Intergenerational comparison of 5-HT₃RA in the prevention of chemotherapy-induced nausea and vomiting in gastric cancer patients receiving cisplatin-based chemotherapy: an observational study using a Japanese administrative claims database

Purpose: In chemotherapy-induced nausea and vomiting (CINV), the superiority of the second-generation 5-hydroxytryptamine-3 receptor antagonist (5-HT₃RA) over the first-generation 5-HT₃RA is shown in the delayed emesis in cycle 1. We evaluate the antiemetic efficacy in real-world clinical practice that has not been sufficiently investigated in clinical trials.

Methods: We included patients who were diagnosed with gastric cancer between April 2012 and June 2017 from the medical claims databases and were treated with cisplatin (≥ 50 mg/m²) and standard antiemetic therapy (5-HT₃RA + neurokinin-1 receptor antagonist [NK1RA] + dexamethasone). We compared the second-generation 5-HT₃RA (2nd group) and the first-generation 5-HT₃RA (1st group) groups to evaluate the additional antiemetic drug as the CINV event.

Results: In total, 3798 patients were extracted; 1440 and 2358 patients were included in the 1st and 2nd groups, respectively. The clinical and demographic characteristics did not differ between the groups. In the overall (days 1-6) in cycle 1, 51.7% and 44.3% of patients in the 1st and 2nd groups, respectively, had a CINV event. In the acute phase (days 1-2), 38.7% and 30.2% and in the delayed phase (days 3-6), 35.8% and 32.1% of patients in the 1st and 2nd groups, respectively, had a CINV event. Furthermore, the CINV event trend was the same as in cycles 1 to 5.

Conclusion: The proportion of CINV events in the 2nd group was smaller than that in the 1st group at any cycle. These findings may suggest consistent antiemetic efficacy of second-generation 5-HT₃RA throughout the cycle.