Drug-Drug Interaction Study to Estimate the Effect of PF-07321332/Ritonavir and Ritonavir on Midazolam in Healthy Participants

COVID-19: A PHASE 1, OPEN-LABEL, 3-TREATMENT, 6-SEQUENCE, 3-PERIOD CROSSOVER STUDY TO ESTIMATE THE EFFECT OF PF-07321332/RITONAVIR AND RITONAVIR ON THE PHARMACOKINETICS OF MIDAZOLAM IN HEALTHY PARTICIPANTS.

The purpose of this study is to estimate the effect PF-07321332/Ritonavir and Ritonavir on Midazolam (a cytochrome P450 [CYP]3A4 substrate) in Healthy Adult Participants.

Study Overview

• Status: Completed
• Conditions: Healthy Participants
• Intervention / Treatment: Drug: Midazolam; Drug: PF-07321332/ritonavir + Midazolam; Drug: Ritonavir + Midazolam

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Phase 1

Contacts and Locations

Study Locations

• Belgium
  • Bruxelles-capitale, Région DE
    • Brussels, Bruxelles-capitale, Région DE, Belgium, B-1070
      • Brussels Clinical Research Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Female participants of childbearing potential must have a negative (urine or serum) pregnancy test.

2. Body mass index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight >50 kg (110 lb).

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Exclusion Criteria:

1. Positive test result for SARS-CoV-2 infection at the time of Screening or Day -1.
2. 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).
3. 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).
4. Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy).
5. History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, HBsAg, or hepatitis C virus (HCVAb). Hepatitis B vaccination is allowed.
6. Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality or other conditions or situations related to COVID-19 pandemic (eg, Contact with positive case, residence, or travel to an area with high incidence) that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Treatment A; Midazolam orally	Drug: Midazolam; Midazolam administered as a single dose on Day 1
Experimental: Treatment B; PF-07321332/ritonavir orally + Midazolam orally	Drug: PF-07321332/ritonavir + Midazolam; PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Active Comparator: Treatment C; Ritonavir orally + Midazolam orally	Drug: Ritonavir + Midazolam; Ritonavir: Administered orally every 12 hours for a total of 9 doses on Day1-5. Midazolam: Administered orally as a single dose on Day 5

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Plasma Concentration (Cmax) of Midazolam When Administered Alone and With PF-07321332/Ritonavir	Cmax for midazolam following single dose administration with and without PF-07321332/ritonavir was observed directly from data. Natural log-transformed Cmax for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
Area Under the Plasma Concentration-time Profile From Time 0 Extrapolated to Infinity Time (AUCinf) of Midazolam When Administered Alone and With PF-07321332/Ritonavir	AUCinf for midazolam following single dose administration with and without PF-07321332/ritonavir was calculated by AUClast + (Clast/kel), where Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis. Natural log-transformed AUCinf for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
Area Under the Plasma Concentration-time Profile From Time 0 to the Time of the Last Quantifiable Concentration (Clast) (AUClast) of Midazolam When Administered Alone and With PF-07321332/Ritonavir	AUClast for midazolam following single dose administration with and without PF-07321332/ritonavir was calculated by Linear/Log trapezoidal method. Natural log-transformed AUClast for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment-emergent Adverse Events (TEAEs)	An adverse event was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dosing day and time/ start time, if collected, but before the last dose plus the lag time (28 days) were flagged as TEAEs. The algorithm did consider any events that started prior to the first dose date. Any events occurring following start of treatment or increasing in severity were counted as treatment emergent. Events that occur in a non-treatment period (for example, Washout or Follow-up) were counted as treatment emergent and attributed to the previous treatment taken.	Baseline up to Day 28
Number of Participants With Laboratory Abnormalities	The haematological, clinical chemistry (serum) and urinalysis safety tests were assessed against the criteria specified in the sponsor reporting standards to determine if there were any clinically significant laboratory abnormalities. The assessment took into account whether each participant's baseline test result was within or outside the laboratory reference range for the particular laboratory parameter. Baseline was defined as the last planned predose measurement taken in each study period.	Baseline up to Day 28
Number of Participants With Vital Signs Abnormalities	Baseline was the last predose recording in each study period. Only post baseline values are included in this analysis	Baseline up to Day 28
Number of Participants With Electrocardiogram (ECG) Abnormalities	Baseline and changes from baseline in PR, QT, QRS, heart rate and QTcF were summarized by treatment and time postdose. Baseline was defined as the average of the triplicate predose recordings in each study period. ECG endpoints and changes from baseline (QTcF, PR, QRS), over all measurements taken postdose, were also summarized descriptively by treatment using categories as defined in the Criteria for Safety Values of Potential Clinical Concern appendix of the protocol and for QTc values corresponding to ICH E14 thresholds, which are: QTcF (msec): 450<value≤480; 480<value≤500; >500; QTcF (msec) increase from baseline: 30<change≤60; change>60	Baseline up to Day 28
Cmax of Midazolam When Administered Alone and With Ritonavir	Cmax for midazolam following single dose administration with and without ritonavir was observed directly form data. Natural log-transformed Cmax for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
AUCinf of Midazolam When Administered Alone and With Ritonavir	AUCinf for midazolam following single dose administration with and without ritonavir was calculated by AUClast + (Clast/kel), where Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis. Natural log-transformed AUCinf for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
AUClast of Midazolam When Administered Alone and With Ritonavir	AUClast for midazolam following single dose administration with and without ritonavir was calculated by Linear/Log trapezoidal method. Natural log-transformed AUClast for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam [test]/midazolam [reference] and 90% CIs) were expressed as percentages.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours post-dose
Apparent Clearance (CL/F) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir	CL/F for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Dose/AUCinf.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
Apparent Volume of Distribution (Vz/F) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir	Vz/F for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Dose/(AUCinf • kel).	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
Time for Cmax (Tmax) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir	Tmax for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by observed directly from data as time of first occurrence.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose
Terminal Half-life (t1/2) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir	t½ for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Loge(2)/kel, where kel was 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.	Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): September 17, 2021
• Primary Completion (Actual): December 9, 2021
• Study Completion (Actual): December 9, 2021

Study Registration Dates

• First Submitted: August 27, 2021
• First Submitted That Met QC Criteria: August 27, 2021
• First Posted (Actual): September 2, 2021

Study Record Updates

• Last Update Posted (Actual): October 4, 2023
• Last Update Submitted That Met QC Criteria: December 1, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Keywords: Midazolam; Drug-drug interaction; COVID-19 (Coronavirus disease 2019); SARS-CoV (severe acute respiratory syndrome coronavirus)
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents; Central Nervous System Depressants; Antiviral Agents; Enzyme Inhibitors; Anti-HIV Agents; Anti-Retroviral Agents; Anesthetics, Intravenous; Anesthetics, General; Anesthetics; Protease Inhibitors; Tranquilizing Agents; Psychotropic Drugs; Hypnotics and Sedatives; Adjuvants, Anesthesia; Anti-Anxiety Agents; GABA Modulators; GABA Agents; Cytochrome P-450 CYP3A Inhibitors; Cytochrome P-450 Enzyme Inhibitors; HIV Protease Inhibitors; Viral Protease Inhibitors; Midazolam; Ritonavir; Nirmatrelvir
• Other Study ID Numbers: C4671013; 2021-003590-62 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No