A Study to Learn About the Tastes of Different Suspensions With the Study Medicine (PF-07923568) in Healthy Adult Participants.

A RANDOMIZED, PHASE 1, SINGLE-BLIND, MULTI-PERIOD STUDY TO INVESTIGATE THE PALATABILITY OF PF-07923568 ORAL SUSPENSION IN DIFFERENT LIQUID VEHICLES IN HEALTHY ADULT PARTICIPANTS

The purpose of this study is to learn about the tastes of different suspensions with the study medicine called PF-07923568 in healthy adult participants. In a suspension, the medicine is mixed with a liquid, usually water, in which it cannot dissolve and therefore remains intact in the form of small particles.

This study is seeking for healthy participants who:

• are aged 18 years of age or older.
• can produce a baby must agree to use a highly effective method of birth control.
• are confirmed to be healthy by some medical tests. This study can include both men and women.
• have body mass index (BMI) of 16 to 32 kg/m2 and a total body weight of more than 45 kilograms.

Participants will take sisunatovir prepared in 5 different suspensions and bitrex over two days to see if they are good to taste. Participants will answer a questionnaire after tasting each suspension. The questionnaire will be completed for each suspension. The questionnaire asks participants to test each suspension at 4 different times after tasting and spitting out the suspension. At least 60 minutes will pass between tasting each suspension.

The total planned time period of participation is around 5 to 8 weeks. This includes the screening period of up to 28 days. Followed by first administration of study medicine. Then a 3 day in-patient stay at the study clinic. It also includes a follow-up phone call that happens 28-35 days after the final taste test.

Inclusion Criteria:

• Male and female participants aged 18 years or older (or the minimum age of consent in accordance with local regulations) at screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, blood pressure, pulse rate and standard 12-lead electrocardiogram (ECG).
• Body mass index (BMI) of 16-32 kg/m2; and a total body weight >45 kg

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine,pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).
• Any medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality or other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Conditions that affect ability to taste eg, dysgeusia, respiratory infection, cold, etc.
• History of hypersensitivity to the active compounds or to any inactive ingredients (excipients) contained in the formulations.
• Previous administration with an investigational product (drug or vaccine) within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer). Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.
• A positive urine drug test at screening or admission.
• A positive serum pregnancy test at screening and/or positive urine/serum pregnancy test in woman/women of childbearing potential (WOCBP) at Day -1
• Use of tobacco/nicotine containing products
• Screening supine blood pressure (BP) ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic) for participants <60 years; and ≥150/90 mm Hg for participants ≥60 years old, following at least 5 minutes of supine rest.
• Renal impairment as defined by an estimated glomerular filtration rate (eGFR) (units of mL/min/1.73m²) <60 mL/min(/1.73m²) based on 2021 chronic kidney disease epidemiology (CKD-EPI).
• Standard 12-lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results
• Alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin (Bili) ≥ 1.05 × upper limit of normal (ULN). Participants with an elevated total bilirubin consistent with Gilbert's Disease should have a direct bilirubin measured and would be eligible for this study provided the direct bilirubin level is ≤ ULN.