IntroductionFew studies have investigated the efficacy and safety of tegoprazan‐amoxicillin (TA) dual therapy for Helicobacter pylori eradication. We aim to evaluate the effectiveness and safety of different dosages of TA dual therapy for H. pylori eradication.MethodsThis prospective, randomized, open‐label, multicenter study was conducted at four centers in Fujian, China. H. pylori‐infective patients were randomized 1:1:1 to receive one of the following treatments: bismuth quadruple therapy (BQT, esomeprazole 20 mg twice daily + potassium bismuth citrate 240 mg twice daily + amoxicillin 1 g twice daily + clarithromycin 500 mg twice daily), tegoprazan‐amoxicillin dual therapies (TA‐qd, tegoprazan 50 mg once daily + amoxicillin 1 g thrice daily; TA‐bid, tegoprazan 50 mg twice daily + amoxicillin 1 g thrice daily) for 14 days. The primary outcome was noninferiority in eradication rates of the different TA groups compared to the BQT group. Secondary outcomes encompassed an assessment of adverse reactions and clinical symptom relief. Additionally, exploratory outcomes were focused on the shifts in gut microbiota and a cost‐effectiveness analysis.ResultsA total of 321 patients were enrolled. The eradication rates in the BQT group, TA‐qd group, and TA‐bid group were 85.05% (91/107), 85.98% (92/107), and 85.98% (92/107) in the intention‐to‐treat analysis (ITT) (BQT vs. TA‐qd, 95% CI −8.50% to 10.36%, noninferiority p = 0.012; BQT vs. TA‐bid, 95% CI −8.50% to 10.36%, noninferiority p = 0.012); 91.00% (91/100), 91.09% (92/101), and 92.93% (92/99) in the modified intention‐to‐treat analysis (mITT) (BQT vs. TA‐qd, 95% CI −7.81% to 7.98%, noninferiority p = 0.006; BQT vs. TA‐bid, 95% CI −5.62% to 9.48%, noninferiority p < 0.001); 90.81% (89/98), 91.00% (91/100), and 93.81% (91/97) in the per‐protocol analysis (PP) (BQT vs. TA‐qd, 95% CI −7.83% to 8.19%, noninferiority p = 0.006; BQT vs. TA‐bid, 95% CI 4.46% to 10.46%, noninferiority p < 0.001). The incidence of adverse reactions in the TA‐qd and TA‐bid groups was significantly lower than in the BQT group (13.33%, 14.56%, and 27.18%, respectively; p = 0.017). The complete remissions of clinical symptoms for BQT, TA‐qd, and TA‐bid were 36.89%, 65.71%, and 68.93%, respectively, had significant differences (p < 0.001). Two weeks of TA therapy altered gut microbiota diversity and composition, but that recovered 4 weeks after discontinuation. The cost‐effectiveness ratios (CERs) for BQT, TA‐qd, and TA‐bid were 1.85 CNY, 2.08 CNY, and 3.69 CNY, respectively.ConclusionBoth TA dual therapies provided satisfactory eradication rates of > 90% for eradicating H. pylori, fewer adverse reactions, and greater clinical symptom relief compared to BQT, with a mild, reversible impact on gut microbiota. In addition, the TA dual therapy with low doses of tegoprazan showed better cost‐effectiveness.Trial RegistrationChinese Clinical Trial Register and registration No.: ChiCTR2300071997