VONOPRAZAN-BASED DUAL AND TRIPLE THERAPY VERSUS BISMUTH-BASED QUADRUPLE THERAPY AS FIRST-LINE THERAPY FOR HELICOBACTER PYLORI INFECTION IN CHINA: A THREE-ARMED, RANDOMIZED CLINICAL TRIAL

Background and Aim: We aimed to compare efficacy of vonoprazan-based therapies and bismuth-based quadruple therapy as first-line treatment for Helicobacter pylori (H. pylori) infection in Southern China, where high primary resistance rates of clarithromycin and levofloxacin (>30%) exist.
Methods: This was an investigator-initiated, three-armed, randomized clinical trial in a single center in Shenzhen, China. Between May 2022 and August 2023, treatment-naïve H. pylori-infected adult subjects, confirmed by 13C-urea breath test (UBT), were randomly assigned in a 1:1:1 ratio to receive one of the three of 14-day regimens: vonoprazan-dual (VA-dual; vonoprazan 20mg twice daily and amoxicillin 1g thrice daily), vonoprazan-triple (VAC-triple; vonoprazan 20mg, amoxicillin 1g and clarithromycin 500mg twice daily), or bismuth-based quadruple therapy (bismuth potassium citrate 220mg twice daily, esomeprazole 20mg twice daily, tetracycline 500mg thrice daily and metronidazole 500mg four time daily). Primary outcome was noninferiority in H. pylori eradication, evaluated by UBT 4-6 weeks post-treatment, by comparing VA-dual and VAC-triple therapy with bismuth-based therapy. Farrington and Manning test was used to establish noninferiority, with a margin set at 10%. Primary outcome was evaluated by intention-to-treat (ITT) and per-protocol (PP) analysis, with noninferiority being determined by a lower 95% CI end more than –10% with a Bonferroni-adjusted p-value of <0.017. PP analysis was based on subjects who completed 14 days of treatment and rechecked UBT.
Results: Two-hundred and ninety-five subjects (VC-dual:99, VAC-triple:98, bismuth-based:98) were enrolled, and 289 (98.0%) completed follow-up to have UBT rechecked. The mean age was 35.7 years (+/-8.4), and there were 134 (45.4%) males, without significant difference in baseline characteristics. ITT analysis showed that both VA-dual and VAC-triple therapies were non-inferior to bismuth-based therapy – eradication rate of VA-dual and bismuth-based therapy was 96.0% and 91.8%, respectively (difference:4.1%, 95% CI:-2.9% to 11.8%;p<0.001), while that of VAC-triple therapy was 95.9% (difference:4.1%, 95% CI:-3.0% to 11.8%;p<0.001). PP analysis revealed non-inferiority also (96.7% vs 96.7% vs 97.3%, respectively; all p<0.017; Table 1). However, superiority could not be demonstrated in both ITT and PP analysis. VA-dual therapy had the lowest frequency of adverse events, in particular dyspepsia, anorexia, nausea, vomiting and dysgeusia (p<0.05) (Table 2).
Conclusions: VA-dual therapy is preferred to VAC-triple and bismuth-based quadruple therapy as first-line treatment for H. pylori infection in Southern China with high background resistance rate to clarithromycin and levofloxacin.