AzTrials
AzTrials

Healthy ParticipantsPhase 1NCT05339334

A Study to Learn About the Study Medicine PF-07321332 and Ritonavir in Adult Healthy Chinese Participants.

A Phase 1 study testing PF-07321332/ritonavir in people with Healthy Participants, run by Pfizer at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

The purpose of this Phase 1 clinical trial is to help us understand how the drug is changed and eliminated from your body after you take it, the safety, and the the extent to which dise effects can be tolerated of PF-07321332 when PF-07321332 and ritonavir are given to healthy adult Chinese participants. Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Healthy Participants
What is being tested?
PF-07321332/ritonavir
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
14 participants
Where
1 siteChina
Study dates
10 Mar 2022to 21 Apr 2022
Phase
Phase 1
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy Chinese participants
  • No clinical relevant abnormalities
  • Body mass index (BMI):17.5-28

Who cannot join

  • Any clinical significant illness
  • History of alcohol abuse
  • Use of prescription or nonprescription drugs and dietary and herbal supplements within 7 days prior the first study dose
  • Abnormal clinical lab tests: aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, estimated glomerular filtration rate (eGFR)
  • Abnormal vital signs, such 12-electrocardiogram (ECG), blood pressure and pulse rate
  • Blood donation within 60 days
  • History of human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb), hepatitis C antibody (HCVAb)
  • Other medical or psychiatric may inappropriate for the study

Trial locations and contacts

1 site in 1 country.

China1 site

  • Huashan Hospital,Fudan University

    Shanghai, Shanghai Municipality, 201107

Other trials in China

About this study

Official title: A Phase 1, Single Center, Open-label Study of PF-07321332 Administrated as Multiple Oral Doses in Healthy Chinese Participants.

The purpose of this Phase 1 clinical trial is to help us understand how the drug is changed and eliminated from your body after you take it, the safety, and the the extent to which dise effects can be tolerated of PF-07321332 when PF-07321332 and ritonavir are given to healthy adult Chinese participants.

Being tested
PF-07321332/ritonavir
Keywords
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19)
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PF-07321332/ritonavirDrug

    PF-07321332/ritonavir will be given by mouth two times a day for 10 days

Study groups in NCT05339334
Study groupRoleWhat they receive
PF-07321332/ritonavirExperimentalPF-07321332/ritonavir will be given by mouth two times a day for 10 days to adult Chinese healthy volunteers
Receives: Drug: PF-07321332/ritonavir

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. PF-07321332 Maximum Observed Plasma Concentration (Cmax) on Day 1

    Cmax is maximum plasma concentration .

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  2. PF-07321332 Maximum Observed Plasma Concentration (Cmax) on Day 10

    Cmax is maximum plasma concentration

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  3. PF-07321332 Time for Maximum Observed Plasma Concentration (Tmax) on Day 1

    Tmax is the time for maximum plasma concentration

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  4. PF-07321332 Time for Maximum Observed Plasma Concentration (Tmax) on Day 10

    Tmax is the time for maximum plasma concentration

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  5. PF-07321332 Area Under the Plasma Concentration-time Profile From Time Zero to Time Point on 12 Hours (AUC12) on Day 1

    Area under the plasma concentration-time profile from time Zero to time point on 12 hours

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  6. PF-07321332 Area Under the Plasma Concentration-time Profile From Time Zero to Time Tau (Where Tau=12 Hours) (AUCtau) on Day 10

    Area under the plasma concentration-time profile from time 0 to the time of the end of the dosing interval (tau), where tau=12 hours.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  7. PF-07321332 Average Plasma Concentration Over the Dosing Interval (Cav) on Day 10

    This was determined by AUCtau/tau.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  8. PF-07321332 Accumulation Ratio for AUCtau (Rac) on Day 10

    Accumulation ratio for AUCtau following multiple dosing was calculated as AUCtau on Day 10 divided by AUC12 on Day 1.

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours); Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  9. PF-07321332 Accumulation Ratio for Cmax (Rac, Cmax) on Day 10

    Observed accumulation ratio for Cmax was calculated as Cmax on Day 10 divided by Cmax on Day 1.

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours); Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  10. PF-07321332 Peak-to-trough Ratio (PTR) on Day 10

    This was determined by Day 10 Cmax/Day 10 Ctrough.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  11. PF-07321332 Apparent Clearance (CL/F) on Day 10

    Apparent oral clearance. This was determined by Dose/AUCtau.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  12. PF-07321332 Apparent Volume of Distribution (Vz/F) on Day 10

    Apparent oral volume of distribution.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  13. PF-07321332 Terminal Elimination Half-life (t½) on Day 10

    Terminal half-life. This was determined by Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24 and 48 hours)

  14. PF-07321332 Area Under the Plasma Concentration-time Profile From Time Zero to the Time of the Last Quantifiable Concentration (AUClast) on Day 10

    Area under the plasma concentration-time profile from time 0 to the time of the last quantifiable concentration (Clast)

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24 and 48 hours)

  15. PF-07321332 Trough Concentration (Ctrough) on Day 5

    Concentration at pre-dose on Day 5. Observed directly from data.

    Measured: Day 5 (pre-dose)

  16. PF-07321332 Trough Concentration (Ctrough) on Day 8

    Concentration at pre-dose on Day 8. Observed directly from data.

    Measured: Day 8 (pre-dose)

  17. PF-07321332 Trough Concentration (Ctrough) on Day 10 (Pre-dose)

    Concentration at pre-dose on Day 10. Observed directly from data.

    Measured: Day 10 (pre-dose)

  18. PF-07321332 Trough Concentration (Ctrough) on Day 10 (12 Hours After Last Dose)

    Concentration at 12 hour time on Day 10. Observed directly from data.

    Measured: Day 10 (12 hours after last dose)

Secondary outcomes (19)

  1. Number of Participants With Treatment-Emergent Adverse Events (TEAEs)

    An adverse event (AE) is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. 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; resulted in congenital anomaly/birth, was a suspected transmission via a Pfizer product of an infectious agent,pathogenic or non-pathogenic. An adverse event is considered a Treatment-Emergent Adverse Event (TEAE) if the event started during the effective duration of treatment. All events that started on or after the first dosing day and time/start time, if collected, but before the end of the study would be flagged as TEAEs.

    Measured: From baseline up to Day 42

  2. Number of Participants With Vital Signs Data Meeting Pre-Specified Categorization Criteria

    Vital signs evaluations included supine blood pressure (BP) and pulse rate. The pre specified criteria for vital signs included systolic blood pressure (BP) minimum (min.) less than (<) 90 millimeter of mercury (mmHg); systolic BP change from baseline maximum (max.) decrease >= 30 mmHg, max. increase >=30 mmHg; diastolic BP min. <50mmHg; diastolic BP change from baseline max. decrease >=20, max. increase >=20; seated pulse rate min. <40 beats per minute (bpm) and max. >120 bpm. Participants who met at least 1 pre- specified criteria would be reported in outcome measure.

    Measured: Day 1 (pre-dose, within 1-2 hours after morning dose), Day 10 (pre-dose, within 1-2 hours after morning dose)

  3. Number of Participants With Laboratory Abnormalities

    Safety laboratory assessments included hematology, urinalysis, and clinical chemistry.

    Measured: Day-1, Day 2, Day 5, Day 8, Day 10, Day 12.

  4. Number of Participants With Electrocardiogram (ECG) Data Meeting Pre-Specified Categorization Criteria

    The average of the triplicate readings collected at each assessment time was calculated for each ECG parameter. Baseline was defined as the average of the triplicate pre-dose recordings on Day 1. Pre-defined categories for corrected QT (Fridericia method) (QTcF): Absolute value (milliseconds[msec]) >450 and ≤480, or >480 and ≤500, or >500; Increase from baseline in QTcF (msec) >30 and ≤60, or>60. Pre-defined categories for PR and QRS: PR (msec) max. ≥300; PR (msec) increase from baseline: baseline >200 and max. ≥25% increase, or baseline ≤200 and max. ≥50% increase; QRS (msec) max. ≥140; QRS (msec) increase from baseline ≥50% increase. Participants who met at least 1 pre- specified criteria would be reported in outcome measure.

    Measured: Day 1 (pre-dose, within 1-2 hours after morning dose), Day 10 (pre-dose, within 1-2 hours after morning dose)

  5. Ritonavir Maximum Observed Plasma Concentration (Cmax) on Day 1

    Cmax is maximum plasma concentration

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  6. Ritonavir Maximum Observed Plasma Concentration (Cmax) on Day 10

    Cmax is maximum plasma concentration

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  7. Ritonavir Time for Maximum Observed Plasma Concentration (Tmax) on Day 1

    Tmax is the time for maximum plasma concentration

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  8. Ritonavir Time for Maximum Observed Plasma Concentration (Tmax) on Day 10

    Tmax is the time for maximum plasma concentration

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

  9. Ritonavir Area Under the Plasma Concentration-time Profile From Time Zero to Time Point on 12 Hours (AUC12) on Day 1

    This was determined by linear/Log trapezoidal method - reported as AUC12 on Day 1.

    Measured: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  10. Ritonavir Area Under the Plasma Concentration-time Profile From Time Zero to Time Tau (Where Tau=12 Hours [Twice Daily Dosing]) (AUCtau) on Day 10

    Area under the plasma concentration-time profile from time 0 to the time of the end of the dosing interval (tau), where tau=12 hours.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  11. Ritonavir Area Under the Plasma Concentration-time Profile From Time Zero to the Time of the Last Quantifiable Concentration (AUClast) on Day 10

    Area under the plasma concentration-time profile from time 0 to the time of the last quantifiable concentration (Clast)

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours)

  12. Ritonavir Average Plasma Concentration Over the Dosing Interval (Cav) on Day 10

    This was determined by AUCtau/tau.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  13. Ritonavir Apparent Clearance (CL/F) on Day 10

    Apparent oral clearance. This was determined by Dose/AUCtau.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  14. Ritonavir Apparent Volume of Distribution (Vz/F) on Day 10

    Apparent oral volume of distribution. This was determined by Dose/(AUCtau*kel)

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

  15. Ritonavir Terminal Elimination Half-life (t½) on Day 10

    Terminal half-life. This was determined by Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

    Measured: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours)

  16. Ritonavir Trough Concentration (Ctrough) on Day 5

    Concentration at pre-dose on Day 5. Observed directly from data.

    Measured: Day 5 (pre-dose)

  17. Ritonavir Trough Concentration (Ctrough) on Day 8

    Concentration at pre-dose on Day 8. Observed directly from data.

    Measured: Day 8 (pre-dose)

  18. Ritonavir Trough Concentration (Ctrough) on Day 10 (Pre-dose)

    Concentration at pre-dose on Day 10. Observed directly from data.

    Measured: Day 10 (pre-dose)

  19. Ritonavir Trough Concentration (Ctrough) on Day 10 (12 Hours After Last Dose)

    Concentration at 12 hour on Day 10. Observed directly from data.

    Measured: Day 10 (12 hours after last dose)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Apr 2022
  2. Study start10 Mar 2022
  3. Primary completion21 Apr 2022
  4. Study completion21 Apr 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Other
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
14 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05339334
Sponsor's protocol ID
C4671016
Status last verified
Sep 2024
First submitted
14 Apr 2022
Last updated
8 Oct 2024
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: 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.

Publications

  • Li N, Yu J, Wu J, Zhang J, Ma Y, Zhang C, Han X, Gerhart J, Cong S. Pharmacokinetics of Nirmatrelvir/Ritonavir after Multiple Administration in a Phase 1, Open-Label Study in Healthy Chinese Adults and Compared with Non-Chinese Participants. Clin Drug Investig. 2026 Jul;46(7):783-793. doi: 10.1007/s40261-026-01554-y. Epub 2026 May 6.

    PubMed 42090083

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing PF-07321332/ritonavir in people with Healthy Participants, run by Pfizer at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 8 Oct 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 8 Oct 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

PF-07321332 Maximum Observed Plasma Concentration (Cmax) on Day 1 (time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)). The study lists 18 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05339334, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2024.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Keep searching with a free account

You’ve used your 3 free searches for this session. Log in or create a free AzTrials account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in