Randomized, Multicenter, Non-inferiority Trial Comparing the Efficacy of Fosfomycin Versus Fluoroquinolones or Cotrimoxazole as Oral Follow-up Treatment in Febrile Urinary Tract Infections in Men Caused by Susceptible Enterobacteria (FOSFORMEN)

November 5, 2026 updated by: Assistance Publique - Hôpitaux de Paris

Essai randomisé, Multicentrique, de Non-infériorité Comparant l'efficacité d'un Traitement Par Fosfomycine Versus Fluoroquinolones ou Cotrimoxazole en Relais Oral Dans Les Infections Urinaires Masculines fébriles Dues à Escherichia Coli

The fosfomycin-trometamol (FT) combination demonstrates microbiological efficacy against the vast majority of Escherichia coli strains responsible for urinary tract infections (UTIs). Moreover, approximately 99% of strains exhibiting multidrug resistance remain suceptible to fosfomycin.

The clinical tolerance profile of this molecule is excellent and has been well established since its market authorization in 1989 for the treatment of cystitis in women.

Its pharmacokinetic and pharmacodynamic properties are compatible with its use in the treatment of UTIs in men.

However, the clinical efficacy of FT (oral fosfomycin) in the treatment of febrile UTIs in men has never been evaluated in prospective trials. FT could represent an innovative treatment option in such cases, offering the use if an antibiotic with significantly fewer side effects than those currently recommended.

The main objective of the trial is to demonstrate that FT is not inferior to fluoroquinolones (FQ) or cotrimoxazole (TMP-SMX) as oral step-down therapy in prostatitisfebrile male urinary tract infections caused by Escherichia coli.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

312

Phase

  • Phase 3

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 Contact Backup

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Male
  • Age ≥ 18
  • Body temperature ≥ 38°C within the 72 hours preceding the diagnosis of UTI
  • At least one of the following symptoms : dysuria, higher urinary frequency, urgency, hematuria, suprapubic pain, prostatic pain, or perineal pain
  • Positive urine microbiological examination (urine culture) : Sample collected before initiation of the empiric antibiotic therapy, ≥ 10 leukocytes/µL, and monomicrobial culture positive for E. coli with bacteriuria ≥ 103 CFU/mL
  • The strain must be suceptible to fosfomycin and to either FQ or TMP-SMX according to EUCAST
  • The strain must be suceptible to the empiric antibiotic therapy received
  • Ability to take oral treatment
  • Favorable clinical evolution after receiving effective empiric antibiotic therapy for 72 ± 24 hours ; Favorable evolution is defined as body temperature < 38°C with clinical improvement or resolution of the clinical signs and symptoms of urinary tract infection present at diagnosis, including the absence or improvement of dysuria, pollakiuria, urinary urgency, hematuria, suprapubic, prostatic, or perineal pain, urethral pain during urination, and/or a burning sensation during urination.

Exclusion Criteria:

  • Presence of another condition that could explain the fever
  • Septic shock of urinary origin
  • Need for a urological procedure
  • Anatomical abnormalities of the urinary tract (e.g., urinary prostheses and implants [except JJ], Bricker, neobladder, total prostatectomy, uretrestomy, nephrostomy, urinary fistula)
  • Presence of an indwelling urinary catheter, except of placed during the current UTI episode
  • Neurogenic bladder
  • Immunosupression
  • Contraindication to the use of FQ , TMP-SMX or FT
  • Severe chronic kidney disease with an estimated flomerular filtration rate < 20 mL/min
  • UTI treated within the past 3 months
  • High probability of death within 3 months
  • Major cognitive disorders
  • Patients deprived of their liberty by judicial or administrative decision, under guardianship or curatorship
  • Lack of social security coverage
  • Absence of written informed consent
  • Participation in another interventional research protocol
  • Absence of written informed consent
  • Participation in another interventional research protocol
  • Patients deprived of their liberty by a judicial or administrative decision

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Fosfomycin-trometamol (FT)

Oral dose : 3g Fosfomycin-trometamol once daily

Active Comparator: Reference treatments as per the French SPLIF guidlines

Reference treatments will bet hose recommended by the French SPLIF guidlines :

  • Oral FQ : three molecules are authorized ; ofloxacin, ciprofloxacin and levofloxacin
  • TMP-SMX

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical cure
Time Frame: At day 26

Defined as body temperature < 38°C and absence of urinary tract infection symptoms, without the need for additional antibiotic therapy up to the primary evaluation on Day 26, which corresponds to 14 days after completion of a 12-day antibiotic treatment assigned by randomization.

At day 26

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cumulative incidence of infectious and urological complications
Time Frame: Up to day 40
Up to day 40
Adherence to treatment
Time Frame: Up to day 40
Up to day 40
Occurence of adverse events related to anticiotics
Time Frame: Up to day 40

Occurrence, nature, and severity of adverse events

Up to day 40
Rectal carriage of phenotypically antibiotic-resistant Enterobacterales
Time Frame: At day 26

Carriage of Enterobacterales resistant to FQ, TMP-SMX, fosfomycin, and third-generation cephalosporins on Day 26, i.e., 14 days after completion of the randomized antibiotic treatment Binary outcome

At day 26
Rates of recurrence of febrile or non-febrile UTIs (relapse or reinfection)
Time Frame: At day 40

Assessed on Day40, i.e., 28 days after completion of the randomized antibiotic treatment

  • UTI : reappearance of urinary symptoms with a positive urine culture (ECBU)
  • Febrile UTI : fever or urinary origin with a positive urine culture
  • Relapse : new infection caused by the same bacteria than as the initial episode
  • Reinfection : new infection caused by a different bacteria than the initial episode
At day 40
Number of patients who experienced treatment failure
Time Frame: Up to day 40

Clinical and biological characteristics of patients who experienced treatment failure compared to those who were cured during the initial episode

Up to day 40

Collaborators and Investigators

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

Sponsor

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 (Estimated)

December 1, 2026

Primary Completion (Estimated)

December 26, 2029

Study Completion (Estimated)

January 15, 2030

Study Registration Dates

First Submitted

November 2, 2026

First Submitted That Met QC Criteria

November 5, 2026

First Posted (Actual)

November 12, 2026

Study Record Updates

Last Update Posted (Actual)

November 12, 2026

Last Update Submitted That Met QC Criteria

November 5, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • APHP240801

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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.