Completed
ZEPHYR

Linezolid In The Treatment Of Subjects With Nosocomial Pneumonia Proven To Be Due To Methicillin-Resistant Staphylococcus Aureus

0 criteria met from your profileSee at a glance how your profile meets each eligibility criteria.
What is being tested

linezolid (Zyvox)

+ vancomycin
Drug
Who is being recruted

Healthcare-Associated Pneumonia
+11

+ Bacterial Infections and Mycoses
+ Bacterial Infections
Over 18 Years
See all eligibility criteria
How is the trial designed

Treatment Study

Phase 4
Interventional
Study Start: October 2004
See protocol details

Summary

Principal SponsorPfizer
Last updated: January 13, 2026
Sourced from a government-validated database.Claim as a partner
Study start date: October 1, 2004Actual date on which the first participant was enrolled.

To determine if linezolid is superior to vancomycin in the treatment of nosocomial (acquired in the hospital) pneumonia due to Methicillin Resistant Staphylococcus Aureus (MRSA) in adult subjects. Subjects entered in to the study will have proven healthcare-associated methicillin-resistant Staphylococcus aureus pneumonia which will be treated with either linezolid or vancomycin.

Official TitleLinezolid In The Treatment Of Subjects With Nosocomial Pneumonia Proven To Be Due To Methicillin-Resistant Staphylococcus Aureus 
NCT00084266
Principal SponsorPfizer
Last updated: January 13, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details
1225 patients to be enrolledTotal number of participants that the clinical trial aims to recruit.
Treatment Study
These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.

How participants are assigned to different groups/arms
In this clinical study, participants are placed into groups randomly, like flipping a coin. This ensures that the study is fair and unbiased, making the results more reliable. By assigning participants by chance, researchers can better compare treatments without external influences.

Other Ways to Assign Participants
Non-randomized allocation: Participants are assigned based on specific factors, such as their medical condition or a doctor's decision.
None (Single-arm trial): If the study has only one group, all participants receive the same treatment, and no allocation is needed.

How treatments are given to participants
Participants are divided into different groups, each receiving a specific treatment at the same time. This helps researchers compare how well different treatments work against each other.

Other Ways to Assign Treatments
Single-group assignment: Everyone gets the same treatment.
Cross-over assignment: Participants switch between treatments during the study.
Factorial assignment: Participants receive different combinations of treatments.
Sequential assignment: Participants receive treatments one after another in a specific order, possibly based on individual responses.
Other assignment: Treatment assignment does not follow a standard or predefined design.

How the effectiveness of the treatment is controlled
In a non placebo-controlled study, no participants receive an inert substance (placebo) to compare outcomes. Instead, all participants receive either the experimental treatment or an alternative treatment (often the Standard of Care). This method allows researchers to compare the effects of the experimental treatment with those of a different active intervention, rather than a placebo.

Other Options
Placebo-Controlled: A placebo is used to compare the effects of the experimental treatment with those of an inert substance, isolating the true treatment effect.

How the interventions assigned to participants is kept confidential
Participants, researchers, outcome assessors, and care providers do not know which treatment is being given. This is the most complete way to prevent bias and keep the study as neutral as possible.

Other Ways to Mask Information
Open-label: Everyone knows which treatment is being given.
Single-blind: Participants do not know which treatment they are receiving, but researchers do.
Double-blind: Neither participants nor researchers know which treatment is given.
Triple-blind: Participants, researchers, and outcome assessors do not know which treatment is given.

Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria
Any sexBiological sex of participants that are eligible to enroll.
Over 18 YearsRange of ages for which participants are eligible to join.
Healthy volunteers not allowedIf individuals who are healthy and do not have the condition being studied can participate.
Conditions
Pathology
Healthcare-Associated Pneumonia
Bacterial Infections and Mycoses
Bacterial Infections
Cross Infection
Iatrogenic Disease
Infections
Lung Diseases
Pathologic Processes
Pneumonia
Respiratory Tract Diseases
Respiratory Tract Infections
Staphylococcal Infections
Gram-Positive Bacterial Infections
Disease Attributes
Criteria

Inclusion Criteria: * Hospitalized male and female subjects with clinically documented nosocomial pneumonia proven to be due to methicillin-resistant staphylococcus aureus. * Chest X-ray at baseline/screen or within 48 hours of treatment consistent with the diagnosis of pneumonia. * Suitable sputum specimen defined as having less than 10 squamous epithelial cells and greater or equal 25 leukocytes or have a culture taken by an invasive technique within 24 hours of study entry. Exclusion Criteria: * Subjects who were treated with a previous antibiotic with MRSA activity (other than linezolid or vancomycin) for more than 48 hours, unless documented to be a treatment failure (72 hours of treatment and not responding). * Subjects with severe neutropenia (\<500 cells/mm3) * Subjects with hypersensitivity to oxazolidinones or vancomycin.

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives
2 intervention groups 

are designated in this study

This study does not include a placebo group 

Treatment Groups
Group I
Experimental
Subjects receiving linezolid for the treatment phase of the study

Subjects to receive either linezolid 600 mg IV (Intravenous) or PO (orally) q 12 h (every 12 hours) for 7-14 days, except in cases of documented bacteremia where it could be extended to 21 days based upon investigator's discretion.
Group II
Active Comparator
Subjects receiving vancomycin for the treatment phase of the study

Subjects to receive vancomycin 15mg/kg IV (Intravenous) q12h (every 12 hours), adjusted for renal function, for 7-14 days, except in cases of documented bacteremia where it could be extended to 21 days based upon investigator's discretion.
Study Objectives
Primary Objectives

Clinical response was based primarily on global assessment of clinical presentation of participant made by investigator at evaluation timepoint. Clinical response was evaluated at EOS Visit as Cure: resolution of clinical signs/symptoms of pneumonia when compared with baseline; Failure: persistence/progression of baseline signs/symptoms of pneumonia or baseline radiographic abnormalities after atleast 2 days of treatment; development of new pulmonary/extrapulmonary clinical findings consistent with active infection; Unknown:extenuating circumstances precluding classification to 1 of the above.
Secondary Objectives

Clinical response was based primarily on global assessment of clinical presentation of participant made by investigator at evaluation timepoint. Clinical response was evaluated at EOS Visit as Cure: resolution of clinical signs/symptoms of pneumonia when compared with baseline; Failure: persistence/progression of baseline signs/symptoms of pneumonia or baseline radiographic abnormalities after atleast 2 days of treatment; development of new pulmonary/extrapulmonary clinical findings consistent with active infection; Unknown:extenuating circumstances precluding classification to 1 of the above.

Clinical response evaluated at EOT visit as Cure:resolution of clinical sign/symptoms of pneumonia when compared with baseline;Improvement: in 2 or more clinical sign/symptoms of pneumonia when compared with baseline,improvement/lack of progression of all chest X-ray abnormalities,Failure: persistence/ progression of baseline signs/symptoms of pneumonia or baseline radiographic abnormalities after atleast 2 days of treatment; development of new pulmonary/extrapulmonary clinical findings consistent with active infection;Unknown: extenuating circumstances precluding classification to 1 of above.

Clinical response evaluated at EOT visit as Cure:resolution of clinical sign/symptoms of pneumonia when compared with baseline;Improvement: in 2 or more clinical sign/symptoms of pneumonia when compared with baseline,improvement/lack of progression of all chest X-ray abnormalities,Failure: persistence/ progression of baseline signs/symptoms of pneumonia or baseline radiographic abnormalities after atleast 2 days of treatment; development of new pulmonary/extrapulmonary clinical findings consistent with active infection;Unknown: extenuating circumstances precluding classification to 1 of above.

Microbiological response assessed at participant level.Eradication:baseline isolate not present in repeat culture from original infection site;Presumed Eradication:clinical response of cure precluded availability of specimen for culture;Persistence:baseline isolate present in repeat culture;Presumed Persistence:culture data not available for participant with clinical response of failure;Superinfection:culture from primary infection site had new pathogen not identified as baseline isolate and clinical response was failure;Indeterminate:any participant who cannot be classified into any of above.

Microbiological response assessed at participant level.Eradication:baseline isolate not present in repeat culture from original infection site;Presumed Eradication:clinical response of cure precluded availability of specimen for culture;Persistence:baseline isolate present in repeat culture;Presumed Persistence:culture data not available for participant with clinical response of failure;Superinfection:culture from primary infection site had new pathogen not identified as baseline isolate and clinical response was failure;Indeterminate:any participant who cannot be classified into any of above.

Microbiological response assessed at participant level.Eradication:baseline isolate not present in repeat culture from original infection site;Presumed Eradication:clinical response of cure precluded availability of specimen for culture;Persistence:baseline isolate present in repeat culture;Presumed Persistence:culture data not available for participant with clinical response of failure;Superinfection:culture from primary infection site had new pathogen not identified as baseline isolate and clinical response was failure;Indeterminate:any participant who cannot be classified into any of above.

Microbiological response assessed at participant level.Eradication:baseline isolate not present in repeat culture from original infection site;Presumed Eradication:clinical response of cure precluded availability of specimen for culture;Persistence:baseline isolate present in repeat culture;Presumed Persistence:culture data not available for participant with clinical response of failure;Superinfection:culture from primary infection site had new pathogen not identified as baseline isolate and clinical response was failure;Indeterminate:any participant who cannot be classified into any of above.

Participant's clinical evaluation of signs and symptoms were based on global assessment by investigator at specific timepoints. Signs and symptoms (mild to severe) of nosocomial pneumonia included cough; production of purulent sputum or change in character of sputum;auscultatory findings on pulmonary examination of rales and/or pulmonary consolidation (dullness on percussion, bronchial breath sounds, or egophony); and dyspnea, tachypnea, or hypoxemia with PaO2 \<60 mmHg or worsening gas exchange or increased oxygen requirements; pleuritic chest pain; chills/rigors; and decreased breath sounds.

Participant's clinical evaluation of signs and symptoms were based on global assessment by investigator at specific timepoints. Signs and symptoms (mild to severe) of nosocomial pneumonia included cough; production of purulent sputum or change in character of sputum;auscultatory findings on pulmonary examination of rales and/or pulmonary consolidation (dullness on percussion, bronchial breath sounds, or egophony); and dyspnea, tachypnea, or hypoxemia with PaO2 \<60 mmHg or worsening gas exchange or increased oxygen requirements; pleuritic chest pain; chills/rigors; and decreased breath sounds.

Participant's clinical evaluation of signs and symptoms were based on global assessment by investigator at specific timepoints. Signs and symptoms (mild to severe) of nosocomial pneumonia included cough; production of purulent sputum or change in character of sputum;auscultatory findings on pulmonary examination of rales and/or pulmonary consolidation (dullness on percussion, bronchial breath sounds, or egophony); and dyspnea, tachypnea, or hypoxemia with PaO2 \<60 mmHg or worsening gas exchange or increased oxygen requirements; pleuritic chest pain; chills/rigors; and decreased breath sounds.

Participant's clinical evaluation of signs and symptoms were based on global assessment by investigator at specific timepoints. Signs and symptoms (mild to severe) of nosocomial pneumonia included cough; production of purulent sputum or change in character of sputum;auscultatory findings on pulmonary examination of rales and/or pulmonary consolidation (dullness on percussion, bronchial breath sounds, or egophony); and dyspnea, tachypnea, or hypoxemia with PaO2 \<60 mmHg or worsening gas exchange or increased oxygen requirements; pleuritic chest pain; chills/rigors; and decreased breath sounds.

For each participant, time to death was estimated from baseline to date of first documented progression or date of death from any cause, whichever came first, assessed up to 60 days after last dose. The distribution of survival was estimated for the treatment groups using the Kaplan-Meier, product-limit method and compared between the treatment groups using the log rank statistic.

For each participant, time to death was estimated from baseline to date of first documented progression or date of death from any cause, whichever came first, assessed up to 60 days after last dose. The distribution of survival was estimated for the treatment groups using the Kaplan-Meier, product-limit method and compared between the treatment groups using the log rank statistic.

For each participant, time to death was estimated from baseline to date of first documented progression or date of death from any cause, whichever came first, assessed up to 60 days after last dose. The distribution of survival was estimated for the treatment groups using the Kaplan-Meier, product-limit method and compared between the treatment groups using the log rank statistic.

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.
This study has 177 locations
Suspended
Pfizer Investigational SiteBirmingham, United StatesSee the location
Suspended
Pfizer Investigational SiteBirmingham, United States
Suspended
Pfizer Investigational SiteBirmingham, United States
Suspended
Pfizer Investigational SiteHuntsville, United States
Completed177 Study Centers