Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients (EPIC-SR).
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ClinicalTrials.gov Identifier: NCT05011513 |
Recruitment Status :
Terminated
(Enrollment ceased due to a very low rate of hospitalization or death observed in the standard-risk patient population)
First Posted : August 18, 2021
Last Update Posted : December 12, 2022
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
COVID-19 | Drug: PF-07321332 Drug: Ritonavir Drug: Placebo | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 1411 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) |
Masking Description: | Double-blind |
Primary Purpose: | Treatment |
Official Title: | AN INTERVENTIONAL EFFICACY AND SAFETY, PHASE 2/3, DOUBLE-BLIND, 2 ARM STUDY TO INVESTIGATE ORALLY ADMINISTERED PF 07321332/RITONAVIR COMPARED WITH PLACEBO IN NONHOSPITALIZED SYMPTOMATIC ADULT PARTICIPANTS WITH COVID-19 WHO ARE AT LOW RISK OF PROGRESSING TO SEVERE ILLNESS |
Actual Study Start Date : | August 25, 2021 |
Actual Primary Completion Date : | July 25, 2022 |
Actual Study Completion Date : | July 25, 2022 |

Arm | Intervention/treatment |
---|---|
Experimental: PF-07321332/ritonavir
Orally administered PF-07321332+ritonavir
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Drug: PF-07321332
PF-07321332 (tablet) Drug: Ritonavir Ritonavir (capsule) |
Placebo Comparator: Placebo
Orally administered Placebo
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Drug: Placebo
Placebo (tablet) Drug: Placebo Placebo (capsule) |
- Time to Sustained Alleviation of All Targeted COVID-19 Signs/Symptoms [ Time Frame: Baseline through Day 28 ]Analysis set includes COVID-19 symptom onset 1-3 days before treatment.
- Percentage of Participants Who Experience Adverse Events (AEs) [ Time Frame: Baseline through Day 34 ]
- Percentage of Participants Who Experience an AE(s) or Serious Adverse Events (SAEs) that Leads to Study Discontinuation [ Time Frame: Baseline through Day 34 ]
- Proportion of Participants With Severe Signs/Symptoms Attributed to COVID-19 [ Time Frame: Baseline through Day 28 ]
- Time to Sustained Resolution of All Targeted COVID-19 Signs/Symptoms [ Time Frame: Baseline through Day 28 ]
- Duration of Each Targeted COVID-19 Sign/Symptom [ Time Frame: Baseline through Day 28 ]
- Proportion of Participants Progressing to a Worsening Status In 1 or More COVID-19 Signs/Symptoms [ Time Frame: Baseline through Day 28 ]
- Proportion of Participants With a Resting Peripheral Oxygen Saturation ≥95% [ Time Frame: Days 1, 5 ]
- Number of COVID-19 Related Medical Visits [ Time Frame: Baseline through Day 28 ]
- Number of Days in Hospital and Intensive Care Unit (ICU) Stay in Participants With COVID-19 Related Hospitalization [ Time Frame: Baseline through Day 28 ]
- Proportion of Participants With COVID-19 Related Hospitalization or Death From Any Cause [ Time Frame: Baseline through Day 28 ]
- Proportion of Participants With Death (all cause) [ Time Frame: Baseline through Week 24 ]
- Minimal Concentration (Ctrough) of PF-07321332 [ Time Frame: Baseline through Day 5 ]
- Viral Titers Measured Via Reverse Transcription Polymerase Chain Reaction (RT-PCR) in Nasal Swabs [ Time Frame: Baseline through Day 14 ]
- Time to Sustained Alleviation of All Targeted COVID-19 Signs/Symptoms [ Time Frame: Baseline through Day 28 ]Analysis set includes COVID-19 symptom onset 1-5 days before treatment.

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 |
Inclusion Criteria:
- Confirmed SARS-CoV-2 infection 5 days prior to randomization
- Initial onset of COVID-19 signs/symptoms within 5 days of randomization
- Fertile participants must agree to use a highly effective method of contraception
Exclusion Criteria:
- Has at least one underlying medical condition associated with an increased risk of developing severe illness from COVID-19
- History of or need for hospitalization for the medical treatment of COVID-19
- Prior diagnosis of SARS-CoV-2 infection (reinfection)
- Known medical history of liver disease
- Receiving dialysis or have known renal impairment
- Known Human Immunodeficiency Virus (HIV) infection with viral load > 400 copies/ml or taking prohibited medications for HIV treatment
- Suspected or confirmed concurrent active systemic infection other than COVID-19
- 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 or is expected to receive monoclonal antibody treatment or convalescent COVID-19 plasma
- Has received any SARS-CoV-2 vaccine within 12 months of screening
- Participating in another interventional clinical study with an investigational compound or device, including those for COVID-19
- Known prior participation in this trial or other trial involving PF-07321332
- Oxygen saturation of < 92% on room air
- 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): NCT05011513

Study Director: | Pfizer CT.gov Call Center | Pfizer |
Responsible Party: | Pfizer |
ClinicalTrials.gov Identifier: | NCT05011513 |
Other Study ID Numbers: |
C4671002 2021-002857-28 ( EudraCT Number ) EPIC-SR ( Other Identifier: Alias Study Number ) |
First Posted: | August 18, 2021 Key Record Dates |
Last Update Posted: | December 12, 2022 |
Last Verified: | December 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 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
SARS-CoV-2 Infection |
COVID-19 Respiratory Tract Infections Infections Pneumonia, Viral Pneumonia Virus Diseases Coronavirus Infections Coronaviridae Infections Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases |
Ritonavir 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 |