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Omadacycline Versus Linezolid for the Treatment of ABSSSI (EudraCT #2013-003644-23)

A Phase 3 Randomized, Double-blind, Multi-center Study to Compare the Safety and Efficacy of Omadacycline IV/PO to Linezolid IV/PO for Treating Adults With Acute Bacterial Skin and Skin Structure Infections (ABSSSI)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02378480
Enrollment
655
Registered
2015-03-04
Start date
2015-06-30
Completion date
2016-05-31
Last updated
2019-03-21

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

Conditions

Bacterial Infections, Skin Structures and Soft Tissue Infections

Brief summary

The purpose of this study is to evaluate the safety and efficacy of omadacycline as compared to linezolid in the treatment of adults with acute bacterial skin and skin structure infections.

Interventions

Injection for IV dosing; Tablets for oral dosing

DRUGLinezolid

Infusion solution for IV dosing; Tablets for oral dosing

Sponsors

Paratek Pharmaceuticals Inc
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

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

Inclusion criteria

* Patients, ages 18 years or older who have signed the informed consent * Has a qualifying skin and skin structure infection * Female patients must not be pregnant at the time of enrollment * Must agree to a reliable method of birth control during the study and for 30 days following the last dose of study drug

Exclusion criteria

* Infections where the outcome is strongly influenced by factors other than protocol-defined treatment and procedures, that require antibacterial treatment for greater than 14 days * Evidence of significant immunological disease * Severe sepsis or septic shock * Has a history of hypersensitivity or allergic reaction to any tetracycline or to linezolid * Has received an investigational drug within past 30 days * Women who are pregnant or nursing

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Early Clinical ResponseScreening; 48 to 72 hours after the first dose of test articleEarly clinical response is defined as clinical success, which is categorized as survival with at least a 20% reduction of acute bacterial skin and skin structure infection (ABSSSI) primary lesion size compared to Screening measurements, without receiving any rescue antibacterial therapy. An indeterminate classification is used for a response that could not be adequately inferred because the participant was not assessed because they withdrew consent, were lost to follow-up, or other specified reason.

Secondary

MeasureTime frameDescription
Number of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitScreening; 7 to 14 days after the last day of therapyAt the PTE Visit the investigator indicated one of the following outcomes relating to the primary infection under study: Clinical Success: participant was alive; the infection was sufficiently resolved such that further antibacterial therapy was not needed. These participants may have had some residual changes related to infection requiring ancillary treatment. Clinical Failure was defined as meeting any of the following criteria: infection required additional treatment with alternative antibacterial therapy; participant received antibacterial therapy between the End-of-Treatment (EOT) Visit and the PTE Visit that may have been effective for the infection under study for a different infection from the one under study; unplanned major surgical intervention for the infection under study between the EOT and PTE Visits; participant died before evaluation. Indeterminate: clinical response to test article could not be adequately inferred.
Number of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) PopulationScreening; 7 to 14 days after the last day of therapyAt the PTE Visit the investigator indicated one of the following outcomes relating to the primary infection under study: Clinical Success: participant was alive; the infection was sufficiently resolved such that further antibacterial therapy was not needed. These participants may have had some residual changes related to infection requiring ancillary treatment. Clinical Failure was defined as meeting any of the following criteria: infection required additional treatment with alternative antibacterial therapy; participant received antibacterial therapy between the EOT Visit and the PTE Visit that may have been effective for the infection under study for a different infection from the one under study; unplanned major surgical intervention for the infection under study between the EOT and PTE Visits; participant died before evaluation.
Number of Participants With the Indicated Type of Adverse Event (AE)0 to 37 daysAn AE is defined as any untoward, undesired, or unplanned event in the form of signs, symptoms, disease, or laboratory or physiologic observations occurring in a person given a test article or in a clinical study. The event does not need to be causally related to the test article or clinical study. A serious adverse event (SAE) is defined as an event that resulted in death, was life-threatening, required hospitalization or prolongation of an existing hospitalization, resulted in a persistent or significant disability or incapacity, resulted in cancer, or resulted in a congenital anomaly or birth defect. A treatment-emergent AE (TEAE) is defined as any AE that newly appeared, increased in frequency, or worsened in severity on or after the initiation of active test article. Vital sign measurements, electrocardiogram findings, and laboratory values classified as adverse events were included in the analysis. Data are presented as the number of participants with at least 1 of the event.

Countries

Bulgaria, Croatia, Greece, Hungary, Israel, Latvia, Peru, Poland, Romania, South Africa, Spain, Turkey (Türkiye), Ukraine, United States

Participant flow

Recruitment details

The study was designed to enroll adult participants with Acute Bacterial Skin and Skin Structure Infection (ABSSSI) that was known or suspected to be due to a Gram-positive pathogen(s). Randomization was stratified across treatment groups by type of infection (wound infection, cellulitis/erysipelas, and major abscess) and geographic region.

Pre-assignment details

Participants who met inclusion criteria and did not meet exclusion criteria were randomly assigned to a treatment group, and received their first dose of test article within 4 hours after randomization. All participants were expected to present with ABSSSI severe enough to require a minimum of at least 3 days of intravenous treatment.

Participants by arm

ArmCount
Omadacycline
Participants received intravenous (IV) omadacycline 100 milligrams (mg) every 12 hours (q12h) (2 doses), followed by 100 mg IV every 24 hours (q24h) (starting 24 hours after the first dose), with the option to switch to a 300 mg oral administration q24h after a minimum of 3 days (6 doses) of IV treatment (6 overall IV doses because of the blinding). Participants received 4 active doses plus 2 placebo doses to maintain the blind. The total treatment duration was 7 to 14 days.
323
Linezolid
Participants received linezolid 600 mg IV q12h with the option to switch to a 600 mg oral administration q12h after a minimum of 3 days (6 doses) of IV treatment. The total treatment duration was 7 to 14 days.
322
Total645

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event01
Overall StudyDeath12
Overall StudyLost to Follow-up1018
Overall StudyMissed EOT/PTE Visit12
Overall StudyPhysician Decision11
Overall StudyRandomized, but Not Treated64
Overall StudyWithdrawal by Subject94

Baseline characteristics

CharacteristicOmadacyclineLinezolidTotal
Age, Customized
18-45 years
146 Participants154 Participants300 Participants
Age, Customized
>45-65 years
141 Participants136 Participants277 Participants
Age, Customized
>65 years
36 Participants32 Participants68 Participants
Race (NIH/OMB)
American Indian or Alaska Native
7 Participants5 Participants12 Participants
Race (NIH/OMB)
Asian
1 Participants2 Participants3 Participants
Race (NIH/OMB)
Black or African American
16 Participants8 Participants24 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
1 Participants3 Participants4 Participants
Race (NIH/OMB)
Unknown or Not Reported
4 Participants4 Participants8 Participants
Race (NIH/OMB)
White
294 Participants300 Participants594 Participants
Sex: Female, Male
Female
120 Participants109 Participants229 Participants
Sex: Female, Male
Male
203 Participants213 Participants416 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
1 / 3232 / 322
other
Total, other adverse events
104 / 323101 / 322
serious
Total, serious adverse events
12 / 3238 / 322

Outcome results

Primary

Number of Participants With Early Clinical Response

Early clinical response is defined as clinical success, which is categorized as survival with at least a 20% reduction of acute bacterial skin and skin structure infection (ABSSSI) primary lesion size compared to Screening measurements, without receiving any rescue antibacterial therapy. An indeterminate classification is used for a response that could not be adequately inferred because the participant was not assessed because they withdrew consent, were lost to follow-up, or other specified reason.

Time frame: Screening; 48 to 72 hours after the first dose of test article

Population: Modified Intent-to-Treat (mITT) Population: all randomized participants without a baseline sole Gram-negative ABSSSI pathogen

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
OmadacyclineNumber of Participants With Early Clinical ResponseClinical success268 Participants
OmadacyclineNumber of Participants With Early Clinical ResponseClinical failure23 Participants
OmadacyclineNumber of Participants With Early Clinical ResponseIndeterminate25 Participants
LinezolidNumber of Participants With Early Clinical ResponseClinical success266 Participants
LinezolidNumber of Participants With Early Clinical ResponseClinical failure19 Participants
LinezolidNumber of Participants With Early Clinical ResponseIndeterminate26 Participants
95% CI: [-6.3, 4.9]
Secondary

Number of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) Population

At the PTE Visit the investigator indicated one of the following outcomes relating to the primary infection under study: Clinical Success: participant was alive; the infection was sufficiently resolved such that further antibacterial therapy was not needed. These participants may have had some residual changes related to infection requiring ancillary treatment. Clinical Failure was defined as meeting any of the following criteria: infection required additional treatment with alternative antibacterial therapy; participant received antibacterial therapy between the EOT Visit and the PTE Visit that may have been effective for the infection under study for a different infection from the one under study; unplanned major surgical intervention for the infection under study between the EOT and PTE Visits; participant died before evaluation.

Time frame: Screening; 7 to 14 days after the last day of therapy

Population: CE-PTE Population: all participants in the mITT Population meeting additional pre-defined criteria

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
OmadacyclineNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) PopulationClinical success259 Participants
OmadacyclineNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) PopulationClinical failure10 Participants
LinezolidNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) PopulationClinical success243 Participants
LinezolidNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the Clinically Evaluable-Post Therapy Evaluation (CE-PTE) PopulationClinical failure17 Participants
95% CI: [-1, 6.9]
Secondary

Number of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) Visit

At the PTE Visit the investigator indicated one of the following outcomes relating to the primary infection under study: Clinical Success: participant was alive; the infection was sufficiently resolved such that further antibacterial therapy was not needed. These participants may have had some residual changes related to infection requiring ancillary treatment. Clinical Failure was defined as meeting any of the following criteria: infection required additional treatment with alternative antibacterial therapy; participant received antibacterial therapy between the End-of-Treatment (EOT) Visit and the PTE Visit that may have been effective for the infection under study for a different infection from the one under study; unplanned major surgical intervention for the infection under study between the EOT and PTE Visits; participant died before evaluation. Indeterminate: clinical response to test article could not be adequately inferred.

Time frame: Screening; 7 to 14 days after the last day of therapy

Population: mITT Population

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
OmadacyclineNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitClinical success272 Participants
OmadacyclineNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitClinical failure20 Participants
OmadacyclineNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitIndeterminate24 Participants
LinezolidNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitClinical success260 Participants
LinezolidNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitClinical failure27 Participants
LinezolidNumber of Participants With the Indicated Investigator Assessment of Clinical Response in the mITT Population at the Post Therapy Evaluation (PTE) VisitIndeterminate24 Participants
95% CI: [-3.2, 8.2]
Secondary

Number of Participants With the Indicated Type of Adverse Event (AE)

An AE is defined as any untoward, undesired, or unplanned event in the form of signs, symptoms, disease, or laboratory or physiologic observations occurring in a person given a test article or in a clinical study. The event does not need to be causally related to the test article or clinical study. A serious adverse event (SAE) is defined as an event that resulted in death, was life-threatening, required hospitalization or prolongation of an existing hospitalization, resulted in a persistent or significant disability or incapacity, resulted in cancer, or resulted in a congenital anomaly or birth defect. A treatment-emergent AE (TEAE) is defined as any AE that newly appeared, increased in frequency, or worsened in severity on or after the initiation of active test article. Vital sign measurements, electrocardiogram findings, and laboratory values classified as adverse events were included in the analysis. Data are presented as the number of participants with at least 1 of the event.

Time frame: 0 to 37 days

Population: Safety Population: all randomized participants who received test article

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)AE158 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE156 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Drug-releated AE58 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Severe TEAE6 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAE12 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Drug-related serious TEAE0 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAE leading to death1 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to premature drug discontinuation6 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to premature discontinuation of study6 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to dose interruption2 Participants
OmadacyclineNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAEs leading to drug discontinuation3 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAEs leading to drug discontinuation3 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)AE157 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAE leading to death2 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to dose interruption0 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Drug-releated AE59 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to premature drug discontinuation7 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Severe TEAE10 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE147 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Serious TEAE8 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)TEAE leading to premature discontinuation of study7 Participants
LinezolidNumber of Participants With the Indicated Type of Adverse Event (AE)Drug-related serious TEAE0 Participants

Source: ClinicalTrials.gov · Data processed: Feb 22, 2026