A randomized, double-blind, placebo-controlled multicenter, phase 3 study to evaluate the efficacy and safety of tezepelumab administered subcutaneously (SC) using an accessorized pre-filled syringe (APFS) versus placebo in adult and adolescent patients with eosinophilic esophagitis (EoE).

The study consists of a screening period of 2 to 8 weeks and a 52-week randomized double-blind placebo-controlled treatment period. After completion of the treatment period, participants will be eligible to participate in an optional active treatment extension period (lasting for 24 weeks), followed by a 12-week off-treatment safety follow-up period. Participants who will not participate in the extension period will participate in a 12-week off-treatment safety follow-up period following completion of the 52-week treatment period.

This study will randomize approximately 360 participants. The participants will be randomized at 1:1:1 ratio to the 3 treatment arms.

Inclusion Criteria:

1. Participant must be 12 to 80 years of age inclusive, at the time of signing the informed consent/assent.
2. Weight ≥ 40 kg at Visit 1
3. Established diagnosis of EoE with a previous EGD and esophageal biopsy confirming a diagnosis of EoE.
4. Participants who have symptomatic EoE as defined by a history of on average at least 2 episodes of dysphagia (any severity of food going down slowly or being stuck in the throat) per week in the 4 weeks prior to Visit 1.
5. Must remain on a stabilized diet for at least 8 weeks prior to Visit 1 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).
6. May be on any background PPI and/or STC, during the course of the study, as long as background medications have been stable for at least 8 weeks prior to the screening/run-in period (Visit 1) and there is agreement not to change background medication or dosage unless medically indicated, during the screening/run-in and treatment period.
7. Participants currently on leukotriene inhibitors and/or steroid treatments for asthma or allergies that are inhaled or administered intranasally, must report a stable dose for at least 4 weeks prior to the screening/run-in period (Visit 1).
8. If a medication for EoE (for example PPI and/or STC) is discontinued prior to the screening/run-in, there should be a washout period of at least 8 weeks prior to Visit 1. Discontinuation of any marketed biologic (monoclonal or polyclonal antibody) should have a washout period of 4 months or 5 half-lives prior to Visit 1, whichever is longer.
9. Participants should have previously documented standard of care treatment, which could include PPI and/or STC and/or diet.

Exclusion Criteria:

1. Other gastrointestinal disorders such as active Helicobacter pylori infection, history of achalasia, esophageal varices, Crohn's disease, ulcerative colitis, inflammatory bowel disease, celiac disease, eosinophilic enteritis, colitis, diverticulitis, irritable bowel syndrome, or other clinically significant gastrointestinal conditions as per Investigator discretion.
2. Esophageal stricture that prevents the easy passage of a standard endoscope or any critical esophageal stricture that requires dilation at screening.
3. Use of a feeding tube, or having a pattern of not eating solid food >3 days of week. Solid food is defined as food that requires chewing before swallowing.
4. Hypereosinophilic syndrome
5. EGPA vasculitis
6. Esophageal dilation performed within 8 weeks prior to screening.

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal.

All request will be evaluated as per the AZ disclosure commitment:

https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool. Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Double-blind