AzTrials
AzTrials

COVID-19Phase 2/3NCT05011513

Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients (EPIC-SR).

A Phase 2/3 study testing PF-07321332 and Ritonavir in people with COVID-19, run by Pfizer at 225 sites in 20 countries.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
Search all trials

Trial summary

The primary hypothesis to be tested is whether or not there is a difference in time to sustained alleviation of all targeted COVID-19 signs and symptoms through Day 28 between PF-07321332/ritonavir and placebo. 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
1,440 participants
Where
225 sitesin 20 countries
Study dates
25 Aug 2021to 25 Jul 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 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

Who cannot join

  • 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
Show all 14Show fewer
  • 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

Trial locations and contacts

225 sites in 20 countries.

225 sites in 20 countries

United States78 sites

  • PharmaTex Research, LLC

    Amarillo, Texas, 79109

  • Accellacare

    Ames, Iowa, 50010

  • McFarland Clinic, PC

    Ames, Iowa, 50010

  • ARC Clinical Research at William Cannon

    Austin, Texas, 78745

  • St Hope Foundation

    Bellaire, Texas, 77401

  • Synergy Healthcare

    Bradenton, Florida, 34208

  • MOORE Clinical Research, Inc.

    Brandon, Florida, 33511

  • TrueBlue Clinical Research

    Brandon, Florida, 33511

  • Mercury Street Medical Group, PLLC

    Butte, Montana, 59701

  • Hope Clinical Research

    Canoga Park, California, 91303

  • 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

  • Omega Research Orlando, LLC

    DeBary, Florida, 32713

  • Lightship

    El Segundo, California, 90245

  • Ascada Research

    Fullerton, California, 92835

  • Eastern Research Inc

    Hialeah, Florida, 33013

  • Inpatient Research Clinic

    Hialeah, Florida, 33013

  • 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

  • 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

  • ASCLEPES Research Centers

    Lutz, Florida, 33549

  • 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

  • Southern Clinical Research Associates, LLC

    Metairie, Louisiana, 70001

  • 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

  • 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, Inc.

    Miami, Florida, 33185

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

    Miami, Florida, 33186

  • Coral Research Clinic Corp

    Miami, Florida, 33186

  • Pro-Care Research Center, Corp.

    Miami Gardens, Florida, 33014

  • Savin Medical Group, LLC

    Miami Lakes, Florida, 33014

  • Monroe Biomedical Research

    Monroe, North Carolina, 28112

  • NYC Health + Hospitals / Harlem

    New York, New York, 10037

  • TMPG Clinical Research

    Newport News, Virginia, 23606

  • TPMG 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

  • CDC Research Institute

    Port Saint Lucie, Florida, 34952

  • Epic Medical Research

    Red Oak, Texas, 75154

  • South Bay Clinical Research Institute

    Redondo Beach, California, 90277

  • Benchmark Research

    Sacramento, California, 95864

  • Endeavor Clinical Trials, LLC

    San Antonio, Texas, 78229

  • BFHC Research

    San Antonio, Texas, 78249

  • Optimus Medical Group

    San Francisco, California, 94102

  • AXCES Research Group

    Santa Fe, New Mexico, 87505

  • Matrix Mobile Health Clinic #49, #35, and #62

    Scottsdale, Arizona, 85258

  • Avera McKennan Hospital & University Health Center

    Sioux Falls, South Dakota, 57105

  • Avera Research Institute

    Sioux Falls, South Dakota, 57108

  • USPA Advance Concept Medical Research Group LLC

    South Miami, Florida, 33143

  • ASCLEPES Research Centers

    Spring Hill, Florida, 34609

  • 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

  • Innovo Research: Wilmington Health

    Wilmington, North Carolina, 28401

  • Clinical Site Partners, Inc. dba CSP Orlando

    Winter Park, Florida, 32789

Other trials in United States

Bulgaria23 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

  • Multiprofile Hospital for Active Treatment - Samokov EOOD

    Samokov, 2000

  • Medical Center-1-Sevlievo EOOD

    Sevlievo, 5400

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

    Sliven, 8800

  • Diagnostic-Consultative Center XXII- Sofia ЕООD

    Sofia, 1113

  • UMHATEM N. I. Pirogov EAD

    Sofia, 1606

  • 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

  • MOBAL "D-r Stefan Cherkezov" AD

    Veliko Tarnovo, 5002

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

    Vratsa, 3000

Other trials in Bulgaria

Brazil15 sites

  • Hospital Dia do Pulmao

    Blumenau, Santa Catarina, 89030-101

  • CECOR - Centro Oncológico de Roraima

    Boa Vista, Roraima/rr, 69304-015

  • Chronos Pesquisa Clinica

    Brasília, Federal District, 72145-450

  • Hospital e Maternidade Celso Pierro - PUC Campinas / Sociedade Campineira de Educação e Instruçã

    Campinas, São Paulo, 13060-904

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

    Jaú, São Paulo, 17201-130

  • Centro de Estudos e Pesquisas em Moléstias Infecciosas

    Natal, Rio Grande do Norte, 59025-050

  • Hospital De Clinicas De Porto Alegre

    Porto Alegre, Rio Grande do Sul, 90035-903

  • Hospital Agamenon Magalhaes

    Recife, Pernambuco, 52051-380

  • IBPClin - Instituto Brasil de Pesquisa Clínica

    Rio de Janeiro, Rio de Janeiro, 20241-180

  • Instituto Nacional de Infectologia Evandro Chagas - INI/FIOCRUZ

    Rio de Janeiro, Rio de Janeiro, 21040-360

  • CEMEC - Centro Multidisciplinar de Estudos Clínicos

    São Bernardo do Campo, São Paulo, 09715-090

  • Hospital Alemão Oswaldo Cruz

    São Paulo, São Paulo, 01327-001

  • Unidade Referenciada Oswaldo Cruz Vergueiro

    São Paulo, São Paulo, 01508-000

  • Instituto de Infectologia Emilio Ribas

    São Paulo, 01246-900

  • Clinica de Alergia Martti Antila

    Sorocaba, São Paulo, 18040-425

Other trials in Brazil

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

  • Cukurova University Medical Faculty

    Balcali, Adana, 01330

  • Gaziantep Universitesi Tip Fakultesi Sahinbey Uygulama ve Arastirma Hastanesi

    Gaziantep, 27310

  • Istanbul University Istanbul Medical Faculty

    Istanbul, 34093

  • Istanbul University Cerrahpasa-Cerrahpasa Medical Faculty

    Istanbul, 34098

  • Medipol Mega University Hospital

    Istanbul, 34214

  • Acibadem University Atakent Hospital

    Istanbul, 34303

  • Basaksehir Cam ve Sakura Sehir Hastanesi

    Istanbul, 34480

  • Izmir Suat Seren Chest Disease and Surgery Training and Research Hospital

    Izmir, 35110

  • Kocaeli University Medical Faculty

    Kocaeli, 41380

  • Mersin University Medical Faculty

    Mersin, 33110

  • Sakarya University Training and Research Hospital

    Sakarya, 54100

  • Karadeniz Teknik Universitesi Farabi Hastanesi

    Trabzon, 61080

Other trials in Turkey (Türkiye)

Ukraine14 sites

  • Regional Communal Nonprofit Institution "Chernivtsi Regional Clinical Hospital"

    Chernivtsi, 58001

  • Communal non-commercial Enterprise "City Clinical Hospital №3" of Chernivtsi City Council

    Chernivtsi, 58002

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

    Ivano-Frankivsk, 76007

  • Municipal Non-profit Enterprise "Ivano-Frankivsk Regional Phthisiopulmonology Center of

    Ivano-Frankivsk, 76018

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

    Ivano-Frankivsk, 76025

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

    Kharkiv, 61096

  • Municipal Non-profit Enterprise "Oleksandrivska Kyiv City Clinical Hospital" Of Executive Body Of

    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 "Lviv City Clinic Hospital #4"

    Lviv, 79011

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

    Poltava, 36011

  • 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

South Africa13 sites

  • Worthwhile Clinical Trials

    Benoni, Gauteng, 1500

  • Reimed Vosloorus

    Boksburg, Gauteng, 1475

  • Synapta Clinical Research Center

    Durban, KwaZulu-Natal, 4001

  • Dr PJ Sebastian Clinical Research Centre

    Durban, KwaZulu-Natal, 4092

  • TASK Eden

    George, Western Cape, 6530

  • Lenasia Clinical Trial Centre

    Johannesburg, Gauteng, 1820

  • Ahmed Al-Kadi Private Hospital

    Mayville, Durban, KwaZulu-Natal, 4091

  • Be Part Research Pty (Ltd)

    Paarl, Western Cape, 7626

  • Global Clinical Trials

    Port Elizabeth, Eastern Cape, 6014

  • Botho Ke Bontle Health Services

    Pretoria, Gauteng, 0184

  • Clinical Trial Systems (Pty) Ltd

    Pretoria, Gauteng, 0186

  • Sandton Medical Clinic

    Sandton, Gauteng, 2196

  • FCRN Clinical Trial Centre

    Vereeniging, Gauteng, 1935

Other trials in South Africa

Mexico11 sites

  • JM Research SC

    Cuernavaca, Morelos, 62290

  • Instituto de Investigaciones Clínicas para la Salud

    Durango, 34000

  • 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

  • Asociación Mexicana para la Investigación Clínica A.C.

    Pachuca, Hidalgo, 42070

  • Clinical Research Institute S.C.

    Saltillo, Coahuila, 25020

  • FAICIC Clinical Research

    Veracruz, 91900

  • Sociedad de Metabolismo y Corazon S.C.

    Veracruz, 91900

Other trials in Mexico

Thailand9 sites

  • Bangkok Centre Hotel

    Bang Rak, Bangkok, 10500

  • Siriraj Hospital, Mahidol University

    BangkokNoi, Bangkok, 10700

  • Riverside Bangkok Hotel

    Bangplud, Bangkok, 10700

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

    Hat Yai, Changwat Songkhla, 90110

  • Khon Kaen Univerisity Field Hospital, Student Dormitory 26, Khon Kaen University

    Khon Kaen, 40002

  • Srinagarind Hospital

    Khon Kaen, 40002

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

    Pathumwan, Bangkok, 10330

  • Thai Red Cross Emerging Infectious Diseases (EDI) Clinic

    Pathumwan,, Bangkok, 10330

  • Baiyoke Suite Hotel

    Ratchathewi, Bangkok, 10400

Other trials in Thailand

Hungary7 sites

  • Trial Pharma Kft.

    Békéscsaba, 5600

  • Semmelweis University Varosmajori Sziv Es Ergyogyaszati Klinika

    Budapest, 1122

  • Varosmajori Sziv- es Ergyogyaszati Klinika

    Budapest, 1122

  • 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

Spain7 sites

  • Complexo Hospitalario Universitario da Coruna

    A Coruña, 15006

  • Hospital Universitari Germans Trias i Pujol

    Badalona, Barcelona, 08916

  • IMED Valencia

    Burjassot, Valencia, 46100

  • Eba Centelles

    Centelles, Barcelona [barcelona], 08540

  • Hospital Universitario de la Paz

    Madrid, 28046

  • Hospital Universitario Virgen de Valme

    Seville, 41014

  • Hospital Alvaro Cunqueiro

    Vigo, Pontevedra, 36312

Other trials in Spain

Argentina5 sites

  • Hospital Privado Centro Médico de Córdoba

    Córdoba, X5016KEH

  • Instituto Médico de la Fundación Estudios Clínicos (Fundación Estudios Clínicos)

    Rosario, Santa Fe Province, 2000

  • Hospital de Clinicas Presidente Nicolas Avellaneda

    San Miguel de Tucumán, Tucumán Province, 4000

  • Clinica Mayo Urgencias Medicas Cruz Blanca SRL

    San Miguel de Tucumán, Tucumán Province, T4000IHE

  • Instituto de Investigaciones Clinicas Zarate

    Zárate, Buenos Aires, B2800DGH

Other trials in Argentina

Japan5 sites

  • Kyushu Medical Center

    Fukuoka, 810-8563

  • Rakuwakai Otowa Hospital

    Kyoto, Kyoto, 607-8062

  • International University of Health and Welfare Narita Hospital

    Narita, Chiba, 286-8520

  • Tokyo Shinagawa Hospital

    Shinagawa-ku, Tokyo, 140-8522

  • Sekino Hospital

    Toshimaku, Tokyo, 171-0014

Other trials in Japan

Malaysia4 sites

  • Hospital Raja Perempuan Zainab II

    Kota Bharu, Kelantan, 15586

  • Hospital Miri

    Miri, Sarawak, 98000

  • Klinik Kesihatan Kuang

    Rawang, Selangor, 48050

  • Hospital Taiping

    Taiping, Perak, 34000

Other trials in Malaysia

Poland4 sites

  • KLIMED Marek Klimkiewicz

    Bialystok, 15-704

  • Tomasz Blicharski Lubelskie Centrum Diagnostyczne

    Świdnik, 21-040

  • WIP Warsaw IBD Point Profesor Kierkus

    Warsaw, 00-728

  • Centrum Badań Klinicznych Piotr Napora Lekarze Spółka Partnerska

    Wroclaw, 51-162

Other trials in Poland

Slovakia4 sites

  • HODOSI - MED, s.r.o.

    Moldava nad Bodvou, 04501

  • MUDr. Viliam Cibik, PhD., s.r.o.

    Pruské, 018 52

  • Plucna ambulancia Hrebenar, s.r.o.

    Spišská Nová Ves, 052 01

  • ALERGIA s.r.o.

    Topoľčany, 955 01

Other trials in Slovakia

Colombia3 sites

  • Fundacion Cardiomet Cequin

    Armenia, Quindío Department, 630004

  • Centro de Investigacion en Reumatologia y Especialidades Medicas S.A.S, CIREEM S.A.S

    Bogota, Cundinamarca, 110221

  • Fundacion Centro de Investigacion Clinica CIC

    Medellín, Antioquia, 050021

Other trials in Colombia

South Korea3 sites

  • Chonnam National University Bitgoeul Hospital

    Gwangju, 61748

  • Boramae Medical Center

    Seoul, 07061

  • SMG-SNU Boramae Medical Center

    Seoul, 07061

Other trials in South Korea

Czechia2 sites

  • Zdraví-Fit, s.r.o.

    Protivín, 398 11

  • Nemocnice Slany

    Slaný, 274 01

Other trials in Czechia

Puerto Rico2 sites

  • Clinical Research Management Group Inc

    Ponce, 00780

  • Advance Medical Research Center

    San Juan, 00926

Other trials in Puerto Rico

Romania1 site

  • Delta Health Care srl

    Bucharest, 014142

Other trials in Romania

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 LOW RISK OF PROGRESSING TO SEVERE ILLNESS

The primary hypothesis to be tested is whether or not there is a difference in time to sustained alleviation of all targeted COVID-19 signs and symptoms through Day 28 between PF-07321332/ritonavir and placebo.

Read the detailed description

Throughout the study period, provision will be made to allow study visits to be conducted at a participant's home or at 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
SARS-CoV-2 Infection
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)

  • PlaceboDrug

    Placebo (capsule)

Study groups in NCT05011513
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. Time to Sustained Alleviation of Overall COVID-19 Signs and Symptoms Through Day 28

    Sustained alleviation of 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. Missing severity at baseline was considered as mild. Time to sustained alleviation of all targeted COVID-19 signs and symptoms through Day 28, was calculated as time (days) from start of study intervention or placebo (Day 1) until sustained alleviation of all targeted COVID-19 associated signs and symptoms. In this outcome measure time to sustained alleviation is reported consolidated for overall COVID-19 signs and symptoms.

    Measured: From Day 1 to Day 28

Secondary outcomes (13)

  1. Number of Participants With Treatment Emergent Adverse Events (TEAEs), Serious AEs and AEs Leading to Study and Study Drug Discontinuation

    An AE was defined as any untoward medical occurrence in a participant or clinical study participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. An SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening ; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity ; congenital anomaly/birth defect; or that was considered as an important medical event. TEAEs were defined as events that started on or after the study medication start date and time. AEs included both serious and all non-serious adverse events. AEs that led to study discontinuation and AEs that led to discontinuation of study intervention and then continued study were also reported in this outcome measure.

    Measured: From start of study intervention (Day 1) up to Day 34

  2. Percentage of Participants With COVID-19 Related Hospitalization or Death From Any Cause Through Day 28

    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.

    Measured: From Day 1 to Day 28

  3. Percentage of Participants With Death Through Week 24

    Percentage of participants with death (all-cause) event were reported in this outcome measure.

    Measured: From Day 1 to Week 24

  4. Number of COVID-19 Related Medical Visits Per Day Through Day 28

    Number of COVID-19 related medical visits per day were reported in this outcome measure.

    Measured: From Day 1 to Day 28

  5. Duration of Hospitalization and Intensive Care Unit (ICU) Stay Through Day 28

    Measured: From Day 1 to Day 28

  6. Percentage of Participants With Severe Signs and Symptoms of COVID-19 Through Day 28

    Participants recorded a daily severity rating of their symptom severity over the past 24 hours based on a 4-point scale in which 0 was reported if no symptoms were present; 1 if mild; 2 if moderate; and 3 if severe. A participant with severe score for any targeted symptoms post-baseline was counted as severe. Vomiting and diarrhea each was rated on a 4-point frequency scale where 0 was reported for no occurrence, 1 for 1 to 2 times, 2 for 3 to 4 times, and 3 for 5 or greater. Sense of smell and sense of taste each be rated on a 3-point Likert scale where 0 was reported if the sense of smell/taste was the same as usual, 1 if the sense of smell/taste was less than usual, and 2 for no sense of smell/taste.

    Measured: From Day 1 to Day 28

  7. Time to Sustained Resolution of Overall COVID-19 Signs and Symptoms Through Day 28

    Sustained resolution was defined as when targeted symptoms are scored as absent for 4 consecutive days. The first day of the 4 consecutive-day period was considered the first event date.

    Measured: From Day 1 to Day 28

  8. Time to Sustained Alleviation of Each COVID-19 Signs and Symptoms Through Day 28

    Sustained alleviation of 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. Missing severity at baseline was treated as mild. Time to sustained alleviation of all targeted COVID-19 signs and symptoms through Day 28, was calculated as time (days) from start of study intervention or placebo (Day 1) until sustained alleviation of all targeted COVID-19 associated signs and symptoms. In this outcome measure time to sustained alleviation is reported for each COVID-19 signs and symptoms.

    Measured: From Day 1 to Day 28

  9. Time to Sustained Resolution of Each COVID-19 Signs and Symptoms Through Day 28

    Sustained resolution was defined as when targeted symptoms are scored as absent for 4 consecutive days. The first day of the 4 consecutive-day period was considered the first event date. In this outcome measure time to sustained resolution is reported consolidated for each COVID-19 signs and symptoms.

    Measured: From Day 1 to Day 28

  10. Percentage of Participants With Progression to Worsening Status of COVID-19 Signs and Symptoms

    Participants recorded a daily severity rating of their symptom severity over the past 24 hours based on a 4-point scale in which 0 was reported if no symptoms were present; 1 if mild; 2 if moderate; and 3 if severe. Vomiting and diarrhea was rated on a 4-point frequency scale where 0 is reported for 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 to Day 28

  11. Percentage of Participants With Resting Peripheral Oxygen Saturation Greater Than or Equal to (>=) 95% at Day 1 and Day 5

    Percentage of participants with a resting peripheral oxygen saturation >=95% were reported in this outcome measure.

    Measured: Day 1 and Day 5

  12. Plasma Concentration Versus Time Summary of PF-07321332

    Measured: Day 1: 1 hour post dose; Day 5: 0 minutes pre-dose

  13. Change From Baseline in Logarithm to Base10 (Log10) Transformed Viral Load at Days 3, 5, 10 and 14

    Nasal samples were collected to estimate the viral load in participants in terms of logarithm to base 10 (log10) copies per milliliter.

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

Timeline

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

  1. First posted18 Aug 2021
  2. Study start25 Aug 2021
  3. Primary completion25 Jul 2022
  4. Study completion25 Jul 2022

Why it stopped: Enrollment ceased due to a very low rate of hospitalization or death observed in the standard-risk patient population

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
1,440 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05011513
Sponsor's protocol ID
C4671002
Other IDs
2021-002857-28, EPIC-SR
Status last verified
Jul 2023
First submitted
30 Jul 2021
Last updated
14 Aug 2023
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

  • Brown TM, Kanu C, Harrington M. Assessing participants' experiences with the COVID-19 symptom diary in a clinical trial. J Patient Rep Outcomes. 2025 Aug 11;9(1):99. doi: 10.1186/s41687-025-00901-5.

    PubMed 40788441

  • 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, Fountaine RJ, Yunis C, Fleishaker D, Almas M, Bao W, Wisemandle W, Baniecki ML, Hendrick VM, Kalfov V, Simon-Campos JA, Pypstra R, Rusnak JM. Nirmatrelvir for Vaccinated or Unvaccinated Adult Outpatients with Covid-19. N Engl J Med. 2024 Apr 4;390(13):1186-1195. doi: 10.1056/NEJMoa2309003.

    PubMed 38598573

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 225 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 3 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: stopped early, as of the sponsor's last update on 14 Aug 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 225 sites in United States, Bulgaria, Brazil, 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 14 Aug 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?

Time to Sustained Alleviation of Overall COVID-19 Signs and Symptoms Through Day 28 (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 NCT05011513, which also lists 3 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 14 Aug 2023.

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