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Placebo-Controlled Trial of Antibiotic Therapy in Adults With Suspect Lower Respiratory Tract Infection (LRTI) and a Procalcitonin Level

Targeted Reduction of Antibiotics Using Procalcitonin in a Multi-center, Randomized, Double-Blinded, Placebo-Controlled Non-Inferiority Study of Azithromycin Treatment in Outpatient Adults With Suspect Lower Respiratory Tract Infection (LRTI) and a Procalcitonin (PCT) Level of < / = 0.25 ng/mL (TRAP-LRTI)

Status
Terminated
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03341273
Enrollment
514
Registered
2017-11-14
Start date
2017-12-08
Completion date
2020-08-15
Last updated
2023-06-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Lower Respiratory Tract Infection

Keywords

Antibiotic Reduction, Antibiotic Therapy, Azyithromycin, Lower Respiratory Tract Infection, Procalcitonin

Brief summary

This is a randomized, double-blinded, placebo-controlled, non-inferiority multicenter clinical trial of azithromycin vs. placebo in adults presenting as outpatients with suspect Lower Respiratory Tract Infection (LRTI) and a Procalcitonin (PCT) level of \< / = 0.25 ng/mL, as a strategy for reducing antibiotic prescriptions. The study is designed to compare the efficacy of azithromycin versus placebo on Day 5 (i.e., after 4 days of treatment) in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach. The study will recruit potential subjects 18 years of age or older who are suspected to have LRTI. The enrollment cap will be 840 participants, for the goal of approximately 674 randomized participants who will be randomized 1:1 to receive oral azithromycin or placebo for five days. Randomized subjects will have efficacy measured from the time of the first dose of study drug (Day 1) through approximately Day 28. The Primary Objective is to compare the efficacy of azithromycin versus placebo on Day 5 (i.e., after 4 days of treatment) in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach.

Detailed description

This is a randomized, double-blinded, placebo-controlled, non-inferiority multicenter clinical trial of azithromycin vs. placebo in adults presenting as outpatients with suspect Lower Respiratory Tract Infection (LRTI) and a Procalcitonin (PCT) level of \< / = 0.25 ng/mL, as a strategy for reducing antibiotic prescriptions. The study is designed to compare the efficacy of azithromycin versus placebo on Day 5 (i.e., after 4 days of treatment) in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach. The study will recruit potential subjects 18 years of age or older who are suspected to have LRTI. The enrollment cap will be 840 participants, for the goal of approximately 674 randomized participants who will be randomized 1:1 to receive oral azithromycin or placebo for five days. Randomized subjects will have efficacy measured from the time of the first dose of study drug (Day 1) through approximately Day 28. The primary objective is to compare the efficacy of azithromycin versus placebo on Day 5 (i.e., after 4 days of treatment) in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach. The secondary objectives are to compare:1) groups receiving azithromycin versus placebo with regard to all antibiotic use by Days 11 and 28; 2) groups receiving azithromycin versus placebo with regard to return visits to a physician's office or urgent care by Days 11 and 28; 3) groups receiving azithromycin versus placebo with regard to emergency department visits by Days 11 and 28; 4) groups receiving azithromycin versus placebo with regard to hospitalization by Days 11 and 28 if not hospitalized at the enrollment and randomization visit; 5) groups receiving azithromycin versus placebo with regard to improvement in presenting symptoms by Days 11 and 28; 6) the efficacy of azithromycin versus placebo on Day 11 in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach; 7) the efficacy of azithromycin versus placebo on Day 28 in subjects with suspect LRTI and PCT levels of \< / = 0.25 ng/mL at enrollment using a non-inferiority approach; 8) the efficacy of azithromycin versus placebo in subjects with suspected LRTI and PCT levels of \< / = 0.25 ng/mL at Day 5 using a superiority approach, employing the Response Adjusted for Days of Antibiotic Risk (RADAR) methodology; 9) groups receiving azithromycin versus placebo in regard to solicited events by Day 5; 10) groups receiving azithromycin versus placebo in regard to hospitalization or visits to an Emergency Department (ED), outpatient clinic, or urgent care center for worsening or persistent LRTI after randomization by Day 5; 11) groups receiving azithromycin versus placebo in regard to improvement in vital sign abnormalities or symptoms present at enrollment, on Day 5; 12) groups receiving azithromycin versus placebo in regard to new vital sign abnormalities or symptoms on Day 5, or deterioration in symptoms relative to the enrollment visit on Day 5.

Interventions

DRUGAzithromycin

Azithromycin is an azalide antibiotic and is derived from erythromycin used to treat many different types of infections caused by bacteria, such as respiratory infections.

OTHERPlacebo

Placebo will be a matching capsule the same size, weight, and color as the capsules containing Azithromycin tablets.

DEVICEVIDAS B.R.A.H.M.S Procalcitonin Test (PCT)

The VIDAS B.R.A.H.M.S PCT is an automated test for use on the VIDAS instruments for the determination of human procalcitonin in human serum or plasma using the Enzyme-Linked Fluorescent Assay (ELFA) technique.

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)
Lead SponsorNIH

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 99 Years
Healthy volunteers
No

Inclusion criteria

1. Clinician suspected Lower Respiratory Tract Infection (LRTI)\* based on the presence of at least two qualifying symptoms\*\* OR one qualifying symptom and at least one qualifying vital sign\*\*\*. \*LRTI will include acute bronchitis, tracheitis, tracheobronchitis, asthma exacerbation, and acute exacerbation of Chronic obstructive pulmonary disease (COPD) but does not include known pneumonia. \*\*New cough, worsening of chronic cough, new sputum production, increased volume or purulence of chronic sputum production, chest pain, and difficulty breathing. \*\*\*Fever (Provider or patient-measured temperature \> / = 37.8 degrees Celsius (100.0 degrees Fahrenheit) or patient-reported feverishness), tachycardia of \> / = 90 beats/minute, tachypnea of \> 20 breaths/minute. 2. Males and females age \> / = 18 years old. 3. Presentation \> / = 24 hours and \< / = 28 days after the onset of at least one qualifying symptom related to the acute episode of illness. 4. Ability to understand study procedures and willing and able to comply with all required procedures and visits for the entire length of study. 5. Provide written informed consent before initiation of any study procedures.

Exclusion criteria

1. Hospitalized prior to screening and enrollment. Subjects enrolled in clinic or Emergency Department (ED) setting and then hospitalized during the same clinical encounter may be included. 2. Chronic pulmonary conditions at the investigator's discretion\*. \*Such as: * Noninvasive ventilation use for any indication other than obstructive sleep apnea * Long-term invasive mechanical ventilation for any indication * Known diagnosis of cystic fibrosis or chronic bronchiectasis. 3. Receipt of an investigational product within 30 days prior to Day 1 or plans to potentially start any investigational product within 30 days after the subject's anticipated study completion. 4. Current enrollment in another clinical trial of an investigational agent. 5. Known or suspected infection at any other anatomic site requiring antibacterial therapy. 6. Immunosuppression\* \*Includes: * Human Immunodeficiency Virus (HIV) infection with CD4 \< 200 based on last known measurement or patient-reported value * History of hematologic malignancies * Receipt of chemotherapy within the previous 6 months or anticipated receipt of chemotherapy during the study period (1 month) * Known to have an absolute neutrophil count of \< 500 cells/mL or an expectation of an absolute neutrophil count of \< 500 cells/mL during course of the study * Current systemic corticosteroid use (equivalent of 20mg prednisone per day for \> / = 2 weeks within the last month) * Systemic non-steroid immunosuppressive or biologic therapy for transplant, rheumatologic conditions, or other conditions within the last month. Biologics used specifically for control of moderate to severe asthma, including anti-IgE monoclonal antibody therapy (Xolair) or IL-5 monoclonal antibodies (Mepolizumab and Reslizumab) are allowed 7. Contraindication to the use of azithromycin including history of allergy or intolerance to azithromycin or known prolonged QTc interval (\> 500 msec). 8. Any condition that in the judgment of the referring provider or site investigator precludes participation because it could affect subject safety or ability of subject to participate in this trial. 9. Prior use of azithromycin in the past two weeks. 10. Use of any systemic antibiotic in the previous 24 hours. 11. Previous randomization in this trial.

Design outcomes

Primary

MeasureTime frameDescription
Clinical Improvement at Day 5 Visit (D5V)Day 5 VisitClinical improvement at Day 5 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D5V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening Lower Respiratory Tract Infection (LRTI) at any time after randomization

Secondary

MeasureTime frameDescription
Clinical Improvement at Day 28 Visit (D28V)Day 28 VisitClinical improvement at Day 28 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D11V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening LRTI at any time after randomization
Composite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitDay 5 VisitDOOR is a composite endpoint created using clinical outcomes from Day 1 through Day 5 Visit. It is based on adequate clinical improvement at Day 5 Visit and solicited events from Day 1 through Day 5 Visit. When comparing two participants with different ordinal clinical outcomes (OCOs), the participant with a better OCO receives a higher DOOR rank. When comparing two participants with the same OCOs, the participant with fewer days of antibiotic use receives a higher DOOR rank.
Number of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 11 VisitDay 11 VisitImprovement in LRTI symptoms was defined as presence of at least one-step improvement in the symptom present at baseline. For fever, improvement was defined as changing from presence of fever at baseline to absence of fever at Day 11 Visit.
Number of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 28 VisitDay 28 VisitImprovement in LRTI symptoms was defined as presence of at least one-step improvement in the symptom present at baseline. For fever, improvement was defined as changing from presence of fever at baseline to absence of fever at Day 28 Visit.
Number of Participants Exhibiting Improvement in at Least Two Presenting Signs or Symptoms at Day 5 VisitDay 5 VisitImprovement in LRTI symptoms was defined as presence of at least one-step improvement in at least two symptoms present at baseline for participants who qualified based on two symptoms or improvement in one LRTI symptom present at baseline and normalization of one abnormal vital sign at Day 5 Visit for participants who qualified based on one symptom and one vital sign abnormality.
Number of Participants Exhibiting Worsening or Deterioration in One or More Symptoms at Day 5 VisitDay 5 VisitClinical deterioration at D5V is defined as at least one-step deterioration (worsening from mild to moderate for example) in any qualifying symptoms or presence of a new vital abnormality at D5V not present at enrollment.
Number of Participants Reporting One or More Hospitalization or Visits to an Emergency Department (ED), Outpatient Clinic, or Urgent Care Center (After Randomization) for Worsening or Persistent Lower Respiratory Tract InfectionDay 1 through Day 5 VisitThis table summarizes the number and percentage of participants reporting any medically attended visits any time after randomization. Note that receipt of a non-study antibiotic after study Day 5 Visit will was not regarded as satisfying this definition if it is related to a new non-respiratory process that is unrelated to the prior diagnosis of LRTI.
Number of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitDay 1 through Day 5 VisitThis table summarizes the number and percentage of participants experiencing any solicited events of mild, moderate or severe severity from Day 1 to Day 5 Visit.
Clinical Improvement at Day 11 Visit (D11V)Day 11 VisitClinical improvement at Day 11 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D11V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening LRTI at any time after randomization The ITT population includes all participants with PCT = 0.25 ng/mL who were randomized to receive study product.
Number of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 VisitDay 1 through Day 28 VisitThis table summarizes the number of participants with one or more Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) in Azithromycin Group from Day 1 through Day 28 Visit.
Number of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 VisitDay 1 through Day 11 VisitThis table summarizes the number of participants with one or more hospitalizations for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.
Number of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 VisitDay 1 through Day 28 VisitThis table summarizes the number of participants with one or more hospitalizations for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 28 Visit.
Number of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 VisitDay 1 through Day 11 VisitThis table summarizes the number of participants with one or more unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.
Number of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 VisitDay 1 through Day 28 VisitThis table summarizes the number of participants with one or more unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 28 Visit.
Number of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitDay 5 VisitThis table summarizes the number and percentage of participants experiencing new vital signs abnormalities at Day 5 Visit that were not present at baseline.
Quantification of All Antibiotic Use From Day 1 Through Day 11 VisitDay 1 through Day 11 VisitThe table summarizes the mean number of days of antibiotic use including study and non-study antibiotics for participants from Day 1 through Day 11 Visit.
Quantification of All Antibiotic Use From Day 1 Through Day 28 VisitDay 1 through Day 28 VisitThe table summarizes the mean number of days of antibiotic use including study and non-study antibiotics for participants from Day 1 through Day 28 Visit.
Number of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 VisitDay 1 through Day 11This table summarizes the number of participants with one or more Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.

Countries

United States

Participant flow

Recruitment details

Adult participants, males and non-pregnant females, aged \>=18 years, presenting as outpatients with suspected Lower Respiratory Tract Infection (LRTI) with a Procalcitonin (PCT) level of \<=0.25 ng/mL were recruited from the community at large. Participants were enrolled between 08DEC2017 and 09MAR2020.

Participants by arm

ArmCount
Azithromycin
500 mg of Azithromycin (2 capsules of 250 mg) administered orally as a single dose on Day 1, followed by 250 mg capsule of Azithromycin administered orally once daily for 4 days (Day 2 through Day 5).
249
Placebo
2 capsules of Azithromycin placebo administered orally as a single dose on Day 1, followed by 1 capsule of Azithromycin placebo administered orally once daily for 4 days (Day 2 through Day 5).
250
Total499

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyBecame ineligible after enrollment10
Overall StudyEnrolled but Treatment Not Administered61
Overall StudyLost to Follow-up77
Overall StudyNot Eligible at Enrollment01
Overall StudyParticipant incarcerated10
Overall StudyPhysician Decision10
Overall StudyProtocol Violation01
Overall StudyWithdrawal by Subject42

Baseline characteristics

CharacteristicAzithromycinTotalPlacebo
Age, Continuous52.8 years
STANDARD_DEVIATION 15.9
52.2 years
STANDARD_DEVIATION 15.5
51.7 years
STANDARD_DEVIATION 15
Ethnicity (NIH/OMB)
Hispanic or Latino
17 Participants33 Participants16 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
228 Participants461 Participants233 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
4 Participants5 Participants1 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants3 Participants3 Participants
Race (NIH/OMB)
Asian
4 Participants5 Participants1 Participants
Race (NIH/OMB)
Black or African American
159 Participants305 Participants146 Participants
Race (NIH/OMB)
More than one race
2 Participants10 Participants8 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants1 Participants1 Participants
Race (NIH/OMB)
Unknown or Not Reported
3 Participants5 Participants2 Participants
Race (NIH/OMB)
White
81 Participants170 Participants89 Participants
Region of Enrollment
United States
249 participants499 participants250 participants
Sex: Female, Male
Female
80 Participants176 Participants96 Participants
Sex: Female, Male
Male
169 Participants323 Participants154 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 2420 / 247
other
Total, other adverse events
114 / 24297 / 247
serious
Total, serious adverse events
0 / 00 / 0

Outcome results

Primary

Clinical Improvement at Day 5 Visit (D5V)

Clinical improvement at Day 5 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D5V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening Lower Respiratory Tract Infection (LRTI) at any time after randomization

Time frame: Day 5 Visit

Population: The ITT population includes all participants with PCT \<= 0.25 ng/mL who were randomized to receive study product.

ArmMeasureValue (NUMBER)
AzithromycinClinical Improvement at Day 5 Visit (D5V)69 percentage of participants
PlaceboClinical Improvement at Day 5 Visit (D5V)63 percentage of participants
Comparison: Null Hypothesis: Proportion in placebo - Proportion in azithromycin = -12.5%95% CI: [-15, 2]
Secondary

Clinical Improvement at Day 11 Visit (D11V)

Clinical improvement at Day 11 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D11V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening LRTI at any time after randomization The ITT population includes all participants with PCT = 0.25 ng/mL who were randomized to receive study product.

Time frame: Day 11 Visit

Population: The ITT population includes all participants with PCT \<= 0.25 ng/mL who were randomized to receive study product.

ArmMeasureValue (NUMBER)
AzithromycinClinical Improvement at Day 11 Visit (D11V)81 percentage of participants
PlaceboClinical Improvement at Day 11 Visit (D11V)76 percentage of participants
Comparison: Null Hypothesis: Proportion in placebo - Proportion in azithromycin = -12.5%95% CI: [-12, 3]
Secondary

Clinical Improvement at Day 28 Visit (D28V)

Clinical improvement at Day 28 Visit is defined as fulfilling all of the following criteria: 1. Improvement in at least two symptoms present at enrollment or one symptom and at least one vital sign abnormality present at enrollment 2. Absence of deterioration in any qualifying symptom or new vital sign abnormality not present at enrollment 3. Absence of fever in the day preceding or at the D11V 4. No medically attended visit to an ambulatory medical facility or hospitalization for persistent or worsening LRTI at any time after randomization

Time frame: Day 28 Visit

Population: The ITT population includes all participants with PCT \<= 0.25 ng/mL who were randomized to receive study product.

ArmMeasureValue (NUMBER)
AzithromycinClinical Improvement at Day 28 Visit (D28V)88 percentage of participants
PlaceboClinical Improvement at Day 28 Visit (D28V)82 percentage of participants
Comparison: Null Hypothesis: Proportion in placebo - Proportion in azithromycin = -12.5%95% CI: [-13, 0]
Secondary

Composite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 Visit

DOOR is a composite endpoint created using clinical outcomes from Day 1 through Day 5 Visit. It is based on adequate clinical improvement at Day 5 Visit and solicited events from Day 1 through Day 5 Visit. When comparing two participants with different ordinal clinical outcomes (OCOs), the participant with a better OCO receives a higher DOOR rank. When comparing two participants with the same OCOs, the participant with fewer days of antibiotic use receives a higher DOOR rank.

Time frame: Day 5 Visit

Population: The ITT population includes all participants with PCT\<= 0.25 ng/mL who were randomized to receive study product.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement (ACI) with no adverse events82 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo ACI with ED, outpatient clinic, or urgent care center visit but no hospitalization9 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with mild adverse events47 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo adequate clinical improvement with no medically attended events62 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with moderate adverse events25 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo adequate clinical improvement with hospitalization1 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 Visit8: Death (any cause)0 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitMissing22 Participants
AzithromycinComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with severe adverse events1 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitMissing12 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo adequate clinical improvement with no medically attended events72 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo ACI with ED, outpatient clinic, or urgent care center visit but no hospitalization15 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 Visit8: Death (any cause)0 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement (ACI) with no adverse events94 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with mild adverse events33 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with severe adverse events3 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitNo adequate clinical improvement with hospitalization3 Participants
PlaceboComposite Overall Desirability of Outcome Ranking (DOOR) Assessed Employing a Superiority Analysis Using the Response Adjusted for Days of Antibiotic Risk (RADAR) Approach at Day 5 VisitAdequate clinical improvement with moderate adverse events18 Participants
Comparison: Null: The sum of the probability that a participant assigned to placebo will have a higher DOOR at Day 5 visit than if assigned to the Azithromycin plus one-half the probability of equal DOORs at Day 5 Visit is 50% (i.e., no difference in DOOR at Day 5 Visit).p-value: <0.00195% CI: [0.57, 0.68]Wilcoxon (Mann-Whitney)
Secondary

Number of Participants Exhibiting Improvement in at Least Two Presenting Signs or Symptoms at Day 5 Visit

Improvement in LRTI symptoms was defined as presence of at least one-step improvement in at least two symptoms present at baseline for participants who qualified based on two symptoms or improvement in one LRTI symptom present at baseline and normalization of one abnormal vital sign at Day 5 Visit for participants who qualified based on one symptom and one vital sign abnormality.

Time frame: Day 5 Visit

Population: ATP-5 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D5V in person within the protocol defined time window, and had sufficient data to define clinical improvement at D5V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Exhibiting Improvement in at Least Two Presenting Signs or Symptoms at Day 5 Visit166 Participants
PlaceboNumber of Participants Exhibiting Improvement in at Least Two Presenting Signs or Symptoms at Day 5 Visit177 Participants
Secondary

Number of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 11 Visit

Improvement in LRTI symptoms was defined as presence of at least one-step improvement in the symptom present at baseline. For fever, improvement was defined as changing from presence of fever at baseline to absence of fever at Day 11 Visit.

Time frame: Day 11 Visit

Population: According-to-protocol at Day 11 (ATP-11) Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D11V within the protocol defined time window, and had sufficient data to define clinical improvement at D11V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 11 Visit206 Participants
PlaceboNumber of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 11 Visit221 Participants
Secondary

Number of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 28 Visit

Improvement in LRTI symptoms was defined as presence of at least one-step improvement in the symptom present at baseline. For fever, improvement was defined as changing from presence of fever at baseline to absence of fever at Day 28 Visit.

Time frame: Day 28 Visit

Population: ATP-28 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D28V within the protocol defined time window, and had sufficient data to define clinical improvement at D28V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 28 Visit207 Participants
PlaceboNumber of Participants Exhibiting Improvement in One or More LRTI Symptoms or Fever at Day 28 Visit220 Participants
Secondary

Number of Participants Exhibiting Worsening or Deterioration in One or More Symptoms at Day 5 Visit

Clinical deterioration at D5V is defined as at least one-step deterioration (worsening from mild to moderate for example) in any qualifying symptoms or presence of a new vital abnormality at D5V not present at enrollment.

Time frame: Day 5 Visit

Population: ATP-5 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D5V in person within the protocol defined time window, and had sufficient data to define clinical improvement at D5V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Exhibiting Worsening or Deterioration in One or More Symptoms at Day 5 Visit29 Participants
PlaceboNumber of Participants Exhibiting Worsening or Deterioration in One or More Symptoms at Day 5 Visit32 Participants
Secondary

Number of Participants Reporting One or More Hospitalization or Visits to an Emergency Department (ED), Outpatient Clinic, or Urgent Care Center (After Randomization) for Worsening or Persistent Lower Respiratory Tract Infection

This table summarizes the number and percentage of participants reporting any medically attended visits any time after randomization. Note that receipt of a non-study antibiotic after study Day 5 Visit will was not regarded as satisfying this definition if it is related to a new non-respiratory process that is unrelated to the prior diagnosis of LRTI.

Time frame: Day 1 through Day 5 Visit

Population: ATP-5 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D5V in person within the protocol defined time window, and had sufficient data to define clinical improvement at D5V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Reporting One or More Hospitalization or Visits to an Emergency Department (ED), Outpatient Clinic, or Urgent Care Center (After Randomization) for Worsening or Persistent Lower Respiratory Tract Infection9 Participants
PlaceboNumber of Participants Reporting One or More Hospitalization or Visits to an Emergency Department (ED), Outpatient Clinic, or Urgent Care Center (After Randomization) for Worsening or Persistent Lower Respiratory Tract Infection15 Participants
Secondary

Number of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 Visit

This table summarizes the number and percentage of participants experiencing any solicited events of mild, moderate or severe severity from Day 1 to Day 5 Visit.

Time frame: Day 1 through Day 5 Visit

Population: ATP-5 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D5V in person within the protocol defined time window, and had sufficient data to define clinical improvement at D5V.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAny Event90 Participants
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAbdominal Pain47 Participants
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitVomiting13 Participants
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitDiarrhea53 Participants
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAllergic Reaction8 Participants
AzithromycinNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitCandidiasis8 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAllergic Reaction9 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAny Event77 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitDiarrhea55 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitAbdominal Pain35 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitCandidiasis8 Participants
PlaceboNumber of Participants Reporting Solicited Adverse Events From Day 1 Through Day 5 VisitVomiting10 Participants
Secondary

Number of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 Visit

This table summarizes the number and percentage of participants experiencing new vital signs abnormalities at Day 5 Visit that were not present at baseline.

Time frame: Day 5 Visit

Population: ATP-5 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D5V in person within the protocol defined time window, and had sufficient data to define clinical improvement at D5V. For vital signs, only participants with without the vital sign abnormality are analyzed. For fever, only participants with non-missing values for fever are analyzed.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitAny Vital Sign19 Participants
AzithromycinNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitTemperature0 Participants
AzithromycinNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitPulse17 Participants
AzithromycinNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitRespiratory Rate3 Participants
PlaceboNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitRespiratory Rate5 Participants
PlaceboNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitAny Vital Sign24 Participants
PlaceboNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitPulse19 Participants
PlaceboNumber of Participants With a New Occurrence of a Vital Sign Abnormality at Day 5 VisitTemperature0 Participants
Secondary

Number of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit

This table summarizes the number of participants with one or more Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.

Time frame: Day 1 through Day 11

Population: ATP-11 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D11V within the protocol defined time window, and had sufficient data to define clinical improvement at D11V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit3 Participants
PlaceboNumber of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit9 Participants
Secondary

Number of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit

This table summarizes the number of participants with one or more Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) in Azithromycin Group from Day 1 through Day 28 Visit.

Time frame: Day 1 through Day 28 Visit

Population: ATP-28 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D28V within the protocol defined time window, and had sufficient data to define clinical improvement at D28V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit3 Participants
PlaceboNumber of Participants With One or More Emergency Department Visits for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit9 Participants
Secondary

Number of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit

This table summarizes the number of participants with one or more hospitalizations for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.

Time frame: Day 1 through Day 11 Visit

Population: ATP-11 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D11V within the protocol defined time window, and had sufficient data to define clinical improvement at D11V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit1 Participants
PlaceboNumber of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit1 Participants
Secondary

Number of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit

This table summarizes the number of participants with one or more hospitalizations for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 28 Visit.

Time frame: Day 1 through Day 28 Visit

Population: ATP-28 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D28V within the protocol defined time window, and had sufficient data to define clinical improvement at D28V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit1 Participants
PlaceboNumber of Participants With One or More Hospitalizations (if Not Hospitalized at Enrollment) for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit1 Participants
Secondary

Number of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit

This table summarizes the number of participants with one or more unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 11 Visit.

Time frame: Day 1 through Day 11 Visit

Population: ATP-11 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D11V within the protocol defined time window, and had sufficient data to define clinical improvement at D11V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit5 Participants
PlaceboNumber of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 11 Visit7 Participants
Secondary

Number of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit

This table summarizes the number of participants with one or more unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) from Day 1 through Day 28 Visit.

Time frame: Day 1 through Day 28 Visit

Population: ATP-28 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D28V within the protocol defined time window, and had sufficient data to define clinical improvement at D28V.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
AzithromycinNumber of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit6 Participants
PlaceboNumber of Participants With One or More Unplanned Return to a Physician's Office or Urgent Care for Persistent or Worsening Lower Respiratory Tract Infection (LRTI) by Day 28 Visit7 Participants
Secondary

Quantification of All Antibiotic Use From Day 1 Through Day 11 Visit

The table summarizes the mean number of days of antibiotic use including study and non-study antibiotics for participants from Day 1 through Day 11 Visit.

Time frame: Day 1 through Day 11 Visit

Population: ATP-11 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D11V within the protocol defined time window, and had sufficient data to define clinical improvement at D11V.

ArmMeasureValue (MEAN)
AzithromycinQuantification of All Antibiotic Use From Day 1 Through Day 11 Visit5.1 days
PlaceboQuantification of All Antibiotic Use From Day 1 Through Day 11 Visit0.3 days
Secondary

Quantification of All Antibiotic Use From Day 1 Through Day 28 Visit

The table summarizes the mean number of days of antibiotic use including study and non-study antibiotics for participants from Day 1 through Day 28 Visit.

Time frame: Day 1 through Day 28 Visit

Population: ATP-28 Population includes randomized participants who had no major protocol deviations and consumed 5 doses of study product by D5V, completed their D28V within the protocol defined time window, and had sufficient data to define clinical improvement at D28V.

ArmMeasureValue (MEAN)
AzithromycinQuantification of All Antibiotic Use From Day 1 Through Day 28 Visit5.5 days
PlaceboQuantification of All Antibiotic Use From Day 1 Through Day 28 Visit0.9 days

Source: ClinicalTrials.gov · Data processed: Feb 12, 2026