost-effectiveness, despite serplulimab not being cost-effective in some subgroups.

Conclusions: Serplulimab might be a valuable and cost-effective therapy in both the US and China. The evidence-based pricing strategy provided by this study could benefit decision-makers in making optimal decisions and clinicians in general clinical practice. More evidence about the budget impact and affordability for patients is needed.