ClinicalTrials.gov record
Withdrawn Phase 2 Interventional

A Study to Learn About the Medicine Called Nirmatrelvir Used in Combination With Ritonavir in People With Weakened Immune Systems or at Increased Risk for Poor Outcomes Who Are Hospitalized Due to Severe COVID-19

ClinicalTrials.gov ID: NCT05545319

Public ClinicalTrials.gov record NCT05545319. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced May 17, 2026, 5:35 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

AN INTERVENTIONAL EFFICACY AND SAFETY, PHASE 2, DOUBLE-BLIND, 2-ARM STUDY TO INVESTIGATE ORALLY ADMINISTERED NIRMATRELVIR/RITONAVIR COMPARED WITH PLACEBO/RITONAVIR FOR THE TREATMENT OF SEVERE COVID-19 IN HOSPITALIZED PARTICIPANTS WHO ARE IMMUNOCOMPROMISED OR AT INCREASED RISK FOR SEVERE COVID-19 OUTCOMES

Study identification

NCT ID
NCT05545319
Recruitment status
Withdrawn
Study type
Interventional
Phase
Phase 2
Lead sponsor
Pfizer
Industry
Enrollment
Not listed

Conditions and interventions

Eligibility (public fields only)

Age range
12 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Dec 12, 2022
Primary completion
Sep 20, 2023
Completion
Jan 5, 2024
Last update posted
Feb 28, 2023

2022 – 2024

United States locations

U.S. sites
2
U.S. states
1
U.S. cities
2
Facility City State ZIP Site status
Bassett Medical Center Cooperstown New York 13326
Harlem Hospital Center New York New York 10037

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 9 non-U.S. sites.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT05545319, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Feb 28, 2023 · Synced May 17, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT05545319 live on ClinicalTrials.gov.

View official ClinicalTrials.gov record →