Comparison of Vonoprazan-Amoxicillin versus Lansoprazole-Amoxicillin Dual Therapy for Treatment-Resistant Helicobacter pylori Infection: A Randomized Clinical Trial

To compare the efficacy of Vonoprazan-Amoxicillin dual therapy with Lansoprazole-Amoxicillin dual therapy in eradicating treatment-resistant Helicobacter pylori infection.

A randomized, double-blind, parallel-group clinical trial, Phase 3, enrolling 160 patients; Randomization is performed using block method.

The study is conducted at selected clinical centers. Double-blind procedure is implemented through identical-looking capsules and uniform packaging of medications; Allocation is concealed using sequentially numbered and sealed envelopes; Participants; care providers; and outcome assessors are blinded.

160 participants aged 18 to 70 years with treatment-resistant Helicobacter pylori infection; Inclusion criteria: Age 18 to 70 years; confirmed infection; failure of at least one prior regimen; Exclusion criteria: Pregnancy; lactation; known drug hypersensitivity; severe hepatic or renal disease.

Vonoprazan group: Vonoprazan (20 mg twice daily) plus Amoxicillin (1 g twice daily) for 14 days; Lansoprazole group (comparison): Lansoprazole (30 mg twice daily) plus Amoxicillin (1 g twice daily) for 14 days.

Helicobacter pylori eradication rate (confirmed by stool antigen test or urea breath test 4 to 12 weeks after treatment completion).

Participant allocation to the two treatment arms (Vonoprazan-Amoxicillin and Lansoprazole-Amoxicillin) will be performed using Block Randomization with variable block sizes. This method is used to ensure an approximately equal distribution of participants between the two groups throughout the recruitment period, thereby maintaining balance.The randomization unit is at the Individual level.The random sequence will be generated by an individual independent of the study's executive team, utilizing a statistical software package (such as R or Stata). This output will establish the allocation sequence (Group A or Group B).Allocation concealment will be ensured through the use of sequentially numbered, opaque, and sealed envelopes. These envelopes, containing the group assignment code (A or B), will be prepared according to the random sequence and held by an independent party (e.g., the study pharmacist). After the final confirmation of eligibility criteria by the physician, the next available numbered envelope will be assigned to the participant and opened to reveal the treatment group. This procedure ensures that neither the treating physician nor the participant can foresee the next assignment prior to enrollment.

The study will employ a double-blind design, ensuring that both the participants (patients) and the clinical team responsible for treatment and outcome assessment (physicians and assessors) are unaware of the treatment allocation. To implement this, the comparative drugs (Vonoprazan and Lansoprazole) will be prepared and packaged by the study pharmacist in capsules or containers that are identical in appearance, color, and size. These medications will be distributed using a secure, pre-assigned coding system (Allocation Concealment). The code will be held by an independent party and remain unbroken until the final data analysis. The primary outcome assessment (H. pylori eradication status via the Stool Antigen Test) will also be performed by a blinded investigator.