A Study to Learn How Paxlovid [Nirmatrelvir-ritonavir/PF-07321332] Works in COVID-19 Patients Who Are Elderly or Have Medical Conditions.

NCT ID: NCT07261085

Last Updated: 2025-12-04

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Total Enrollment

99000 participants

Study Classification

OBSERVATIONAL

Study Start Date

2025-10-27

Study Completion Date

2026-03-30

Brief Summary

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The purpose of this study is to learn about the effects of the study medicine called Paxlovid \[nirmatrelvir-ritonavir/PF-07321332\], for the potential treatment of COVID-19.

This study will use patient health records in Ontario, to find people who were sick with COVID-19 and visited a pharmacist to be treated, anytime from December 1st, 2022, to March 31st, 2024. To be included in our study, the people must be over 18 years of age and be registered in the Ontario health system for at least one year. People were not included in our study if they have been pregnant in the past year or have serious kidney or liver disease.

We will separate the people in the study into two groups: those who received treatment with Paxlovid \[nirmatrelvir-ritonavir/PF-07321332\] and those who received no treatment. We will monitor their healthcare visits or if they die for any reason, for up to 60 days after the date that they visited their pharmacist. Then we will compare participant experiences when they are taking the study medicine to when they are not. This will help us determine if the study medicine is effective.

Detailed Description

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Conditions

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COVID-19

Study Design

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Observational Model Type

COHORT

Study Time Perspective

RETROSPECTIVE

Study Groups

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Assessed and Treated Cohort

Participants who were assessed with Covid prescribed and subsequently dispensed nirmatrelvir-ritonavir during the selection period

nirmatrelvir-ritonavir

Intervention Type DRUG

Participants who were assessed with Covid prescribed and subsequently dispensed nirmatrelvir-ritonavir during the selection period

Assessed and Untreated Cohort

Participants who were assessed with Covid for nirmatrelvir-ritonavir but either were not prescribed the medication or did not have it dispensed during the selection period

No treatment

Intervention Type OTHER

Participants who were assessed with Covid for nirmatrelvir-ritonavir but either were not prescribed the medication or did not have it dispensed during the selection period

Interventions

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No treatment

Participants who were assessed with Covid for nirmatrelvir-ritonavir but either were not prescribed the medication or did not have it dispensed during the selection period

Intervention Type OTHER

nirmatrelvir-ritonavir

Participants who were assessed with Covid prescribed and subsequently dispensed nirmatrelvir-ritonavir during the selection period

Intervention Type DRUG

Other Intervention Names

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paxlovid

Eligibility Criteria

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Inclusion Criteria

* Record of at least 1 nirmatrelvir-ritonavir prescription and at least 1 dispensation issued by the pharmacist (Treated Cohort only) within 5 days of prescription, identified through pharmacy billing codes
* Record of at least 1 assessment for nirmatrelvir-ritonavir, without a prescription issued by the pharmacist (Untreated Cohort only), OR record of at least 1 prescription for nirmatrelvir-ritonavir without dispensation (Untreated Cohort only), identified through pharmacy billing codes

Exclusion

* Invalid or incomplete records (e.g., missing age, missing sex, death before index)
* Record of a positive PCR test for SARS-CoV-2 between 5 and 90 days prior to the index date
* Had a prescription for antivirals within 3 days prior to or on the index date
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Pfizer

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Pfizer CT.gov Call Center

Role: STUDY_DIRECTOR

Pfizer

Locations

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Pfizer New York

New York, New York, United States

Site Status

Countries

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United States

Related Links

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https://pmiform.com/clinical-trial-info-request?StudyID=C4671071

To obtain contact information for a study center near you, click here.

Other Identifiers

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C4671071

Identifier Type: -

Identifier Source: org_study_id

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