This is a drug-drug interaction study to assess the effects of a single dose of PF-07321332/ritonavir after multiple dose administrations of carbamazepine. Pharmacokinetic (PK) will be evaluated for PF-07321332 and ritonavir. Carbamazepine is being utilized as a cytochrome P450 3A4 (CYP3A4) inducer.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
12
PF-07321332/ritonavir administered orally as a single dose on Day 1, Period 1
In Period 2, Days 1-3, participants will receive low-dose of carbamazepine twice daily (BID), then a titrated mid-dose of carbamazepine BID on Days 4-7, and finally maintaining carbamazepine at the high-dose on Days 8-15.
In Period 2, Day 14, participants will receive a single dose of PF-07321332/ritonavir orally.
Pfizer New Haven Clinical Research Unit
New Haven, Connecticut, United States
Maximum Observed Plasma Concentration (Cmax) of PF-07321332
Cmax was defined as maximum observed plasma concentration and can be observed directly from data.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Area Under the Curve From Time Zero to Extrapolated Infinite Time (AUCinf) of PF-07321332
AUCinf was defined as area under the concentration-time curve from time 0 to infinity and was calculated as AUClast + (Clast\*/kel), where Clast\* is the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Cmax of Ritonavir
Cmax was defined as maximum observed plasma concentration and can be observed directly from data.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
AUCinf of Ritonavir
AUCinf was defined as area under the concentration-time curve from time 0 to infinity and was calculated as AUClast + (Clast\*/kel), where Clast\* is the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
An Adverse event (AE) was any untoward medical occurrence in a participant. A serious AE was any untoward medical occurrence at any dose that resulted in death; was life-threatening; required hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity, congenital anomaly/birth. An AE was considered treatment-emergent AE (TEAE) if the event occurred during the on-treatment period. A treatment-related AE was any untoward medical occurrence attributed to the study drug in a participant who received study drug. A treatment-related SAE was a treatment-related AE and was defined as any untoward medical occurrence at any dose that: was fatal or life-threatening; resulted in persistent or significant disability/incapacity; constituted a congenital anomaly/birth defect; was medically significant; required inpatient hospitalization or prolongation of existing hospitalization. Relatedness to study drug was assessed by the investigator.
Time frame: Screening up to Day 3 in Period 1; Day 1 up to 35 days from administration of the final dose of study intervention or early termination/discontinuation in Period 2 (maximum of approximately 12 weeks)
Number of Participants With Laboratory Abnormalities
Safety laboratory assessments included hematology, urinalysis, and clinical chemistry. All the safety laboratory samples were collected following at least a 4 hour fast.
Time frame: Screening, Day -1 prior to dosing, and Day 2 in Period 1; Days 3, 6, 9, 12, 16 or early termination/discontinuation in Period 2
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Vital signs including single supine blood pressure and pulse rate were performed following at least a 5 minute rest in a supine position. Blood pressure (BP) and pulse rate (PR) assessments were performed after collection of electrocardiograms (ECGs) and prior to collection of blood draws if planned together. Respiratory rate (RR) was also evaluated.
Time frame: Screening and Day 1 pre-dose, and at 1.5, 8, and 24 hours post dose in Period 1; Days 2, 3, 4, 6, 8, 10, 12, Day 14 pre-dose, and at 1.5, 8, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Number of Participants With Clinically Significant Change in Electrocardiogram (ECG) Findings
All ECG assessments (triplicate) were made after at least a 10 minute rest in a supine position and prior to any blood draws or vital sign measurements.
Time frame: Screening and Day 1 pre-dose, and at 1.5, 8, and 24 hours post dose in Period 1; Days 2, 3, 4, Day 14 pre-dose, and at 1.5, 8, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Time to Reach Maximum Observed Plasma Concentration (Tmax) of PF-07321332
Tmax was defined as time to reach maximum observed plasma concentration and can be observed directly from data as time of first occurrence.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Area Under the Curve From Time Zero to Last Quantifiable Concentration (AUClast) of PF-07321332
AUClast was defined as area under the plasma concentration-time profile from time 0 to the time of last observed quantifiable plasma concentration (Clast) and was determined by Linear/Log trapezoidal method.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Apparent Oral Clearance (CL/F) of PF-07321332
CL/F was defined as apparent clearance. Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Clearance obtained after oral dose (apparent oral clearance) is a quantitative measure of the rate at which a drug substance is removed from the blood. CL/F is calculated as dose/AUCinf. AUCinf = area under the plasma concentration versus time curve from time zero extrapolated to infinite time.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Apparent Volume of Distribution (Vz/F) of PF-07321332
Vz/F was defined as apparent volume of distribution. Vz/F is calculated as Dose/(AUCinf \* kel), where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Terminal Half-Life ( t1/2) of PF-07321332
t1/2 was defined as the time measured for the plasma concentration of drug to decrease by one half. t1/2 is calculated as Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve. Only those data points judged to describe the terminal log-linear decline was used in the regression.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Tmax of Ritonavir
Tmax was defined as time to reach maximum observed plasma concentration and can be observed directly from data as time of first occurrence.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
AUClast of Ritonavir
AUClast was defined as area under the plasma concentration-time profile from time 0 to the time of Clast and was determined by Linear/Log trapezoidal method.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
CL/F of Ritonavir
CL/F was defined as apparent clearance. Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Clearance obtained after oral dose (apparent oral clearance) is a quantitative measure of the rate at which a drug substance is removed from the blood. CL/F is calculated as dose/AUCinf. AUCinf = area under the plasma concentration versus time curve from time zero extrapolated to infinite time.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
Vz/F of Ritonavir
Vz/F was defined as apparent volume of distribution. Vz/F is calculated as Dose/(AUCinf \* kel), where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2
t1/2 of Ritonavir
t1/2 was defined as the time measured for the plasma concentration of drug to decrease by one half. t1/2 is calculated as Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve. Only those data points judged to describe the terminal log-linear decline was used in the regression.
Time frame: Day 1 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post dose in Period 1; Day 14 pre-dose, and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 16, 24, and 48 hours post-dose or early termination/discontinuation in Period 2