The efficacy of vonoprazan combined with different dose amoxicillin on eradication of Helicobacter pylori: an open, multicenter, randomized clinical study

BACKGROUND: The use of vonoprazan (VPZ) has improved the Helicobacter pylori (H. pylori) eradication therapy in Japan. There is no agreement on the dosage and frequency of amoxicillin administration in the VPZ dual treatment in China. We aimed to investigate the clinical effectiveness and safety of 3 treatment regimens using VPZ as an acid-suppressing medication to eradicate H. pylori. METHODS: This experiment involved an open, multicenter, randomized, and parallel controlled clinical investigation. A total of 230 newly diagnosed H. pylori-infected patients were then randomly assigned to 1 of 3 groups: (I) H-VA (high-dose amoxicillin combined with VPZ): VPZ 20 mg b.i.d with amoxicillin 750 mg q.i.d for 7 days; (II) L-VA (low-dose amoxicillin combined with VPZ): VPZ 20 mg b.i.d plus amoxicillin 500 mg q.i.d for 7 days; (III) VAC (amoxicillin combined with VPZ and clarithromycin): VPZ 20 mg b.i.d plus amoxicillin 750 mg plus clarithromycin 500 mg for 7 days. At least 4 weeks after treatment, the urea breath test (UBT) was reexamined. The effectiveness of various regimens was assessed based on compliance, safety, and eradication rate. RESULTS: The regimen effectiveness was 63.5% (54/85) in the H-VA group, 58.3% (49/84) in the L-VA group, and 60.7% (37/61) in the VAC group, according to intention to treat (ITT) analysis. According to per protocol (PP) analysis, the eradication rate of the H-VA group was 65.1% (54/83), that of the L-VA group was 66.2% (49/74), and that of the VAC group was 64.9% (37/57). There was no discernible difference in the eradication rate across the 3 regimens, as shown by the results of ITT analysis (χ(2)=0.032, P=0.984) and PP analysis (χ(2)=0.480, P=0.786). The rate of adverse effect was 16.90% in the H-VA group, 13.20% in the L-VA group, and 24.10% in the VAC group. There was no discernible difference in the incidence of adverse effect between the three groups (χ(2)=2.784, P=0.266). CONCLUSIONS: None of the 7-day elimination regimens investigated in this study, which included the acid-suppressing medicine VPZ and either a dual treatment paired with amoxicillin, or a triple treatment combined with amoxicillin and clarithromycin, achieved an acceptable eradication rate of H. pylori. Further research is required to identify an effective and safe treatment regimen. TRIAL REGISTRATION: Chinese Clinical Trial Registry identifier: ChiCTR2000040955.