Comparing GAG therapy to antibiotics for preventing recurrent urinary tract infections

Gag Therapy for Recurrent Urinary Tract Infection Assessing Comparability to International Nitrofurantoin Gold Standard Study

Phase 4 Interventional Radboud University Medical Center · NCT05652374

This study is testing whether a new bladder treatment using hyaluronic acid and chondroitin sulfate can help women with recurrent urinary tract infections just as well as antibiotics.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexFemale
SponsorRadboud University Medical Center Academic / other
Locations3 sites (Nijmegen, Gelderland and 2 other locations)
Trial IDNCT05652374 on ClinicalTrials.gov

What this trial studies

This study evaluates the effectiveness of hyaluronic acid-chondroitin sulfate (HA-CS) bladder installations compared to the standard antibiotic treatment for preventing recurrent urinary tract infections (rUTI) in women. It is designed as a non-inferiority, parallel group crossover randomized controlled trial, where participants will receive both treatments in a randomized order over a total period of 12 months. The primary endpoint is the number of UTIs per patient-year, while secondary endpoints include quality of life assessments and patterns of antibiotic resistance. A total of 100 female patients over 18 years with a history of rUTIs will be enrolled.

Who should consider this trial

Good fit: Ideal candidates are adult females over 18 years who have experienced at least three symptomatic UTIs in the past year and have no adequate curable therapeutic options.

Not a fit: Patients who are male, under 18 years, pregnant, or have specific urinary tract conditions such as urinary stones or cancer will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could provide a non-antibiotic alternative for preventing recurrent urinary tract infections, potentially reducing antibiotic resistance.

How similar studies have performed: While the use of GAG therapy is gaining interest, this specific comparison to the gold standard antibiotic treatment is relatively novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Adult female patients (\>18 years) who had at least 3 symptomatic UTI's in the previous year with no adequate curable therapeutic options (e.g. bladder stones)
2. At least one UTI's must be confirmed with a positive culture and antibiogram, further UTI's must be confirmed with a urine sediment with positive nitrite or a positive culture.

Exclusion Criteria:

1. Male
2. \< 18 years
3. Pregnant
4. Already on GAG therapy
5. Already on prophylactic antibiotics
6. Started or stopped cranberry/d-mannose therapy or vaginal estrogenic creme in the last two months
7. Had Gentamicin or other antibiotic instillations in the previous 2 months
8. Allergic to \>3 regular used antibiotics in Dutch guidelines (ed. Nitrofurantoin, trimethoprim, Fosfomycin)
9. A urinary fistula
10. Urinary stones
11. Urogenital cancer
12. Bladder Pain Syndrome - Interstitial Cystitis
13. Chronic pelvic pain
14. Had a STD untreated or treated in the previous 2 months
15. A urinary diversion
16. An Indwelling catheter
17. A suprapubic catheter
18. Performing \>1/day self-catheterization
19. A residue after voiding (PVR) of \>200ml
20. Unable (also legal) to give informed consent
21. Recurrent urosepsis
22. Multiresistant bacteria in previous urine cultures
23. Contra-indications and interactions for Nitrofurantoin: severe kidney disfunction (GFR \< 30), lung- or liver problems or neuropathy after previous use of nitrofurantoin, acute porphyria, known G6PD deficiency, use of magnesium trisilicate.
24. Contra-indications and interactions for trimethoprim: severe kidney or liver dysfunction, blood count abnormality, use of vitamin K antagonists, use of folic acid antagonists, use of ace inhibitors
25. Severe lung/respiratory disfunction (reduced lung capacity, lung cancer, fibrosis, COPD)
26. Does not tolerate catheterization

Where this trial is running

Nijmegen, Gelderland and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Recurrent Urinary Tract InfectionGAG therapyProphylactic antibiotics
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.