Staphylococcal Aureus InfectionNCT07155590
Subphenotype- and Complication-guided Adjunctive Fosfomycin Therapy for Staphylococcus Aureus Bacteraemia
An observational study of Staphylococcal Aureus Infection and Staphylococcus Aureus Bacteraemia, run by Hospital Universitari de Bellvitge at 2 sites in Spain.
Trial summary
Staphylococcus aureus bacteraemia (SAB) is a major global cause of sepsis-related mortality. Randomised trials of adjunctive antibiotics, including fosfomycin, have not shown consistent benefit, possibly due to inclusion of unselected SAB populations. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Staphylococcal Aureus Infection, Staphylococcus Aureus Bacteraemia
- How many people
- 369 participants
- Where
- 2 sitesSpain
- Study dates
- 21 Jul 2025to 15 Sep 2025
- Phase
- Observational
- 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
Study population: The BACSAFO cohort pools individual participant data from two multicentre, randomised, superiority trials evaluating adjunctive fosfomycin for the treatment of SAB: BACSARM and SAFO. The BACSARM trial included 155 adult patients with methicillin-resistant (MRSA), randomised 1:1 to receive either daptomycin alone or daptomycin plus fosfomycin. The SAFO trial enrolled 214 adult patients with methicillin-susceptible (MSSA) bacteraemia, randomised to cloxacillin alone or cloxacillin plus fosfomycin.
Who may be able to join
- > or = 18 years old
- Monomicrobial Staphylococcus aureus bacteraemia
- Evidence of active infection
- Common exclusion criteria for the BACSARM and SAFO RCTs:
- Polymicrobial bacteraemia
- Severe clinical status with expected survival < 24 hours
Show all 17Show fewer
- Severe liver disease with Child-Pugh score class C
- Diagnosis of prosthetic infective endocarditis
- Allergy or known resistance to study drugs
- Pregnancy at the time of inclusion
- Particular exclusion criteria for the BACSARM RCT:
- Diagnosis of MRSA pneumonia
- Prior history of eosinophilic pneumonia
- Use of additional antibiotic therapy with microbiological activity against MRSA
- Particular exclusion criteria for the SAFO RCT:
- Prior history of myasthenia gravis
- Acute SARS-CoV2 infection
Who cannot join
None listed.
Trial locations and contacts
2 sites in 1 country.
Spain2 sites
Hospital Universitari de Bellvitge
L'Hospitalet de Llobregat, Catalonia, 08907
Hospital Universitario Virgen de Macarena
Seville, 41009
About this study
Official title: Subphenotype- and Complication-guided Adjunctive Fosfomycin Therapy for Staphylococcus Aureus Bacteraemia: Pooled Analysis of Two Randomised Trials
Staphylococcus aureus bacteraemia (SAB) is a major global cause of sepsis-related mortality. Randomised trials of adjunctive antibiotics, including fosfomycin, have not shown consistent benefit, possibly due to inclusion of unselected SAB populations. The FEN-AUREUS classification enables early risk stratification based on clinical subphenotypes. The investigators aim to validate this framework in a pooled trial cohort and assess whether combining subphenotypes with IDSA-defined complicated SAB could identify patients most likely to benefit from adjunctive fosfomycin. The investigators will conduct a post-hoc analysis of individual-level data from two multicentre randomised trials-BACSARM and SAFO-evaluating fosfomycin in SAB. Participants will be classified using FEN-AUREUS into source phenotypes (A, B and C) and risk subphenotypes (1 = low-risk, 2 = high-risk). Associations between subphenotype, treatment arm, and outcomes (30/60-day mortality, 8-week treatment success) will be assessed using multivariable models. Monte Carlo simulations will explore power by subgroup. FEN-AUREUS subphenotypes combined with complication status have the potential to identify patients with SAB that could likely benefit form combination therapy with fosfomycin.
- Keywords
- Staphylococcus aureus bacteraemia, Risk stratification, Clinical phenotypes, Subphenotypes, Monotherapy, Adjunctive therapy, Fosfomycin, Complicated bacteraemia, Randomised clinical trials
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Adjunctive fosfomycin therapy | Patients with Staphylococcus aureus bacteraemia from the BACSAFO cohort treated with any regimen including fosfomycin | |
| Monotherapy | Patients with Staphylococcus aureus bacteraemia from the BACSAFO cohort treated with any regimen not containing fosfomycin |
What is being measured
The primary outcome is the main question the study is designed to answer.
All-cause mortality at 60 days
All-cause mortality at 60 days after randomisation
Measured: At 60 days from randomisation
Secondary outcomes (2)
All-cause mortality at 30 days
All-cause mortality at 30 days after randomisation
Measured: At 30 days after randomisation
Treatment success at 8 weeks
Survival without clinical relapse and with resolution of symptoms at 8 weeks after randomisation
Measured: At 8 weeks after randomisation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Sep 2025
- Study start21 Jul 2025
- Primary completion4 Aug 2025
- Study completion15 Sep 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Staphylococcal Aureus InfectionStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 369 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hospital Universitari de Bellvitge
- Sponsor type
- University, hospital or other
- Collaborators
- Institut d'Investigació Biomèdica de Bellvitge, University of Barcelona, Hospital Universitario Virgen Macarena, University of Seville
- Responsible party
- Principal investigator, Francesc Escrihuela-Vidal, Hospital Universitari de Bellvitge
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07155590
- Sponsor's protocol ID
- FENAUREUS-BACSAFO
- Status last verified
- Sep 2025
- First submitted
- 27 Aug 2025
- Last updated
- 11 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Raw anonymised data relating to primary and secondary outcomes and safety may be shared upon request with researchers who provide a methodologically reasonable proposal. Requests for data should be sent to the corresponding author (JC). Interested researchers must obtain the approval of the Bellvitge University Hospital Ethics Committee.
Publications
Escrihuela-Vidal F, Larrauri JG, Lopez-Contreras J, Euba G, Vazquez A, Gomez-Zorrilla S, Lopez-Cortes LE, Gasch O, Aparicio-Minguijon E, Escudero-Sanchez R, Perez-Rodriguez MT, Rodriguez-Pardo D, Jover-Saenz A, Garcia-Pardo G, Rodriguez-Bano J, Pujol M, Carratala J, Gutierrez-Gutierrez B; BACSAFO/FEN-AUREUS Group. Subphenotype- and complication-guided adjunctive fosfomycin versus standard monotherapy in Staphylococcus aureus bacteraemia: pooled analysis of two randomised trials. Lancet Reg Health Eur. 2026 Feb 17;62:101611. doi: 10.1016/j.lanepe.2026.101611. eCollection 2026 Mar.
PubMed 41788427
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Subphenotype- and Complication-guided Adjunctive Fosfomycin Therapy for Staphylococcus Aureus Bacteraemia: Pooled Analysis of Two Randomised Trials
- ClinicalTrials.gov ID
- NCT07155590
- Acronym / sponsor ID
- FENAUREUS-BACSAFO
- Keywords
- Staphylococcus aureus bacteraemia, Risk stratification, Clinical phenotypes, Subphenotypes, Monotherapy, Adjunctive therapy, Fosfomycin, Complicated bacteraemia
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 369 participants (actual)
- Lead sponsor
- Hospital Universitari de BellvitgeUniversity, hospital or other
- Collaborators
- Institut d'Investigació Biomèdica de Bellvitge, University of Barcelona, Hospital Universitario Virgen Macarena, University of Seville
- Study start
- 21 Jul 2025 (actual)
- Primary completion
- 4 Aug 2025 (actual)
- Study completion
- 15 Sep 2025 (estimated)
- First posted
- 4 Sep 2025 (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.
Staphylococcus aureus bacteraemia (SAB) is a major global cause of sepsis-related mortality. Randomised trials of adjunctive antibiotics, including fosfomycin, have not shown consistent benefit, possibly due to inclusion of unselected SAB populations. The FEN-AUREUS classification enables early risk stratification based on clinical subphenotypes. The investigators aim to validate this framework in a pooled trial cohort and assess whether combining subphenotypes with IDSA-defined complicated SAB could identify patients most likely to benefit from adjunctive fosfomycin. The investigators will conduct a post-hoc analysis of individual-level data from two multicentre randomised trials-BACSARM and SAFO-evaluating fosfomycin in SAB. Participants will be classified using FEN-AUREUS into source phenotypes (A, B and C) and risk subphenotypes (1 = low-risk, 2 = high-risk). Associations between subphenotype, treatment arm, and outcomes (30/60-day mortality, 8-week treatment success) will be assessed using multivariable models. Monte Carlo simulations will explore power by subgroup. FEN-AUREUS subphenotypes combined with complication status have the potential to identify patients with SAB that could likely benefit form combination therapy with fosfomycin.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Adjunctive fosfomycin therapy | – | –Patients with Staphylococcus aureus bacteraemia from the BACSAFO cohort treated with any regimen including fosfomycin |
| Monotherapy | – | –Patients with Staphylococcus aureus bacteraemia from the BACSAFO cohort treated with any regimen not containing fosfomycin |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The BACSAFO cohort pools individual participant data from two multicentre, randomised, superiority trials evaluating adjunctive fosfomycin for the treatment of SAB: BACSARM and SAFO. The BACSARM trial included 155 adult patients with methicillin-resistant (MRSA), randomised 1:1 to receive either daptomycin alone or daptomycin plus fosfomycin. The SAFO trial enrolled 214 adult patients with methicillin-susceptible (MSSA) bacteraemia, randomised to cloxacillin alone or cloxacillin plus fosfomycin.
Key inclusion criteria (17 listed)
- > or = 18 years old
- Monomicrobial Staphylococcus aureus bacteraemia
- Evidence of active infection
- Polymicrobial bacteraemia
- Severe clinical status with expected survival < 24 hours
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
All-cause mortality at 60 days
Time frame: At 60 days from randomisation
All-cause mortality at 60 days after randomisation
2 secondary outcomes
All-cause mortality at 30 days
Time frame: At 30 days after randomisation
Treatment success at 8 weeks
Time frame: At 8 weeks after randomisation
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 11 Sep 2025.
- Derived from this study: PubMed 41788427Escrihuela-Vidal F, Larrauri JG, Lopez-Contreras J, Euba G, Vazquez A, Gomez-Zorrilla S, Lopez-Cortes LE, Gasch O, Aparicio-Minguijon E, Escudero-Sanchez R, Perez-Rodriguez MT, Rodriguez-Pardo D, Jover-Saenz A, Garcia-Pardo G, Rodriguez-Bano J, Pujol M, Carratala J, Gutierrez-Gutierrez B; BACSAFO/FEN-AUREUS Group. Subphenotype- and complication-guided adjunctive fosfomycin versus standard monotherapy in Staphylococcus aureus bacteraemia: pooled analysis of two randomised trials. Lancet Reg Health Eur. 2026 Feb 17;62:101611. doi: 10.1016/j.lanepe.2026.101611. eCollection 2026 Mar.
- Individual participant dataSharing planned: Yes. Raw anonymised data relating to primary and secondary outcomes and safety may be shared upon request with researchers who provide a methodologically reasonable proposal. Requests for data should be sent to the corresponding author (JC). Interested researchers must obtain the approval of the Bellvitge University Hospital Ethics Committee.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Staphylococcal Aureus Infection and Staphylococcus Aureus Bacteraemia, run by Hospital Universitari de Bellvitge at 2 sites in Spain.
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 17 inclusion and 0 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: under way, not looking for participants, as of the sponsor's last update on 11 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Spain. 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
All-cause mortality at 60 days (time frame: At 60 days from randomisation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07155590, which also lists 1 linked publication.
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 11 Sep 2025.