Dupilumab Versus Topical Corticosteroid Effectiveness - Comparison in the Treatment of Stenotic EoE

• Seen at CHCO for clinical care.
• Age 12 - 25 years old inclusive
• Weight ≥40 kg at the time of screening visit
• Confirmed EoE as diagnosed by biopsy with eosinophils ≥15 eosinophils/hpf in at least 2 esophageal regions at screening endoscopy
• Report of an average of at least 2 episodes of dysphagia per week in the 4 weeks prior to screening.
• Evidence of fibrostenotic features at time of screening endoscopy (grade 2 or 3 esophageal rings, stricture, delayed passage of barium tablet on fluoroscopy, and/or distensibility ≤15mm)

Exclusion Criteria:

• Esophageal dilation performed at index endoscopy
• Patients with stricture undergoing dilation at index endoscopy may be rescreened if they meet all other eligibility criteria.
• Patients with acute food impaction will not be enrolled at their therapeutic endoscopy but are eligible for enrollment subsequently if they meet all other eligibility criteria.
• Eligible patients on current STCs can be enrolled but need to be on stable dosing less than or equal to 440 mcg two times daily fluticasone equivalent for 3 months prior to enrollment.
• Patients who have received dupilumab in the past 12 months for any indication are excluded.
• Diet restrictions and PPI use must stay unchanged in the 8 weeks prior to index endoscopy and through the study period.
• Patients with a fasting morning cortisol \<5 within 2 months of screening will not be enrolled. If repeat cortisol levels are normal, patients can be reconsented.
• Known other esophageal disease or esophageal injury (e.g. achalasia, tracheoesophageal fistula, congenital stricture, caustic injury, history of esophageal surgery), inflammatory bowel disease, liver disease, connective tissue disorder, or bleeding disorder.
• Patients with a known gelatin allergy will be excluded from EST collection.