The Impact of Fast Antimicrobial Sensitivity Testing Tools on Stewardship Antibiotic and Clinical Outcome (ACT-FAST) (ACT-FAST)

March 18, 2026 updated by: Istituto Clinico Humanitas

The Impact of Fast Antimicrobial Sensitivity Testing Tools on Stewardship Antibiotic and Clinical Outcome: a Randomized Clinical Trial Within an Adaptive Platform Trial for Patients With Bloodstream Infections

The ACT-FAST study aims to compare commercially available Rapid Antimicrobial Susceptibility Testing (R-AST) tools with the current standard of care for patients with Bloodstream Infections (BSI). The primary objective is to evaluate whether "early targeted" antibiotic prescriptions, guided by these rapid tests, can improve antimicrobial stewardship and patient clinical outcomes.

To facilitate the evaluation of various diagnostic tools-including those currently on the market and those emerging in the near future-this study utilizes an adaptive clinical trial platform. This flexible design allows for the continuous assessment of different R-AST technologies within a single master protocol, ensuring that the most effective diagnostic strategies are identified efficiently.

Study Overview

Detailed Description

ACT-FAST is a multicenter, open-label, randomized, adaptive clinical trial designed as the first domain of a broader adaptive platform. The study evaluates the clinical and stewardship impact of "early targeted" antibiotic therapy guided by Rapid Antimicrobial Susceptibility Testing (R-AST) compared to standard empirical therapy in patients with suspected bloodstream infections (BSI).

The study population consists of patients with positive blood cultures for whom pathogen identification and susceptibility results are still pending. Participants are randomized into one of two diagnostic strategies:

  • Experimental Arm: Blood cultures are processed using R-AST testing tools to provide rapid phenotypic or genotypic susceptibility data.
  • Standard of Care (SoC) Arm: Blood cultures are processed according to the standard laboratory diagnostic workflow of the participating center.

In both arms, results are communicated to the treating clinicians, who adjust antibiotic therapy based on their clinical judgment and routine practice. As an adaptive trial, the randomization ratios may be adjusted based on the number of active intervention arms. To ensure scientific rigor, outcome assessors remain blinded to the treatment allocation.

Patients are followed for a total of 28 days to assess clinical outcomes and antimicrobial stewardship objectives. The platform design allows for the integration of additional R-AST tools or interventions through future protocol amendments, ensuring the study remains at the forefront of diagnostic innovation.

Study Type

Interventional

Enrollment (Estimated)

400

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Milan
      • Rozzano, Milan, Italy, 20089
        • Recruiting
        • Infectious Disease Unit - IRCCS Humanitas Research Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients admitted to emergency department or hospitalized for any cause in participating hospitals with clinically suspected BSI and positive blood culture.
  • At least 18 years of age.

Exclusion Criteria:

  • Have previously taken part in this trial.
  • Concurrently participating in the active phase of a study considered incompatible.
  • Patient with severe or terminal disease with life expectancy shorter than 48 h.
  • Have an existing directive to withhold life-sustaining treatment, in relation to antibiotic use.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Experimental arm
Diagnostic approach to blood cultures using rapid microbiological diagnosis testing (R-AST)
In patients randomized to the intervention arm, the test under evaluation will be performed by the Humanitas Core Lab on positive blood cultures. The test is expected to provide results in a certain amount of time. The Lab will notify the ID consultant as soon as the test provides the first result (even if partial). The ID physician is expected to revise the antibiotic therapy according to the identified species, guided by the tool.
Active Comparator: Standard of care
Diagnostic approach to blood cultures using the standard method
Patients will be managed as usual, which typically consists of receiving standard empirical antibiotics, according to the local prescribing policy, continued until the results of the routine standard AST protocol in current use. In any case, both arms have standard microbiology culture and susceptibility testing performed, according to standard laboratory procedures and current guidelines, with results typically available after 48-72 hours from a blood culture positive result (day 3).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Compare commercially available R-AST testing tools with the current standard of care in BSI patients
Time Frame: 24 hours
The primary objective is to determine if a management strategy based on a R-AST test results shorten the time for randomization to antimicrobial stewardship goals compared to standard care. "Antimicrobial stewardship goals" is defined by the administration of an antimicrobial agent that meets both conditions: i) an antimicrobial agent active against the organism(s) documented at conventional AST on blood culture (in vitro); AND ii) an antimicrobial agent targeted for the pathogen(s) identified, and not excessively broad spectrum
24 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 19, 2025

Primary Completion (Estimated)

November 19, 2027

Study Completion (Estimated)

November 19, 2027

Study Registration Dates

First Submitted

March 18, 2026

First Submitted That Met QC Criteria

March 18, 2026

First Posted (Actual)

March 24, 2026

Study Record Updates

Last Update Posted (Actual)

March 24, 2026

Last Update Submitted That Met QC Criteria

March 18, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Bloodstream Infection

Clinical Trials on Diagnostic Test: Rapid Antimicrobial Susceptibility Testing (R-AST) guided Stewardship

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