Oral Favipiravir Compared to Placebo in Subjects With Mild COVID-19
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04346628 |
Recruitment Status :
Completed
First Posted : April 15, 2020
Results First Posted : April 21, 2022
Last Update Posted : July 13, 2022
|
- Study Details
- Tabular View
- Study Results
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Sars-CoV2 COVID-19 | Drug: Favipiravir Drug: Placebo Other: Standard of care treatment | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 149 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Treatment |
Official Title: | A Phase 2 Randomized, Double Blinded, Placebo Controlled Study of Oral Favipiravir Compared to Standard Supportive Care in Subjects With Mild or Asymptomatic COVID-19 |
Actual Study Start Date : | July 12, 2020 |
Actual Primary Completion Date : | April 16, 2021 |
Actual Study Completion Date : | April 16, 2021 |

Arm | Intervention/treatment |
---|---|
Experimental: Favipiravir
In addition to SOC, participants will receive favipiravir for 10 days, and be evaluated for health outcomes through day 28.
|
Drug: Favipiravir
Favipiravir administered orally, 1800 mg on the first dose (day 1) followed by 800 mg twice daily for the next 9 days (days 2-10). Other: Standard of care treatment Standard of care treatment for COVID-19 infection |
Active Comparator: Placebo
In addition to SOC, participants will receive placebo to match favipiravir for 10 days, and be evaluated for health outcomes through day 28.
|
Drug: Placebo
Placebo to match favipiravir administered orally through day 10. Other: Standard of care treatment Standard of care treatment for COVID-19 infection |
- Time Until Cessation of Oral Shedding of SARS-CoV-2 Virus [ Time Frame: Up to 28 days ]Time in days from randomization to the first two negative results of nasal and/or oropharyngeal swab.
- Sars-CoV-2 Viral Load [ Time Frame: Up to 28 days ]Viral load (nucleic acid) will be assessed by RT-PCR Ct over time. Cycle threshold (Ct) denotes how many PCR cycles are required before the SARS-CoV-2 viral RNA reached a detectable level. Higher Ct values correspond to lower viral copy numbers. For reference, Ct values of 20 correspond to ~2.12 x 106 viral copies per milliliter, while a Ct value of 40 is undetectable and is considered the lower limit of detection of this RT-PCR test for SARS-CoV-2.
- Count of Participants With Clinical Worsening of COVID-19 Disease [ Time Frame: Up to 28 days ]Clinical worsening is reported as the number of participants with hospitalization or emergency department (ED) visits.
- Count of Participants With Development of SARS-CoV-2 Antibodies [ Time Frame: Up to 28 days ]
- Time Until Cessation of Symptoms [ Time Frame: Up to 28 days ]Time until cessation of symptoms is reported as days until initial resolution and sustained resolution of symptoms.
- Count of Participant With Absence of Development of Any Symptoms [ Time Frame: Up to 28 days ]This outcome will be assessed in patient who are asymptomatic of COVID-19 infection at the time of enrollment
- Cmax of Favipiravir [ Time Frame: Days 1 and 10 (samples taken 30 minutes prior to and 1 hour following favipiravir administration) ]Cmax is a pharmacokinetic parameter that measures the maximum concentration of drug in plasma.
- Cmin of Favipiravir [ Time Frame: Days 1 and 10 (samples taken 30 minutes prior to and 1 hour following favipiravir administration) ]Cmin is a pharmacokinetic parameter that measures the minimum concentration of drug in plasma.

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:
-
Diagnosis of COVID-19 disease:
- If symptomatic, presence of mild to moderate symptoms without signs of respiratory distress, with positive for SARS-CoV-2 diagnostic assay within 72 hours prior to.informed consent.
- If asymptomatic, initial diagnosis obtained no more than 72 hours prior to informed consent
- Subject agrees to maintain home or other quarantine as recommended by the study physician, except to visit the study site as required by the protocol
- Members of the same household may participate in the study as long as the inclusion and exclusion criteria are met
- Males must be sterile, OR agree not to donate semen AND agree to strictly adhere to contraceptive measures during the study and for seven days following the last dose of study medication
- Females must be unable to bear children, OR ensure that their male partner is incapable of fathering a child, OR, if of childbearing potential will strictly adhere to contraceptive measures during the study and for seven days following the last dose of study medication
- Females must agree to stop breast-feeding prior to first dose of study drug and through seven days after completing therapy
- Females must have a negative pregnancy test at screening
- Participant agrees to maintain home or other quarantine as recommended by the study physician, except to visit the study site as required by the protocol
Exclusion Criteria:
- Concomitant bacterial respiratory infection documented by respiratory culture. NOTE: Subjects on empirical antibiotic treatment for possible but unproven bacterial pneumonia, but who are positive for SARS-CoV-2, are allowed in the study (will be randomized to the same treatment to maintain blinding).
- History of abnormal uric acid metabolism.
- History of hypersensitivity to an anti-viral nucleoside-analog drug targeting a viral RNA polymerase.
- Abnormal laboratory test results at screening:
- Use of adrenocorticosteroids (except topical or inhaled preparations or oral preparations equivalent to or less than 10 mg of oral prednisone) or immunosuppressive or immunomodulatory drugs (e.g., immunosuppressants, anticancer drugs, interleukins, interleukin antagonists or interleukin receptor blockers). NOTE: Treatment of study participants following institutional COVID-19 treatment policies or guidelines, including the use of immunomodulatory medications, is permitted. This excludes treatment with agents that have the potential for direct antiviral activity, including convalescent plasma and NO, and co-enrollment into other clinical studies that evaluate investigational agents for COVID-19.
- Serious chronic disease (e.g., human immunodeficiency virus [HIV], cancer requiring chemotherapy within the preceding 6 months, and/or moderate or severe hepatic insufficiency).
- Previously received favipiravir within the past 30 days.
- Advanced kidney disease
- Advanced liver disease
- History of alcohol or drug abuse in the previous two years.
- Psychiatric illness that is not well controlled (defined as stable on a regimen for more than one year).
- Taken another investigational drug within the past 30 days.
- Seemed by the Investigator to be ineligible for any reason.

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): NCT04346628
United States, California | |
Stanford University | |
Stanford, California, United States, 94305 |
Principal Investigator: | Yvonne (Bonnie) A Maldonado, MD | Stanford University |
Documents provided by Stanford University:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Stanford University |
ClinicalTrials.gov Identifier: | NCT04346628 |
Other Study ID Numbers: |
56032 |
First Posted: | April 15, 2020 Key Record Dates |
Results First Posted: | April 21, 2022 |
Last Update Posted: | July 13, 2022 |
Last Verified: | July 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Plan Description: | No current plan to share individual participant data (IPD). |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | No |
COVID-19 Pneumonia, Viral Pneumonia Respiratory Tract Infections Infections Virus Diseases Coronavirus Infections Coronaviridae Infections |
Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases Favipiravir Antiviral Agents Anti-Infective Agents |