Gemcitabine + Cisplatin + S-1 Treatment for Advanced Cholangiocarcinoma: Cost-Effective, with Better Progression-Free Survival Versus Standard Treatment with Gemcitabine + Cisplatin + Durvalumab

<i>Objectives</i>: To evaluate the prognosis and costs of gemcitabine + cisplatin + S-1 (GCS) versus gemcitabine + cisplatin + durvalumab (GCD), the standard of care for advanced cholangiocarcinoma, in a prospective observational study. <i>Methods</i>: We enrolled 52 patients who received GCS as first-line treatment from April 2020 to April 2024 and 44 patients who received GCD from March 2023 to April 2024. Overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) were examined. Propensity score matching (PSM) was performed to balance baseline characteristics between the two groups, and OS, PFS and ORR were then analysed in the matched cohorts. Drug costs were compared until the end of treatment. <i>Results</i>: OS was not significantly different between GCS and GCD at 18.6 months (95% confidence interval [CI]: 13.3-21.9) (<i>p</i> = 0.0935) versus 12.2 months (95% CI: 7.5-16). PFS was 10.2 months (95% CI: 6.5-13.8) versus 6.2 months (95% CI: 3.2-8.8) for GCS versus GCD, respectively (<i>p</i> = 0.0151). The ORR was also higher for GCS (36.5%) than for GCD (15.9%) (<i>p</i> = 0.0234). Twenty-seven patients were included in the PSM analysis, which showed no significant differences in OS or ORR, and better PFS for GCS (9.3 months, 95% CI: 7.4-21.1 versus 4.8 months, 95% CI: 2.7-8.8; <i>p</i> = 0.007). The cost of GCS versus GCD was $6350 (95% CI: 2300-9800) versus $97,200 (95% CI: 69,400-138,800) by treatment end (<i>p</i> = 0.0001). <i>Conclusions</i>: GCS was significantly less expensive than GCD and showed comparable OS and better PFS.