Pilot studies of vonoprazan‐containing Helicobacter pylori eradication therapy suggest Thailand may be more similar to the US than Japan

Abstract Background Vonoprazan‐containing Helicobacter pylori eradication is reliably effective in Japan. Its effectiveness in other countries remains unclear. Here, we examined vonoprazan‐ H. pylori therapies in Thailand. Materials and Methods This was pilot study of four different vonoprazan containing therapies. Subjects were randomized to: 14‐day dual therapy (500 mg amoxicillin q.i.d. plus 20 mg vonoprazan b.i.d.), 14‐day triple therapy (amoxicillin 1 g b.i.d., slow release clarithromycin‐MR, 1 g daily plus vonoprazan 20 mg b.i.d.), 7‐day high‐dose vonoprazan triple therapy (amoxicillin 1 g b.i.d., clarithromycin‐MR 1 g daily and 60 mg vonoprazan once daily), and 14‐day vonoprazan triple therapy plus bismuth (amoxicillin 1 g b.i.d., clarithromycin‐MR 1 g daily, vonoprazan 20 mg b.i.d., and bismuth subsalicylate 1048 mg b.i.d.). Eradication was confirmed 4 weeks after therapy. Antimicrobial susceptibility and CYP3A4/5 genotyping were performed. Results One hundred H. pylori‐ infected patients (mean age 54.3 ± 13 years, 51% men) were randomized. All were CYP3A4 extensive metabolizers. Cure rates with both 14‐day vonoprazan dual therapy and 14‐day triple therapy were low: 66.7%; 95% CI = 43–85% (14/21), and 59.3%; 95% CI = 39–78%) (16/27), respectively. In contrast, 7‐day high‐dose vonoprazan triple therapy and 14‐day vonoprazan triple plus bismuth proved effective 92.3%; 95% CI = 75%–99% (24/26) and 96.2%; 95% CI = 80%–100% (25/26), respectively. Conclusion Both 14‐day vonoprazan dual and triple therapy were ineffective for H. pylori eradication in Thailand. Higher dosage of vonoprazan, and/or the addition of bismuth may be required to achieve high H. pylori eradication rates. High‐dose vonoprazan triple therapy and vonoprazan triple therapy adding bismuth might be used as first‐line treatments in some regions with high efficacy irrespective of CYP3A4/5 genotype and clarithromycin resistance.