A Study in Adolescents and Adults With Eosinophilic Esophagitis (EoE) Measuring Histologic Response and Determine if Reduction in Dysphagia is Achieved

Inclusion Criteria

• Participants 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.
• Participant is male or female aged 11-55 years, inclusive, at time of consent.
• Participant has histologic evidence of eosinophilic esophagitis (EoE) with a peak eosinophil count of greater than or equal to (>=) 15/ high-powered field (HPF), from 2 of 3 (proximal, mid-, and/or distal) levels of the esophagus at the screening endoscopy.
• Participant has a history of clinical symptoms of esophageal dysfunction (for example, eating problems, abdominal pain, heartburn, dysphagia, vomiting, food impaction, weight loss) intermittently or continuously at screening (Visit -1).
• Participants must have experienced dysphagia (response of "yes" to question 2 on Dysphagia Symptom Questionnaire [DSQ]) on a minimum of 4 days and completed the DSQ on >= 70 percent (%) of days in any 2 consecutive weeks of the screening period and in the last 2 weeks prior to the baseline visit (Visit 1).
• Participant must not have PPI-responsive EoE based on esophageal biopsies performed after the patient has been on at least 8 weeks of high-dose PPI therapy (high-dose therapy refers to the total daily dose, which may have been administered as a once or twice daily dosing regimen). This may occur at the time of the qualifying esophagogastroduodenoscopy (EGD) (in which case the same proton pump inhibitor (PPI) regimen must be continued), or this may have been done previously (in which case PPI therapy may have been stopped if there was no response to therapy based on esophageal biopsy results). If PPI responsiveness was excluded by a previous EGD and biopsy, the historical EGD and biopsy must have been performed after the patient had been on a minimum of 6 weeks of high-dose PPI therapy.
• Participant will be on a stable (no changes) diet >=3 months prior to the screening visit (Visit -1).
• Participant is willing and able to continue any dietary therapy, environmental therapy, and/or medical regimens (including gastric acid suppression) in effect at the screening visit (Visit -1). There should be no change to these regimens during study participation.
• All female participants 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 (for example, abstinence, 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 defined in this protocol.

Exclusion Criteria

• Participant has any condition or abnormality (including laboratory abnormalities), current or past, that, in the opinion of the principal investigator or medical monitor, would compromise the safety of the participant or interfere with or complicate the assessment of signs or symptoms of EoE. Such conditions may include psychiatric problems; neurologic deficits or disease; developmental delay; cardiovascular, metabolic, or pulmonary disease; or previous gastroesophageal surgery. These should be discussed with the medical monitor.
• Participant has used immunomodulatory therapy within 8 weeks prior to the qualifying EGD or between the qualifying EGD and baseline visit (Visit 1) or anticipates using immunomodulatory therapy during the treatment period (except for any ongoing regimen of allergy shots). Use of long-acting immunomodulatory therapy (for example, Rituxan) within 3 months of the qualifying EGD should be reviewed with the medical monitor.
• Participant has been using swallowed topical corticosteroid for EoE or systemic corticosteroid for any condition within the 4 weeks prior to the qualifying EGD, between the qualifying EGD and baseline visit (Visit 1), or a