Efficacy and Tolerability of Second-Line Metronidazole Triple Therapy Using Vonoprazan for Helicobacter pylori Eradication in Japan—Comparative Study: Vonoprazan vs. Proton Pump Inhibitors

Aim: To investigate the efficacy and tolerability of second-line metronidazole triple therapy with vonoprazan (VPZ) for Helicobacter pylori (H. pylori). Methods: We retrospectively reviewed medical records of patients who experienced clarithromycin triple therapy failure and were treated with second-line (20 mg VPZ (n = 274)/30 mg lansoprazole (n = 323) or 10 mg rabeprazole (n = 141) twice daily, 750 mg amoxicillin twice daily, 250 mg metronidazole twice daily for 7 days) eradication therapies. Successful eradication rates were compared between two groups: those receiving VPZ and those receiving a proton pump inhibitor (PPI). Adverse events were also investigated. Results: Successful second-line eradication rates according to ITT analysis and PP analysis, respectively, were 79.9% and 92.4% for VPZ therapy and 83.6% and 93.3% for PPI therapy. There were no significant differences between treatment groups. The eradication rates in those who had received first-line VPZ therapy previously according to ITT and PP analysis were 75.2% and 88.1%, respectively; in contrast, values were 82.5% and 95.4%, respectively, for those who had received first-line PPI therapy previously. In second-line therapy, the overall adverse event rate for VPZ therapy was the same as for PPI therapy. Conclusions: The efficacy and tolerability of metronidazole-containing second-line triple therapy with VPZ or a PPI were equivalent.