Abstract
OBJECTIVE: Nivolumab and trifluridine/tipiracil have significantly improved the overall survival of patients with heavily pretreated metastatic gastric cancer in different placebo-controlled phase III trials. Accordingly, nivolumab and trifluridine/tipiracil have been approved and recommended for patients with heavily pretreated metastatic gastric cancer in Japan. The aim of this study was to assess the cost-effectiveness of trifluridine/tipiracil against nivolumab. METHODS: A partitioned survival model, which consisted of three health states, namely, 'pre-progression,' 'post-progression,' and 'death,' was constructed. Efficacy and safety data were derived from the TAGS and ATTRACTION-2 trials. Costs were estimated based on the standard clinical pathway and national insurance fee schedules. One-way and probabilistic sensitivity analyses were performed. The threshold value was set to JPY 7 500 000 (USD 68 182) for each quality-adjusted life-year. RESULTS: The expected median overall survival and progression-free survival were 5.59 and 1.99 months for trifluridine/tipiracil and 5.26 and 1.55 months for nivolumab, respectively. The quality-adjusted life-year and expected costs per patient were 0.4379 and JPY 2 054 625 (USD 18 678) for trifluridine/tipiracil and 0.5295 and JPY 5 018 148 (USD 45 620) for nivolumab, respectively. The expected median progression-free survival and overall survival were equivalent with trifluridine/tipiracil and nivolumab, whereas the expected quality-adjusted life-year with trifluridine/tipiracil was slightly lower than that with nivolumab. However, trifluridine/tipiracil reduced the total treatment cost by JPY 2 963 523 (USD 26 996) compared with that of nivolumab. The incremental cost-effectiveness ratio of nivolumab versus trifluridine/tipiracil was JPY 32 352 489 (USD 294 113) per quality-adjusted life-year gained. CONCLUSIONS: Trifluridine/tipiracil was more cost-effective than nivolumab for patients with heavily pretreated metastatic gastric cancer.