A Study of How Ibuzatrelvir is Taken up Into the Blood of Healthy Adults After Taking Different Tablets of Ibuzatrelvir

Healthy adults will be enrolled into this open-label, Phase 1 research study. Participants will spend about 9 nights and 10 days in the clinical research unit (CRU) and the total time in the study will be about 11 weeks. The goal of this clinical trial is to compare how much of the study drug ibuzatrelvir is in participants' blood after taking one of the two different types of tablets containing the same amount of ibuzatrelvir without food. The study will also measure how much ibuzatrelvir is in participants' blood after taking one type of the tablets dispersed in water and when one type of the tablets is taken with food. This study drug is taken by mouth.

Inclusion criteria: 1. 18 years of age 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, and ECGs. 2. BMI of 16-32 kg/m2; and a total body weight \>45 kg. 3. Participants who are capable of giving signed informed consent and willing and able to comply with all scheduled visits, treatment plans, laboratory tests, lifestyle considerations, and other study procedures. Exclusion Criteria 1. 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 condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy). * History of HIV infection, hepatitis B, or hepatitis C; positive testing for HIV, HBsAg, or HCVAb. Hepatitis B vaccination is allowed. 2. Any medical or psychiatric condition including any active suicidal ideation in the past year or suicidal behavior in the past 5 years 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. 3. Use of prescription or nonprescription drugs and dietary and herbal supplements within 14 days or 5 half-lives (whichever is longer) prior to the first dose of study intervention with the exception of moderate or strong CYP3A inducers which are prohibited within 14 days plus 5 half-lives prior to the first dose of study intervention. 4. Previous administration of an investigational product (drug or vaccine) within 30 days or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer). 5. Participation in studies of other investigational products (drug or vaccine) at any time during participation in this study. 6. A positive urine drug test. A single repeat for positive drug screen may be allowed. 7. Screening supine BP ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic) for participants \1.5× ULN. 11. History of alcohol abuse or repeated binge drinking and/or any other illicit drug use or dependence within 6 months of screening. Binge drinking is defined as a pattern of 5 (male) and 4 (female) or more alcoholic drinks in about 2 hours. As a general rule, alcohol intake should not exceed 14 units per week (1 unit = 8 ounces (240 mL) beer, 1 ounce (30 mL) of 40% spirit, or 3 ounces (90 mL) of wine). 12. Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members. 13. Use of tobacco/nicotine containing products in excess of the equivalent of 5 cigarettes/day or 2 chews of tobacco/day. 14. History of sensitivity reactions to ibuzatrelvir or any of the formulation components of ibuzatrelvir.