Efficacy and safety of vonoprazan-amoxicillin dual therapy for Helicobacter pylori first-line treatment: a single-center, randomized, controlled trial

Background: With the increase in antibiotic resistance, the success rate of Helicobacter pylori (H. pylori) eradication therapy has declined in recent years. Vonoprazan-amoxicillin (VA) dual therapy has been reported to be a promising regimen.Objectives: To compare the efficacy and safety of VA dual therapy and bismuth quadruple therapy containing amoxicillin and clarithromycin for H. pylori first-line eradication, and to further analyze the effects of clarithromycin resistance on eradication rate.Design: This study was a single-center, open-label, randomized controlled trial.Methods: Treatment-naive H. pylori-infected patients were randomly allocated 1:1 to the VA group (vonoprazan 20 mg twice daily and amoxicillin 750 mg four times daily, for 14 days) or the RBAC group (rabeprazole 10 mg, bismuth potassium citrate 220 mg, amoxicillin 1000 mg and clarithromycin 500 mg twice daily, for 14 days). H. pylori clarithromycin resistance and CYP2C19 gene polymorphisms were detected with real-time polymerase chain reaction (PCR) technique. The eradication rates and adverse events were analyzed.Results: A total of 151 patients were enrolled. The intention-to-treat (ITT), modified intention-to-treat (mITT), and per-protocol (PP) eradication rates and their 95% confidence intervals (95% CIs) were 94.6% (86.0-98.3%), 98.6% (91.3-99.9%), and 98.5% (90.9-99.9%) for VA group and 87.0% (77.0-93.3%), 91.8% (82.3-96.6%), and 93% (83.7-97.4%) for RBAC group. The eradication rate of the VA group was noninferior to the RBAC group in ITT, mITT, and PP analyses (p < 0.0001). In patients infected with strains of clarithromycin resistance point mutation, the eradication rate of the RBAC group decreased to lower than 90%, but the difference from the VA group did not achieve statistical significance (ITT eradication rate: 81.5% in the RBAC group and 96.2% in the VA group, p = 0.192). The incidence of adverse events in the VA group was 39.2%, which was significantly lower than that in the RBAC group (79.2%, p = 0.000).Conclusion: The efficacy of VA dual therapy is noninferior to RBAC in H. pylori first-line eradication, with fewer adverse reactions.Registration: This study was registered at the Chinese Clinical Trial Registry (ChiCTR2100052550) on 30 October 2021.