A Unblinded Study of TAK-438 (20 mg) for Prevention of Recurrence of Gastric or Duodenal Ulcer During Long-Term Non-Steroid Anti-Inflammatory Drug (NSAID) Therapy

Inclusion criteria

• Participants who, in the opinion of the principal investigator or subinvestigator, are capable of understanding the details of the study and complying with them.
• Prior to study commencement, participants who are capable of signing and dating the information/consent form.
• Participants with a chronic disease (rheumatoid arthritis, osteoarthritis, etc.) which requires continuous NSAID oral therapy for pain control during treatment period.
• Participants who meet either 1 or 2 below according to gastric or duodenal endoscopy:

• Ulcer scar (defined, in this study, as regenerative mucosa, convergence of mucosal fold, gastric wall transformation, etc) has been confirmed during endoscopy on the study drug initiation day (Visit 2).
• Ulcer (mucosal defects of 3 mm or larger with white moss) or ulcer scar has been endoscopically confirmed before the study drug initiation day (Visit 2).
• Outpatient participants (inpatients for examinations are acceptable)
• Women with child-bearing potential must agree to routinely take appropriate contraceptive measures throughout treatment period, from giving consent to the study until 4 weeks after the final dose

Exclusion criteria

• Participants who received treatment with another study drug (including approved drugs under post-marketing surveillance) within 84 days prior to commencement of screening
• Participants who have previously received TAK-438 in a clinical study or as a treatment
• Participants who are employees of institutions participating in this study and family members of such employees, participants in a dependent relationship with employees of institutions involved in conduct of the study (e.g., spouse, parent, child, sibling), and participants who are under duress in giving their consent
• Participants who have donated 400 mL or more of blood within 90 days prior to the commencement of screening
• Participants with a plan to change the type, dosage or administration of NSAID
• Participants with ulcer (mucosal defects of 3 mm or larger with white moss) or active hemorrhage confirmed during gastric or duodenal endoscopy on the study drug initiation day (Visit 2)
• Participants with small intestinal hemorrhage, large intestinal hemorrhage, or gastrointestinal hemorrhage of unknown cause
• Participants with a history of surgery or scheduled surgery influencing gastric acid secretion (resection of upper gastrointestinal tract or vagotomy etc)
• Participants with a history or complication of Zollinger-Ellison syndrome, or other gastric acid hypersecretion disorders
• Participants with a history or complication of aspirin asthma
• Participants who have a history of hypersensitivity or allergy to TAK-438 (including its excipients) or NSAIDs
• Participants with current use of illicit drug or a history of drug abuse. and/or alcohol dependence within one year prior to the commencement of screening
• Participants who require treatment with prohibited concomitant drugs or therapies (see 7.3)
• Female participants who are pregnant or lactating; those who plan to become pregnant or donate ova during treatment period, from giving consent until 4 weeks after final dose
• Participants with serious central nervous system disorders, cardiovascular disease, pulmonary disease, hepatic disease, renal disease, metabolic disease, gastrointestinal disorders, urinary disorders, endocrine disease, or blood dyscrasia
• Participants who plan to undergo surgery requiring hospitalization or requires surgery during the study period.
• Participants with a history of a malignancy (or treatment thereof) within 5 years prior to the commencement of screening; however, participants with completely cured basal cell carcinoma of skin or carcinoma in situ of the cervix may be included in the study.
• Participants with acquired immune deficiency syndrome (AIDS; including HIV carriers) or hepatitis (including viral hepatitis carriers [HBs antigen or HCV antibody positive]); however, participants who are hepatitis C virus (HCV) antigen negative or HCV-RNA negative may be included in the study.
• Participants who meet either of the following laboratory test values at the beginning of screening (Visit 1)

• Serum creatinine value: higher than 2 mg/dL
• Alanine transaminase (ALT) or aspartate aminotransferase (AST): higher than 2.5 × the upper limit of normal
• Total bilirubin: higher than 2.0 × the upper limit of normal