A Study in Adult Participants With EoE to Evaluate Vonoprazan 20 mg Compared to Placebo After 12 Weeks and to Evaluate Vonoprazan 20 mg Up to 24 Weeks

NCT06851559 | Recruiting Phase 2 FDA Drug

• 1 other identifier: EoE-201
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 41

Brief Summary

The primary objective of this study is to assess the efficacy of vonoprazan 20 mg once daily (QD) compared to placebo QD in the number of participants with a peak eosinophilic histologic response \<15 eosinophils per high-power field (eos/hpf) after 12 weeks of therapy.

Conditions

Eosinophilic Esophagitis

Keywords

Vonoprazan; Adults

Outcome Measures

Primary Outcomes (1)

• Number of Participants at Week 12 Achieving Peak Esophageal Intraepithelial Eosinophil Count <15 eos/hpf.

  Week 12

Secondary Outcomes (3)

• Mean Change from Baseline to Week 12 in Dysphagia Days

  Baseline and Week 12

• Mean Change from Baseline to Week 12 in EoE Endoscopic Reference Score (EREFS).

  Baseline and Week 12

• Mean Change from Baseline to Week 12 in Peak Esophageal Intraepithelial Eosinophil Count.

  Baseline and Week 12

Study Arms (2)

Vonoprazan 20 mg

EXPERIMENTAL

Participants will be administered vonoprazan at a dose of 20 mg for 12 weeks. Participants will continue to receive the same dose for an additional 12 weeks.

Drug: Vonoprazan

Placebo

EXPERIMENTAL

Participants will be administered placebo for 12 weeks. Participants will then receive vonoprazan 20 mg for an additional 12 weeks.

Drug: Placebo

Interventions

Vonoprazan DRUG

Vonoprazan will be administered orally as a tablet

Vonoprazan 20 mg

Placebo DRUG

Placebo will be administered orally as tablet

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• The participant is ≥18 years of age at the time of informed consent signing.
• In the opinion of the investigator or subinvestigators, the participant is capable of understanding and complying with protocol requirements, including completion and compliance with the electronic diary. The diary must be completed on at least 11 of the last 14 days in the 2 weeks prior to Visit 2 (Day -1).
• The participant signs and dates a written informed consent form (ICF) and any required privacy authorization prior to the initiation of any study procedures.
• The participant has a peak eosinophil count of at least 15 eos/hpf \[X 400\] from at least 2 of the 3 esophageal levels on screening endoscopy as measured in at least 6 biopsies, at least 2 each from the proximal, mid, and distal segments of the esophagus based on central reading.
• The participant has 4 or more days with dysphagia episodes documented via electronic diary in the 2 weeks prior to Visit 2 (Day -1).
• The participant must remain on a stable diet for at least 6 weeks prior to the Screening Period and is expected to remain on a stable diet during the course of the study; stable diet is defined as not initiating new elimination diets or reintroducing previously eliminated foods.
• A female participant of childbearing potential who is or may be sexually active with a non-sterilized male partner agrees to routinely use adequate contraception from the signing of informed consent until 4 weeks after the last dose of study drug.

You may not qualify if:

• The participant is on a pure liquid diet.
• The participant has documented erosive esophagitis at the screening endoscopy.
• The participant has other known causes of esophageal eosinophilia or either of the following conditions: hypereosinophilic syndrome, or eosinophilic granulomatosis with polyangiitis (Churg-Strauss Syndrome).
• The participant has a documented diagnosis of eosinophilic gastritis, duodenitis, jejunitis, ileitis, proctitis, or colitis.
• The participant has endoscopic Barrett's esophagus (\>1 cm of columnar-lined esophagus) or dysplastic changes in the esophagus.
• The participant has a history of achalasia, Crohn's disease, ulcerative colitis, or celiac disease.
• The participant has a known active Helicobacter pylori infection.
• The participant has any other clinically significant structural conditions affecting the esophagus, including: esophageal varices, viral or fungal infection, and history of radiation therapy, radiofrequency ablation, endoscopic mucosal resection, cryotherapy to the esophagus, caustic or physiochemical trauma (including sclerotherapy or esophageal variceal band ligation), or esophageal surgery.
• The participant has a history of surgery or non-EoE endoscopic intervention, such as gastric bypass, fundoplication, gastric sleeve, or a history of gastric or duodenal surgery (except endoscopic removal of benign polyps).
• The participant has gastric ulcer(s) or duodenal ulcer(s) within 4 weeks before the first dose of study drug.
• The participant has had clinically significant upper or lower gastrointestinal bleeding within 4 weeks prior to the Screening Period.
• The participant has esophageal stricture(s) unable to be passed with an 8 to 10 mm endoscope, clinically requires dilation, or has a history of dilation within the 3 months prior to the Screening Period.
• Use of prescription or non-prescription PPIs or PCABs within 2 months prior to the Screening Period.
• Use of swallowed topical corticosteroid or budesonide oral suspension for EoE within 2 months prior to the Screening Period.
• Use of systemic corticosteroid for any condition within 3 months prior to the Screening Period.

Sponsors & Collaborators

• Phathom Pharmaceuticals, Inc.: lead

Study Sites (41)

Preferred Research Partners, Inc

Little Rock, Arkansas, 72211, United States

RECRUITING

GW Research, Inc

Chula Vista, California, 91910, United States

RECRUITING

Southern California Research Institute Medical Group

Los Angeles, California, 90045, United States

ACTIVE NOT RECRUITING

Rocky Mountain Gastroenterology

Lakewood, Colorado, 80228, United States

RECRUITING

Western States Clinical Research, Inc.

Wheat Ridge, Colorado, 80033, United States

RECRUITING

Connecticut Clinical Research Institute

Bristol, Connecticut, 06010, United States

RECRUITING

Nature Coast Clinical Research

Inverness, Florida, 34452, United States

RECRUITING

Encore Borland-Groover Clinical Research

Jacksonville, Florida, 32256, United States

RECRUITING

International Center for Research

Tampa, Florida, 33614, United States

RECRUITING

Gastroenterology Associates of Central Georgia, LLC

Macon, Georgia, 31201, United States

RECRUITING

Treasure Valley Medical Research

Boise, Idaho, 83706, United States

RECRUITING

Grand Teton Research Group

Idaho Falls, Idaho, 83404, United States

RECRUITING

Northwestern Medicine Digestive Health Center

Chicago, Illinois, 60611, United States

RECRUITING

GI Alliance - Gurnee

Gurnee, Illinois, 60031, United States

RECRUITING

Combined Gastro, LLC

Lafayette, Louisiana, 70503, United States

RECRUITING

Tandem Clinical Research GI, LLC

Marrero, Louisiana, 70072, United States

RECRUITING

Woodholme Gastroenterology Associates

Glen Burnie, Maryland, 21061, United States

RECRUITING

Boston Specialists

Boston, Massachusetts, 02111, United States

RECRUITING

Brigham and Women's Hospital

Boston, Massachusetts, 02115, United States

RECRUITING

Huron Gastroenterology Associates

Ypsilanti, Michigan, 48197, United States

RECRUITING

Advanced Research Institute

Reno, Nevada, 89511, United States

RECRUITING

Weill Cornell Medicine, New York Presbyterian Hospital

New York, New York, 10065, United States

RECRUITING

UNC Clinical & Translational Research Center

Chapel Hill, North Carolina, 27514, United States

RECRUITING

GCGA Physicians, LLC dba/Gastro Health Research

Cincinnati, Ohio, 45219, United States

RECRUITING

Great Lakes Gastroenterology Research LLC

Mentor, Ohio, 44060, United States

RECRUITING

University of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

RECRUITING

Galen Medical Group - Galen Digestive Health

Chattanooga, Tennessee, 37404, United States

RECRUITING

Quality Medical Research

Nashville, Tennessee, 37211, United States

RECRUITING

GI Alliance

Cedar Park, Texas, 78613, United States

RECRUITING

The Hospitals of Providence Memorial Campus

El Paso, Texas, 79902, United States

RECRUITING

Texas Digestive Specialists

Harlingen, Texas, 78550, United States

RECRUITING

Houston Endoscopy and Research Center

Houston, Texas, 77079, United States

RECRUITING

Research Physicians Network, LLC

Houston, Texas, 77089, United States

RECRUITING

Biopharma Informatic, LLC

McAllen, Texas, 78503, United States

RECRUITING

Pearland Physicians

Pearland, Texas, 77581, United States

RECRUITING

Gastroenterology Research of San Antonio

San Antonio, Texas, 78229, United States

RECRUITING

Texas Gastro Consultants

Tomball, Texas, 73375, United States

RECRUITING

Care Access - Ogdon

Ogden, Utah, 84403, United States

RECRUITING

Advanced Research Institute

Ogden, Utah, 84405, United States

RECRUITING

Advanced Research Institute

Sandy City, Utah, 84070, United States

RECRUITING

Blue Ridge Medical Research

Lynchburg, Virginia, 25402, United States

RECRUITING

MeSH Terms

Conditions

Eosinophilic Esophagitis

Interventions

1-(5-(2-fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl)-N-methylmethanamine

Condition Hierarchy (Ancestors)

Esophagitis; Esophageal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Gastroenteritis; Eosinophilia; Leukocyte Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Study Officials

• Medical Director

  Phathom Pharmaceuticals

  STUDY DIRECTOR

Central Study Contacts

Phathom Medical Information

CONTACT

1-888-775-PHAT (7428); medicalinformation@phathompharma.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: The study will enroll participants ≥18 years of age.

Study Record Dates

• First Submitted: February 24, 2025
• First Posted: February 28, 2025
• Study Start: October 30, 2025
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): March 1, 2027
• Last Updated: April 28, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (41)