COVID-19MOLCOVredNCT07720596
Molnupiravir and COVID-19 Mortality Reduction in the Omicron Era
An observational study of COVID-19 and SARS-CoV-2, run by Charles University, Czech Republic at 1 site in Czechia.
Trial summary
This retrospective real-world target trial emulation uses complete Czech nationwide registry data to evaluate whether molnupiravir treatment is associated with lower COVID-19 mortality during the Omicron era. Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- COVID-19, SARS-CoV-2
- What is being tested?
- Molnupiravir
- Type of treatment
- Pill or oral medicine
- How many people
- 1,795,570 participants
- Where
- 1 siteCzechia
- Study dates
- 1 Jan 2022to 31 Dec 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
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 20 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All adult patients with confirmed SARS-CoV-2 infection recorded in Czech nationwide health registry data from January 1, 2022, through December 31, 2024.
Who may be able to join
- Adult infection episodes among patients aged 20 years or older.
- Confirmed acute SARS-CoV-2 positivity recorded in the Infectious Disease Information System (ISIN) during the Omicron-era study period.
- Eligible for analysis at time zero, defined as the date of molnupiravir dispensing for treated patients and the matched date for controls.
- Mild-to-moderate COVID-19 suitable for oral antiviral treatment, operationalized by excluding those already dead, in ICU, or receiving mechanical ventilation at time zero.
Who cannot join
- Age below 20 years at time of positivity.
- Death, ICU hospitalization, or mechanical ventilation at time zero.
- Receipt of molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days before positivity.
- Receipt of molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days after the qualifying SARS-CoV-2 positivity, but outside the treatment-initiation eligibility window according to the SmPC.
Trial locations and contacts
1 site in 1 country.
Czechia1 site
Department of Pharmacology, Third Faculty of Medicine, Charles University
Prague, 10000
About this study
Official title: Effect of Molnupiravir on COVID-19 Mortality in the Omicron Era: A Real-World Target Trial Emulation Using Complete Czech Nationwide Data
This retrospective real-world target trial emulation uses complete Czech nationwide registry data to evaluate whether molnupiravir treatment is associated with lower COVID-19 mortality during the Omicron era. The study compares adults with confirmed acute COVID-19 treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir. Patients are followed for three months from time zero, and primary endpoints are the COVID-19 case fatality rate and all-cause mortality.
Read the detailed description
This observational, retrospective, nationwide study is designed as a target trial emulation. It emulates a pragmatic randomized controlled trial comparing treatment with molnupiravir in addition to standard care versus standard care without molnupiravir in adults with confirmed acute COVID-19. The analysis uses linked national registry data administered by the Institute of Health Information and Statistics of the Czech Republic, including infectious disease records, healthcare diagnoses, prescription and medication-administration records, hospital care data, and death certificate data.
Eligible infection episodes will include adult COVID-19 cases recorded during the Omicron era, beginning January 1, 2022. Each infection episode will be analyzed separately, with reinfection defined as SARS-CoV-2 positivity occurring at least 60 days after a previous SARS-CoV-2 positivity. Time zero will be defined as the date on which a patient first meets all eligibility criteria and is assigned to one of the treatment strategies. For patients treated with molnupiravir, time zero will be the date of molnupiravir treatment initiation, proxied by dispensing; treatment initiation must occur on or after the date of the qualifying SARS-CoV-2 positivity. For controls, time zero will be the matched index date, defined as the same number of days from SARS-CoV-2 positivity as in the corresponding treated patient, so that treated and untreated patients are compared at a similar stage of infection.
To approximate treatment initiation within the recommended period for molnupiravir use, the eligible time-zero window will be defined using available registry information on the interval between symptom onset and SARS-CoV-2 positivity. Molnupiravir dispensing will be considered eligible only if the expected interval from symptom onset to treatment initiation is consistent with initiation within five days of symptom onset, in accordance with the SmPC.
Treated patients and matched controls will be followed for three months from time zero. Since registry follow-up data are available through December 31, 2024, only episodes with sufficient follow-up to ascertain three-month outcomes will be included. Patients who had died, were hospitalized in an intensive care unit, or were receiving mechanical ventilation at time zero will be excluded. Patients who received molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir in the 14 days before the qualifying SARS-CoV-2 positivity will be excluded. Patients who received molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days after the qualifying SARS-CoV-2 positivity, but outside the treatment-initiation eligibility window according to the SmPC, will also be excluded.
Treated patients will be matched 1:2 with controls by exact matching on baseline covariates measured at time zero, including age group, sex, selected comorbidities, vaccination status, post-infection immunity, care setting, concomitant targeted COVID-19 therapy, and calendar half-year. The study follows STROBE guidelines and the TARGET framework for target trial emulations.
- Conditions
- COVID-19, SARS-CoV-2
- Being tested
- Molnupiravir
- Keywords
- SARS-CoV-2 Infection, COVID-19, Omicron, pandemic, Molnupiravir, mortality, case fatality rate, CFR, risk factor, target trial emulation, real-world evidence
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MolnupiravirDrug
Also called Lagevrio, EIDD-2801
800 mg of molnupiravir administered twice daily, i.e., four capsules every 12 hours for five days.
| Study group | Role | What they receive |
|---|---|---|
| Molnupiravir treatment in addition to standard care | Adults with confirmed COVID-19 who received molnupiravir in addition to standard care. Time zero is the date of molnupiravir treatment initiation proxied by dispensing. Receives: Drug: Molnupiravir | |
| Standard care without molnupiravir | Matched controls with confirmed COVID-19 who did not receive molnupiravir. Time zero is the matched date corresponding to the same number of days from positivity as the matched treated patient. |
What is being measured
The primary outcome is the main question the study is designed to answer.
COVID-19 CFR comparing patients treated with molnupiravir versus those not treated with molnupiravir.
COVID-19 case fatality rate (CFR) comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19.
Measured: Three months from time zero.
ACM comparing patients treated with molnupiravir versus those not treated with molnupiravir.
All-cause mortality (ACM) comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19.
Measured: Three months from time zero.
Secondary outcomes (4)
CFR and ACM comparing outpatients treated with molnupiravir versus those not treated with molnupiravir.
COVID-19 CFR and ACM comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19 not hospitalized at time zero.
Measured: Three months from time zero.
COVID-19 CFR and ACM comparing hospitalized patients treated with molnupiravir versus those not treated with molnupiravir.
COVID-19 CFR and ACM comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19 hospitalized at time zero.
Measured: Three months from time zero.
COVID-19 CFR and ACM comparing treatment with molnupiravir versus standard care alone among patients not receiving other targeted COVID-19 agents.
COVID-19 CFR and ACM comparing patients receiving molnupiravir as a standalone targeted COVID-19 agent in addition to standard care versus matched controls treated with standard care without molnupiravir or other targeted COVID-19 agents among patients with acute COVID-19.
Measured: Three months from time zero.
COVID-19 CFR and ACM comparing treatment with molnupiravir versus standard care among patients receiving other targeted COVID-19 agents.
COVID-19 CFR and ACM comparing molnupiravir recipients receiving also other targeted COVID-19 agents in addition to standard care versus matched controls receiving targeted COVID-19 agents other than molnupiravir in addition to standard care among patients with acute COVID-19.
Measured: Three months from time zero.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2026
- Study start1 Jan 2022
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by Charles University, Czech RepublicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 1,795,570 participants (actual)
Sponsor and investigators
- Lead sponsor
- Charles University, Czech Republic
- Sponsor type
- University, hospital or other
- Collaborators
- Institute of Health Information and Statistics of the Czech Republic
- Responsible party
- Principal investigator, Dalibor Veselý, Charles University, Czech Republic
- Investigators
- Dalibor Veselý, M.D., Principal investigator, Charles University, Prague, Third Faculty of MedicineJiří Slíva, M.D., Ph.D., Study director, Charles University, Prague, Third Faculty of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07720596
- Sponsor's protocol ID
- COVID-OMICRON-MPN-CFR
- Acronym
- MOLCOVred
- Status last verified
- Jul 2026
- First submitted
- 14 Jun 2026
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- Yes: Anonymized/blurred data suitable for public sharing. The raw non-public National Health Information System (NHIS)/Institute of Health Information and Statistics of the Czech Republic (IHIS) data cannot be published due to personal data protection regulations; permission was granted to publish individual-level data with matching parameters for COVID-19-positive patients from the study period as a public appendix. These data are anonymized and blurred to prevent re-identification while allowing reproduction of analyses.
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Molnupiravir on COVID-19 Mortality in the Omicron Era: A Real-World Target Trial Emulation Using Complete Czech Nationwide Data
- ClinicalTrials.gov ID
- NCT07720596
- Acronym / sponsor ID
- MOLCOVred / COVID-OMICRON-MPN-CFR
- Conditions
- COVID-19, SARS-CoV-2
- Keywords
- SARS-CoV-2 Infection, COVID-19, Omicron, pandemic, Molnupiravir, mortality, case fatality rate, CFR
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 1,795,570 participants (actual)
- Lead sponsor
- Charles University, Czech RepublicUniversity, hospital or other
- Collaborators
- Institute of Health Information and Statistics of the Czech Republic
- Study start
- 1 Jan 2022 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 22 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This retrospective real-world target trial emulation uses complete Czech nationwide registry data to evaluate whether molnupiravir treatment is associated with lower COVID-19 mortality during the Omicron era. The study compares adults with confirmed acute COVID-19 treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir. Patients are followed for three months from time zero, and primary endpoints are the COVID-19 case fatality rate and all-cause mortality.
Detailed description
This observational, retrospective, nationwide study is designed as a target trial emulation. It emulates a pragmatic randomized controlled trial comparing treatment with molnupiravir in addition to standard care versus standard care without molnupiravir in adults with confirmed acute COVID-19. The analysis uses linked national registry data administered by the Institute of Health Information and Statistics of the Czech Republic, including infectious disease records, healthcare diagnoses, prescription and medication-administration records, hospital care data, and death certificate data.
Eligible infection episodes will include adult COVID-19 cases recorded during the Omicron era, beginning January 1, 2022. Each infection episode will be analyzed separately, with reinfection defined as SARS-CoV-2 positivity occurring at least 60 days after a previous SARS-CoV-2 positivity. Time zero will be defined as the date on which a patient first meets all eligibility criteria and is assigned to one of the treatment strategies. For patients treated with molnupiravir, time zero will be the date of molnupiravir treatment initiation, proxied by dispensing; treatment initiation must occur on or after the date of the qualifying SARS-CoV-2 positivity. For controls, time zero will be the matched index date, defined as the same number of days from SARS-CoV-2 positivity as in the corresponding treated patient, so that treated and untreated patients are compared at a similar stage of infection.
To approximate treatment initiation within the recommended period for molnupiravir use, the eligible time-zero window will be defined using available registry information on the interval between symptom onset and SARS-CoV-2 positivity. Molnupiravir dispensing will be considered eligible only if the expected interval from symptom onset to treatment initiation is consistent with initiation within five days of symptom onset, in accordance with the SmPC.
Treated patients and matched controls will be followed for three months from time zero. Since registry follow-up data are available through December 31, 2024, only episodes with sufficient follow-up to ascertain three-month outcomes will be included. Patients who had died, were hospitalized in an intensive care unit, or were receiving mechanical ventilation at time zero will be excluded. Patients who received molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir in the 14 days before the qualifying SARS-CoV-2 positivity will be excluded. Patients who received molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days after the qualifying SARS-CoV-2 positivity, but outside the treatment-initiation eligibility window according to the SmPC, will also be excluded.
Treated patients will be matched 1:2 with controls by exact matching on baseline covariates measured at time zero, including age group, sex, selected comorbidities, vaccination status, post-infection immunity, care setting, concomitant targeted COVID-19 therapy, and calendar half-year. The study follows STROBE guidelines and the TARGET framework for target trial emulations.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Molnupiravir treatment in addition to standard care | – | Drug: MolnupiravirAdults with confirmed COVID-19 who received molnupiravir in addition to standard care. Time zero is the date of molnupiravir treatment initiation proxied by dispensing. |
| Standard care without molnupiravir | – | –Matched controls with confirmed COVID-19 who did not receive molnupiravir. Time zero is the matched date corresponding to the same number of days from positivity as the matched treated patient. |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All adult patients with confirmed SARS-CoV-2 infection recorded in Czech nationwide health registry data from January 1, 2022, through December 31, 2024.
Key inclusion criteria (4 listed)
- Adult infection episodes among patients aged 20 years or older.
- Confirmed acute SARS-CoV-2 positivity recorded in the Infectious Disease Information System (ISIN) during the Omicron-era study period.
- Eligible for analysis at time zero, defined as the date of molnupiravir dispensing for treated patients and the matched date for controls.
- Mild-to-moderate COVID-19 suitable for oral antiviral treatment, operationalized by excluding those already dead, in ICU, or receiving mechanical ventilation at time zero.
Key exclusion criteria (4 listed)
- Age below 20 years at time of positivity.
- Death, ICU hospitalization, or mechanical ventilation at time zero.
- Receipt of molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days before positivity.
- Receipt of molnupiravir, monoclonal antibodies, remdesivir, or nirmatrelvir/ritonavir within 14 days after the qualifying SARS-CoV-2 positivity, but outside the treatment-initiation eligibility window according to the SmPC.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MolnupiravirAlso: Lagevrio, EIDD-2801800 mg of molnupiravir administered twice daily, i.e., four capsules every 12 hours for five days. | Drug | Molnupiravir treatment in addition to standard care |
Primary outcome
COVID-19 CFR comparing patients treated with molnupiravir versus those not treated with molnupiravir.
Time frame: Three months from time zero.
COVID-19 case fatality rate (CFR) comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19.
ACM comparing patients treated with molnupiravir versus those not treated with molnupiravir.
Time frame: Three months from time zero.
All-cause mortality (ACM) comparing patients treated with molnupiravir in addition to standard care versus matched controls treated with standard care without molnupiravir among patients with acute COVID-19.
4 secondary outcomes
CFR and ACM comparing outpatients treated with molnupiravir versus those not treated with molnupiravir.
Time frame: Three months from time zero.
COVID-19 CFR and ACM comparing hospitalized patients treated with molnupiravir versus those not treated with molnupiravir.
Time frame: Three months from time zero.
COVID-19 CFR and ACM comparing treatment with molnupiravir versus standard care alone among patients not receiving other targeted COVID-19 agents.
Time frame: Three months from time zero.
COVID-19 CFR and ACM comparing treatment with molnupiravir versus standard care among patients receiving other targeted COVID-19 agents.
Time frame: Three months from time zero.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Individual participant dataSharing planned: Yes. Anonymized/blurred data suitable for public sharing. The raw non-public National Health Information System (NHIS)/Institute of Health Information and Statistics of the Czech Republic (IHIS) data cannot be published due to personal data protection regulations; permission was granted to publish individual-level data with matching parameters for COVID-19-positive patients from the study period as a public appendix. These data are anonymized and blurred to prevent re-identification while allowing reproduction of analyses.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Dalibor Veselý, M.D. principal investigator
Charles University, Prague, Third Faculty of Medicine
Jiří Slíva, M.D., Ph.D. study director
Charles University, Prague, Third Faculty of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19 and SARS-CoV-2, run by Charles University, Czech Republic at 1 site in Czechia.
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 4 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 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Czechia. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
COVID-19 CFR comparing patients treated with molnupiravir versus those not treated with molnupiravir. (time frame: Three months from time zero.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 15 Sep 2026.