A Study to Evaluate Tegoprazan as a Diagnostic Tool for GERD

Inclusion criteria

• Patients aged 19 to 75 years who have experienced symptoms of acid regurgitation or heartburn at least twice a week starting at least 3 months prior to screening.
• Baseline Symptom Assessment Questionnaire score of at least 6 at screening.
• 7-Day Symptom Assessment Questionnaire score of at least 4 at randomization.

Exclusion criteria

• Known hypersensitivity to Potassium-Competitive Acid Blockers (P-CABs) or benzimidazoles.
• Presence of gastrointestinal warning symptoms (e.g., progressive dysphagia, bleeding, unintentional weight loss within 3 months, hematemesis, anemia, hematochezia, or rectal bleeding) without a confirmed negative tumor finding on endoscopy.
• History of or planned gastrointestinal surgery that potentially affects gastric acid secretion.
• Diagnosed with Zollinger-Ellison syndrome or other gastric acid secretion disorders.
• Endoscopic evidence of esophageal stricture, ulcer stenosis, esophageal varices, Barrett's esophagus (> 3 cm), eosinophilic esophagitis, gastrointestinal bleeding, active peptic ulcer, or malignant tumor.
• Clinically significant hepatic or renal impairment (AST, ALT, ALP, GGT, total bilirubin, and creatinine greater than or equal to 2 times the upper limit of normal [ULN]) at Screening.
• Use of any prohibited medications within the specified wash-out periods or requiring continuous use during the study:

• Within 2 weeks prior to screening: Acid suppressants (PPIs, P-CABs).
• Within 1 week prior to screening: Prokinetics, H2 receptor antagonists, gastric mucosal protectors, antacids, or anticholinergics.
• During the study period (continuous use): Corticosteroids, NSAIDs, antithrombotics, anticoagulants, antipsychotics, antidepressants, or anxiolytics.