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Safety and Efficacy of AT-527 in Subjects With Moderate Coronavirus Disease (COVID-19) in a Hospital Setting

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: NCT04396106
Recruitment Status : Terminated (Study closed out early due to evolving COVID-19 standard of care)
First Posted : May 20, 2020
Results First Posted : March 9, 2023
Last Update Posted : March 9, 2023
Information provided by (Responsible Party):
Atea Pharmaceuticals, Inc.

Brief Summary:
The objectives of this study are to evaluate the safety, tolerability, antiviral activity and efficacy of AT-527 in adult subjects ≥18 years of age with moderate COVID-19 and risk factors for poor outcomes (such as obesity (BMI>30), hypertension, diabetes or asthma). Eligible subjects will be randomized to blinded AT-527 (nucleotide analog) tablets or matching placebo tablets to be administered orally for 5 days. Part A will evaluate an AT-527 dose of 550 mg BID and Part B will evaluate a second dose of AT-527 (1100 mg BID). Local supportive standard of care (SOC) will be allowed for all subjects. Efficacy, antiviral activity and safety observations will be compared for treatment with active AT-527 tablets vs. placebo tablets.

Condition or disease Intervention/treatment Phase
COVID-19 Drug: AT-527 Other: Placebo Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 83 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Masking Description: Blinded
Primary Purpose: Treatment
Official Title: A Phase 2 Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety and Efficacy of AT-527 in Subjects With Moderate COVID-19
Actual Study Start Date : May 26, 2020
Actual Primary Completion Date : January 10, 2022
Actual Study Completion Date : February 28, 2022

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: AT-527 - 550 mg BID
Part A
Drug: AT-527
One 550 mg tablet of AT-527 administered every ~12 hours (twice a day) for a total of 5 days

Placebo Comparator: Placebo for 550 mg BID
Part A
Other: Placebo
One placebo tablet administered every ~12 hours (twice a day) for a total of 5 days

Active Comparator: AT-527 - 1100 mg BID
Part B
Drug: AT-527
Two 550 mg tablets of AT-527 administered every ~12 hours (twice a day) for a total of 5 days

Placebo Comparator: Placebo for 1100 mg BID
Part B
Other: Placebo
Two placebo tablets administered every ~12 hours (twice a day) for a total of 5 days

Primary Outcome Measures :
  1. Proportions (Active vs. Placebo) of Subjects With Progressive Respiratory Insufficiency (PRI) on or Before Day 14. [ Time Frame: Day 14 ]

    Progressive respiratory insufficiency defined as a ≥ 2-tier increase in respiratory support methods required to maintain satisfactory oxygenation (SpO2 ≥ 93%), using the 6-tier hierarchical scale of respiratory support methods, within the 14-day study period.

    Level 1:Normal oxygenation on room air (SpO2 ≥93), no need for supplemental O2 Level 2:Persistent hypoxemia on room air (SpO2 <93) with requirement for low-level supplemental O2 by nasal cannula/mask (up to 2L/min) to maintain SpO2 ≥93 Level 3:Requirement for higher levels of passive supplemental O2 by nasal cannula or mask (≥2 L/min) to maintain SpO2 ≥93 Level 4:Requirement for oxygenation by positive-pressure devices Level 5:Required invasive respiratory support (intubated mechanical ventilation or ECMO) Level 6:Death

Secondary Outcome Measures :
  1. Change From Baseline in Amount of SARS-CoV-2 Virus RNA by Nasopharyngeal Swab [ Time Frame: Through Day 14 ]
    Change in the viral load as measured by swab of the upper part of the pharynx.

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

Key Inclusion Criteria:

  • Hospitalized or in a hospital-affiliated confinement facility
  • SARS-CoV-2 positive
  • Initial COVID-19 symptom onset within 5 days prior to Screening
  • SpO2 ≥ 93% on room air or requires ≤ 2L/min oxygen by nasal cannula or mask to maintain SpO2 ≥ 93%
  • Must also have a history of at least one of the following known risk factors for poor outcomes: obesity (BMI>30), hypertension, diabetes or asthma.

Key Exclusion Criteria:

  • Severe or critical COVID-19 illness: RR ≥30, HR ≥125, SpO2 <93% on room air or requires >2L/min oxygen by nasal cannula or mask to maintain SpO2 ≥93%, systolic blood pressure < 90 mm Hg, diastolic blood pressure < 60 mm Hg or PaO2/FiO2 <300
  • Requires mechanical ventilation
  • Lobar or segmental consolidation on chest imaging.
  • Treatment with other drugs thought to possibly have activity against SARS-CoV-2
  • ALT or AST > 5 x upper limit of normal (ULN)
  • Female subject is pregnant or breastfeeding
  • Has received or is expected to receive any dose of a SARS-CoV-2 vaccine before the Day 14 visit (Part B).

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): NCT04396106

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United States, Arizona
Atea Study Site
Scottsdale, Arizona, United States, 85258
United States, California
Atea Study Site
Davis, California, United States, 95817
Atea Study Site
Los Angeles, California, United States, 90017
United States, District of Columbia
Atea Study Site
Washington, District of Columbia, United States, 20037
United States, Florida
Atea Study Site
Orlando, Florida, United States, 32804
United States, Georgia
Atea Study Site
Atlanta, Georgia, United States, 30303
United States, Illinois
Atea Study Site
Chicago, Illinois, United States, 60611
Atea Study Site
Chicago, Illinois, United States, 60612
United States, Massachusetts
Atea Study Site
Boston, Massachusetts, United States, 02115
United States, Montana
Atea Study Site
Butte, Montana, United States, 59701
United States, North Carolina
Atea Study Site
Charlotte, North Carolina, United States, 28204
United States, Ohio
Atea Study Site
Cincinnati, Ohio, United States, 45219
Atea Study Site
Columbus, Ohio, United States, 43203
United States, South Carolina
Atea Study Site
Charleston, South Carolina, United States, 29425
Atea Study Site
Columbia, South Carolina, United States, 29203
Atea Study Site
Rosario, Argentina
Atea Study Site
Vicente Lopez, Argentina
Atea Study Site
Brussels, Belgium
Atea Study Site
Mechelen, Belgium
Atea Study Site
Belo Horizonte, Brazil
Atea Study Site
Brasília, Brazil
Atea Study Site
Campo Largo, Brazil
Atea Study Site
Porto Alegre, Brazil
Atea Study Site
São Paulo, Brazil
Atea Study Site
Cairo, Egypt
Moldova, Republic of
Atea Study Site
Chisinau, Moldova, Republic of
Atea Study Site
Bucharest, Romania
South Africa
Atea Study Site
Bloemfontein, South Africa
Atea Study Site
Cape Town, South Africa
Atea Study Site
Centurion, South Africa
Atea Study Site
George, South Africa
Atea Study Site
Worcester, South Africa
Atea Study Site
Barcelona, Spain
Atea Study Site
Madrid, Spain
Atea Study Site
Pozuelo De Alarcón, Spain
Atea Study Site
Brovary, Ukraine
Atea Study Site
Kyiv, Ukraine
Sponsors and Collaborators
Atea Pharmaceuticals, Inc.
  Study Documents (Full-Text)

Documents provided by Atea Pharmaceuticals, Inc.:
Study Protocol  [PDF] August 26, 2021
Statistical Analysis Plan  [PDF] March 16, 2022

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Responsible Party: Atea Pharmaceuticals, Inc.
ClinicalTrials.gov Identifier: NCT04396106    
Other Study ID Numbers: AT-03A-001
First Posted: May 20, 2020    Key Record Dates
Results First Posted: March 9, 2023
Last Update Posted: March 9, 2023
Last Verified: February 2023

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
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