Cost-effectiveness analysis of disitamab vedotin plus toripalimab versus chemotherapy as first-line treatment for HER2-expressing advanced urothelial cancer

The RC48-C016 trial conducted in China demonstrated that disitamab vedotin plus toripalimab (DV+Torip) significantly extended overall survival and progression-free survival in comparison to chemotherapy for patients with HER2-expressing advanced urothelial cancer. However, the economic value of this combination regimen remains uncertain. This study aimed to assess the cost-effectiveness of DV+Torip vs. chemotherapy as a first-line treatment for HER2-expressing advanced urothelial cancer from the Chinese healthcare system perspective. A partitioned survival model with a 10 y time horizon was developed to evaluate the cost-effectiveness. The primary outcomes included costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Sensitivity, subgroup, and scenario analyses were employed to examine the uncertainty associated with the model results. The ICER of DV+Torip vs. chemotherapy was estimated at $18,448.74 per QALY, which was below the willingness-to-pay (WTP) threshold of $40,334 per QALY. In the majority of sensitivity, subgroup, and scenario analyses, the ICER values remained below the WTP threshold, thereby affirming the robustness of these findings. However, in one scenario analysis, where treatment durations were not aligned with the median treatment cycles and subsequent drug treatment costs were excluded, the economic advantage of the DV+Torip group was nullified, resulting in an ICER of $66,303.62 per QALY. These results suggest that DV+Torip is cost-effective, though its economic advantage may be influenced by treatment duration and subsequent therapy costs.