Clinical impact of vonoprazan-based dual therapy with amoxicillin for H. pylori infection in a treatment-naïve cohort of junior high school students in Japan

Background: Although 7-day triple therapy, consisting of vonoprazan, amoxicillin (AMO), and clarithromycin (CLA), is recommended for Helicobacter pylori (H. pylori) eradication in adults. However, the importance of reducing antibiotic use in pediatric patients is well recognized. Therefore, our aim was to compare the effectiveness and safety of vonoprazan and AMO (VA) dual therapy to vonoprazan-based (VAC) triple therapy for H. pylori eradication in a cohort of treatment-naïve junior high school students in Japan. Methods: This was a prospective observational study of second-year junior high-school students in Yurihonjo and Nikaho Cities, Japan. Between 2015 and 2017, 161 students were treated with VAC-triple therapy (20 mg vonoprazan, 750 mg AMO, and 200 mg CLA, twice a day for 7 days), while 60 students were treated with VA-dual therapy (20 mg vonoprazan and 750 mg AMO, twice a day for 7 days) since 2018. The success rate of H. pylori eradication and drug-related adverse events were compared between the two therapy groups. Intention-to-treat (ITT) and per-protocol (PP) analyses were performed. Results: Groups were comparable at baseline. The ITT and PP eradication rates were 85.0% (95% confidence interval [CI] 75.8–94.2%) and 86.4% (95% CI 77.4–95.5%), respectively, with VA-dual therapy and 82.0% (95% CI 76.0%–87.9%) and 84.1% (95% CI 78.3–89.8%), respectively, with VAC-triple therapy. VA-dual therapy was non-inferior to VAC-triple therapy (ITT, p = 0.018; PP, p = 0.020). The adverse event rate was 10.0% with VA-dual therapy and 19.8% with VAC-triple therapy (p = 0.108). Conclusions: The effectiveness of VA-dual therapy was comparable to that of VAC-triple therapy in H. pylori treatment-naïve junior high school students, while reducing the use of antibiotics.