This is a phase 1, double-blind, parallel group study in participants with Helicobacter pylori (HP positive) who are, additionally, cytochrome P-450 (CYP)2C19 extensive metabolizers (EM) to evaluate the safety, tolerability and pharmacokinetics (PK) of a quadruple therapy with bismuth, clarithromycin, amoxicillin, and TAK-438 versus quadruple therapy with bismuth, clarithromycin, amoxicillin, and lansoprazole. The study will enroll 30 participants.~The treatment phase consists of quadruple therapy twice daily (BID) with tripotassium bismuth dicitrate (600 mg), clarithromycin (500 mg), amoxicillin (1000 mg), and TAK-438 (20 mg) (Group B) or quadruple therapy BID with tripotassium bismuth dicitrate (600 mg), clarithromycin (500 mg), amoxicillin (1000 mg),and lansoprazole (30 mg) (Group A) from Days 1 to 14. Participants will be discharged on Day 15 after final PK blood samples are collected and all procedures performed.~This single-center will be conducted in Korea. Participants will remain confined to the study site from check-in (Day -1) through Day 15 and will followed up through call on Day 17 and return on Day 42 for a follow-up assessment.
To evaluate the safety, tolerability, and pharmacokinetics (PK) of quadruple therapy with bismuth, clarithromycin, amoxicillin, and TAK-438 versus quadruple therapy with bismuth, clarithromycin, amoxicillin, and lansoprazole.