ObjectiveThe effectiveness of sugemalimab vs. placebo in post-chemoradiotherapy patients with locally advanced, unresectable stage III NSCLC has been demonstrated and approved by China National Medical Products Administration. The purpose of this study was to assess the cost-effectiveness of sugemalimab vs. placebo for consolidation treatment of stage III NSCLC from the perspective of the Chinese healthcare system.MethodsA 3-state Markov model with a 3-week cycle length was performed to appraise the incremental cost-utility ratio (ICUR) of sugemalimab consolidation therapy based on the GEMSTONE-301 clinical trial over a 10-year time horizon. Only direct medical costs, including costs of drug (maintenance and subsequent treatment), routine follow-up, best supportive care, and terminal care in end of life were considered in this model. Costs and health utilities were obtained from local databases and published articles. Sensitivity and scenario analyses were adopted to evaluate the model uncertainty. Internal and external data sources were used to justify the plausibility of the extrapolated portion of the survival model chosen.ResultsIn comparison with the placebo, sugemalimab consolidation therapy was not cost-effective as it yielded an ICUR value of $90,277 and $49,692 for the concurrent chemoradiotherapy (cCRT) and the sequential chemoradiotherapy (sCRT) population at the willingness-to-pay (WTP) threshold of $37,663/QALYs, respectively. When taking the sugemalimab patient assistance program (PAP) into consideration, sugemalimab consolidation therapy was cost-effective with an ICUR dramatic decreases below the WTP. Sensitivity analyses demonstrated that the ICUR was most sensitive to the discount rate and subsequent treatment. However, none of the sensitive parameters could affect the cost-effective conclusions without or with PAP. Scenario analyses revealed that the model was particularly affected by assumptions regarding discount in sugemalimab, time horizon, mean duration of sugemalimab maintenance treatment.ConclusionsFrom the perspective of Chinese healthcare system, sugemalimab consolidation therapy was not a cost-effective strategy in cCRT and sCRT patients with unresectable stage III NSCLC. Given that the sugemalimab PAP was available, sugemalimab consolidation therapy became a cost-effective option.