AzTrials
AzTrials

COVID-19Phase 2/3NCT04960202

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

A Phase 2/3 study testing PF-07321332 and Ritonavir in people with COVID-19, run by Pfizer at 201 sites in 20 countries.

Completed

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

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
COVID-19
What is being tested?
PF-07321332 and Ritonavir
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
2,091 participants
Where
201 sitesin 20 countries
Study dates
16 Jul 2021to 25 Apr 2022
Phase
Phase 2/3
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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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
Show all 14Show fewer
  • 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

Trial locations and contacts

201 sites in 20 countries.

201 sites in 20 countries

United States73 sites
  • PharmaTex Research, LLC

    Amarillo, Texas, 79109

  • ARC Clinical Research at William Cannon

    Austin, Texas, 78745

  • St Hope Foundation

    Bellaire, Texas, 77401

  • Xera Med Research

    Boca Raton, Florida, 33487

  • MOORE Clinical Research, Inc.

    Brandon, Florida, 33511

  • Mercury Street Medical Group, PLLC

    Butte, Montana, 59701

  • Hope Clinical Research

    Canoga Park, California, 91303

  • Research by Design, LLC

    Chicago, Illinois, 60643

  • Premier Medical Group

    Clarksville, Tennessee, 37040

  • Innovative Research of West Florida, Inc.

    Clearwater, Florida, 33756

  • Future Innovative Treatments, LLC

    Colorado Springs, Colorado, 80907

  • Conroe Willis Medical Research

    Conroe, Texas, 77304

  • Herco Medical and Research Center Inc

    Coral Gables, Florida, 33134

  • South Texas Clinical Research

    Corpus Christi, Texas, 78413

  • Advance Clinical Research Group

    Cutler Bay, Florida, 33157

  • Beautiful Minds Clinical Research Center

    Cutler Bay, Florida, 33157

  • Meridian Clinical Research, LLC

    Endwell, New York, 13760

  • Ascada Research

    Fullerton, California, 92835

  • Qway Research

    Hialeah, Florida, 33010

  • Eastern Research Inc

    Hialeah, Florida, 33013

  • Inpatient Research Clinic

    Hialeah, Florida, 33013

  • Doral Medical Research LLC.

    Hialeah, Florida, 33016

  • Doral Medical Research,LLC

    Hialeah, Florida, 33016

  • Unlimited Medical Research Group, LLC

    Hialeah Gardens, Florida, 33018

  • SignatureCare Emergency Center

    Houston, Texas, 77008

  • Trio Clinical Trials, LLC

    Houston, Texas, 77008

  • C & R Research Services USA

    Houston, Texas, 77022

  • Next Level Urgent Care

    Houston, Texas, 77057

  • Atella Clinical Research LLC.

    La Palma, California, 90623

  • Excel Clinical research

    Las Vegas, Nevada, 89109

  • Ark Clinical Research

    Long Beach, California, 90806

  • American Institute of Research

    Los Angeles, California, 90017

  • Advanced Pulmonary Research Institute

    Loxahatchee Groves, Florida, 33470

  • New Orleans Sinus Center (COVID-19 Testing)

    Marrero, Louisiana, 70072

  • Tandem Clinical Research GI, LLC

    Marrero, Louisiana, 70072

  • The Institute for Liver Health dba Arizona Clinical Trials

    Mesa, Arizona, 85210

  • SMS Clinical Research, LLC

    Mesquite, Texas, 75149

  • SMS Clinical Research

    Mesquite, Texas, 75149

  • Angels Clinical Research Institute

    Miami, Florida, 33122

  • LCC Medical Research Institute, LLC

    Miami, Florida, 33126

  • Premium Medical Research Corp

    Miami, Florida, 33126

  • Global Health Clinical Trials Corp

    Miami, Florida, 33135

  • South Florida Research Center, Inc.

    Miami, Florida, 33135

  • Suncoast Research Group, LLC

    Miami, Florida, 33135

  • I.V.A.M. Clinical & Investigational Center, LLC

    Miami, Florida, 33144

  • C'A Research

    Miami, Florida, 33174

  • ProLive Medical Research, Corp.

    Miami, Florida, 33175

  • Entrust Clinical Research

    Miami, Florida, 33176

  • Reed Medical Research

    Miami, Florida, 33176

  • Kendall South Medical Center

    Miami, Florida, 33185

  • Clinical Site Partners, Inc d/b/a CSP Miami

    Miami, Florida, 33186

  • Coral Research Clinic Corp

    Miami, Florida, 33186

  • Savin Medical Group, LLC

    Miami Lakes, Florida, 33014

  • Monroe Biomedical Research

    Monroe, North Carolina, 28112

  • TPMG (Tidewater Physicians Multispecialty Group) Clinical Research

    Newport News, Virginia, 23606

  • Omega Research Orlando, LLC

    Orlando, Florida, 32808

  • LinQ Research, LLC

    Pearland, Texas, 77584

  • Cahaba Research Inc

    Pelham, Alabama, 35124

  • NAPA Research LLC

    Pompano Beach, Florida, 33064

  • CDC Research Institute

    Port Saint Lucie, Florida, 34952

  • Epic Medical Research

    Red Oak, Texas, 75154

  • South Bay Clinical Research Institute

    Redondo Beach, California, 90277

  • Sun Research Institute

    San Antonio, Texas, 78215

  • BFHC Research

    San Antonio, Texas, 78249

  • USPA Advance Concept Medical Research Group LLC

    South Miami, Florida, 33143

  • GCP, Global Clinical Professionals

    St. Petersburg, Florida, 33705

  • Sunrise Research Institute

    Sunrise, Florida, 33325

  • Santos Research Center, CORP

    Tampa, Florida, 33615

  • The Institute for Liver Health dba Arizona Clinical Trials

    Tucson, Arizona, 85712

  • Tranquility Research

    Webster, Texas, 77598

  • Hope Clinical Research (COVID Satellite Site)

    West Hills, California, 91304

  • Accellacare

    Wilmington, North Carolina, 28401

  • Clinical Site Partners, Inc. dba CSP Orlando

    Winter Park, Florida, 32789

Other trials in United States

Bulgaria24 sites
  • Individual Practice for Primary Medical Care - IPPMC - Dr. P. Panayotov EOOD

    Burgas, 8001

  • "Specialized Hospital for Active Treatment of Pneumo-Phthisiatric Diseases-Haskovo" Ltd

    Haskovo, 6300

  • MHAT "Sv.Ivan. Rilski'' Kozloduy EOOD

    Kozloduy, 3320

  • Diagnostic-Consultative Center I Lom EOOD

    Lom, 3600

  • Multiprofile Hospital for Active Treatment- Sveti Nikolay Chudotvoretz EOOD

    Lom, 3600

  • Medical centre Leo Clinic EOOD

    Lovech, 5500

  • MHAT Heart and Brain EAD

    Pleven, 5800

  • DCC Sveti Georgi EOOD

    Plovdiv, 4000

  • MHAT "St. Panteleimon "- Plovdiv

    Plovdiv, 4004

  • Multiprofile Hospital for Active Treatment Sveti Ivan Rilski - Razgrad AD

    Razgrad, 7200

  • "Specialized Hospital for Active Treatment of Pneumo-Physiatric Diseases Dr. Dimitar Gramatikov -

    Rousse, 7002

  • UMHAT Medica Ruse OOD

    Rousse, 7013

  • Multiprofile Hospital for Active Treatment - Samokov EOOD

    Samokov, 2000

  • Medical Center-1-Sevlievo EOOD

    Sevlievo, 5400

  • Multiprofile Hospital For Active Treatment Shumen AD

    Shumen, 9700

  • Multiprofile hospital for active treatment - Sliven to Military Medical Academy

    Sliven, 8800

  • MHAT "Dr. Ivan Seliminski" AD, Sliven

    Sliven, 8801

  • Diagnostic-Consultative Center XXII- Sofia ЕООD

    Sofia, 1113

  • MHAT "St. Sofia" EOOD

    Sofia, 1618

  • Specialized hospital for active treatment in pulmonology and phthisiology "Stara Zagora" EOOD

    Stara Zagora, 6000

  • Multiprofile Hospital for Active Treatment Targovishte AD

    Targovishte, 7700

  • Outpatient Clinic for Primary Outpatient Medical Care "Puls" - Dr. Mladen Buchvarov EOOD

    Tsarevo, 8260

  • Medical center Leo Clinic EOOD

    Varna, 9020

  • Specialized Hospital for Active Treatment of Pneumo-Phthisiatric Diseases Vratsa EOOD

    Vratsa, 3000

Other trials in Bulgaria

Mexico16 sites
  • Centro de Investigacion Clinica Del Pacifico SA de CV

    Acapulco

  • Hospital Cardiologica Aguascalientes

    Aguascalientes, CP 201230

  • InfectoLab Consultorios de Especialidad en Infectologia

    Baja California, Tijuana, 22010

  • JM Research SC

    Cuernavaca, Morelos, 62290

  • Instituto de Investigaciones Clínicas para la Salud

    Durango, 34000

  • Instituto Jalisciense de Metabolismo, S.C.

    Guadalajara, Jalisco, 44670

  • EME RED Hospitalaria

    Mérida, Yucatán, 97000

  • Kohler & Milstein Research S.A. de C.V.

    Mérida, Yucatán, 97070

  • Christus - Latam Hub Center of Excellence and Innovation Center S.C.

    Monterrey, Nuevo León, 64060

  • Eukarya Pharmasite S.C.

    Monterrey, Nuevo León, 64718

  • Oaxaca Site Management Organization

    Oaxaca City, Oaxaca, 68000

  • Asociacion Mexicana para la Investigacion Clinica A.C. (AMIC)

    Pachuca, Hidalgo, 42070

  • Clinical Research Institute Saltillo S.A. de C.V.

    Saltillo, Coahuila, 25020

  • FAICIC S. de R.L. de C.V.

    Veracruz, 91900

  • Sociedad de Metabolismo y Corazon S.C.

    Veracruz, 91900

  • Arké SMO S.A de C.V

    Veracruz, 91910

Other trials in Mexico

Turkey (Türkiye)15 sites
  • Ankara University Medical Faculty, Ibni-Sina Hospital

    Ankara, 06230

  • Hacettepe University Medical Faculty Hospital

    Ankara, 06230

  • Akdeniz Universitesi Hastanesi

    Antalya, 07059

  • Istanbul Medipol University Clinical Research Ethics Committee

    Beykoz / Istanbul, 34810

  • Gaziantep University Medical Faculty

    Gaziantep, 27300

  • Istanbul Yedikule Gogus Hastaliklari ve Gogus Cerrahisi Egitim Arastirma Hastanesi

    Istanbul, 34020

  • Istanbul University Cerrahpasa-Cerrahpasa Medical Faculty

    Istanbul, 34098

  • Acibadem Saglik Hizmetleri ve Tic.A.S, Acibadem Atakent Hastanesi

    Istanbul, 34303

  • Istanbul Universitesi Klinik Arastirmalar Mukemmeliyet Uygulama ve Arastirma Merkezi

    Istanbul, 34452

  • Basaksehir Cam ve Sakura Sehir Hastanesi

    Istanbul, 34480

  • Kocaeli University Medical Faculty

    Kocaeli, 41380

  • Sbü Dr. Suat Seren Göğüs Hastaliklari Ve Cerrahisi Eğitim Ve Araştirma Hastanesi

    Konak/Izmir, 35170

  • Mersin University Health Research and Application Hospital

    Mersin, 33110

  • Sakarya University Training and Research Hospital

    Sakarya, 54100

  • Karadeniz Teknik Universitesi Farabi Hastanesi

    Trabzon, 61080

Other trials in Turkey (Türkiye)

Ukraine15 sites
  • Communal non-profit enterprise "City Clinical Hospital #16" of Dnipro City Council

    Dnipro, 49069

  • Municipal Nonprofit Enterprise "Ivano-Frankivsk Regional Clinical Infectious Diseases Hospital of

    Ivano-Frankivsk, 76007

  • Communal nonprofit enterprise "Central City Clinical Hospital of Ivano-Frankivsk City Council"

    Ivano-Frankivsk, 76018

  • Municipal Nonprofit Enterprise "City Student Hospital" of Kharkiv City Council

    Kharkiv, 61002

  • Municipal Nonprofit Enterprise of Kharkiv Regional Council "Regional Clinical Infectious Diseases

    Kharkiv, 61096

  • "Municipal Non-Profit Enterprise "Alexander Clinical Hospital of Kyiv" of the Kyiv City Council

    Kyiv, 01601

  • Municipal non-commercial enterprise "Kyiv City Clinical Hospital #1" Of Executive Body Of the Kyiv

    Kyiv, 02091

  • Kyiv Railway Clinical Hospital No.2 of Branch "Health Center of the Public Joint Stock Company

    Kyiv, 03049

  • Polyclinic of Center for Medical Services and Rehabilitation of State Joint-Stock Holding Company

    Kyiv, 04050

  • Municipal NonProfit Enterprise of the Lviv Regional Council Lviv Regional Information and Analitical

    Lviv, 79008

  • Municipal Nonprofit Enterprise "Lviv City Clinic Hospital #4"

    Lviv, 79011

  • Municipal Enterprise "Poltava Regional Clinical Infectious Diseases Hospital" of Poltava Regional

    Poltava, 36011

  • Municipal Enterprise "Volyn Regional Clinical Hospital" of Volyn Regional Council

    Tarasove Village, 45625

  • Municipal Non-commercial Enterprise "Vinnytsia City Clinical Hospital №1"

    Vinnytsia, 21029

  • Communal Enterprise "Hospital #1" of Zhytomyr City Council

    Zhytomyr, 10002

Other trials in Ukraine

India12 sites
  • Jawahar Lal Nehru Medical College

    Ajmer, Rajasthan, 305001

  • BGS Global Institute of Medical Sciences and Hospital

    Bangalore, Karnataka, 560060

  • Apex Hospitals Pvt Ltd

    Jaipur, Rajasthan, 302017

  • Maharaja Agrasen Superspeciality Hospital

    Jaipur, Rajasthan, 302039

  • Lisie Hospital

    Kochi, Kerala, 682018

  • Nil Ratan Sircar Medical College and Hospital

    Kolkata, West Bengal, 700014

  • Aakash Healthcare Private Limited

    New Delhi, 110075

  • Sardar Patel Medical College

    Pavan PURI Bikaner, Rajasthan, 334003

  • Jehangir Clinical Development Centre Pvt. Ltd

    Pune, Maharashtra, 411001

  • Lifepoint Research LLP

    Pune, Maharashtra, 411057

  • AIIMS Raipur

    Raipur, Chhattisgarh, 492099

  • Jupiter Hospital

    Vadodara, Gujarat, 390012

Other trials in India

South Africa6 sites
  • East Rand Research Centre T/A Worthwhile Clinical Trials

    Benoni, Gauteng, 1500

  • Synapta Clinical Research Center

    Durban, KwaZulu-Natal, 4001

  • MERC Middelburg

    Middelburg, Mpumalanga, 1055

  • Botho Ke Bontle Health Services

    Pretoria, Gauteng, 0122

  • Limpopo Clinical Research Initiative

    Thabazimbi, Limpopo, 0380

  • MERC Welkom

    Welkom, Free State, 9460

Other trials in South Africa

Thailand6 sites
  • Bangkok Centre Hotel

    Bang Rak, Bangkok, 10500

  • Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University,

    Hat Yai, Changwat Songkhla, 90110

  • Faculty of Medicine - Khon Kaen University

    Muang, Changwat Khon Kaen, 40002

  • Chula Field Hospital, Chulalongkorn University Sport center (Chantanayingyong Gymnasium)

    Pathum Wan District,, Bangkok, 10330

  • The HIV Netherlands Australia Thailand Research Collaboration (HIV-NAT),

    Pathumwan, Bangkok, 10330

  • Thai Red Cross Emerging Infectious Diseases (EDI) Clinic

    Pathumwan,, Bangkok, 10330

Other trials in Thailand

Hungary5 sites
  • Trial Pharma Kft.

    Békéscsaba, 5600

  • Debreceni Egyetem Klinikai Kozpont Infektologiai Klinika

    Debrecen, 4031

  • Agria-Study Kft.

    Eger, 3300

  • Trial Pharma Kft.

    Gyula, 5700

  • Medifarma-98 Kft.

    Nyíregyháza, 4400

Other trials in Hungary

Japan5 sites
  • Tokyo Medical University Hachioji Medical Center

    Hachiōji, Tokyo, 1930998

  • Rinku General Medical Center

    Izumisano, Osaka, 598-8577

  • International University of Health and Welfare Narita Hospital

    Narita, Chiba, 286-8520

  • National Hokkaido Medical Center

    Sapporo, Hokkaido, 063-0005

  • National Center for Global Health and Medicine

    Shinjuku, Tokyo, 162-8655

Other trials in Japan

Russia4 sites
  • Barnaul City Hospital Number 5

    Barnaul, 656045

  • KDC "Evromedservis", OJSC

    Moscow, 115419

  • LLC Trekhgorka Medicine

    Odintsovo, Moscow Oblast, 143005

  • Smolensk State Medical University

    Smolensk, 214019

Other trials in Russia

South Korea4 sites
  • Kyungpook National University Chilgok Hospital

    Daegu, 41404

  • Incheon Medical Center

    Incheon, 22532

  • Chonnam National University Bitgoeul Hospital

    Nam-gu, 61748

  • SMG-SNU Boramae Medical Center

    Seoul, 07061

Other trials in South Korea

Brazil3 sites
  • Chronos Pesquisa Clinica

    Brasília, Federal District, 72145-450

  • CECIP JAÚ - Centro de Estudos Clínicos do Interior Paulista - LTDA

    Jaú, São Paulo, 17201-130

  • Hospital Agamenon Magalhaes

    Recife, Pernambuco, 52051-380

Other trials in Brazil

Argentina2 sites
  • Hospital De Clínicas Presidente Dr.Nicolas Avellaneda

    San Miguel de Tucumán, Tucumán Province, 4000

  • Instituto de Investigaciones Clinicas Zarate

    Zárate, Buenos Aires, B2800DGH

Other trials in Argentina

Czechia2 sites
  • Zdraví-Fit, s.r.o.

    Protivín, 398 11

  • Nemocnice Slany

    Slaný, 274 01

Other trials in Czechia

Malaysia2 sites
  • Hospital Umum Sarawak

    Kuching, Sarawak, 93586

  • Hospital Miri

    Miri, Sarawak, 98000

Other trials in Malaysia

Poland2 sites
  • KLIMED Marek Klimkiewicz

    Bialystok, 15-704

  • Centrum Badań Klinicznych Piotr Napora Lekarze Spółka Partnerska

    Wroclaw, 51-162

Other trials in Poland

Puerto Rico2 sites
  • Clinical Research Management Group Inc

    Ponce, 00780

  • Advance Medical Research Center

    San Juan, 00926

Other trials in Puerto Rico

Spain2 sites
  • Complexo Hospitalario Universitario da Coruna

    A Coruña, 15006

  • Eba Centelles

    Centelles, Barcelona [barcelona], 08540

Other trials in Spain

Colombia1 site
  • Fundacion Cardiomet Cequin

    Armenia, Quindío Department, 630004

Other trials in Colombia

About this study

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 INCREASED RISK OF PROGRESSING TO SEVERE ILLNESS

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.

Conditions
COVID-19
Being tested
PF-07321332, Ritonavir, Placebo
Keywords
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
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-07321332Drug

    PF-07321332 (tablet)

  • RitonavirDrug

    Ritonavir (capsule)

  • PlaceboDrug

    Placebo (tablet or capsule)

Study groups in NCT04960202
Study groupRoleWhat they receive
PF-07321332/ritonavirExperimentalOrally administered PF-07321332+ritonavir
Receives: Drug: PF-07321332; Drug: Ritonavir
PlaceboPlacebo comparatorOrally administered placebo
Receives: Drug: Placebo

What is being measured

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

  1. Percentage of Participants With Covid-19 Related Hospitalization or Death From Any Cause Through Day 28- Modified Intent-To-Treat (mITT) Population

    Percentage of participants with COVID-19 related hospitalization or death from any cause during the first 28 days of the study was estimated using the Kaplan-Meier (KM) method. Using KM method, survival probability for each time interval was calculated as the number of participants surviving divided by the number of participants at risk. Participants who had the event, dropped out, or moved out were not counted as "at risk" i.e., participants who were lost were considered "censored" and were not counted in the denominator.

    Measured: From Day 1 to Day 28

Secondary outcomes (37)
  1. Number of Participants With Treatment Emergent Adverse Events (TEAEs)

    An adverse event (AE) was any untoward medical occurrence in a participant, temporarily associated with the use of study intervention, whether or not considered related to the study intervention. Serious adverse event (SAE) was any untoward medical occurrence that, at any dose: resulted in death; required inpatient hospitalization or prolongation of existing hospitalization; was life-threatening; resulted in persistent or significant disability/ incapacity; congenital anomaly/birth defect; a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical events. AEs included both SAEs and all non-SAEs. An AE was considered as TEAE if the event started on or after start date of study intervention.

    Measured: From start of study intervention (Day 1) up to end of safety follow-up (Day 34)

  2. Number of Participants With AEs Leading to Discontinuation and Serious Adverse Events (SAEs)

    An AE was any untoward medical occurrence in a participant, temporarily associated with the use of study treatment, whether or not considered related to the study treatment. An SAE was any untoward medical occurrence that, at any dose: resulted in death; required inpatient hospitalization or prolongation of existing hospitalization; was life-threatening; resulted in persistent or significant disability/ incapacity; congenital anomaly/birth defect; a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical events.

    Measured: From start of study intervention (Day 1) up to end of safety follow-up (Day 34)

  3. Percentage of Participants With Covid-19 Related Hospitalization or Death From Any Cause Through Day 28- Modified Intent-To-Treat 1 (mITT1) Population

    Percentage of participants with COVID-19 related hospitalization or death from any cause during the first 28 days of the study was estimated using the Kaplan-Meier method.

    Measured: From Day 1 to Day 28

  4. Time to Sustained Alleviation of All Targeted COVID-19 Signs and Symptoms Through Day 28- mITT Population

    Sustained alleviation of all targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when all symptoms scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  5. Time to Sustained Alleviation of All Targeted COVID-19 Signs and Symptoms Through Day 28- mITT1 Population

    Sustained alleviation of all targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when all symptoms scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  6. Time to Sustained Alleviation of All Targeted COVID-19 Signs and Symptoms Through Day 28- Modified Intent-to-Treat 2 (mITT2) Population

    Sustained alleviation of all targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when all symptoms scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  7. Percentage of Participants With Severe Covid-19 Signs and Symptoms Through Day 28- mITT Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale ranging from 0 to 3, higher scores indicated more severity. The scale was reported as 0= no symptoms, 1=mild, 2=moderate and 3=severe. A participant with severe score for any targeted symptoms post-baseline was counted as severe. Percentage of participants with severe Covid-19 signs and symptoms were reported.

    Measured: From Day 1 to Day 28

  8. Percentage of Participants With Severe Covid-19 Signs and Symptoms Through Day 28- mITT1 Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale ranging from 0 to 3, higher scores indicated more severity. The scale was reported as 0= no symptoms, 1=mild, 2=moderate and 3=severe. A participant with severe score for any targeted symptoms post-baseline was counted as severe. Percentage of participants with severe Covid-19 signs and symptoms were reported.

    Measured: From Day 1 to Day 28

  9. Percentage of Participants With Severe Covid-19 Signs and Symptoms Through Day 28- mITT2 Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale ranging from 0 to 3, higher scores indicated more severity. The scale was reported as 0= no symptoms, 1=mild, 2=moderate and 3=severe. A participant with severe score for any targeted symptoms post-baseline was counted as severe. Percentage of participants with severe Covid-19 signs and symptoms were reported.

    Measured: From Day 1 to Day 28

  10. Time to Sustained Resolution of All Targeted COVID-19 Signs and Symptoms Through Day 28- mITT Population

    Sustained resolution was defined as when all targeted symptoms were scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  11. Time to Sustained Resolution of All Targeted COVID-19 Signs and Symptoms Through Day 28- mITT1 Population

    Sustained resolution was defined as when all targeted symptoms were scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  12. Time to Sustained Resolution of All Targeted COVID-19 Signs and Symptoms Through Day 28- mITT2 Population

    Sustained resolution was defined as when all targeted symptoms were scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  13. Time to Sustained Alleviation of Each Targeted COVID-19 Signs and Symptoms- mITT Population

    Sustained alleviation of each targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when each symptom scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  14. Time to Sustained Alleviation of Each Targeted COVID-19 Signs and Symptoms- mITT1 Population

    Sustained alleviation of each targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when each symptom scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  15. Time to Sustained Alleviation of Each Targeted COVID-19 Signs and Symptoms- mITT2 Population

    Sustained alleviation of each targeted COVID-19 signs/symptoms was defined as the event occurring on the first 4 consecutive days when each symptom scored as moderate or severe at the time of enrollment were scored as mild or absent and those scored mild or absent at the time of enrollment were scored as absent. The first day of the 4 consecutive-day period was considered date of first event. Time to sustained alleviation (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained alleviation (censored), time was calculated as censoring date (last date on which symptom alleviation was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  16. Time to Sustained Resolution of Each Targeted COVID-19 Signs and Symptoms- mITT Population

    Sustained resolution was defined as when each targeted symptom was scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  17. Time to Sustained Resolution of Each Targeted COVID-19 Signs and Symptoms- mITT1 Population

    Sustained resolution was defined as when each targeted symptom was scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  18. Time to Sustained Resolution of Each Targeted COVID-19 Signs and Symptoms- mITT2 Population

    Sustained resolution was defined as when each targeted symptom was scored as absent for 4 consecutive days. Time to sustained resolution (event) was calculated as first event date minus first dose date plus 1, for participants with event. For participants who completed Day 28 or discontinued the study before Day 28 without sustained resolution (censored), time was calculated as censoring date (last date on which symptom resolution was assessed) minus first dose date plus 1 or Day 25 whichever occurred first.

    Measured: From Day 1 (baseline) to Day 28

  19. Number of Participants With Progression to a Worsening Status in 1 or More Self-reported COVID-19 Associated Symptoms Through Day 28-mITT Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale where 0 = no symptoms; 1= mild; 2= moderate; and 3= severe. Vomiting and diarrhea were each rated on a 4-point frequency scale where 0= no occurrence, 1= mild for 1 to 2 times, 2= moderate for 3 to 4 times, and 3= severe for 5 or greater. Progression to a worsening status for any targeted symptom was based up on increasing severity (i.e. the first time any targeted symptoms worsened after treatment relative to baseline).

    Measured: From Day 1 (baseline) to Day 28

  20. Number of Participants With Progression to a Worsening Status in 1 or More Self-reported COVID-19 Associated Symptoms Through Day 28-mITT1 Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale where 0 = no symptoms; 1= mild; 2= moderate; and 3= severe. Vomiting and diarrhea were each rated on a 4-point frequency scale where 0= no occurrence, 1= mild for 1 to 2 times, 2= moderate for 3 to 4 times, and 3= severe for 5 or greater. Progression to a worsening status for any targeted symptom was based up on increasing severity (i.e. the first time any targeted symptoms worsened after treatment relative to baseline).

    Measured: From Day 1 (baseline) to Day 28

  21. Number of Participants With Progression to a Worsening Status in 1 or More Self-reported COVID-19 Associated Symptoms Through Day 28-mITT2 Population

    Participants were required to record the severity of their Covid-19 symptoms over the past 24 hours daily on a 4-point scale where 0 = no symptoms; 1= mild; 2= moderate; and 3= severe. Vomiting and diarrhea were each rated on a 4-point frequency scale where 0= no occurrence, 1= mild for 1 to 2 times, 2= moderate for 3 to 4 times, and 3= severe for 5 or greater. Progression to a worsening status for any targeted symptom was based up on increasing severity (i.e. the first time any targeted symptoms worsened after treatment relative to baseline).

    Measured: From Day 1 (baseline) to Day 28

  22. Percentage of Participants With a Resting Peripheral Oxygen Saturation >=95% at Days 1 and 5- mITT Population

    In this outcome measure, the percentage of participants with a resting peripheral oxygen saturation >=95% were reported.

    Measured: Day 1, 5

  23. Percentage of Participants With a Resting Peripheral Oxygen Saturation >=95% at Days 1 and 5- mITT1 Population

    In this outcome measure, the percentage of participants with a resting peripheral oxygen saturation >=95% were reported.

    Measured: Day 1, 5

  24. Percentage of Participants With a Resting Peripheral Oxygen Saturation >=95% at Days 1 and 5- mITT2 Population

    In this outcome measure, the percentage of participants with a resting peripheral oxygen saturation >=95% were reported.

    Measured: Day 1, 5

  25. Percentage of Participants Who Died Through Week 24- mITT Population

    In this outcome measure, percentage of participants with death due to any cause was presented.

    Measured: From Day 1 up to Week 24

  26. Percentage of Participants Who Died Through Week 24- mITT1 Population

    In this outcome measure, percentage of participants with death due to any cause was presented.

    Measured: From Day 1 up to Week 24

  27. Percentage of Participants Who Died Through Week 24- mITT2 Population

    In this outcome measure, percentage of participants with death due to any cause was presented.

    Measured: From Day 1 up to Week 24

  28. Plasma Concentration Versus Time Summary of PF-07321332

    Measured: 1 Hour post-dose on Day 1 and pre-dose on Day 5

  29. Change From Baseline in Logarithm to Base10 (Log10) Transformed Viral Load at Day 3, 5, 10 and 14- mITT Population

    The viral load was measured in nasal or nasopharyngeal samples using reverse transcription polymerase chain reaction (RT-PCR).

    Measured: Baseline, Day 3, 5, 10 and 14

  30. Change From Baseline in Log10 Transformed Viral Load at Day 3, 5, 10 and 14- mITT1 Population

    The viral load was measured in nasal or nasopharyngeal samples using RT-PCR.

    Measured: Baseline, Day 3, 5, 10 and 14

  31. Change From Baseline in Log10 Transformed Viral Load at Day 3, 5, 10 and 14- mITT2 Population

    The viral load was measured in nasal or nasopharyngeal samples using RT-PCR.

    Measured: Baseline, Day 3, 5, 10 and 14

  32. Number of COVID-19 Related Medical Visits- mITT Population

    Medical visits included emergency room, practitioner's office, home healthcare services, urgent care, telephone consultation, outpatient infusion center, other, COVID-19-related-hospitalization (intensive care unit [ICU] and non-ICU stays). In this outcome measure, COVID-19-related medical visits of participants were reported.

    Measured: From Day 1 up to Day 34

  33. Number of COVID-19 Related Medical Visits- mITT1 Population

    Medical visits included emergency room, practitioner's office, home healthcare services, urgent care, telephone consultation, outpatient infusion center, other, COVID-19-related-hospitalization (ICU and non-ICU stays). In this outcome measure, COVID-19-related medical visits of participants were reported.

    Measured: From Day 1 up to Day 34

  34. Number of COVID-19 Related Medical Visits- mITT2 Population

    Medical visits included emergency room, practitioner's office, home healthcare services, urgent care, telephone consultation, outpatient infusion center, other, COVID-19-related-hospitalization (ICU and non-ICU stays). In this outcome measure, COVID-19-related medical visits of participants were reported.

    Measured: From Day 1 up to Day 34

  35. Number of Days in Hospital and ICU for the Treatment of COVID-19- mITT Population

    Measured: From Day 1 up to Day 34

  36. Number of Days in Hospital and ICU for the Treatment of COVID-19- mITT1 Population

    Measured: From Day 1 up to Day 34

  37. Number of Days in Hospital and ICU for the Treatment of COVID-19- mITT2 Population

    Measured: From Day 1 up to Day 34

Timeline

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

  1. First posted13 Jul 2021
  2. Study start16 Jul 2021
  3. Primary completion9 Dec 2021
  4. Study completion25 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 2/3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
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 blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
2,091 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04960202
Sponsor's protocol ID
C4671005
Other IDs
2021-002895-38, EPIC-HR
Status last verified
Jul 2025
First submitted
10 Jul 2021
Last updated
10 Jul 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: 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

  • Ansari W, Coetzer H, Gebo KA, Ren J, Scott A, Cappelleri JC, Cha-Silva AS, Leister-Tebbe H. Patient-Reported Outcomes of Nirmatrelvir Treatment for High-Risk, Nonhospitalized Adults With Symptomatic COVID-19. Open Forum Infect Dis. 2025 Aug 1;12(8):ofaf449. doi: 10.1093/ofid/ofaf449. eCollection 2025 Aug.

    PubMed 40809391
  • Baniecki ML, Guan S, Rai DK, Yang Q, Lee JT, Hao L, Weinstein E, Hyde C, Cardin RD, Soares H, Hammond J. Integrated virologic analysis of resistance to nirmatrelvir/ritonavir in individuals across four phase 2/3 clinical studies for the treatment of COVID-19. EBioMedicine. 2025 Aug;118:105819. doi: 10.1016/j.ebiom.2025.105819. Epub 2025 Jun 30.

    PubMed 40592258
  • Hammond J, Leister-Tebbe H, Gardner A, Abreu P, Bao W, Wisemandle W, Ansari W, Harrington MA, Simon-Campos A, Chew KW, Pypstra R, Rusnak JM. Alleviation of COVID-19 Symptoms and Reduction in Healthcare Utilization Among High-risk Patients Treated With Nirmatrelvir/Ritonavir (NMV/R): A Phase 3 Randomized Trial. Clin Infect Dis. 2025 Feb 24;80(2):323-330. doi: 10.1093/cid/ciae551.

    PubMed 39523543
  • Hammond J, Leister-Tebbe H, Gardner A, Abreu P, Bao W, Wisemandle W, Baniecki M, Hendrick VM, Damle B, Simon-Campos A, Pypstra R, Rusnak JM; EPIC-HR Investigators. Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19. N Engl J Med. 2022 Apr 14;386(15):1397-1408. doi: 10.1056/NEJMoa2118542. Epub 2022 Feb 16.

    PubMed 35172054

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing PF-07321332 and Ritonavir in people with COVID-19, run by Pfizer at 201 sites in 20 countries.

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 4 inclusion and 14 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 10 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 201 sites in United States, Bulgaria, Mexico, Turkey (Türkiye), Ukraine and 15 more countries. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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 9 Feb 2023). 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?

Percentage of Participants With Covid-19 Related Hospitalization or Death From Any Cause Through Day 28- Modified Intent-To-Treat (mITT) Population (time frame: From Day 1 to Day 28). 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 NCT04960202, which also lists 4 linked publications.

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 10 Jul 2025.

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