Head-to-head Study of Tegoprazan 50 mg BID Plus Amoxicillin 1 g TID vs. Vonoprazan 20 mg BID Plus Amoxicillin 1 g TID for H. Pylori Eradication

This investigator-initiated, randomized, open-label, parallel-group study is designed to compare two potassium-competitive acid blocker (P-CAB)-based dual therapies for the eradication of Helicobacter pylori (H. pylori) infection. The study evaluates a 14-day regimen of tegoprazan 50 mg twice daily combined with amoxicillin 1 g three times daily versus a 14-day regimen of vonoprazan 20 mg twice daily combined with amoxicillin 1 g three times daily.

H. pylori infection is a major cause of chronic gastritis, peptic ulcer disease, and gastric cancer. Rising antimicrobial resistance and variable acid suppression with conventional proton pump inhibitors (PPIs) have highlighted the need for alternative treatment strategies. P-CABs, including tegoprazan and vonoprazan, provide rapid, potent, and sustained acid suppression and may enhance the efficacy of high-dose amoxicillin dual therapy. Despite their increasing clinical use, head-to-head comparative evidence between different P-CAB-based dual therapies is limited.

The primary objective of this study is to determine whether the tegoprazan-based dual regimen is non-inferior to the vonoprazan-based dual regimen in terms of H. pylori eradication rate, assessed by a ^13C-urea breath test performed 4 to 8 weeks after treatment completion. Secondary assessments include treatment-emergent adverse events, serious adverse events, gastrointestinal symptom changes, and medication adherence.

Eligible participants are adults with confirmed H. pylori infection who have not received recent eradication therapy or antibiotics with anti-H. pylori activity. The study drugs have established safety profiles and are administered orally. Participants will be randomized in a 1:1 ratio and followed until completion of eradication testing and safety assessments. Data will be analyzed using both intention-to-treat and per-protocol populations.

This study is conducted at Hangzhou First People's Hospital and is intended to provide direct comparative data to guide the selection of P-CAB-based dual therapy regimens in clinical practice.

Inclusion criteria

• 1. Adults aged 18 to 70 years. 2. Confirmed Helicobacter pylori infection based on at least one positive test (13C-urea breath test, rapid urease test, histology, or stool antigen test). 3. Able and willing to provide written informed consent. 4. Able to comply with study procedures and visits. 5. For females of childbearing potential: agreement to use effective contraception during the study period.

Exclusion criteria

• 1. Previous Helicobacter pylori eradication therapy within the past 12 months. 2. Use of antibiotics, bismuth compounds, or other medications with anti-H. pylori activity within 4 weeks before baseline testing. 3. Use of proton pump inhibitors, P-CABs, or H2-receptor antagonists within 2 weeks before baseline testing. 4. Known allergy or intolerance to tegoprazan, vonoprazan, amoxicillin, or any beta-lactam antibiotic. 5. Known severe hepatic impairment (e.g., Child-Pugh C) or severe renal impairment (e.g., eGFR < 30 mL/min/1.73 m²). 6. History of gastric surgery (except minor endoscopic procedures that do not affect gastric anatomy).

• Active gastrointestinal bleeding or suspected gastric malignancy. 8. Pregnant or breastfeeding women. 9. Participation in another interventional clinical trial within the past 30 days.

• Any medical or psychiatric condition that, in the investigator's judgment, could interfere with study participation or pose unacceptable risk.