Clinical Trial Finder

Inclusion Criteria:

• - Participant completed the SHP621-302 (NCT02736409) extension study and is considered by the investigator to potentially benefit from continued BOS investigational treatment.

• - Participant is able to provide written informed consent (participant, parent or legal guardian and, as appropriate, participant assent) to participate in the study before completing any study-related procedures.

• - Females of childbearing potential must agree to continue acceptable birth control measures (example (e.g.): abstinence, surgically sterile male partner, stable oral contraceptives, or double-barrier methods) throughout study participation.

• - Participant is willing and has an understanding and ability to fully comply with study procedures and restrictions as defined in protocol.

Exclusion Criteria:

• - Participant has changes in medications or diet during the SHP621-302 (NCT02736409) study that could affect participation in this continuation study.

• - Participant anticipates using swallowed topical corticosteroid for EoE or systemic corticosteroid for any condition during the treatment period; any temporary use (less than or equal to [≤] 7 days) or initiation of new steroid treatment during the study should be documented and discussed with the medical monitor prospectively but should be avoided within 4 weeks of the scheduled esophagogastroduodenoscopy (EGDs).

• - Participant anticipates use of Cytochrome P450 3A4 inhibitors (e.g., ketoconazole, grapefruit juice) during the continuation study.

• - Participant has an appearance at the EGD at the final treatment evaluation visit of SHP621-302 (NCT02736409) (Visit 8) 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 (e.g., with an insertion tube diameter of greater than (>) 9 millimeter [mm]).

• - Participant has presence of esophageal varices at the EGD at the final treatment evaluation visit (Visit 8) of the SHP621-302 (NCT02736409) study.

• - Participant has any current disease of the gastrointestinal tract, aside from EoE, including eosinophilic gastritis, enteritis, colitis, or proctitis, inflammatory bowel disease, or celiac disease.

• - Participant has other diseases causing or associated with esophageal eosinophilia, including hypereosinophilic syndrome, collagen vascular disease, vasculitis, achalasia, or parasitic infection.

• - Participant has oropharyngeal or esophageal candidiasis that failed to respond to previous treatment.

Diagnosis with oropharyngeal or esophageal candidiasis at or since the final treatment evaluation visit (Visit 8) of the SHP621-302 (NCT02736409) study is not an exclusion as long as the participant is expected to respond to treatment.

• - Participant has a potentially serious acute or chronic infection or immunodeficiency condition, including tuberculosis, fungal, bacterial, viral/parasite infection, ocular herpes simplex, or chicken pox/measles.

• - Participant has upper gastrointestinal bleeding identified at the EGD at the final treatment evaluation visit (Visit 8) of the SHP621-302 (NCT02736409) study.

• - Participant has evidence of active infection with Helicobacter pylori.

• - Participant has evidence of unstable asthma.

• - Participant is female and pregnant or nursing.

• - Participant has a history of intolerance, hypersensitivity, or idiosyncratic reaction to budesonide (or any other corticosteroids), or to any other ingredients of the study medication.

• - Participant has a history or high risk of noncompliance with treatment or regular clinic visits.

Arms

Experimental: Budesonide Oral Suspension

Participants will be initiated on 10 milliliter (mL) of Budesonide oral suspension (0.2 milligram/mL) twice daily up to 72 months (Visit 12) or early termination (ET).

Interventions

Drug: - Budesonide oral suspension

Budesonide oral suspension (BOS) 10 mL twice daily