Clinical Trial to Evaluate the Efficacy and Safety of JP-1366 in Patients With Gastric Ulcer

* Inclusion Criteria: Subjects who meet all of the following criteria can participate in this study: 1. Male or female, ≥ 19 years of age at the time of obtaining consent 2. Confirmation via upper gastrointestinal endoscopy within 14 days from Visit 2 for the following: º One or more GUs with the largest ulcer ≥ 3 mm to ≤ 30 mm º Largest ulcer classified as A1 or A2 based on Sakita-Miwa classification 3. Subjects who fully understand this study and voluntarily signed the informed consent form * Exclusion Criteria: Subjects who meet any of the following criteria cannot participate in this trial: \[Medical History\] 1. Subjects who have undergone gastric acid secretion suppression surgery, gastric surgery (e.g., gastrectomy and gastromucosectomy), resection of entire small bowel (excluding simple ulcer closure and endoscopic benign tumor resection) or esophageal surgery 2. Subjects with history of Zollinger-Ellison syndrome or gastric hypersecretion 3. Subjects with hypersensitivity (present or past) to any substance in the IP, drugs in the same class as them (potassium-competitive acid blocker \[P-CAB\] and proton pump ingibitor\[PPI\]), or benzimidazole 4. Subjects with genetic problems such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption 5. Subjects with malignant gastrointestinal cancer regardless of the period, Subjects with a history of malignancy within 5 years from Visit 1 (however, subjects with basal cell carcinoma or squamous cell carcinoma who require steady long-term follow-up only without therapeutic dosing/procedure/surgery, etc. can participate in this trial) 6. Subjects with a history of drug or alcohol abuse within 1 year from Visit 1. 7. Subjects who have had or are scheduled to have major surgery that may affect gastric acid secretion within 30 days from Visit 1 \[Comorbidity\] 8. Subjects with gastrointestinal bleeding, esophageal stricture, ulcer-induced stenosis, pyloric stenosis, gastroesophageal varices, Barrett's esophagus (\> 3 cm), esophageal dysplasia, duodenal ulcer, glandular ulcer, refractory ulcer, perforation ulcer, or surgery-induced ulcer at Visit 1 9. Subjects with signal symptoms (dysphagia, severe dysphagia, bleeding, weight loss, anemia, and bloody stools) that suggest malignant tumors of gastrointestinal tract at Visit 1 (except a tumor confirmed negative in endoscopy, etc.) 10. Subjects with pancreatitis, inflammatory bowel Disease (Crohn's disease, ulcerative colitis, or Behcet's enteritis) at Visit 1 11. Subjects with known acquired immune deficiency syndrome (AIDS) or hepatitis (including Hepatitis B surface (HBs) antigen positive, Hepatitis C virus (HCV) antibody positive, or hepatitis virus carrier) (except subjects that are HCV-RNA negative) 12. Subject with clinically significant mental illness 13. Thrombotic patients (cerebral thrombosis, myocardial infarction, thrombophlebitis, etc.) 14. Subjects who confirmed malignant tumors by upper gastrointestinal endoscopy during the Screening (Visit 1). If a biopsy is required. Subject who may have an impact on the lesion evaluated in this clinical trial needs to be excluded, and the biopsy should not be delayed for registration in this clinical trial. \[Drug Dosing/Treatment History\] 15. Subjects with a history of taking any of the following drugs or those required to take them until the end of treatment (EOT): For participation in this trial, stable drugs must not be discontinued.: \<Drugs prohibited from within 2 weeks of Visit 1 to EOT\> º All acid blockers other than the IPs: H2 receptor antagonists, proton pump inhibitors (PPIs) and potassium-competitive gastric acid blockers º Gastromucosal protection agents: Prostaglandins (however, local administration is allowed) and mucosal blood flow stimulants Antacids º Gastrointestinal motility stimulants º Anticholinergics (however, local administration is allowed) º Cholinergic agents (however, local administration is allowed) º Glucocorticosteroids (however, local administration is allowed) º Gastrin receptor antagonist, other drugs for the treatment of peptic ulcer \<Drugs prohibited from Visit 1 to EOT\> º Rilpivirine, atazanavir, and nelfinavir º Antipsychotics, antidepressants, and antianxiety drugs \<1 week prior to the date of upper gastrointestinal endoscopy(EGD)\> º Non-steroidal anti-inflammatory drugs (NSAIDs) º Antithrombotic agents: Anticoagulants or antiplatelet drugs However, among the above drugs, drugs administered as a pre-treatment for upper gastrointestinal endoscopy or for an urea breath test are allowed : midazolam, propofol, simethicone, hyoscine butylbromide, cimetropium bromide, magmil, pethidine, gasocol, urea, etc. 16. Subjects who have participated in another clinical trial within 4 weeks from Visit 1 and have been administered with or used an IP or medical device at least once 17. Subjects who have received H.pylori eradication treatment within 4 weeksfrom the date of upper gastrointestinal endoscopy. 18. Subjects who have clinically significant abnormal electrocardiogram \[Laboratory Tests\] 19. Blood test results meet the criteria below at Visit 1: º ALT, AST, ALP, GGT, Total bilirubin \> 2.0 x ULN º eGFR \< 60 mL/min/1.73 m2 \[Other\] 20. Subjects who cannot undergo upper gastrointestinal endoscopy 21. Pregnant or breast-feeding women 22. Women and men of childbearing potential who are unwilling to use an appropriate medically acceptable method of contraception during the entire study period (Visit 1 through the end of study visit) 23. Subjects who are judged unsuitable for participation in this trial by the investigators for other reasons