A Study of a Potential Oral Treatment to Prevent COVID-19 in Adults Who Are Exposed to Household Member(s) With a Confirmed Symptomatic COVID-19 Infection
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT05047601|
Recruitment Status : Completed
First Posted : September 17, 2021
Last Update Posted : November 14, 2022
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The purpose of this clinical trial is to learn whether the study medicine prevent symptoms of COVID-19 in adults who have been exposed to household member(s) with a confirmed symptomatic COVID-19 infection.
All participants in the study will receive treatment for COVID-19 as needed, based on their regular doctor's recommendation. Two-thirds of participants will also receive two study medicines (PF-07321332 and ritonavir) by mouth twice a day for either five or ten days. We will compare the experiences of people receiving the study medicines to those of the people who do not. This will help us determine if the study medicines are safe and effective
|Condition or disease||Intervention/treatment||Phase|
|COVID-19||Drug: PF-07321332 Drug: Placebo for PF-07321332 Drug: Placebo for Ritonavir Drug: Ritonavir||Phase 3|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||2954 participants|
|Intervention Model:||Parallel Assignment|
|Intervention Model Description:||
Eligible participants who are asymptomatic household contacts of an individual with symptomatic COVID-19 will be randomized (1:1:1) to receive orally every 12 hours:
PF-07321332/ritonavir for 5 days followed by placebo for 5 days or PF-07321332/ritonavir for 10 days or Placebo for 10 days
|Masking:||Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)|
|Masking Description:||Double Blind Double Dummy|
|Official Title:||A PHASE 2/3, RANDOMIZED, DOUBLE-BLIND, DOUBLE-DUMMY, PLACEBO CONTROLLED STUDY TO EVALUATE THE SAFETY AND EFFICACY OF 2 REGIMENS OF ORALLY ADMINISTERED PF 07321332/RITONAVIR IN PREVENTING SYMPTOMATIC SARS-COV-2 INFECTION IN ADULT HOUSEHOLD CONTACTS OF AN INDIVIDUAL WITH SYMPTOMATIC COVID-19|
|Actual Study Start Date :||September 9, 2021|
|Actual Primary Completion Date :||April 12, 2022|
|Actual Study Completion Date :||April 12, 2022|
Experimental: PF-07321332/ritonavir (5 days)
Participants will receive PF-07321332/ritonavir every 12 hours from Day 1 through Day 5 followed by Placebo every 12 hours from Day 6 through Day 10
Drug: Placebo for PF-07321332
Drug: Placebo for Ritonavir
Experimental: PF-07321332/ritonavir (10-Day)
Participants will receive PF-07321332/ritonavir every 12 hours from Day 1 through Day 10.
Placebo Comparator: Placebo
Participants will receive placebo every 12 hours from Day 1 through Day 10.
Drug: Placebo for PF-07321332
Drug: Placebo for Ritonavir
- Proportion of participants who have a negative reverse transcription polymerase chain reaction (RT-PCR) result at baseline who develop a symptomatic, RT-PCR or rapid antigen test confirmed SARS-CoV-2 infection. [ Time Frame: Day 1 through Day 14 ]
- Percentage of participants who experience adverse events [ Time Frame: Day 1 through Day 38 ]
- Efficacy in preventing symptomatic COVID-19 in participants who have a negative RT-PCR result at baseline and are at increased risk of severe COVID-19 illness [ Time Frame: Day 1 through Day 14 ]Proportion of participants with symptomatic, RT-PCR or Rapid Antigen Test confirmed SARS-CoV-2 infection through Day 14
- Efficacy in preventing symptomatic COVID-19 in participants who have a negative RT-PCR result at baseline and are at increased risk of severe COVID-19 illness [ Time Frame: Day 1 through Day 28 ]Proportion of participants with COVID-19 related hospitalization or death from any cause
- Prevention of SARS CoV-2 infection in participants by RT-PCR status at enrolment [ Time Frame: Day 1 through Day 14 ]Proportion of participants with symptomatic or asymptomatic, RT-PCR or Rapid Antigen Test confirmed SARS-CoV-2 infection.
- Prevention of SARS CoV-2 infection in participants who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 14 ]Time to SARS-CoV-2 infection.
- Compare the duration of COVID-19 related signs and symptoms in participants who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 28 ]
- Compare the severity of COVID-19 related signs and symptoms in participants who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 28 ]
- Minimal Concentration (Ctrough) of PF-07321332 [ Time Frame: Day 1 post dose, Day 5 pre dose ]
- All cause mortality in participants who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 38 ]
- Viral titers measured via RT-PCR in nasal swabs in participants who have a negative or positive RT-PCR result at baseline [ Time Frame: Day 1 through Day 14 ]
- Number of days of hospital and intensive care unit stay in participants with COVID-19 related hospitalization who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 28 ]
- Number of COVID-19 related medical visits in participants who have a negative RT-PCR result at baseline [ Time Frame: Day 1 through Day 28 ]
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
|Ages Eligible for Study:||18 Years and older (Adult, Older Adult)|
|Sexes Eligible for Study:||All|
|Accepts Healthy Volunteers:||No|
- Participants who have a negative screening SARS-CoV-2 rapid antigen test result and who are asymptomatic household contacts with exposure within 96 hours to an individual who is symptomatic and recently tested positive for SARS CoV-2.
- Fertile participants must agree to use a highly effective method of contraception
- History of SARS-CoV-2 infection in the past 6 months
- Experiencing measured fever (documented temperature >38˚C or 100.4˚F) or other signs or symptoms consistent with COVID-19
- Known medical history of active liver disease
- Chronic Kidney Disease or have known moderate to severe renal impairment.
- Known Human Immunodeficiency Virus (HIV) infection with viral load > 400 copies/ml within the last 6 months or taking prohibited medications for HIV treatment
- Suspected or confirmed concurrent active systemic infection
- Active cancer requiring treatment with prohibited medication.
- Current or expected use of any medications or substances that are highly dependent on Cytochrome P450 3A4 (CYP3A4) for clearance or are strong inducers of CYP3A4
- Has received approved, authorized, or investigational anti-SARS-CoV-2 mAb, convalescent plasma, other drugs for treatment of COVID-19, or other anti-SARS-CoV-2 biologic products within 6 months of screening
- Has received any SARS-CoV-2 vaccine within 6 months prior to screening or is expected to receive a SARS-CoV-2 vaccine or other approved, authorized, or investigational postexposure prophylaxis treatments through Day 38.
- Participating in another interventional clinical study with an investigational compound or device, including those for COVID-19
- Known or prior participation in this trial or another trial involving PF-07321332.
- Females who are pregnant or breastfeeding.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05047601
|Study Director:||Pfizer CT.gov Call Center||Pfizer|
|Other Study ID Numbers:||
2021-002894-24 ( EudraCT Number )
EPIC-PEP ( Other Identifier: Alias Study Number )
|First Posted:||September 17, 2021 Key Record Dates|
|Last Update Posted:||November 14, 2022|
|Last Verified:||November 2022|
|Individual Participant Data (IPD) Sharing Statement:|
|Plan to Share IPD:||Yes|
|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.|
|Studies a U.S. FDA-regulated Drug Product:||Yes|
|Studies a U.S. FDA-regulated Device Product:||No|
Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)
Respiratory Tract Infections
RNA Virus Infections
Respiratory Tract Diseases
HIV Protease Inhibitors
Viral Protease Inhibitors
Molecular Mechanisms of Pharmacological Action
Cytochrome P-450 CYP3A Inhibitors
Cytochrome P-450 Enzyme Inhibitors