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A Study to Evaluate the Efficacy and Safety of Vonoprazan Compared to Placebo in Participants With Symptomatic Non-Erosive Gastroesophageal Reflux Disease

A Phase 2, Randomized, Double-Blind, Multicenter Study to Evaluate the Efficacy and Safety of Vonoprazan 10 mg, 20 mg, and 40 mg Compared to Placebo for Relief of Episodic Heartburn in Subjects With Symptomatic Non-Erosive Gastroesophageal Reflux Disease

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04799158
Enrollment
458
Registered
2021-03-16
Start date
2021-03-25
Completion date
2022-01-17
Last updated
2023-01-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heartburn, Non-Erosive Gastro-Esophageal Reflux Disease

Keywords

Symptomatic Non-Erosive Gastroesophageal Reflux Disease, NERD, Vonoprazan, Heartburn

Brief summary

The primary objectives of this study are to assess the efficacy of vonoprazan (10 mg, 20 mg, and 40 mg On-Demand) compared to placebo (On-Demand) in relief of episodic heartburn over 6 weeks in participants with symptomatic non-erosive gastroesophageal reflux disease (NERD), and to assess the safety of vonoprazan (10 mg, 20 mg, and 40 mg On-Demand) compared to placebo (On-Demand) in participants with symptomatic NERD.

Interventions

DRUGVonoprazan

Orally via capsules

DRUGPlacebo

Orally via capsules

Sponsors

Phathom Pharmaceuticals, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Masking description

During the Run-In Period, participants will receive open-label vonoprazan.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

for Run-In Period 1. The participant is ≥18 years of age at the time of informed consent signing. 2. In the opinion of the investigator or sub investigators, the participant is capable of understanding and complying with protocol requirements. 3. 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 is informed of the full nature and purpose of the study, including possible risks and side effects. The participant has the ability to cooperate with the investigator. Ample time and opportunity should be given to read and understand verbal and/or written instructions. 4. The participant identified their main symptom as heartburn, a burning sensation in the retrosternal area (behind the breastbone). 5. History of episodes of heartburn for 6 months or longer prior to screening. 6. Heartburn reported on 4 or more days during any 7 consecutive days in the Screening Period as recorded in the electronic diary. 7. 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. Inclusion Criteria for On-Demand Treatment Period 1. The participant completes the Run-In Period, during which the participant was at least 80% compliant with open-label study drug. 2. The participant has stable disease, ie, no heartburn the last 7 days of the Run-In Period. 3. The participant continues to fulfill all eligibility criteria for the Run-In Period (except Inclusion Criteria 4). 4. Participant completes at least 80% of diary entries during Run-In Period, including 80% of diary entries over the last 7 days.

Exclusion criteria

for Run-In Period 1. Endoscopically confirmed erosive esophagitis (EE) during the Screening Period assessed by the investigator. Endoscopy should be performed after participants meet Inclusion Criteria 6. Any endoscopic confirmation performed in a routine clinical setting within 7 days before signing the informed consent is acceptable to use for the purpose of fulfilling the screening requirement. 2. The participant has active irritable bowel syndrome (IBS) or had a flare of IBS requiring therapy within the prior 6 months. 3. The participant has a history of or is suspected of having functional heartburn diagnosed by the Rome IV criteria. 4. The participant has a history of or is suspected of having functional dyspepsia diagnosed by the Rome IV criteria. 5. The participant has endoscopic Barrett's esophagus (\>1 cm of columnar-lined esophagus) and/or definite dysplastic changes in the esophagus. 6. The participant has any other clinically significant condition affecting the esophagus, including eosinophilic esophagitis; esophageal varices; viral or fungal infection; esophageal stricture; a history of radiation therapy, radiofrequency ablation, endoscopic mucosal resection, or cryotherapy to the esophagus; or any history of caustic or physiochemical trauma (including sclerotherapy or esophageal variceal band ligation). However, participants diagnosed with Schatzki's ring (mucosal tissue ring around lower esophageal sphincter) or hiatal hernia are eligible to participate. 7. The participant has scleroderma (systemic sclerosis). 8. The participant has a history of surgery or endoscopic treatment affecting gastroesophageal reflux, including fundoplication and dilation for esophageal stricture (except Schatzki's ring) or a history of gastric or duodenal surgery (except endoscopic removal of benign polyps). 9. The participant has an active gastric or duodenal ulcer within 4 weeks before the first dose of study drug. 10. Use of prescription or non-prescription proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) throughout the study. 11. The participant has received vonoprazan in a clinical trial at any time or any other investigational compound (including those in post-marketing studies) within 30 days prior to the start of the Screening Period. A participant who has been screen failed from another clinical study and who has not been dosed may be considered for enrollment in this study. 12. The participant is a study site employee, an immediate family member, or is in a dependent relationship with a study site employee who is involved in the conduct of this study (eg, spouse, parent, child, sibling) or who may have consented under duress. 13. The participant has cutaneous lupus erythematosus or systemic lupus erythematosus. 14. The participant has had clinically significant upper or lower gastrointestinal bleeding within 4 weeks prior to screening. 15. The participant has Zollinger-Ellison syndrome or other gastric acid hypersecretory conditions. 16. The participant has a history of hypersensitivity or allergies to vonoprazan (including the formulation excipients: D-mannitol, microcrystalline cellulose, hydroxypropyl cellulose, fumaric acid, croscarmellose sodium, magnesium stearate, hypromellose, macrogol 8000, titanium oxide, or red or yellow ferric oxide). Skin testing may be performed according to local standard practice to confirm hypersensitivity. 17. The participant has a history of alcohol abuse, illegal drug use, drug addiction, or regularly consumes \>21 units of alcohol (1 unit = 12 oz/300 mL beer, 1.5 oz/25 mL hard liquor/spirits, or 5 oz/100 mL wine) per week based on self-report within the 12 months prior to screening. Participants must have a negative urine drug screen for cannabinoids/ tetrahydrocannabinol and nonprescribed medications at screening. Participants taking prescription drugs (except prescription cannabinoids/tetrahydrocannabinol) will be allowed. 18. The participant is taking any excluded medications or treatments listed in the protocol. 19. If female, the participant is pregnant, lactating, or intending to become pregnant before, during, or within 4 weeks after participating in this study, or intending to donate ova during such time period. 20. The participant has a history or clinical manifestations of significant central nervous system, cardiovascular, pulmonary, hepatic, renal, metabolic, other gastrointestinal, urological, endocrine, or hematological disease that, in the opinion of the investigator, would confound the study results or compromise participant safety. 21. The participant requires hospitalization or has surgery scheduled during the course of the study or has undergone major surgical procedures within 30 days prior to the Screening Visit. 22. The participant has a history of malignancy or has been treated for malignancy within 5 years prior to the start of the Screening Period (Visit 1). (The participant may be included in the study if he/she has recovered from cutaneous basal cell carcinoma or cervical carcinoma in situ). 23. The participant has acquired immune deficiency syndrome (AIDS) or human immunodeficiency virus (HIV) infection, or tests positive for the hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody, or HCV ribonucleic acid (HCV-RNA). However, participants who test positive for HCV antibody but negative for HCV-RNA are permitted to participate. 24. The participant has any of the following abnormal laboratory test values at the start of the Screening Period: 1. Creatinine levels: \>2 mg/dL (\>177 μmol/L) 2. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \>2 × the upper limit of normal (ULN) or total bilirubin \>2 × ULN (except participants with Gilbert Syndrome)

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study DrugOn-Demand Treatment Period: Day 1 to Day 42An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.

Secondary

MeasureTime frameDescription
Percentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study DrugOn-Demand Treatment Period: Day 1 to Day 42An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.
Mean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment PeriodOn-Demand Treatment Period: Day 1 to Day 42
Percentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study DrugOn-Demand Treatment Period: Day 1 to Day 42An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug.
Percentage of Days Study Drug Was Taken Over the On-Demand Treatment PeriodOn-Demand Treatment Period: Day 1 to Day 42
Percentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment PeriodOn-Demand Treatment Period: Day 1 to Day 42A 24-hour heartburn-free day was defined as a day having no heartburn among all diary entries for that day. The percentage of 24-hour heartburn-free days was calculated using all days with at least 1 evening or morning diary entry during the treatment period of this phase.
Percentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study DrugOn-Demand Treatment Period: Day 1 to Day 42An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.

Countries

United States

Participant flow

Recruitment details

This study was performed at 54 sites in the United States between 25 March 2021 and 17 January 2022. Of the 1115 participants screened for the study, 458 participants were enrolled into the Run-In Period. Of these participants, 207 participants were randomized to receive study drug in the On-Demand treatment period.

Pre-assignment details

Eligible participants who had symptomatic NERD were initially dosed during an open-label Run-In Period with vonoprazan 20 mg once per day (QD) for 4 weeks. Participants with stable disease (defined by those who had no heartburn on the last 7 consecutive days of the Run-In Period) and were compliant with the electronic diary and study drug were randomized using a 1:1:1:1 allocation ratio to receive either vonoprazan 10 mg, 20 mg, or 40 mg or placebo during the 6-week On-Demand Treatment Period.

Participants by arm

ArmCount
Vonoprazan 10 mg: On-Demand Treatment Period
Participants who had stable disease (no heartburn on the last 7 days of the Run-In Period) received oral vonoprazan 10 mg when heartburn occurred during the 6 week On-Demand Treatment Period. Participants could take no more than one dose in a 24-hour period.
49
Vonoprazan 20 mg: On-Demand Treatment Period
Participants who had stable disease (no heartburn on the last 7 days of the Run-In Period) received oral vonoprazan 20 mg when heartburn occurred during the 6 week On-Demand Treatment Period. Participants could take no more than one dose in a 24-hour period.
49
Vonoprazan 40 mg: On-Demand Treatment Period
Participants who had stable disease (no heartburn on the last 7 days of the Run-In Period) received oral vonoprazan 40 mg when heartburn occurred during the 6 week On-Demand Treatment Period. Participants could take no more than one dose in a 24-hour period.
48
Placebo: On-Demand Treatment Period
Participants who had stable disease (no heartburn on the last 7 days of the Run-In Period) received oral placebo when heartburn occured during the 6 week On-Demand Treatment Period. Participants could take no more than one dose in a 24-hour period.
47
Total193

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004
On-Demand Treatment PeriodAdverse Event01001
On-Demand Treatment PeriodLack of Efficacy00001
On-Demand Treatment PeriodLost to Follow-up00001
On-Demand Treatment PeriodMiscellaneous00001
On-Demand Treatment PeriodSignificant Protocol Deviation00010
On-Demand Treatment PeriodWithdrawal by Subject00010
Run-In PeriodAdverse Event60000
Run-In PeriodDid not meet On-Demand Eligibility Criteria2260000
Run-In PeriodLost to Follow-up40000
Run-In PeriodMiscellaneous30000
Run-In PeriodSignificant Protocol Deviation10000
Run-In PeriodWithdrawal by Subject110000

Baseline characteristics

CharacteristicVonoprazan 10 mg: On-Demand Treatment PeriodVonoprazan 40 mg: On-Demand Treatment PeriodVonoprazan 20 mg: On-Demand Treatment PeriodPlacebo: On-Demand Treatment PeriodTotal
Age, Continuous54.1 years
STANDARD_DEVIATION 11.89
52.0 years
STANDARD_DEVIATION 14.6
55.7 years
STANDARD_DEVIATION 12.87
52.7 years
STANDARD_DEVIATION 15.2
53.7 years
STANDARD_DEVIATION 13.65
Ethnicity (NIH/OMB)
Hispanic or Latino
16 Participants15 Participants17 Participants12 Participants60 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
33 Participants33 Participants32 Participants35 Participants133 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants
Race/Ethnicity, Customized
American Indian or Alaska Native
0 Participants0 Participants1 Participants0 Participants1 Participants
Race/Ethnicity, Customized
Asian
8 Participants3 Participants6 Participants7 Participants24 Participants
Race/Ethnicity, Customized
Black or African-American
7 Participants6 Participants5 Participants10 Participants28 Participants
Race/Ethnicity, Customized
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants0 Participants
Race/Ethnicity, Customized
Not reported
1 Participants0 Participants1 Participants1 Participants3 Participants
Race/Ethnicity, Customized
Other
0 Participants0 Participants0 Participants0 Participants0 Participants
Race/Ethnicity, Customized
Unknown
1 Participants0 Participants0 Participants0 Participants1 Participants
Race/Ethnicity, Customized
White
32 Participants39 Participants36 Participants29 Participants136 Participants
Sex: Female, Male
Female
27 Participants25 Participants33 Participants33 Participants118 Participants
Sex: Female, Male
Male
22 Participants23 Participants16 Participants14 Participants75 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
0 / 4570 / 490 / 490 / 480 / 47
other
Total, other adverse events
29 / 4578 / 499 / 498 / 4810 / 47
serious
Total, serious adverse events
4 / 4570 / 490 / 490 / 480 / 47

Outcome results

Primary

Percentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug

An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: Intent-to-Treat (ITT) On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period.

ArmMeasureValue (NUMBER)
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug56.0 percentage of heartburn episodes
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug60.6 percentage of heartburn episodes
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug70.0 percentage of heartburn episodes
Placebo: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug27.3 percentage of heartburn episodes
p-value: <0.000195% CI: [21.84, 35.55]Fisher Exact
p-value: <0.000195% CI: [26.28, 40.23]Fisher Exact
p-value: <0.000195% CI: [35.92, 49.42]Fisher Exact
Secondary

Mean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment Period

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period.

ArmMeasureValue (MEAN)Dispersion
Vonoprazan 10 mg: On-Demand Treatment PeriodMean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment Period0.1 tablets of rescue antacid per dayStandard Deviation 0.21
Vonoprazan 20 mg: On-Demand Treatment PeriodMean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment Period0.2 tablets of rescue antacid per dayStandard Deviation 0.29
Vonoprazan 40 mg: On-Demand Treatment PeriodMean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment Period0.1 tablets of rescue antacid per dayStandard Deviation 0.26
Placebo: On-Demand Treatment PeriodMean Number of Tablets of Rescue Antacid Taken Per Day Over the On-Demand Treatment Period0.5 tablets of rescue antacid per dayStandard Deviation 0.87
p-value: 0.3395Wilcoxon rank-sum test
p-value: 0.4882Wilcoxon rank-sum test
p-value: 0.0722Wilcoxon rank-sum test
Secondary

Percentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment Period

A 24-hour heartburn-free day was defined as a day having no heartburn among all diary entries for that day. The percentage of 24-hour heartburn-free days was calculated using all days with at least 1 evening or morning diary entry during the treatment period of this phase.

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period.

ArmMeasureValue (MEAN)Dispersion
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment Period74.95 percentage of daysStandard Deviation 21.41
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment Period73.57 percentage of daysStandard Deviation 21.465
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment Period74.01 percentage of daysStandard Deviation 22.277
Placebo: On-Demand Treatment PeriodPercentage of 24-Hour Heartburn-Free Days Over the On-Demand Treatment Period71.22 percentage of daysStandard Deviation 28.867
p-value: 0.9896Wilcoxon rank-sum test
p-value: 0.6916Wilcoxon rank-sum test
p-value: 0.9316Wilcoxon rank-sum test
Secondary

Percentage of Days Study Drug Was Taken Over the On-Demand Treatment Period

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period.

ArmMeasureValue (MEAN)Dispersion
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of Days Study Drug Was Taken Over the On-Demand Treatment Period21.93 percentage of daysStandard Deviation 19.241
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of Days Study Drug Was Taken Over the On-Demand Treatment Period20.75 percentage of daysStandard Deviation 16.95
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of Days Study Drug Was Taken Over the On-Demand Treatment Period21.01 percentage of daysStandard Deviation 17.302
Placebo: On-Demand Treatment PeriodPercentage of Days Study Drug Was Taken Over the On-Demand Treatment Period22.15 percentage of daysStandard Deviation 23.266
p-value: 0.4684Wilcoxon rank-sum test
p-value: 0.656Wilcoxon rank-sum test
p-value: 0.6324Wilcoxon rank-sum test
Secondary

Percentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study Drug

An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug.

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period.

ArmMeasureValue (NUMBER)
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study Drug72.1 percentage of heartburn episodes
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study Drug65.7 percentage of heartburn episodes
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study Drug79.6 percentage of heartburn episodes
Placebo: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes Completely Relieved Within 3 Hours After Taking Study Drug41.9 percentage of heartburn episodes
p-value: <0.000195% CI: [23.41, 37.09]Fisher Exact
p-value: <0.000195% CI: [16.67, 31.05]Fisher Exact
p-value: <0.000195% CI: [31, 44.35]Fisher Exact
Secondary

Percentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug

An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period. Only participants with at least one evaluable heartburn episode during the On-Demand Treatment Period are included.

ArmMeasureValue (MEAN)Dispersion
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug60.08 % of heartburn episodes per participantStandard Deviation 38.452
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug60.78 % of heartburn episodes per participantStandard Deviation 37.458
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug71.99 % of heartburn episodes per participantStandard Deviation 28.894
Placebo: On-Demand Treatment PeriodPercentage of Evaluable Heartburn Episodes for Each Participant That Are Completely Relieved Within 3 Hours and With No Further Heartburn Reported for 24 Hours After Taking Study Drug47.77 % of heartburn episodes per participantStandard Deviation 40.998
p-value: 0.1771Wilcoxon rank-sum test
p-value: 0.1551Wilcoxon rank-sum test
p-value: 0.0094Wilcoxon rank-sum test
Secondary

Percentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study Drug

An evaluable heartburn episode was an episode for which study drug was taken and for which the participant completed at least one entry in the heartburn episode diary. For a heartburn episode to be considered completely relieved, a participant must not have taken rescue antacid within 3 hours of taking study drug. For sustained relief, complete relief must have been accompanied by 24 hours without another heartburn episode after taking study drug.

Time frame: On-Demand Treatment Period: Day 1 to Day 42

Population: ITT On-Demand Set: includes all participants in the Safety Run-In set who were randomized and completed at least one heartburn episode diary during the On-Demand Treatment Period. Only participants with at least one evaluable heartburn episode during the On-Demand Treatment Period are included.

ArmMeasureValue (NUMBER)
Vonoprazan 10 mg: On-Demand Treatment PeriodPercentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study Drug56.5 percentage of participants
Vonoprazan 20 mg: On-Demand Treatment PeriodPercentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study Drug61.9 percentage of participants
Vonoprazan 40 mg: On-Demand Treatment PeriodPercentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study Drug62.8 percentage of participants
Placebo: On-Demand Treatment PeriodPercentage of Participants With Complete Relief of Heartburn Within 3 Hours After the First Episode and With No Further Heartburn Reported for 24 Hours After Taking Study Drug60.5 percentage of participants
p-value: 0.8395% CI: [-24.41, 16.52]Fisher Exact
p-value: >0.999995% CI: [-19.28, 22.16]Fisher Exact
p-value: >0.999995% CI: [-18.22, 22.88]Fisher Exact

Source: ClinicalTrials.gov · Data processed: Feb 11, 2026