An Extension Study to Evaluate Maintenance of Efficacy and Long-term Treatment Effect of Oral Budesonide Suspension (OBS) in Adults and Adolescents With Eosinophilic Esophagitis (EoE)

Inclusion Criteria

• Subject completed SHP621-301 induction study.
• Subject is able to provide written informed consent (subject, parent or legal guardian and, as appropriate, subject assent) to participate in the study before completing any study-related procedures.
• Subject is male or female aged 11-55 years, inclusive, at time of consent for SHP621-301 study.
• Subject is willing and able to continue any dietary therapy, environmental therapy, and/or medical regimens (including gastric acid suppression; see exclusions below) in effect at the screening visit (Visit 0). There should be no changes to these regimens during study participation.
• All female subjects must have a negative serum pregnancy test (beta-human chorionic gonadotropin [β-hCG]) prior to enrollment into the study. Females of childbearing potential must agree to continue acceptable birth control measures (eg, abstinence, stable oral contraceptives, or double-barrier methods) throughout study participation and for 30 days following the last dose of investigational product.
• Subject is willing and has an understanding and ability to fully comply with study procedures including DSQ compliance (completed the DSQ on ≥70% of days in any 2 consecutive weeks of the screening period)and restrictions defined in this protocol

Exclusion Criteria

• Subject has changes in medications that could affect the study or diet in the weeks since the final treatment evaluation visit (Visit 4) of the SHP621-301 study.
• Subject using immunomodulatory therapy since the final treatment evaluation visit (Visit 4) of the SHP621-301 study or anticipated use of immunomodulatory therapy during the treatment period (except for any ongoing regimen of allergy shots); any temporary use (≤7 days) or initiation of new steroid treatment during the study should be documented and discussed with the medical monitor prospectively but cannot occur within 4 weeks of scheduled EGDs.
• Subject using swallowed topical corticosteroid for EoE or systemic corticosteroid for any condition since the final treatment evaluation visit (Visit 4) of the SHP621-301 study or anticipated use during the treatment period; any temporary use (≤7 days) or initiation of new steroid treatment during the study should be documented and discussed with medical monitor prospectively but cannot occur within the 4 weeks of the scheduled EGDs.
• Subject on inhaled or intranasal steroids and not on a stable dose between the baseline visit (Visit 1) of the SHP621-301 study and the screening EGD of this study.
• Subject has initiated, discontinued, or changed dosage regimen of proton pump inhibitors (PPIs), H2 antagonists, antacids, antihistamines, or leukotriene inhibitors for any condition (such as gastroesophageal reflux disease, asthma or allergic rhinitis) since the final treatment evaluation visit (Visit 4) of the SHP621-301 study or anticipated changes in the use of such medications during the treatment period.
• Subject using Cytochrome P450 3A4 inhibitors (eg, ketoconazole, grapefruit juice) since the final treatment evaluation visit (Visit 4) of the SHP621-301 study or anticipated use of such medications during the treatment period.
• Subject has an appearance on screening EGD of an esophageal stricture (high grade), as defined by the presence of a lesion that does not allow passage of a diagnostic adult upper endoscope (eg, with an insertion tube diameter of >9mm).
• Subject is on a pure liquid diet or the six-food elimination diet.
• Subject has presence of esophageal varices at the EGD at the final treatment evaluation visit (Visit 4) of the SHP621-301 study.
• Subject has any current disease of the gastrointestinal tract, aside from EoE, including eosinophilic gastritis, enteritis, colitis, or proctitis, inflammatory bowel disease, or celiac disease.
• Subject has other diseases causing or associated with esophageal eosinophilia, including hypereosinophilic syndrome, collagen vascular disease,