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Molnupiravir to Prevent Severe COVID-19 Illness

This study is testing molnupiravir to see if it can prevent severe illness from COVID-19 in people who are at high risk. Molnupiravir is a medicine designed to stop the COVID-19 virus from making copies of itself in the body. Participants will receive either molnupiravir or a placebo (an inactive pill) for 5 days. Researchers will look at how many people are hospitalized, die, or need a COVID-19 related doctor's visit within 29 days. They will also track any side effects. You may be able to join if you are 18 or older, have a recent COVID-19 infection, and have had symptoms for 4 days or less. The current status of this study is unclear, but it plans to enroll 3082 people.

Study design
This is an interventional study comparing molnupiravir to a placebo, planning to enroll 3082 participants.
What's involved
You would take two pills twice a day for 5 days. Researchers will monitor you for side effects for about 5 months.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for up to 29 days to assess severe illness and up to approximately 5 months for adverse events.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06667700

A Clinical Study of Molnupiravir to Prevent Severe Illness From Coronavirus Disease 2019 (COVID-19) in People Who Are High Risk (MK-4482-023)

Recruiting
PHASE3Ages 18+InterventionalTreatment
Merck Sharp & Dohme LLC
~3,082 participants
Updated 2026-08-28 on ClinicalTrials.gov
What's tested:MolnupiravirPlacebo

At a glance

Recruiting sites
203 of 224 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Percentage of Participants Who Experienced One or More of Following Through Day 29: All-cause Hospitalization, All-cause Mortality, or Covid-19-related Medically-attended Visit (MAV)
Measured over Up to 29 days
+2 more outcomes measured

Conditions

Coronavirus Disease (COVID-19)

Explore related trials

COVID-19 Infection

Where it's being run

224 sites across 114 states
Florida21
Bulgaria10
California8
Texas8
Taiwan7
Kyivska Oblast6
Georgia5
Adjara5

Study leadership

  • Medical Director · STUDY_DIRECTOR · Merck Sharp & Dohme LLC

Who to contact

Toll Free Number
[email protected]
1-888-577-8839
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Is an individual of any sex/gender, ≥18 years of age
Has documentation of SARS-CoV-2 infection with sample collection ≤4 days prior to randomization
Has initial onset of signs/symptoms attributable to COVID-19 for ≤4 days prior to the day of randomization and ≥2 of the following signs/symptoms attributable to COVID-19 on the day of randomization: cough, sore throat, nasal congestion, shortness of breath or difficulty breathing with exertion, muscle or body aches, fatigue, fever \>38.0°C or chills, nausea or vomiting or diarrhea, change in sense of smell or change in sense of taste, or headache
Has ≥1 of the following characteristics or medical conditions associated with the highest risk of severe illness from COVID-19:
Advanced age of ≥75 years of age
Immunocompromised
Neurocognitive or physical disability
Has ≥3 characteristics or medical conditions which increase the risk of severe illness due to COVID-19 (e.g., chronic lung disease, obesity with body mass index (BMI) ≥35, diabetes)
Is unable or unwilling to receive treatment with nirmatrelvir/ritonavir (NMV/r) due to 1 or more of the following:
Is receiving drug(s) highly dependent on cytochrome P450 3A (CYP3A) for clearance and for which elevated concentrations are associated with serious and/or life-threatening consequences or drug(s) with a clinically significant drug-drug interaction for which co-administration is not possible
Is receiving potent CYP3A inducers where significantly reduced nirmatrelvir or ritonavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance
Has severe hepatic impairment
Has experienced prior adverse reactions or hepatotoxicity to NMV/r that would preclude future use
Has known or suspected NMV/r resistance
Has uncontrolled HIV infection
NMV/r is not approved/authorized in the participant's country or it is not accessible to participant (e.g., drug shortage)
Is unwilling to receive treatment with NMV/r

Exclusion

Is currently hospitalized or is expected to need hospitalization for COVID-19 imminently
Has received or plans to receive SARS-CoV-2 directed oral antivirals or monoclonal antibodies for current episode of COVID-19 (other than study intervention and, if applicable, remdesivir as standard of care)
Has ≥1 of the following signs/symptoms that are attributable to severe or critical COVID-19:
Shortness of breath at rest
Respiratory rate ≥30 breaths per minute
Heart rate ≥125 beats per minute
Peripheral oxygen saturation (SpO2) ≤93% on room air or on supplemental oxygen for a reason other than COVID-19 which has not increased since onset of COVID-19 signs/symptoms
New or increasing need for supplemental oxygen: receiving \>4 liters/minute supplemental oxygen due to COVID-19 OR on supplemental oxygen for a reason other than COVID-19 which has increased due to COVID-19
Has received a COVID-19 vaccine within 30 days prior to randomization
Has a history of confirmed influenza, respiratory syncytial virus (RSV), or SARS-CoV-2 infection (with or without symptoms; excluding current infection) within 30 days prior to randomization
Has known or suspected hypersensitivity to active or inactive ingredients of molnupiravir

What this trial measures

  • Percentage of Participants Who Experienced One or More of Following Through Day 29: All-cause Hospitalization, All-cause Mortality, or Covid-19-related Medically-attended Visit (MAV)Up to 29 days

    Hospitalization is defined as ≥24 hours of acute care in a hospital or similar acute care facility, including emergency rooms or facilities created to address hospitalization needs specifically for COVID-19. Hospitalization and death may be due to any cause. An MAV is defined as any unscheduled, nonroutine healthcare visit where the participant is evaluated by a licensed (according to local/national guidelines) healthcare provider. As prespecified by the protocol, the percentage of participants who experience ONE OR MORE of these 3 events (hospitalization, death, or COVID-19-related MAV) occurring from randomization through Day 29 will be presented.

  • Percentage of Participants Who Experienced an Adverse Event (AE)Up to approximately 5 months

    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The percentage of participants with at least 1 AE will be presented.

  • Percentage of Participants Who Discontinued Study Intervention Due to AEUp to approximately 5 days

    An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The percentage of participants who discontinue study intervention due to an AE will be presented.