Staphylococcus Aureus BacteremiaPhase 4COMBAT-SABNCT07376889
Combination Antibiotic Therapy for Staphylococcus Aureus Bacteremia
A Phase 4 study testing Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB) and Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB) in people with Staphylococcus Aureus Bacteremia, run by Intermountain Health Care, Inc. at 13 sites in United States.
Trial summary
The purpose of this study is to see if, in selected patients with a serious bacterial infection of the bloodstream, treating the bacterial infection with a combination of antibiotics is more effective than treating the infection with a single antibiotic. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Staphylococcus Aureus Bacteremia
- What is being tested?
- Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB) and Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2,096 participants
- Where
- 13 sitesUnited States
- Study dates
- 1 Feb 2026to Jan 2029
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years
- Alive and admitted to an Intermountain Health (IH) hospital acute care unit at enrollment
- Initial positive blood culture with either methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA), collected:
- on or during the index admission to an IH hospital, or
- in an ambulatory setting (laboratory, clinic or emergency department) within 48 hours of the index admission, or
- at a non-IH network hospital within 24 hours of subsequent transfer to an IH hospital
Who cannot join
- Patient requests that patient health data not be included in the analysis
Trial locations and contacts
13 sites in 1 country. Contact the study team or a site near you to ask about taking part.
13 sites in 1 country
United States13 sites, 13 recruiting
- Recruiting
St. Vincent Regional Hospital
Billings, Montana, 59101
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Platte Valley Hospital
Brighton, Colorado, 80601
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
St. James Hospital
Butte, Montana, 59701
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Saint Joseph Hospital
Denver, Colorado, 80218
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
St. Mary's Regional Hospital
Grand Junction, Colorado, 81501
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Good Samaritan Hospital
Lafayette, Colorado, 80026
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Holy Rosary Hospital
Miles City, Montana, 59301
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Intermountain Medical Center
Murray, Utah, 84107
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
McKay-Dee Hospital
Ogden, Utah, 84403
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Utah Valley Hospital
Provo, Utah, 84604
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
LDS Hospital
Salt Lake City, Utah, 84143
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
St. George Regional Hospital
St. George, Utah, 84790
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
- Recruiting
Lutheran Medical Center
Wheat Ridge, Colorado, 80401
Brandon J Webb, MD, 801-507-7781, Brandon.Webb@imail.org
Whitney R Buckel, PharmD, 801-284-1046, Whitney.Buckel@imail.org
About this study
Official title: COMBAT-SAB: Combination Antibiotic Therapy for Staphylococcus Aureus Bacteremia
The purpose of this study is to see if, in selected patients with a serious bacterial infection of the bloodstream, treating the bacterial infection with a combination of antibiotics is more effective than treating the infection with a single antibiotic. Participants must have blood cultures which are positive for a certain type of bacteria.
Read the detailed description
Staphyloccocus aureus bacteremia (SAB) is a common infectious disease condition in hospitalized patients which is associated with significant morbidity, excessive costs, and high mortality, despite effective antibiotic therapy. This pragmatic study is designed to test the hypothesis that outcomes in adults hospitalized with SAB will be improved by using combination antibiotic therapy (CAT) as early, targeted therapy in a high-risk subgroup. A group of patients identified early in their course as meeting at least one high-risk criterion who have no contraindications will be treated with one of two antibiotic strategies commonly used within usual care, namely: 1) antibiotic monotherapy or 2) combination antibiotic therapy, depending on the random assignment for each hospital, each month. Low-risk patients will be treated per usual care. Data from all patients admitted to participating hospitals with SAB will be included in the analysis.
- Conditions
- Staphylococcus Aureus Bacteremia
- Being tested
- Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB), Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Combination Antibiotic Therapy (CAT) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)
- Keywords
- Combination antibiotic therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)Drug
Intravenous anti-staphylococcal beta-lactam, either cefazolin or nafcillin, per the discretion of the treating physician.
Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)Drug
Vancomycin or daptomycin, per discretion of the treating physician
Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)Drug
Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) and no contraindications will receive an anti-staphylococcal beta-lactam, either cefazolin or nafcillin, plus ertapenem
Combination Antibiotic Therapy (CAT) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)Drug
Daptomycin plus ceftaroline
| Study group | Role | What they receive |
|---|---|---|
| Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) | Experimental | Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) will be assigned to one of two different antibiotic treatment strategies appropriate for MSSA: 1) antibiotic monotherapy, or 2) combination antibiotic therapy Receives: Drug: Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB); Drug: Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB) |
| Patients with methicillin-resistant S. aureus bacteremia (MRSAB) | Experimental | Patients with methicillin-resistant S. aureus bacteremia (MRSAB) will be assigned to one of two different antibiotic treatment strategies appropriate for MRSA: 1) antibiotic monotherapy, or 2) combination antibiotic therapy Receives: Drug: Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB); Drug: Combination Antibiotic Therapy (CAT) for patients with methicillin-resistant S. aureus bacteremia (MRSAB) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Desirability of Outcome Ranking (DOOR)
The DOOR ordinal scale includes four possible outcomes: treatment failure, infectious complications, antibiotic-associated adverse events and death. The ordinal scale comprises five levels: levels 1-4 are defined by survival at 30 days and the presence of either none, one, two or three of three possible outcomes; level 5 indicates death before 30 days. A DOOR analysis estimates the probability that overall outcomes in any given subject in one group are overall superior to those in a random subject from the other treatment group; probabilities >50% reject the null hypothesis.
Measured: From enrollment to 30 days post enrollment
Secondary outcomes (10)
90-day hospital-free days alive
Number of days the patient is alive and out of the hospital
Measured: From enrollment to 90 days after enrollment
30-day all cause mortality
Number of deaths from any cause within 30 days after enrollment
Measured: From enrollment to 30 days after enrollment
90-day all-cause mortality
Number of deaths from any cause within 90 days after enrollment
Measured: From enrollment to 90 days after enrollment
30-day bacteremia-free days
Number of days without bacteremia within 30 days after enrollment
Measured: From enrollment to 30 days after enrollment
Length of stay
Number of days in the hospital following enrollment
Measured: Measured at the time of hospital discharge, up to 30 days after enrollment
Total hospital direct costs
Total financial charges incurred by a patient during their hospitalization
Measured: Measured at the time of hospital discharge, up to 30 days after enrollment
Total inpatient antibiotic cost
Total cost of all antibiotics received by a patient while hospitalized
Measured: Measured at the time of hospital discharge, up to 30 days after enrollment
Combination antibiotic days
Number of days a patient receives combination antibiotic therapy (CAT) as defined in protocol, instead of antibiotic monotherapy (AM)
Measured: Measured from the time of enrollment until study day 7, death, or hospital discharge
Antibiotic-associated adverse events
Number and type of patient adverse events definitively associated with the receipt of antibiotics while hospitalized
Measured: From enrollment to 30 days after enrollment
Clostridioides difficile infection
Presence of infection with Clostridioides difficile while hospitalized
Measured: From enrollment to 30 days after hospital discharge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jan 2026
- Study start1 Feb 2026
- Primary completionJan 2029 (estimated)
- Study completionJan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Staphylococcus Aureus BacteremiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Platform, embedded, pragmatic clinical trial using a multiple-crossover cluster-randomized design.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 2,096 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Intermountain Health Care, Inc.
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Brandon Webb, Intermountain Health Care, Inc.
- Investigators
- Brandon J Webb, MD, Principal investigator, Intermountain Health Care, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07376889
- Sponsor's protocol ID
- 1053331
- Acronym
- COMBAT-SAB
- Status last verified
- Sep 2026
- First submitted
- 21 Jan 2026
- Last updated
- 25 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: In order to protect patient privacy and comply with relevant regulations, identified data will be unavailable. Requests for deidentified data from qualified researchers with appropriate ethics board approvals and relevant data use agreements will be processed by the Intermountain Office of Research, officeofresearch@imail.org
Study at a glance
From the registry record, last updated by the sponsor on 25 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- COMBAT-SAB: Combination Antibiotic Therapy for Staphylococcus Aureus Bacteremia
- ClinicalTrials.gov ID
- NCT07376889
- Acronym / sponsor ID
- COMBAT-SAB / 1053331
- Conditions
- Staphylococcus Aureus Bacteremia
- Keywords
- Combination antibiotic therapy
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 2,096 participants (estimated)
- Lead sponsor
- Intermountain Health Care, Inc.University, hospital or other
- Study start
- 1 Feb 2026 (actual)
- Primary completion
- Jan 2029 (estimated)
- Study completion
- Jan 2029 (estimated)
- First posted
- 29 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to see if, in selected patients with a serious bacterial infection of the bloodstream, treating the bacterial infection with a combination of antibiotics is more effective than treating the infection with a single antibiotic. Participants must have blood cultures which are positive for a certain type of bacteria.
Detailed description
Staphyloccocus aureus bacteremia (SAB) is a common infectious disease condition in hospitalized patients which is associated with significant morbidity, excessive costs, and high mortality, despite effective antibiotic therapy. This pragmatic study is designed to test the hypothesis that outcomes in adults hospitalized with SAB will be improved by using combination antibiotic therapy (CAT) as early, targeted therapy in a high-risk subgroup. A group of patients identified early in their course as meeting at least one high-risk criterion who have no contraindications will be treated with one of two antibiotic strategies commonly used within usual care, namely: 1) antibiotic monotherapy or 2) combination antibiotic therapy, depending on the random assignment for each hospital, each month. Low-risk patients will be treated per usual care. Data from all patients admitted to participating hospitals with SAB will be included in the analysis.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Platform, embedded, pragmatic clinical trial using a multiple-crossover cluster-randomized design.
| Arm | Type | Receives |
|---|---|---|
| Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) | Experimental | Drug: Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Drug: Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) will be assigned to one of two different antibiotic treatment strategies appropriate for MSSA: 1) antibiotic monotherapy, or 2) combination antibiotic therapy |
| Patients with methicillin-resistant S. aureus bacteremia (MRSAB) | Experimental | Drug: Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB), Drug: Combination Antibiotic Therapy (CAT) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)Patients with methicillin-resistant S. aureus bacteremia (MRSAB) will be assigned to one of two different antibiotic treatment strategies appropriate for MRSA: 1) antibiotic monotherapy, or 2) combination antibiotic therapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥18 years
- Alive and admitted to an Intermountain Health (IH) hospital acute care unit at enrollment
- Initial positive blood culture with either methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA), collected:
Key exclusion criteria (1 listed)
- Patient requests that patient health data not be included in the analysis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)Intravenous anti-staphylococcal beta-lactam, either cefazolin or nafcillin, per the discretion of the treating physician. | Drug | Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) |
| Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)Vancomycin or daptomycin, per discretion of the treating physician | Drug | Patients with methicillin-resistant S. aureus bacteremia (MRSAB) |
| Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB)Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) and no contraindications will receive an anti-staphylococcal beta-lactam, either cefazolin or nafcillin, plus ertapenem | Drug | Patients with methicillin-sensitive S. aureus bacteremia (MSSAB) |
| Combination Antibiotic Therapy (CAT) for patients with methicillin-resistant S. aureus bacteremia (MRSAB)Daptomycin plus ceftaroline | Drug | Patients with methicillin-resistant S. aureus bacteremia (MRSAB) |
Primary outcome
Desirability of Outcome Ranking (DOOR)
Time frame: From enrollment to 30 days post enrollment
The DOOR ordinal scale includes four possible outcomes: treatment failure, infectious complications, antibiotic-associated adverse events and death. The ordinal scale comprises five levels: levels 1-4 are defined by survival at 30 days and the presence of either none, one, two or three of three possible outcomes; level 5 indicates death before 30 days. A DOOR analysis estimates the probability that overall outcomes in any given subject in one group are overall superior to those in a random subject from the other treatment group; probabilities >50% reject the null hypothesis.
10 secondary outcomes
90-day hospital-free days alive
Time frame: From enrollment to 90 days after enrollment
30-day all cause mortality
Time frame: From enrollment to 30 days after enrollment
90-day all-cause mortality
Time frame: From enrollment to 90 days after enrollment
30-day bacteremia-free days
Time frame: From enrollment to 30 days after enrollment
Length of stay
Time frame: Measured at the time of hospital discharge, up to 30 days after enrollment
Total hospital direct costs
Time frame: Measured at the time of hospital discharge, up to 30 days after enrollment
Total inpatient antibiotic cost
Time frame: Measured at the time of hospital discharge, up to 30 days after enrollment
Combination antibiotic days
Time frame: Measured from the time of enrollment until study day 7, death, or hospital discharge
Antibiotic-associated adverse events
Time frame: From enrollment to 30 days after enrollment
Clostridioides difficile infection
Time frame: From enrollment to 30 days after hospital discharge
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Sep 2026.
- Individual participant dataSharing planned: Yes. In order to protect patient privacy and comply with relevant regulations, identified data will be unavailable. Requests for deidentified data from qualified researchers with appropriate ethics board approvals and relevant data use agreements will be processed by the Intermountain Office of Research, officeofresearch@imail.org
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Brandon J Webb, MD principal investigator
Intermountain Health Care, Inc.
13 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Antibiotic Monotherapy (AM) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB), Antibiotic Monotherapy (AM) for patients with methicillin-resistant S. aureus bacteremia (MRSAB) and Combination Antibiotic Therapy (CAT) for patients with methicillin-sensitive S. aureus bacteremia (MSSAB) in people with Staphylococcus Aureus Bacteremia, run by Intermountain Health Care, Inc. at 13 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 13 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Brandon J Webb, MD (801-507-7781, Brandon.Webb@imail.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Desirability of Outcome Ranking (DOOR) (time frame: From enrollment to 30 days post enrollment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Sep 2026.