Relative Bioavailability Study of Nirmatrelvir/Ritonavir Oral Powder Relative to the Commercial Tablets and Estimation of the Effect of Food on Bioavailability of the Nirmatrelvir/Ritonavir Oral Powder in Healthy Participants.

A PHASE 1, OPEN-LABEL, RANDOMIZED, SINGLE DOSE, CROSSOVER STUDY TO ESTIMATE THE RELATIVE BIOAVAILABILITY OF NIRMATRELVIR (PF-07321332) /RITONAVIR ORAL POWDER IN 3 DIFFERENT FOOD DELIVERY VEHICLES RELATIVE TO THE NIRMATRELVIR (PF-07321332) /RITONAVIR COMMERCIAL TABLETS UNDER FASTED CONDITIONS, AND THE EFFECT OF FOOD ON RELATIVE BIOAVAILABILITY OF NIRMATRELVIR (PF-07321332) /RITONAVIR ORAL POWDER IN HEALTHY ADULT PARTICIPANTS

The purpose of this study is to estimate the relative bioavailability (rBA) of nirmatrelvir/ritonavir oral powder in 3 different food vehicles relative to the Paxlovid® tablets under fasted condition in healthy adult participants, and to estimate the effect of food on the rBA of the nirmatrelvir/ritonavir oral powder formulation. The study will also assess the safety, tolerability, and palatability of nirmatrelvir/ritonavir oral powder in healthy adult participants.

Inclusion Criteria:

• Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination (PE), laboratory tests, vital signs and standard 12 lead ECGs.
• Body mass index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight >50 kg (110 lb).
• Participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures

Exclusion Criteria:

• Positive test result for SARS-CoV-2 infection at the time of Screening or Day -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).
• Clinically relevant abnormalities requiring treatment (eg, acute myocardial infarction, unstable ischemic conditions, evidence of ventricular dysfunction, serious tachy or brady arrhythmias) or indicating serious underlying heart disease (eg, prolonged PR interval, cardiomyopathy, heart failure greater than New York Heart Association (NYHA) 1, underlying structural heart disease, Wolff Parkinson-White syndrome).
• Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy).
• History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B surface antigen (HBsAg), or hepatitis B surface antibody (HCVAb). Hepatitis B vaccination is allowed.
• Use of prescription or nonprescription drugs and dietary and herbal supplements within 7 days or 5 half lives (whichever is longer) prior to the first dose of study intervention.
• Participant who have received a COVID-19 vaccine within 7 days before screening or admission, or who are to be vaccinated with a COVID-19 vaccine at any time during the study confinement period.
• A positive urine drug test.