Efficacy of DA-5204 on Gastroesophageal Reflux Disease

Inclusion Criteria: * Age is over 20 years old, under 75 years old, men or women * Patients diagnosed with erosive esophagitis by gastroscopy * Signed the informed consent forms Exclusion Criteria: * Patients who is impossible to receive gastroscopy * Patients with esophageal stricture, esophageal varix, Barrett's esophagus, peptic ulcer or gastrointestinal bleeding * Patients administered with prokinetics, H2 receptor antagonists, proton pump inhibitors, anticholinergic drugs or non-steroid anti-inflammatory drugs prior to study in 4 weeks * Patients with surgery related to gastroesophageal * Patients with Zollinger-Ellison syndrome * Patients with any kind of malignant tumor * Patients administered with anti-thrombotic drugs * Patients with significant cardiovascular, pulmonary, heptic, renal, hemopoietic or endocrine system primary disease * Patients with neuropsychiatric disorder, alcoholism, or drug abuse * Patients taking other investigational drugs or participating in other clinical studies in 4 weeks. * Women either pregnant or breast feeding