A Study to Assess the Efficacy, Safety and Tolerability of IRL201104 in Adults With Active Eosinophilic Esophagitis

Inclusion Criteria

• Age 18 to 75 years old, inclusive, at the time of signing the informed consent form.
• Documented diagnosis of EoE by endoscopy prior to screening. Note: Must include a demonstration of intraepithelial eosinophilic infiltration (peak cell count ≥ 15 eos/hpf [400×]) from esophageal biopsy specimens from endoscopy.
• History (by participant report) of on average at least 2 episodes of dysphagia (with intake of solids off anti-inflammatory therapy) per week in the 4 weeks prior to screening, and on average at least 2 episodes of documented dysphagia per week during any 2 consecutive weeks (qualifying period) between screening and baseline; dysphagia is defined as trouble swallowing solid food, or having solid food stick, by participant report; and completed the DSQ on ≥ 70% of days during the qualifying period prior to baseline (Visit 1).
• Must remain on a stabilized diet for at least 6 weeks prior to screening and during the course of the study; stable diet is defined as no initiation of single or multiple elimination diets or reintroduction of previously eliminated food groups.
• Must be willing and able to continue any dietary therapy and/or medical regimens (including gastric acid suppression) in effect at the screening visit. There should be no change to these regimens during the study participation.
• Willing and able to comply with all clinic visits and study-related procedures.
• Able to understand and complete study-related questionnaires.
• Provide signed informed consent.
• Esophagogastroduodenoscopy (EGD) with photographs performed at screening (qualifying EGD), with a demonstration of intraepithelial eosinophilic infiltration (peak cell count ≥15 eos/hpf) in at least 2 of the 3 biopsied esophageal regions (proximal, mid, or distal).

Exclusion Criteria

• Prior participation in an IRL201104 clinical study.
• Has any current disease of the gastrointestinal tract (aside from EoE) that may impact, in the investigator's opinion, the patient's EoE disease status. This includes, but not limited to: eosinophilic gastritis, eosinophilic enteritis, eosinophilic duodenitis, eosinophilic colitis, or proctitis; inflammatory bowel disease; or celiac disease.
• Has other causes of esophageal eosinophilia or the following diseases: hypereosinophilic syndromes, Churg-Strauss vasculitis (eosinophilic granulomatosis with polyangiitis), or peripheral blood absolute eosinophil count of > 1500 eosinophils/μL.
• Has presence of oral or esophageal mucosal infection of any type.
• Has any condition affecting the esophageal mucosa or altering esophageal motility other than EoE.
• History of achalasia, active Helicobacter pylori infection, Crohn's disease, ulcerative colitis, celiac disease, and prior esophageal surgery (with the exception of a surgical repair of an EoE complication).
• Any esophageal stricture unable to be passed with a standard, diagnostic, adult (9 to 10 mm) upper endoscope or any critical esophageal stricture that requires dilation at screening; or dilation within 2 months prior to screening.
• On a pure liquid diet or any mouth or dental condition that prevents normal eating.
• Has initiated, discontinued, or changed dosage regimen of PPIs within the 4 weeks prior to the qualifying EGD, between the qualifying EGD and baseline visit (Visit 1), or anticipates changes in the use of PPI during the study. PPI must remain constant throughout the study.
• History of bleeding disorders or esophageal varices.
• Use of anticoagulants within 2 weeks prior to screening. Participants should not stop these agents solely to become eligible for entry into this study.
• Treatment with an investigational drug within 2 months or within 5 half-lives (if known), whichever is longer, prior to screening.
• Use of systemic corticosteroids within 3 months or swallowed topical corticosteroids within 6 weeks prior to screening.
• Treatment with oral immunotherapy (OIT) within 6 months prior to s