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EPIC-HR: Study of Oral PF-07321332/Ritonavir Compared With Placebo in Nonhospitalized High Risk Adults With COVID-19

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: NCT04960202
Recruitment Status : Completed
First Posted : July 13, 2021
Last Update Posted : October 25, 2022
Information provided by (Responsible Party):

Brief Summary:
The purpose of this study is to determine whether PF-07321332/ritonavir is safe and effective for the treatment of adults who are ill with COVID-19 and do not need to be in the hospital, but are at an increased risk of developing severe illness. Throughout the study period, provision will be made to allow study visits to be conducted at a participant's home or another non-clinic location if available. The total study duration is up to 24 weeks.

Condition or disease Intervention/treatment Phase
COVID-19 Drug: PF-07321332 Drug: Ritonavir Drug: Placebo Phase 2 Phase 3

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 2245 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: Eligible participants with a confirmed diagnosis of SARS-CoV-2 infection will be randomized (1:1) to receive PF-07321332/ritonavir or placebo orally every 12 hours for 5 days (10 doses total).
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Actual Study Start Date : July 16, 2021
Actual Primary Completion Date : December 9, 2021
Actual Study Completion Date : April 25, 2022

Arm Intervention/treatment
Experimental: PF-07321332/ritonavir
Orally administered PF-07321332+ritonavir
Drug: PF-07321332
PF-07321332 (tablet)

Drug: Ritonavir
Ritonavir (capsule)

Placebo Comparator: Placebo
Orally administered placebo
Drug: Placebo
Placebo (tablet or capsule)

Primary Outcome Measures :
  1. Proportion of participants with COVID-19 related hospitalization or death from any cause [ Time Frame: Day 1 through Day 28 ]

Secondary Outcome Measures :
  1. Incidence of Adverse Events (AEs) and Serious Adverse Events (SAEs)of PF-07321332/ritonavir relative to placebo [ Time Frame: Day 1 through Day 34 ]
  2. Incidence of Treatment-emergent Adverse Events (TEAEs) of PF-07321332/ritonavir relative to placebo of PF-07321332/ritonavir relative to placebo [ Time Frame: Day 1 through Day 34 ]
  3. Duration of each targeted COVID-19 sign/symptom [ Time Frame: Day 1 through Day 28 ]
  4. Severity of each targeted COVID-19 sign/symptom [ Time Frame: Day 1 through Day 28 ]
  5. Proportion of participants with death (all cause) [ Time Frame: Day 1 through Week 24 ]
  6. Plasma Concentration in whole blood of PF-07321332 in nonhospitalized symptomatic adult participants with COVID 19 who are at increased risk of progression to severe disease [ Time Frame: Day 1: 30-90 minutes postdose, and Day 5: predose ]
  7. Viral titers measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR) in nasal swabs [ Time Frame: Day 1 through Day 14 ]
  8. Number of COVID-19 related medical visits other than hospitalization [ Time Frame: Day 1 through Day 34 ]
  9. Number of days in hospital and intensive care unit for the treatment of COVID-19 [ Time Frame: Day 1 through Day 34 ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Confirmed SARS-CoV-2 infection within 5 days prior to randomization
  • Initial onset of COVID-19 signs/symptoms within 5 days prior to the day of randomization and at least 1 of the specified COVID-19 signs/symptoms present on the day of randomization
  • Fertile participants must agree to use a highly effective method of contraception
  • Has at least 1 characteristic or underlying medical condition associated with an increased risk of developing severe illness from COVID-19

Exclusion Criteria:

  • History of or need for hospitalization for the medical treatment of COVID-19
  • Prior to current disease episode, any confirmed SARS-CoV-2 infection
  • Known medical history of active liver disease
  • Receiving dialysis or have known moderate to severe renal impairment
  • Known human immunodeficiency virus (HIV) infection with a viral load greater than 400 copies/mL or taking prohibited medications for HIV treatment
  • Suspected or confirmed concurrent active systemic infection other than COVID-19
  • History of hypersensitivity or other contraindication to any of the components of the study intervention
  • Current or expected use of any medications or substances that are highly dependent on CYP3A4 for clearance or are strong inducers of CYP3A4
  • Has received or is expected to receive convalescent COVID-19 plasma
  • Has received or is expected to receive any dose of a SARS-CoV-2 vaccine before the Day 34 visit
  • Participating in another interventional clinical study with an investigational compound or device, including those for COVID-19 through the long-term follow-up visit
  • Known prior participation in this trial or other trial involving PF-07321332
  • Oxygen saturation of <92% on room air, or on their standard home oxygen supplementation for those who regularly receive chronic supplementary oxygen for an underlying lung condition
  • Females who are pregnant or breastfeeding

Information from the National Library of Medicine

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): NCT04960202

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Sponsors and Collaborators
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Study Director: Pfizer CT.gov Call Center Pfizer
Additional Information:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Pfizer
ClinicalTrials.gov Identifier: NCT04960202    
Other Study ID Numbers: C4671005
2021-002895-38 ( EudraCT Number )
EPIC-HR ( Other Identifier: Alias Study Number )
First Posted: July 13, 2021    Key Record Dates
Last Update Posted: October 25, 2022
Last Verified: October 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.
URL: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Pfizer:
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
Additional relevant MeSH terms:
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Respiratory Tract Infections
Pneumonia, Viral
Virus Diseases
Coronavirus Infections
Coronaviridae Infections
Nidovirales Infections
RNA Virus Infections
Lung Diseases
Respiratory Tract Diseases
HIV Protease Inhibitors
Viral Protease Inhibitors
Protease Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Anti-HIV Agents
Anti-Retroviral Agents
Antiviral Agents
Anti-Infective Agents
Cytochrome P-450 CYP3A Inhibitors
Cytochrome P-450 Enzyme Inhibitors