COVID-19NCT05890612
A Study on Paxlovid Once in the Market, to Observe Its Safety and Effectiveness in Patients Who Have a High Chance of Getting Severe COVID-19
An observational study of COVID-19, run by Pfizer at 1 site in South Korea.
Trial summary
The purpose of this study is to look at the safety and effectiveness of PAXLOVID in the real world and not in clinical studies. The study observes patients who have a high chance of getting severe COVID-19 in Korea. Read more about this study
- Who is it for?
- Ages 19 years and older
- Conditions the study is for
- COVID-19
- How many people
- 3,000 participants
- Where
- 1 siteSouth Korea
- Study dates
- 29 Nov 2023to 17 Feb 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 19 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
Who may be able to join
- Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
- Patients (or a legally acceptable representative) who are willing to provide written informed consent/assent prior to study enrollment.
Who cannot join
- Patients with contraindication according to locally approved label of PAXLOVID.
- Patients who are going to receive any investigational medicine during the observation period.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: POST MARKETING SURVEILLANCE TO OBSERVE SAFETY AND EFFECTIVENESS OF PAXLOVID IN PATIENTS, AND WHO ARE AT HIGH RISK FOR PROGRESSION TO SEVERE COVID-19
The purpose of this study is to look at the safety and effectiveness of PAXLOVID in the real world and not in clinical studies. The study observes patients who have a high chance of getting severe COVID-19 in Korea.
This study is seeking participants who are:
Read more
- Patients with mild-to-moderate COVID-19 symptoms and at high chance of getting severe COVID-19, including hospitalization or death.
- Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
- Patients who have signed informed consent documents after understanding all the important parts of the study.
All participants are treated according to routine medical practice and there are no scheduled visits required by this study. All participants will be studied for a follow-up period of 28 days from the last PAXLOVID treatment to understand the safety and the effectiveness of treatment.
- Conditions
- COVID-19
- Keywords
- severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), PAXLOVID, post marketing surveillance (PMS), Korea
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Participants receiving PAXLOVID | Participants receiving PAXLOVID according to locally approved label. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of patients with an adverse event (AE)
The number of AEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with an adverse drug reaction (ADR)
The number of ADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with a serious AE (SAE)
The number of SAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with a serious ADR (SADR)
The number of SADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with an unexpected AE (UAE)
The number of UAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with an unexpected ADR (UADR)
The number of UADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with a serious unexpected AE (SUAE)
The number of SUAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of patients with a serious unexpected ADR (SUADR)
The number of SUADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of COVID-19-related hospitalization from any cause
The number and rate of COVID-19-related hospitalizations among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of COVID-19-related death from any cause
The number and rate of COVID-19-related deaths among all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Baseline through Day 33
Proportion of subjective assessment of COVID-19-related symptomatic change
The rate of subjective assessment change (improve/no change/worsened) compared to the baseline for COVID-19-related overall symptoms of all subjects who received the drug and received at least one safety evaluation will be measured.
Measured: Day 5, Day 14, Day 33
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Jun 2023
- Study start29 Nov 2023
- Primary completion17 Feb 2029 (estimated)
- Study completion17 Feb 2029 (estimated)
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 PfizerThe 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
- Case only
- Time perspective
- Other
- Enrolment
- 3,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05890612
- Sponsor's protocol ID
- C4671020
- Other IDs
- NCT05890612
- Status last verified
- Aug 2026
- First submitted
- 2 Jun 2023
- Last updated
- 12 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 12 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- POST MARKETING SURVEILLANCE TO OBSERVE SAFETY AND EFFECTIVENESS OF PAXLOVID IN PATIENTS, AND WHO ARE AT HIGH RISK FOR PROGRESSION TO SEVERE COVID-19
- ClinicalTrials.gov ID
- NCT05890612
- Acronym / sponsor ID
- C4671020
- Conditions
- COVID-19
- Keywords
- severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), PAXLOVID, post marketing surveillance (PMS), Korea
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 3,000 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 29 Nov 2023 (actual)
- Primary completion
- 17 Feb 2029 (estimated)
- Study completion
- 17 Feb 2029 (estimated)
- First posted
- 6 Jun 2023 (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.
The purpose of this study is to look at the safety and effectiveness of PAXLOVID in the real world and not in clinical studies. The study observes patients who have a high chance of getting severe COVID-19 in Korea.
This study is seeking participants who are:
- Patients with mild-to-moderate COVID-19 symptoms and at high chance of getting severe COVID-19, including hospitalization or death.
- Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
- Patients who have signed informed consent documents after understanding all the important parts of the study.
All participants are treated according to routine medical practice and there are no scheduled visits required by this study. All participants will be studied for a follow-up period of 28 days from the last PAXLOVID treatment to understand the safety and the effectiveness of treatment.
Study design
- Observational model
- Case only
- Time perspective
- Other
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants receiving PAXLOVID | – | –Participants receiving PAXLOVID according to locally approved label. |
Who may qualify
- Ages
- 19 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
Key inclusion criteria (2 listed)
- Patients who received, are currently receiving, or are going to receive PAXLOVID according to locally approved label.
- Patients (or a legally acceptable representative) who are willing to provide written informed consent/assent prior to study enrollment.
Key exclusion criteria (2 listed)
- Patients with contraindication according to locally approved label of PAXLOVID.
- Patients who are going to receive any investigational medicine during the observation period.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Proportion of patients with an adverse event (AE)
Time frame: Baseline through Day 33
The number of AEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with an adverse drug reaction (ADR)
Time frame: Baseline through Day 33
The number of ADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with a serious AE (SAE)
Time frame: Baseline through Day 33
The number of SAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with a serious ADR (SADR)
Time frame: Baseline through Day 33
The number of SADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with an unexpected AE (UAE)
Time frame: Baseline through Day 33
The number of UAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with an unexpected ADR (UADR)
Time frame: Baseline through Day 33
The number of UADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with a serious unexpected AE (SUAE)
Time frame: Baseline through Day 33
The number of SUAEs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of patients with a serious unexpected ADR (SUADR)
Time frame: Baseline through Day 33
The number of SUADRs experienced, the incidence rate, and the number of occurrences among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of COVID-19-related hospitalization from any cause
Time frame: Baseline through Day 33
The number and rate of COVID-19-related hospitalizations among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of COVID-19-related death from any cause
Time frame: Baseline through Day 33
The number and rate of COVID-19-related deaths among all subjects who received the drug and received at least one safety evaluation will be measured.
Proportion of subjective assessment of COVID-19-related symptomatic change
Time frame: Day 5, Day 14, Day 33
The rate of subjective assessment change (improve/no change/worsened) compared to the baseline for COVID-19-related overall symptoms of all subjects who received the drug and received at least one safety evaluation will be measured.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Aug 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. 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.
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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.
Pfizer CT.gov Call Center study director
Pfizer
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, run by Pfizer at 1 site in South Korea.
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 2 inclusion and 2 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: looking for participants now, as of the sponsor's last update on 12 Aug 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 South Korea. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of patients with an adverse event (AE) (time frame: Baseline through Day 33). The study lists 11 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 12 Aug 2026.