Study to Assess the Efficacy and Safety of NEXIUM for Maintenance of Healing of Erosive Esophagitis

Inclusion Criteria:

1. Patient must be 1 to 11 years of age
2. Patients must have a history of GERD for at least 3 months before the start of study
3. For the healing phase: Patients must have confirmed presence of EE at endoscopy performed within one week of the start of the healing phase.
4. For the maintenance phase: Patients must have completed the healing phase and have endoscopy-verified healed EE at the 8-week endoscopy visit.
5. Patients must weigh ≥ 10 kg.
6. Patients may be male or female.
7. All postmenarcheal female patients must have a negative pregnancy test (urine) before starting treatment.
8. Sexually active patients must be abstinent or maintain effective contraception from informed consent day up to the last day of IMP treatment.
9. Patient's guardian must be capable of giving signed informed consent

Exclusion Criteria:

1. Presence of other diseases, such as severe heart, lung, liver, renal, blood, or neurological disease or similar
2. Significant clinical illness within 4 weeks prior to the start of treatment
3. Any conditions that are predicted to require a surgery during the study period (from the day of informed consent to the day of the last scheduled visit)
4. Previous total gastrectomy
5. Anticipated need for concomitant therapy with PPIs (except for the IMPs), H2-receptor antagonists and other drugs outlined in EC#5 after enrollment in this study
6. Participation in another clinical study with an IMP administered in the last 4 weeks before enrollment.
7. Patients with a known hypersensitivity to NEXIUM, or any other PPI, or any of the excipients of the product
8. Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site).
9. Judgment by the Investigator that the patient should not participate in the study if the patient or guardian is unlikely to comply with study procedures, restrictions, and requirements
10. Previous screening, or enrollment and randomization in the present study