GERD, Acid Reflux, TreatmentNCT07707011

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

A study testing PCAB-test guided in people with GERD, Acid Reflux, Treatment, run by Mahidol University at 1 site in Thailand.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts

Official record

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Trial 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. Read more about this study

Who is it for?: Ages 18 to 70 yearsHealthy volunteers can take part
Conditions the study is for: GERD, Acid Reflux, Treatment
What is being tested?: PCAB-test guided
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 120 participants
Where: 1 siteThailand
Study dates: 18 Mar 2026to Mar 2027
Phase: Interventional
Are there results?: Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 70 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

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.

Who cannot join

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).

Show all 9Show fewer

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.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Thailand1 site

Faculty of Medicine Siriraj Hospital, Mahidol University
Bangkok Noi, Bangkok, 10700

Other trials in Thailand

About this study

Official title: Potassium Competitive Acid Blocker (PCAB) Test-Guided vs Physiologic Test-Guided Treatment in Patients With Typical Reflux Symptoms: A Randomized Non-inferiority Trial

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

Read the detailed description

This protocol describes a single-center, randomized, controlled, open-label, parallel-group, non-inferiority trial comparing a potassium-competitive acid blocker (PCAB) test-guided strategy with physiologic test-guided management in adults with typical reflux symptoms suggestive of gastroesophageal reflux disease (GERD).

The study will enroll approximately 120 participants aged 18-70 years with heartburn, regurgitation, or non-cardiac chest pain, and will exclude patients with Barrett's esophagus, peptic ulcer, prior upper GI surgery, significant comorbidities, or recent use of potent anti-secretory, neuromodulator, or prokinetic agents.

Participants are randomized in a 1:1 ratio to either a 7-day vonoprazan-based PCAB test or to a reference strategy using esophagogastroduodenoscopy (EGD) plus 24-hour pH-impedance monitoring and high-resolution manometry in accordance with Lyon Consensus 2.0 and Rome IV criteria.

The primary objective is to determine whether PCAB test-guided treatment is non-inferior to physiologic test-guided treatment with respect to clinical response, defined by improvement in reflux symptoms after 4 weeks of allocated therapy.

Secondary objectives include: (1) assessment of the diagnostic performance of the PCAB test for pathologic acid reflux using 24-hour pH-impedance monitoring as the reference standard; (2) comparison of changes in Reflux Disease Questionnaire (RDQ) scores, Likert symptom scales for heartburn, regurgitation and chest pain, EQ-5D quality-of-life scores, symptom-free days, rescue antaciduse, and patient satisfaction; and (3) evaluation of treatment-emergent adverse events andserious adverse events.

In the PCAB arm, vonoprazan 20 mg twice daily for 7 days constitutes the diagnostic test; PCAB responders and non-responders are then allocated to proton pump inhibitor (omeprazole-based) or neuromodulator (nortriptyline-based) regimens with matching placebos according to the underlying GERD phenotype (erosive esophagitis, non-erosive reflux disease,reflux hypersensitivity, or functional heartburn). In the physiologic-test arm, treatment selection (omeprazole versus nortriptyline, with placebos) is based directly on EGD and 24-hour pH-impedance findings and symptom association analysis. Outcomes are measured at multiple time points over 4 weeks using RDQ, symptom Likert scales, EQ-5D, symptom and antacid diaries, and standard safety assessments, and data will be analyzed primarily using non-inferiority methods for proportions and standard diagnostic accuracy metrics (sensitivity, specificity, predictive values, and likelihood ratios), with appropriate parametric ornon-parametric tests and longitudinal models.

Conditions: GERD, Acid Reflux, Treatment
Being tested: PCAB-test guided
Keywords: GERD, Heartburn, Regurgitation, Non-cardiac chest pain, PCABs
Medical subject headings: Gastroesophageal Reflux, Heartburn

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

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

Study groups in NCT07707011
Study group	Role	What they receive
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. Receives: 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.

What is being measured

The primary outcome is the main question the study is designed to answer.

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.
Measured: 4 weeks

Secondary outcomes (11)

Diagnostic Performance of the PCAB Test for Pathologic Acid Reflux
To evaluate the diagnostic accuracy, sensitivity, and specificity of the PCAB test in identifying pathologic acid reflux. Upper gastrointestinal endoscopy (EGD) and physiological testing, interpreted according to the Lyon Consensus 2.0 criteria, will be used as the reference standard.
Measured: Baseline
Change in GERD Symptom Severity (Likert Scale)
To compare treatment outcomes between the PCAB test-guided and physiological testing-guided groups using a Likert scale to assess the severity of heartburn, regurgitation, and chest pain. Subgroup analysis will be performed for erosive esophagitis, non-erosive reflux disease (NERD), reflux hypersensitivity, and functional heartburn.
Measured: Baseline and at 4 weeks
Change in Reflux Disease Questionnaire (RDQ) Score
The Reflux Disease Questionnaire (RDQ) is a 12-item self-administered questionnaire assessing the frequency and severity of heartburn, regurgitation, and dyspeptic symptoms. Each item is scored from 0 to 5, and the overall RDQ score is calculated as the mean of the item scores, ranging from 0 to 5. Higher scores indicate more frequent and/or severe symptoms and therefore a worse outcome.
The change in RDQ score from baseline to week 4 will be compared between the potassium-competitive acid blocker (P-CAB) test-guided group and the physiological testing-guided group. A greater reduction in the RDQ score indicates greater symptom improvement.
Measured: Baseline and at 4 weeks
Percentage of Symptom-Free Days
To compare the percentage of 24-hour days without GERD symptoms between the two study arms over the 4-week study period.
Measured: Up to 4 weeks
Frequency of Rescue Antacid Use
To compare the frequency of rescue antacid use and the percentage of 24-hour days without the need for rescue antacids between the two study arms.
Measured: Up to 4 weeks
Change in Quality of Life (EQ-5D)
The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire assesses health-related quality of life across five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has five response levels, ranging from no problems to extreme problems or inability to perform the activity.
Responses will be converted into an EQ-5D-5L index score using the Thai value set. Index scores range from -0.4212 to 1.000, with 1.000 representing full health and scores below 0 representing health states considered worse than death. Higher scores indicate better health-related quality of life. Change will be calculated as the week 4 score minus the baseline score; a positive change indicates improvement. The change in index score will be compared between the P-CAB test-guided and physiological testing-guided groups.
Measured: Baseline and at 4 weeks
Proportion of Participants Satisfied With the Assigned Treatment Protocol at Week 4
Overall treatment satisfaction will be assessed using a single-item 5-point Likert scale: 1 = very dissatisfied, 2 = dissatisfied, 3 = neither satisfied nor dissatisfied, 4 = satisfied, and 5 = very satisfied. Participants selecting a score of 4 or 5 will be classified as satisfied. The proportion of satisfied participants will be compared between the P-CAB test-guided and physiological testing-guided groups.
Measured: At 4 weeks
Rate of Study Withdrawal Due to Severe Symptoms
To compare the number of participants in each arm who discontinue the study due to symptoms severely interfering with their daily life activities.
Measured: Up to 4 weeks
Incidence of Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
To assess and compare the safety profile, including the number of participants experiencing TEAEs and SAEs, between the PCAB test-guided treatment group and the physiological testing-guided treatment group.
Measured: Up to 4 weeks
Participant Satisfaction With the Diagnostic Testing Method Assessed Using a Study-Specific 5-Point Likert Scale
Immediately after completing the assigned diagnostic procedure, participants will rate their overall satisfaction with the diagnostic testing method using a study-specific single-item 5-point Likert scale: 1 = very dissatisfied, 2 = dissatisfied, 3 = neither satisfied nor dissatisfied, 4 = satisfied, and 5 = very satisfied. Scores range from 1 to 5, with higher scores indicating greater satisfaction. Satisfaction scores will be compared between participants undergoing the P-CAB test and those undergoing physiological testing.
Measured: Immediately after completion of diagnostic testing on Day 0
Prevalence of GERD Phenotypes
To determine the prevalence of erosive esophagitis, non-erosive reflux disease (NERD), reflux hypersensitivity, and functional heartburn among participants with typical GERD symptoms. Diagnosis and phenotyping will be established using 24-hour pH monitoring combined with EGD, according to the Lyon Consensus 2.0 criteria.
Measured: Baseline

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

18 Mar 2026Mar 2027

First posted16 Jul 2026
Study start18 Mar 2026
Primary completionMar 2027 (estimated)
Study completionMar 2027 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (35)Papers the sponsor has linked to this study.
Other trials for GERD, Acid Reflux, TreatmentStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Model description: 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.
Masking: Double blind
Who is masked: Participant, Care provider
Enrolment: 120 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07707011
Sponsor's protocol ID: Si 057/2026
Status last verified: Jul 2026
First submitted: 21 Jun 2026
Last updated: 16 Jul 2026
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No: To protect participant confidentiality and comply with institutional and regulatory requirements, no IPD will be shared unless with reasonable request.

Publications

Nasseri-Moghaddam S, Razjouyan H, Nouraei M, Alimohammadi M, Mamarabadi M, Vahedi H, Pourshams A, Mohamadnejad M, Zamani F, Sadr F, Darvish-Moghaddam S, Farsi P, Malekzadeh R. Inter- and intra-observer variability of the Los Angeles classification: a reassessment. Arch Iran Med. 2007 Jan;10(1):48-53.
PubMed 17198454
Dong P, Lin L, Sun K, Tang F, Li Q, Zhou X, Liu F, Yang Z, Li J, Jiang L, Zhao P, Sun X, Wang Q. Accuracy of the diagnosis of gastroesophageal reflux disease by a trial of potassium-competitive acid blocker treatment. BMC Gastroenterol. 2025 May 26;25(1):406. doi: 10.1186/s12876-025-03981-1.
PubMed 40419956
Dickman R, Maradey-Romero C, Fass R. The role of pain modulators in esophageal disorders - no pain no gain. Neurogastroenterol Motil. 2014 May;26(5):603-10. doi: 10.1111/nmo.12339.
PubMed 24750261
Shah ED, Gyawali CP, Chan WW. Optimizing the Cost-Effective Evaluation of Gastroesophageal Reflux by Typical Symptom Phenotypes After Failure of Empiric Acid Suppression Trial. Am J Gastroenterol. 2026 Mar 1;121(3):635-648. doi: 10.14309/ajg.0000000000003576. Epub 2025 Jun 5.
PubMed 40471840
Otake K, Sakurai Y, Nishida H, Fukui H, Tagawa Y, Yamasaki H, Karashima M, Otsuka K, Inatomi N. Characteristics of the Novel Potassium-Competitive Acid Blocker Vonoprazan Fumarate (TAK-438). Adv Ther. 2016 Jul;33(7):1140-57. doi: 10.1007/s12325-016-0345-2. Epub 2016 Jun 10.
PubMed 27287852
Oshima T, Miwa H. Potent Potassium-competitive Acid Blockers: A New Era for the Treatment of Acid-related Diseases. J Neurogastroenterol Motil. 2018 Jul 30;24(3):334-344. doi: 10.5056/jnm18029.
PubMed 29739175
Rawla P, Sunkara T, Ofosu A, Gaduputi V. Potassium-competitive acid blockers - are they the next generation of proton pump inhibitors? World J Gastrointest Pharmacol Ther. 2018 Dec 13;9(7):63-68. doi: 10.4292/wjgpt.v9.i7.63.
PubMed 30595950
Numans ME, Lau J, de Wit NJ, Bonis PA. Short-term treatment with proton-pump inhibitors as a test for gastroesophageal reflux disease: a meta-analysis of diagnostic test characteristics. Ann Intern Med. 2004 Apr 6;140(7):518-27. doi: 10.7326/0003-4819-140-7-200404060-00011.
PubMed 15068979
Dickman R, Emmons S, Cui H, Sewell J, Hernandez D, Esquivel RF, Fass R. The effect of a therapeutic trial of high-dose rabeprazole on symptom response of patients with non-cardiac chest pain: a randomized, double-blind, placebo-controlled, crossover trial. Aliment Pharmacol Ther. 2005 Sep 15;22(6):547-55. doi: 10.1111/j.1365-2036.2005.02620.x.
PubMed 16167971
Bautista J, Fullerton H, Briseno M, Cui H, Fass R. The effect of an empirical trial of high-dose lansoprazole on symptom response of patients with non-cardiac chest pain--a randomized, double-blind, placebo-controlled, crossover trial. Aliment Pharmacol Ther. 2004 May 15;19(10):1123-30. doi: 10.1111/j.1365-2036.2004.01941.x.
PubMed 15142202
Xia HH, Lai KC, Lam SK, Hu WH, Wong NY, Hui WM, Lau CP, Chen WH, Chan CK, Wong WM, Wong BC. Symptomatic response to lansoprazole predicts abnormal acid reflux in endoscopy-negative patients with non-cardiac chest pain. Aliment Pharmacol Ther. 2003 Feb;17(3):369-77. doi: 10.1046/j.1365-2036.2003.01436.x.
PubMed 12562449
Pandak WM, Arezo S, Everett S, Jesse R, DeCosta G, Crofts T, Gennings C, Siuta M, Zfass A. Short course of omeprazole: a better first diagnostic approach to noncardiac chest pain than endoscopy, manometry, or 24-hour esophageal pH monitoring. J Clin Gastroenterol. 2002 Oct;35(4):307-14. doi: 10.1097/00004836-200210000-00006.
PubMed 12352293
Juul-Hansen P, Rydning A, Jacobsen CD, Hansen T. High-dose proton-pump inhibitors as a diagnostic test of gastro-oesophageal reflux disease in endoscopic-negative patients. Scand J Gastroenterol. 2001 Aug;36(8):806-10. doi: 10.1080/003655201750313315.
PubMed 11495074
Schindlbeck NE, Klauser AG, Voderholzer WA, Muller-Lissner SA. Empiric therapy for gastroesophageal reflux disease. Arch Intern Med. 1995 Sep 11;155(16):1808-12.
PubMed 7654116
Fass R, Ofman JJ, Gralnek IM, Johnson C, Camargo E, Sampliner RE, Fennerty MB. Clinical and economic assessment of the omeprazole test in patients with symptoms suggestive of gastroesophageal reflux disease. Arch Intern Med. 1999 Oct 11;159(18):2161-8. doi: 10.1001/archinte.159.18.2161.
PubMed 10527293

Interested in taking part?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See sites and contacts

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All GERD, Acid Reflux, Treatment trials

Study at a glance

From the registry record, last updated by the sponsor on 16 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Potassium Competitive Acid Blocker (PCAB) Test-Guided vs Physiologic Test-Guided Treatment in Patients With Typical Reflux Symptoms: A Randomized Non-inferiority Trial
ClinicalTrials.gov ID: NCT07707011
Acronym / sponsor ID: Si 057/2026
Conditions: GERD, Acid Reflux, Treatment
Keywords: GERD, Heartburn, Regurgitation, Non-cardiac chest pain, PCABs
Study type: Interventional
Recruitment status: Enrolling by invitation
Enrolment: 120 participants (estimated)
Lead sponsor: Mahidol UniversityUniversity, hospital or other
Study start: 18 Mar 2026 (actual)
Primary completion: Mar 2027 (estimated)
Study completion: Mar 2027 (estimated)
First posted: 16 Jul 2026 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

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

Detailed description

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind (participant, care provider)
Number of arms: 2
Model description: 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.

Arm	Type	Receives
PCAB-test guided	Experimental	Diagnostic Test: PCAB-test guidedAll 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.
Physiologic-test guided	No intervention	–All patients assigned in Physiologic-test guided group will receive esophagodeuodenoscopy, 24-hr pH and impedance monitoring.

Who may qualify

Ages: 18 to 70 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (2 listed)

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.

Key exclusion criteria (9 listed)

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.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
PCAB-test guidedAll participants in PCAB-test guided group will receive vonoprazan 20 mg orally twice daily for 7 days	Diagnostic test	PCAB-test guided

Primary outcome

Proportion of Participants with Clinical Response to Treatment
Time frame: 4 weeks
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.

11 secondary outcomes

Diagnostic Performance of the PCAB Test for Pathologic Acid Reflux
Time frame: Baseline
Change in GERD Symptom Severity (Likert Scale)
Time frame: Baseline and at 4 weeks
Change in Reflux Disease Questionnaire (RDQ) Score
Time frame: Baseline and at 4 weeks
Percentage of Symptom-Free Days
Time frame: Up to 4 weeks
Frequency of Rescue Antacid Use
Time frame: Up to 4 weeks
Change in Quality of Life (EQ-5D)
Time frame: Baseline and at 4 weeks
Proportion of Participants Satisfied With the Assigned Treatment Protocol at Week 4
Time frame: At 4 weeks
Rate of Study Withdrawal Due to Severe Symptoms
Time frame: Up to 4 weeks
Incidence of Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame: Up to 4 weeks
Participant Satisfaction With the Diagnostic Testing Method Assessed Using a Study-Specific 5-Point Likert Scale
Time frame: Immediately after completion of diagnostic testing on Day 0
Prevalence of GERD Phenotypes
Time frame: Baseline

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 16 Jul 2026.
Background: PubMed 17198454Nasseri-Moghaddam S, Razjouyan H, Nouraei M, Alimohammadi M, Mamarabadi M, Vahedi H, Pourshams A, Mohamadnejad M, Zamani F, Sadr F, Darvish-Moghaddam S, Farsi P, Malekzadeh R. Inter- and intra-observer variability of the Los Angeles classification: a reassessment. Arch Iran Med. 2007 Jan;10(1):48-53.
Background: PubMed 40419956Dong P, Lin L, Sun K, Tang F, Li Q, Zhou X, Liu F, Yang Z, Li J, Jiang L, Zhao P, Sun X, Wang Q. Accuracy of the diagnosis of gastroesophageal reflux disease by a trial of potassium-competitive acid blocker treatment. BMC Gastroenterol. 2025 May 26;25(1):406. doi: 10.1186/s12876-025-03981-1.
Background: PubMed 24750261Dickman R, Maradey-Romero C, Fass R. The role of pain modulators in esophageal disorders - no pain no gain. Neurogastroenterol Motil. 2014 May;26(5):603-10. doi: 10.1111/nmo.12339.
Background: PubMed 40471840Shah ED, Gyawali CP, Chan WW. Optimizing the Cost-Effective Evaluation of Gastroesophageal Reflux by Typical Symptom Phenotypes After Failure of Empiric Acid Suppression Trial. Am J Gastroenterol. 2026 Mar 1;121(3):635-648. doi: 10.14309/ajg.0000000000003576. Epub 2025 Jun 5.
Background: PubMed 27287852Otake K, Sakurai Y, Nishida H, Fukui H, Tagawa Y, Yamasaki H, Karashima M, Otsuka K, Inatomi N. Characteristics of the Novel Potassium-Competitive Acid Blocker Vonoprazan Fumarate (TAK-438). Adv Ther. 2016 Jul;33(7):1140-57. doi: 10.1007/s12325-016-0345-2. Epub 2016 Jun 10.
Background: PubMed 29739175Oshima T, Miwa H. Potent Potassium-competitive Acid Blockers: A New Era for the Treatment of Acid-related Diseases. J Neurogastroenterol Motil. 2018 Jul 30;24(3):334-344. doi: 10.5056/jnm18029.
Background: PubMed 30595950Rawla P, Sunkara T, Ofosu A, Gaduputi V. Potassium-competitive acid blockers - are they the next generation of proton pump inhibitors? World J Gastrointest Pharmacol Ther. 2018 Dec 13;9(7):63-68. doi: 10.4292/wjgpt.v9.i7.63.
Background: PubMed 15068979Numans ME, Lau J, de Wit NJ, Bonis PA. Short-term treatment with proton-pump inhibitors as a test for gastroesophageal reflux disease: a meta-analysis of diagnostic test characteristics. Ann Intern Med. 2004 Apr 6;140(7):518-27. doi: 10.7326/0003-4819-140-7-200404060-00011.
Background: PubMed 16167971Dickman R, Emmons S, Cui H, Sewell J, Hernandez D, Esquivel RF, Fass R. The effect of a therapeutic trial of high-dose rabeprazole on symptom response of patients with non-cardiac chest pain: a randomized, double-blind, placebo-controlled, crossover trial. Aliment Pharmacol Ther. 2005 Sep 15;22(6):547-55. doi: 10.1111/j.1365-2036.2005.02620.x.
Background: PubMed 15142202Bautista J, Fullerton H, Briseno M, Cui H, Fass R. The effect of an empirical trial of high-dose lansoprazole on symptom response of patients with non-cardiac chest pain--a randomized, double-blind, placebo-controlled, crossover trial. Aliment Pharmacol Ther. 2004 May 15;19(10):1123-30. doi: 10.1111/j.1365-2036.2004.01941.x.
Background: PubMed 12562449Xia HH, Lai KC, Lam SK, Hu WH, Wong NY, Hui WM, Lau CP, Chen WH, Chan CK, Wong WM, Wong BC. Symptomatic response to lansoprazole predicts abnormal acid reflux in endoscopy-negative patients with non-cardiac chest pain. Aliment Pharmacol Ther. 2003 Feb;17(3):369-77. doi: 10.1046/j.1365-2036.2003.01436.x.
Background: PubMed 12352293Pandak WM, Arezo S, Everett S, Jesse R, DeCosta G, Crofts T, Gennings C, Siuta M, Zfass A. Short course of omeprazole: a better first diagnostic approach to noncardiac chest pain than endoscopy, manometry, or 24-hour esophageal pH monitoring. J Clin Gastroenterol. 2002 Oct;35(4):307-14. doi: 10.1097/00004836-200210000-00006.
Individual participant dataSharing planned: No. To protect participant confidentiality and comply with institutional and regulatory requirements, no IPD will be shared unless with reasonable request.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.

Monthira Maneerattanaporn, MD principal investigator

Mahidol University

Somchai Leelakusolvong, MD study chair

Mahidol University

Tanawat Geeratragool, MD study chair

Mahidol University

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study testing PCAB-test guided in people with GERD, Acid Reflux, Treatment, run by Mahidol University at 1 site in Thailand.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: enrolling by invitation, as of the sponsor's last update on 16 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Thailand. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Proportion of Participants with Clinical Response to Treatment (time frame: 4 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07707011, which also lists 35 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jul 2026.