Biomarker Signature-Supported Antibiotic Treatment Decisions in ICU (BAST-ICU)

Biomarker Signature-Supported Antibiotic Treatment Decisions in Intensive Care Units

The goal of this randomized clinical trial is to determine whether a biomarker-signature (BV) supported antibiotic treatment decision matrix can have a beneficial impact on antibiotic use and patient outcomes in an ICU population.

Study Overview

• Status: Recruiting
• Conditions: Intensive Care Unit (ICU) Admission
• Intervention / Treatment: Diagnostic test: Clinical assessment for antibiotic treatment decision; Diagnostic test: Biomarker-signature supported antibiotic treatment recommendation

Detailed Description

This study will pragmatically combine the evaluation of a diagnostic test with an antibiotic treatment decision matrix, in a manner that mimics real-life but is as close as possible to a "best-case" scenario.

Primary objective is to evaluate the combined endpoint of efficacy and safety at 28 days (approximately 4 weeks). This will include:

• Efficacy: Assessed by the use of antibiotics.
• Safety: Assessed by clinical outcomes.

Eligible participants will be randomized 1:1 to either the intervention or control groups. Evaluation of safety and efficacy will be combined to provide a global evaluation of the benefits and risks of the intervention, using the Desirability of Outcome Ranking (DOOR) further combined with Response Adjusted for Duration of Antibiotic Risk (RADAR).

The hypothesis is that participants in the intervention group will have lower antibiotic exposure, without increased harm (worse clinical outcomes related to infection or significant adverse events) .

• Study Type: Interventional
• Enrollment (Estimated): 1200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Makeda Semret, MD; Phone Number: 35081 15149341934; Email: makeda.semret@mcgill.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H3G 1A4
      • Recruiting
      • Montreal General Hospital
      • Contact: Makeda Semret, MD, FRCP(C); Email: makeda.semret@mcgill.ca
    • Montreal, Quebec, Canada, H4A 3J1
      • Recruiting
      • Royal Victoria Hospital
      • Contact: Makeda Semret, MD, FRCP(C); Email: makeda.semret@mcgill.ca
    • Montreal, Quebec, Canada, H4A 3J1
      • Recruiting
      • Research Institute of McGill University Health Center (RI-MUHC)
      • Contact: MD, FRCP(C); Email: makeda.semret@mcgill.ca
      • Principal Investigator: Makeda Semret, MD, FRCP(C)
    • Montreal, Quebec, Canada, H4A3J1
      • Recruiting
      • Research Institute McGill University Health Centre
      • Contact: Makeda Semret, MD; Phone Number: 35081 5149341934; Email: makeda.semret@mcgill.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Admitted to the Intensive Care Unit (ICU)
• Started on antibiotics for any suspected or confirmed infection in the preceding 72 hours (about 3 days)
• Treating doctor(s) willing to consider BV test result in antibiotic treatment decision making

Exclusion Criteria:

• Severe immunocompromise/immunosuppression

  1. Congenital immunodeficiency
  2. HIV with CD4 < 20
  3. Active chemotherapy and profound neutropenia (ANC < 100) expected to last > 7 days;
  4. solid organ or stem cell transplant within preceding 6 months AND active GVHD
  5. Receiving high dose steroids (Pred > 20mg/day for > or = 2 weeks)
• Advanced metastatic cancer irrespective of treatment
• Palliative intent, death imminent and inevitable within 4 weeks
• Antibiotic to be discontinued within 24h (ex. Prophylaxis)
• Active infection diagnosed and treated with antibiotics within preceding 2 weeks
• Previously included during the same hospitalization

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Clinically-Supported Antibiotic Treatment Recommendation; Participants in the control group will have antibiotic treatment recommendations based on clinical assessment alone. The BV-signature test result will remain hidden.	Diagnostic test: Clinical assessment for antibiotic treatment decision; Antibiotic treatment decision will be based on clinical assessment only (BV test result remains masked)
Experimental: Combined clinical and BV-supported antibiotic treatment recommendation; The result of the BV test will be unmasked for the investigators and combined with the clinical assessment of the antibiotic prescription, using a decision matrix. The recommendation will be shared with the treating team.	Diagnostic test: Clinical assessment for antibiotic treatment decision; Antibiotic treatment decision will be based on clinical assessment only (BV test result remains masked); Diagnostic test: Biomarker-signature supported antibiotic treatment recommendation; The antibiotic treatment recommendation will be based on a decision matrix that combines the results of the BV-signature (a score ranging from 0 -100) with the clinical assessment of likelihood of bacterial infection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Desirability of Outcome Ranking Adjusted for Antibiotic Risk (DOOR-RADAR)	The primary outcome is the Desirability of Outcome Ranking (DOOR), which ranks each participant according to overall clinical outcome based on a hierarchical composite that incorporates mortality, infection recurrence, infection relapse and treatment-related adverse events. Participants are assigned to mutually exclusive outcome ranks (1 to 5), with 1 representing the most desirable outcome (alive, none of treatment failure/recurrence or adverse events) and 5 representing the least desirable outcome (death). Within each clinical outcome category, participants will be further ranked according to antibiotic exposure using the Response Adjusted for Duration of Antibiotic Risk (RADAR) approach, such that shorter duration of antibiotic therapy is considered more desirable. The primary analysis will estimate the probability that a randomly selected participant in the intervention group has a more desirable outcome than a participant in the comparator group.	28 days+/- 2

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
All cause mortality	Death from any cause during the follow-up period.	28 +/- 2 days
Days of antibiotic therapy (DOT)	Total number of days each participant received systemic antibacterial therapy during the study period.	28 +/- 2 days
Antibiotic-free days	Number of days alive and not receiving systemic antibiotic therapy during the follow-up period.	28 days+/- 2
Adverse events	Number of participants experiencing treatment-related adverse events during the follow-up period, including serious adverse events.	28 +/- 2 days
Length of stay in the Intensive Care Unit	Duration of stay in the intensive care unit, measured in days from ICU admission to ICU discharge.	28 +/- 2 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of drug-resistant organisms.	To assess the incidence of colonization or infection with drug-resistant organisms (Carbapenem-resistant Gram-negative bacilli, Vancomycin-Resistant Enteroocci VRE, Methicillin-Resistant S. aureus MRSA, C. difficile).	28 days+/- 2

Collaborators and Investigators

• Sponsor: McGill University Health Centre/Research Institute of the McGill University Health Centre
• Collaborators: Canadian Institutes of Health Research (CIHR)

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2025
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): August 1, 2028

Study Registration Dates

• First Submitted: February 24, 2026
• First Submitted That Met QC Criteria: March 14, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): March 19, 2026
• Last Update Submitted That Met QC Criteria: March 14, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Antimicrobial Stewardship; Antimicrobial Resistance; ICU, Antibiotic Assesment, Diagnostic, Intervention, Medical Device
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Disease
• Other Study ID Numbers: 2025-10747; FRN 194227 (Other Grant/Funding Number: Canadian Institutes of Health Research (CIHR))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Probably will be shared, but will need to review with funders and sponsors.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No