A Study to Evaluate Vonoprazan in Children Who Have Symptomatic Gastroesophageal Reflux Disease

Inclusion criteria

• The participant has a body weight within the 5th through 95th percentile by age, inclusive, as determined by the National Center for Health Statistics.
• The participant must have a diagnosis of GERD prior to randomization and medical history of signs or symptoms of GERD for at least 3 months prior to screening, based on physical examination, current symptoms (eg, heartburn), or diagnostic tests (eg, pH or endoscopy). Notes in the medical records and/or other source documents, such as prior endoscopies, can be used to support the diagnosis and will be recorded in the electronic case report form (eCRF).
• The participant has at least one moderate GERD symptom based on the GERD Symptom Assessment Investigator scale performed at screening.
• The participant must be able to swallow study drug tablet with water.
• Parent or legal guardian (ie, legally authorized representative [LAR]) is willing and able to complete the informed consent process and participants are able to comply with study procedures and visit schedule.
• Female participants who have experienced menarche must have a negative pregnancy test and will be counseled on pregnancy avoidance.

Exclusion criteria

• The participant has used prescription or non-prescription proton pump inhibitors (PPIs) or histamine-2 receptor antagonist (H2RAs) within 7 days prior to randomization or requires use during the Treatment Period.
• The participant has used sucralfate, or antacids within 1 day prior to randomization or requires their use during the Treatment Period.
• The participant has received other agents affecting digestive organs, including muscarinic antagonists (eg, hyoscyamine), prokinetics, oral anticholinergic agents, prostaglandins, bismuth from 30 days prior to Day 1 or requires their use during the course of the study.
• The participant has received atazanavir sulfate or rilpivirine hydrochloride from 5 days prior to Day 1 or requires their use during the course of the study.
• The participant has received any investigational compound (including vonoprazan) within 30 days prior to the start of the Screening Period.
• The participant is 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, child, sibling) or participant may have consented under duress.
• 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 Period.
• The participant has undergone prior gastrointestinal surgeries.
• The participant has any abnormal laboratory test values that are considered clinically significant in the opinion of the investigator during the Screening Period.
• The participant has a history of hypersensitivity or allergies to vonoprazan (including the formulation excipients: D-mannitol, microcrystalline cellulose, hydroxypropylcellulose, fumaric acid, ascorbic acid, croscarmellose sodium, magnesium stearate, hypromellose, macrogol 8000, and titanium dioxide, or red or yellow ferric oxide).
• The participant has used any prescription or over-the-counter medications (including herbal or nutritional supplements), other than those already excluded in criteria 1 to 5 above, within 14 days before the first dose of study drug or throughout the study. That is, unless the medication(s) is permitted by the sponsor following a review of available data which confirms concomitant administration of the medication is unlikely to affect either the safety of the participant or the pharmacokinetics of vonoprazan.
• The participant has consumed grapefruit or grapefruit juice, Seville orange or Seville orange-containing products (eg, marmalade), or other food products that may be CYP3A4 inhibitors (eg, vegetables from the mustard green family [kale, broccoli, watercress, collard greens, kohlrabi, Brussels sprouts, mustard] and charbroiled meats) within 7 days (or 5 half-lives) before the first dose of study drug or throughout the study.
• The participant has positive results at screening for human immunodeficiency virus, hepatitis B virus, or hepatitis C virus (HCV).
• The participant has severe renal impairment (estimated glomerular filtration rate < 30 mL/min).
• The participant has moderate to severe hepatic impairment (Child-Pugh Class B and Child-Pugh Class C).
• The participant has any of the following abnormal laboratory test values at the start of the Screening Period:

• Creatinine levels: >0.8 mg/dL (>70 μmol/L).
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2 × the upper limit of normal (ULN) or total bilirubin >2 × ULN (except participants with Gilbert Syndrome).
• In the opinion of the investigator, the participant is not suitable for entry into the study.