Potassium Competitive Acid Blocker (PCAB) Test-Guided vs Physiologic Test-Guided Treatment in Patients With Typical Reflux Symptoms

NCT07707011 | Enrolling By Invitation DMC

• 1 other identifier: Si 057/2026
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if a short course of a potassium-competitive acid blocker (PCAB) test can guide treatment of adults with typical reflux symptoms as effectively as standard physiologic testing with endoscopy and 24-hour pH-impedance monitoring. It will also learn about the safety of PCAB-guided management. The main questions it aims to answer are:

• Is PCAB test-guided treatment as effective as physiologic test-guided treatment in improving reflux symptoms after 4 weeks?
• How accurate is the PCAB test at detecting pathologic acid reflux compared with 24-hour pH-impedance monitoring?
• What medical problems do participants have when receiving PCAB-, proton-pump inhibitor-, or neuromodulator-based treatment?
• In this study, researchers will compare two strategies: one group will receive a 7-day course of vonoprazan (PCAB) as a diagnostic test and then treatment guided by the PCAB response, while the other group will undergo endoscopy and 24-hour pH-impedance monitoring with treatment guided by those results. Participants will:
• Be randomly assigned to either the PCAB test-guided group or the physiologic test-guided group
• Take study medicines by mouth (such as vonoprazan, omeprazole, and/or nortriptyline or matching placebos) for about 4 weeks, depending on their test results and symptom type
• Attend scheduled clinic visits for checkups, questionnaires, and safety monitoring
• Keep a diary of their reflux symptoms, quality of life, and any use of rescue antacid medicine

Conditions

GERD, Acid Reflux, Treatment

Keywords

GERD; Heartburn; Regurgitation; Non-cardiac chest pain; PCABs

Outcome Measures

Primary Outcomes (1)

• Proportion of Participants with Clinical Response to Treatment

  To compare the proportion of participants with typical gastroesophageal reflux disease (GERD) symptoms who achieve a clinical response to treatment. This will be compared between the group receiving treatment guided by the PCAB (Potassium-Competitive Acid Blocker) test and the group receiving treatment guided by physiological testing.

  4 weeks

Secondary Outcomes (11)

• Diagnostic Performance of the PCAB Test for Pathologic Acid Reflux

  Baseline

• Change in GERD Symptom Severity (Likert Scale)

  Baseline and at 4 weeks

• Change in Reflux Disease Questionnaire (RDQ) Score

  Baseline and at 4 weeks

• Percentage of Symptom-Free Days

  Up to 4 weeks

• Frequency of Rescue Antacid Use

  Up to 4 weeks

Study Arms (2)

PCAB-test guided

EXPERIMENTAL

All patients assigned in PCAB-test guide group will receive esophagodeuodenoscopy, 24-hr pH and impedance monitoring then Vonoprazan 20 mg orally twice daily was prescribed for 7 days.

Diagnostic Test: PCAB-test guided

Physiologic-test guided

NO INTERVENTION

All patients assigned in Physiologic-test guided group will receive esophagodeuodenoscopy, 24-hr pH and impedance monitoring.

Interventions

PCAB-test guided DIAGNOSTIC_TEST

All participants in PCAB-test guided group will receive vonoprazan 20 mg orally twice daily for 7 days

PCAB-test guided

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 70 years.
• Presence of specific gastroesophageal reflux disease (GERD) symptoms, including heartburn, regurgitation, and/or esophageal chest pain, occurring at least 4 times per week for more than 4 weeks prior to enrollment.

You may not qualify if:

• Presence of GERD complications, including esophageal stricture and/or Barrett's esophagus.
• Concomitant symptoms that may interfere with GERD treatment, such as frequent belching or rumination syndrome.
• History of gastric or duodenal ulcers.
• History of upper gastrointestinal surgery (involving the esophagus, stomach, or small intestine).
• Use of any of the following medications within 4 weeks prior to enrollment: aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), mucoprotective agents, prokinetics, or neuromodulators.
• Use of proton pump inhibitors (PPIs), histamine H2-receptor antagonists (H2RAs), or potassium-competitive acid blockers (PCABs) within 2 weeks prior to enrollment. (Note: Patients may become eligible if they complete a minimum 2-week washout period).
• Any contraindications for ambulatory esophageal reflux monitoring.
• Known history of hypersensitivity, allergy, or adverse reactions to the study medications: vonoprazan, omeprazole, or nortriptyline.
• Pregnant or breastfeeding women.

Sponsors & Collaborators

• Mahidol University: lead

Study Sites (1)

Faculty of Medicine Siriraj Hospital, Mahidol University

Bangkok Noi, Bangkok, 10700, Thailand

Location

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MeSH Terms

Conditions

Gastroesophageal Reflux; Heartburn

Condition Hierarchy (Ancestors)

Esophageal Motility Disorders; Deglutition Disorders; Esophageal Diseases; Gastrointestinal Diseases; Digestive System Diseases; Signs and Symptoms, Digestive; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Monthira Maneerattanaporn, MD

  Mahidol University

  PRINCIPAL INVESTIGATOR

• Somchai Leelakusolvong, MD

  Mahidol University

  STUDY CHAIR

• Tanawat Geeratragool, MD

  Mahidol University

  STUDY CHAIR

• Siwakan Phuetphaichit, MD

  Mahidol University

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This single-center, randomized, open-label, parallel-group trial consists of two phases and aims to evaluate patients with typical gastroesophageal reflux disease GERD symptoms. In phase 1, participants are randomized to either a PCAB-test-guided group or a physiologic-test-guided group. All patients undergo esophagogastroduodenoscopy, 24-hour pH-impedance monitoring, and related baseline assessments; patients in the PCAB-guided group additionally receive vonoprazan 20 "mg" twice daily for 7 days. A positive PCAB test is defined as a greater than 50% reduction in Reflux Disease Questionnaire RDQ score from baseline, and its diagnostic performance is compared with the Lyon Consensus 2.0 criteria. In phase 2, treatment is assigned according to prior test results, with patients receiving either omeprazole or nortriptyline, and clinical response at week 4 is compared between the PCAB-guided and physiologic-test-guided strategies.

Study Record Dates

• First Submitted: June 21, 2026
• First Posted: July 16, 2026
• Study Start: March 18, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): March 1, 2027
• Last Updated: July 16, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

TH (1)