• In the opinion of the investigator or sub-investigators, the subject is capable of understanding and complying with protocol requirements, including compliance with completing nightly online questionnaires in one of the IRB-approved languages.

• Subject signs and dates an electronic (Screening Phase Part 1) and site-specific written informed consent form (ICF) and any required privacy authorization prior to the initiation of any study procedures.

• Ability, during Remote Screening Phase 2-Week Assessment, to complete all required online nightly RESQ-eD questionnaires, medication questionnaires, 4-item Patient Health Questionnaire for Depression and Anxiety (PHQ-4) questionnaire and Participant Global Assessment questionnaire.

• Access to a computer/tablet/phone with internet access and active email account in order to complete online questionnaires daily throughout study participation.

• Males or females ≥18 and ≤75 years of age, with a BMI ≥ 18 and \< 35 kg/m2.

• Female subjects must be postmenopausal or surgically sterile or, if of childbearing potential, must agree to use a medically acceptable form of contraception from the time of signing the informed consent form through completion of study. If only the barrier method is used, a single barrier or better is adequate. Postmenopausal women must have had ≥ 12 months of spontaneous amenorrhea. Surgically sterile women are defined as those who have had a hysterectomy, bilateral ovariectomy, or bilateral tubal ligation. All women of childbearing potential must have a negative pregnancy test result before administration of study drug.

• Must be on stable doses of medications, if any, prescribed for chronic conditions other than GERD.

• Subject must be taking daily PPI (defined as 5-7 days/week on average) for at least four (4) consecutive weeks with self-reported symptom improvement (frequency and/or severity) prior to the Screening Call selected from the following list of medications:

• omeprazole

• esomeprazole

• lansoprazole

• dexlansoprazole

• pantoprazole

• rabeprazole

• Onset of GERD-related heartburn symptoms for a minimum of 3 months prior to Screening Call (i.e., burning feeling behind the breastbone and/or pain behind your breastbone and/or heartburn per questions 1, 2 or 3 of RESQ-eD).

• Subject has maintained a stable diet and exercise regimen for ≥ 30 days prior to the Screening Call and is willing to maintain that diet and exercise regimen for the duration of the study (i.e., if subject is currently following diets including, but not limited to, Keto, FODMAP, Vegan, Vegetarian, s/he must be willing to continue this dietary lifestyle through end-of-study visit).