This study is designed to confirm the non-inferiority of Tegoprazan 25mg, compared to Lansoprazole 15mg as maintenance therapy in patients with healed erosive esophagitis confirmed by endoscopy following oral administration once daily(QD) for 6 months.

This is a double blind, randomized, active-controlled, phase 3 study. Subjects will be randomly assigned to one of the two treatment groups (tegoprazan 25mg, lansoprazole 15mg).

Inclusion Criteria:

1. Erosive eshophagitis(LA classification Grades A to D) within 12 weeks prior to Randomization
2. Healed erosive esophagitis within 7 days prior to Randomization
3. No heartburn and regurgitation within 7 days prior to Randomization

Exclusion Criteria:

1. Unable to undergo upper GI endoscopy
2. Presence of esophageal stricture, ulcerated stricture, gastroesophageal varix, long segment Barrett's esophagus with >3 cm length(LSBE), active digestive ulcer, gastric bleeding or malignant tumors on an upper GI endoscopy
3. Diagnosed with primary esophageal motility disorder, irritable bowel syndome(IBS) or inflammatory bowel disease(IBD)
4. History of acid-suppressive, esophageal or gastric surgeries