Trial · NCT05263908
A Study to Learn About PAXLOVID (a Commercial Medicine) In People With COVID-19
NCT05263908, Completed, Pfizer; results first posted 2025-09-03
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. A Study to Learn About PAXLOVID (a Commercial Medicine) In People With COVID-19. Trials, record NCT05263908. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT05263908
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- A Study to Learn About PAXLOVID (a Commercial Medicine) In People With COVID-19
- NCT number
- NCT05263908
- Status
- Completed
- Enrollment
- 3,346 participants, actual
- Lead sponsor
- Pfizer
- Conditions
- SARS-CoV-2 Infection
- Interventions
- nirmatrelvir / ritonavir
- First posted
- 2022-03-03
- Last updated
- 2025-09-03
- Results first posted
- 2025-09-03
Source ClinicalTrials.gov
Registered outcomes6
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Incidence of Adverse Drug Reactions | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 45 days. | Adverse drug reaction (ADR) was a treatment-related adverse event and any untoward medical occurrence attributed to Paxlovid PACK in a participant who received Paxlovid PACK. Serious adverse drug reaction (SADR) was a treatment-related adverse event resulting in any of the following outcomes or deemed significant for any other reason: death; life-threatening; initial or prolonged inpatient hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect. Relatedness to Paxlovid PACK was assessed by the physician. |
| Secondary | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 45 days. | Whether the severity of infection caused by SARS-CoV-2 had worsened was evaluated. However, when the severity was severe at the start of Paxlovid PACK and did not worsen during the observation period, it was considered as "severe at the start of treatment." |
| Secondary | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 35 days. | Whether the severity of infection caused by SARS-CoV-2 had worsened was evaluated. However, when the severity was severe at the start of Paxlovid PACK and did not worsen during the observation period, it was considered as "severe at the start of treatment." |
| Secondary | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #3) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 35 days. | Whether the severity of infection caused by SARS-CoV-2 had worsened was evaluated. However, when the severity was severe at the start of Paxlovid PACK and did not worsen during the observation period, it was considered as "severe at the start of treatment." |
| Secondary | Cumulative Incidence Rate of COVID-19 Related Hospitalization or Death From Any Cause Through Day 28 (Efficacy Analysis Set #3) | 3, 5, 7, 14, 21 and 28 days after the start of administration with Paxlovid PACK. | The percent probability is the percent of the participants who had COVID-19 related hospitalization or death from any cause. |
| Secondary | Cumulative Incidence Rate of COVID-19 Related Hospitalization or Death From Any Cause Through Day 28 (Sensitivity Analysis) (Efficacy Analysis Set #3) | 3, 5, 7, 14, 21 and 28 days after the start of administration with Paxlovid PACK. | The percent probability is the percent of the participants who had COVID-19 related hospitalization or death from any cause. Sensitivity analysis was conducted by changing the event definition of "hospitalization for treatment of infection caused by SARS-CoV-2" as follows: there were concomitant medications for infection caused by SARS-CoV-2 or concomitant non-drug therapies due to infection caused by SARS-CoV-2 on or after the date of administration. |
Source ClinicalTrials.gov
Outcomes6
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Incidence of Adverse Drug Reactions | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 45 days. | The safety analysis set (2829 participants) comprised of participants who satisfied the inclusion criteria. Participants with no informed consent for publication of study results, no information on administration, and no information on adverse events - no re-visits were excluded. | Participants | COUNT_OF_PARTICIPANTS |
| SECONDARY | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 45 days. | For the efficacy analysis set #1 (2828 participants), participant with disease not subject to the study (1 participant) was excluded from the safety analysis set. | Percentage of participants | NUMBER |
| SECONDARY | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 35 days. | For the efficacy analysis set #2 (1965 participants), participants other than outpatient at the start of treatment (863 participants) were excluded from the efficacy analysis set #1. | Percentage of participants | NUMBER |
| SECONDARY | Percentage of Participants With Worsening Severity (Efficacy Analysis Set #3) | From the start date of treatment with Paxlovid PACK to 28 days after the end of treatment, up to approximately 35 days. | For the efficacy analysis set #3 (1905 participants), participants with no risk factors of progressing to severe illness (60 participants) were excluded from the efficacy analysis set #2. | Percentage of participants | NUMBER |
| SECONDARY | Cumulative Incidence Rate of COVID-19 Related Hospitalization or Death From Any Cause Through Day 28 (Efficacy Analysis Set #3) | 3, 5, 7, 14, 21 and 28 days after the start of administration with Paxlovid PACK. | For the efficacy analysis set #3 (1905 participants), participants with no risk factors of progressing to severe illness (60 participants) were excluded from the efficacy analysis set #2. | Percent probability | NUMBER |
| SECONDARY | Cumulative Incidence Rate of COVID-19 Related Hospitalization or Death From Any Cause Through Day 28 (Sensitivity Analysis) (Efficacy Analysis Set #3) | 3, 5, 7, 14, 21 and 28 days after the start of administration with Paxlovid PACK. | For the efficacy analysis set #3 (1905 participants), participants with no risk factors of progressing to severe illness (60 participants) were excluded from the efficacy analysis set #2. | Percent probability | NUMBER |
Source ClinicalTrials.gov
Results by group26
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Incidence of Adverse Drug Reactions | Paxlovid PACK (Nirmatrelvir/Ritonavir) | ADR | 423 | Participants | |
| Incidence of Adverse Drug Reactions | Paxlovid PACK (Nirmatrelvir/Ritonavir) | SADR | 6 | Participants | |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Worsened | 2.19 | 95% Confidence Interval 1.68 to 2.80 | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Not worsened | 94.77 | 95% Confidence Interval NA to NA | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Severe at the start of treatment | 0 | 95% Confidence Interval NA to NA | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #1) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Unknown (worsening unknown) | 3.04 | 95% Confidence Interval NA to NA | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Worsened | 1.63 | 95% Confidence Interval 1.12 to 2.29 | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Not worsened | 94.66 | 95% Confidence Interval NA to NA | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Severe at the start of treatment | 0 | 95% Confidence Interval NA to NA | Percentage of participants |
| Percentage of Participants With Worsening Severity (Efficacy Analysis Set #2) | Paxlovid PACK (Nirmatrelvir/Ritonavir) | Unknown (worsening unknown) | 3.72 | 95% Confidence Interval NA to NA | Percentage of participants |
1 to 10 of 26Source ClinicalTrials.gov
See all 26 results by groupParticipant flow3
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 3,346 | |
| Overall Study | COMPLETED | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 2,948 | |
| Overall Study | NOT COMPLETED | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 398 |
Source ClinicalTrials.gov
Adverse events84
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Vertigo | Ear and labyrinth disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 3 | 2,829 | |
| other | Abdominal discomfort | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 5 | 2,829 | |
| other | Abdominal pain | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 6 | 2,829 | |
| other | Constipation | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 13 | 2,829 | |
| other | Diarrhoea | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 92 | 2,829 | |
| other | Faeces soft | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 5 | 2,829 | |
| other | Gastrooesophageal reflux disease | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 3 | 2,829 | |
| other | Nausea | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 35 | 2,829 | |
| other | Oral discomfort | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 6 | 2,829 | |
| other | Stomatitis | Gastrointestinal disorders | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 4 | 2,829 |
1 to 10 of 84Source ClinicalTrials.gov
See all 84 adverse eventsAdverse event totals3
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 16 | 2,829 |
| Total, other adverse events | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 474 | 2,829 |
| Total, serious adverse events | Paxlovid PACK (Nirmatrelvir/Ritonavir) | 51 | 2,829 |
Source ClinicalTrials.gov
Papers1
The papers the trial lists on ClinicalTrials.gov.
| PMID | Listed as |
|---|---|
| 41621946 | DERIVED |
Source PubMed
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
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GET https://conductscience.org/api/trials/v1/NCT05263908/results?page=2