A Phase 3 interventional study of Fosfomycin-trometamol (FT) and Alternative antibiotic treatment in Escherichia Coli Infection, Elderly Women and Antibiotherapy, sponsored by Assistance Publique - Hôpitaux de Paris. Not yet recruiting. Open to female participants aged 75 Years and older. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Assistance Publique - Hôpitaux de Paris · Phase 3, Interventional, and Treatment
Acute pyelonephritis (APN) is among the most common bacterial infections in older women. Oral step-down antibiotic therapy may potentially be associated with toxicity, particularly with fluoroquinolones or trimethoprim-sulfamethoxazole, espcially in geriatric patients. The emergence of resistant strains reduces the choice of oral step-down treatment, thereby increasing the risk of nosocomial complications related to intravenous access and prolonged hospitalization.
Fosfomycin trometamol (FT) has broad activity against Enterobacterales, including resistant strains. It has an excellent safety profile and moderate ecological impact, and has been used for several years to treat cystitis. Recent studies have demonstrated its efficacy as an oral step-down therapy for the treatment of E.coli APN in younger women. Its efficacy in a geriatric population remains to be demonstrated.
The primary objective is to demonstrate the non-inferiority, in terms of clinical cure, of FT compared with an alternative active antibiotic as step-down therapy for E. coli APN in older women.
FOSFOLD is a national, multicenter, randomised, comparative, phase 3, non-inferiority trial (1:1), open-label with two parallel treatment groups. After 3 or 4 days of appropriate empirical antibiotic therapy, women aged 75 or over with E.coli APN will be randomised to receive either 3g of FT once daily or an alternative antibiotic treatment in accordance with current french guidelines, for a total of 10 days.
The primary endpoint is clinical cure at Day 17, i.e. 10 days after completion of antibiotic therapy.
If non-inferiority of FT is confirmed, it could provide a new therapeutic approach for oral step-down therapy in the older patients with APN. Its favorable tolerability profile could help prevent common geriatric complications, such as delirium, falls and malnutrition. Ultimately, it could help prevent some of the iatrogenic functional decline associated with hospitalisation.
99 studies on the registry are indexed under Escherichia coli Infections; 21 are open to participants now.
This study's planned enrollment of 312 is above the median of 72 across 63 interventional studies indexed under Escherichia coli Infections.
Browse Escherichia coli Infections studies →Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,592 studies on the registry; 1,033 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Fosfomycin-trometamol (FT)
Drug: Alternative antibiotic treatment
One sachet (3g), once daily, orally for 6 or 7 days, following 4 or 3 days, respectivelly of effective antibiotic therapy, for a total of 10 days of effective antibiotic treatment.
Treatment will be selected at the investigator's discretion, in accordance with the 2017 recommandations of the French Society for Infectious Diseases (SPILF) and the 2025 French National Authority for Health (HAS) guidelines. Therapy will be administrated for 6 or 7 days (Day 1 - Day 6/7), following 4 or 3 days, respectively of effective antibiotic therapy. The total duration of effective antibiotic therapy will be 10 days. Injection antibiotic therapy will be offered in the absence of an active oral antibiotic option.
Clinical resolution
Clinical cure defined as : * Body temperature \< 38 °C and resolution of all urinary symptoms present at the time of the APN diagnosis, with no occurrence of new clinical signs (urinary urgency, dysuria, increased urinary frequency, gross hematuria, painful/burningurination, flank pain \[spontaneous or provoked\], suprapubic pain, or urinary incontinence) between treatment discontinuation and assessment of the primary endpoint at Day 17, except for a temperature ≥ 38°C unrelated to a urinary tract condition * No resumption of antibiotic therapy active against the causative pathogen responsible for the APN following completion of the antibiotic treatment course
Time frame: Day 17
Occurence of antibiotic-related adverse events
Occurrence, nature, and severity of antibiotic-related adverse events, assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) scale.
Time frame: Up to 37 days
Occurence of geriatric complications
* Occurrence of delirium, defined according the Confusion Assessment Method (CAM) * Fall(s) (one or more episodes) * Weight loss, assessed as the percentage change between admission body weight and discharge body weight or Day 17 weight if the patient remains hospitalized * Occurrence of pressure ulcers, staged according to the National Pressure Ulcer Advisory Panel (NPUAP) pressure ulcer staging classification (HAS Guidelines, Prevention and Treatment of Pressure Ulcers in Adults and Older Persons, 2001)
Time frame: Up to 37 days
Functional autonomy
According to the Activities of Daily Living (ADL) scale: score ranges from 0 (complete dependence) to 6 (complete independence), with higher scores indicating greater independence in basic daily activities such as bathing, dressing, toileting, transferring and eating.
Time frame: Up to 37 days
Incidence of Infectious and urological complications
* Renal abscess (yes/no) * Need for urinary drainage * Transfer to an continuous care unit or intensive care unit due to the infection At the end of antibiotic treatment (Day 7)
Time frame: Up to day 7
Cumulative incidence of recurrent febrile or non-febrile urinary tract infectious (UTIs) (relapse or reinfection)
* Cystitis : recurrence of urinary symptoms in the absence of fever, associated with a positive urine culture. * Acute pyelonephritis :; recurrence of urinary symptoms with fever and a positive urine culture. * Reinfection : new infection caused by a microorganism different from that isolated during the initial episode. * Relapse : recurrence of infection due to the same microorganism as that isolated during the initial episode.
Time frame: From Day 17 to Day 37
Rate of hospitalization or rehospitalization following treatment for APN
Time frame: Up to day 37
Length of hospital stay following randomization
Time frame: Up to day 37
All-cause mortality
Time frame: Up to day 37
Rate of rectal colonization with antibiotic-resistant Enterobacterales
fluoroquinolones, trimethoprim-sulfamethoxazole, fosfomycin, and third-generation cephalosporins
Time frame: Up to day 37
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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