Chlorhexidine and/or Metronidazole Plus FB301 Pre-treatment Trial

NCT07481955 | Not Yet Recruiting Phase 2

• 2 other identifiers: FRB-0042025-524362-20
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to evaluate how treatment with FB301 affects the balance of vaginal bacteria in women (aged 18-45) with bacterial vaginosis after pre-treatment with either a vaginal antiseptic wash (chlorhexidine), an oral antibiotic (metronidazole), or both. The main question it aims to answer is: Does treatment with FB301, with or without pre-treatment using a vaginal antiseptic (chlorhexidine) or an oral antibiotic (metronidazole), change the balance of vaginal bacteria, measured by the proportion of two key bacteria (Lactobacillus crispatus and Lactobacillus jensenii), between the start of treatment and follow-up visits over the next 10 weeks? Researchers will compare participants randomly assigned to 4 different groups:

• Group 1 will receive FB301for 15 days with the antibiotic (metronidazole) for the first seven days. In the next menstrual cycle, they will receive just FB301 for an additional 15-days.
• Group 2 will receive FB301for 15 days. On the first day only, they will first undergo a vaginal cleanse with chlorhexidine (antiseptic solution). In the next menstrual cycle, they will receive just FB301 for an additional 15-days.
• Group 3 will receive FB301for 15 days with the antibiotic (metronidazole) for the first seven days. On the first day only, they will first undergo a vaginal cleanse with chlorhexidine (antiseptic solution). In the next menstrual cycle, they will receive FB301 for an additional 15-days following a vaginal cleanse with chlorhexidine (antiseptic solution) on the first day only.
• Group 4 will receive just FB301for 15 days. In the next menstrual cycle, they will receive just FB301 for an additional 15-days. Participants will:
• Attend the study centre for up to 6 visits
• Provide vaginal swab samples at up to 6 visits
• Provide vaginal secretion samples using a menstrual disc at up to 4 visits
• Have blood samples taken at up to 6 visits
• Receive the study treatments for the randomly assigned group over two consecutive menstrual cycles.

Conditions

Bacterial Vaginosis (BV)

Outcome Measures

Primary Outcomes (1)

• The change in vaginal microbiome in terms of relative abundance of combined Lactobacillus crispatus and jensenii species

  Metagenomic sequencing is performed on cervical vaginal swab samples. Relative abundance is expressed as a percentage of bacterial sequencing reads that are assigned to a specific bacterial species. The change in vaginal microbiome in terms of relative abundance of combined Lactobacillus crispatus and jensenii species measured by metagenomic sequencing of vaginal samples obtained from Visit 2 (Baseline) to Visit 3 (Week 3).

  Baseline to visit 3 (week 3)

Secondary Outcomes (2)

• The change in vaginal microbiome in terms of relative abundance of combined Lactobacillus crispatus and jensenii species.

  Visit 2 (Baseline) to visit 6 (week 10)

• The change in vaginal microbiome in terms of relative abundance of combined vaginal Lactobacillus crispatus, jensenii, mulieris, gasseri and paragasseri

  Visit 2 Baseline to Visit 6 (week 10)

Other Outcomes (1)

• The change in vaginal microbiome in terms of relative abundance of Bifidobacterium species (previously Gardnerella species), Atopobium species, and Fannyhessea species.

  Visit 2 (Baseline) to Visit 6 (week 10)

Study Arms (4)

Metronidazole 500 mg plus intravaginal FB301

EXPERIMENTAL

Oral metronidazole 500 mg twice daily for 7 days starting 1 day after menses, plus intravaginal FB301 once daily for 15 days, followed by a second course of intravaginal FB301 once daily for additional 15 days starting 1 day after menses

Drug: FB 301; Drug: metronidazole 500 mg

single dose of 0.5% chlorhexidine solution followed by intravaginal FB301

EXPERIMENTAL

Intravaginal antisepsis with a single dose of 0.5% chlorhexidine solution 1 day after menses, then intravaginal FB301 once daily for 15 days, followed by second course of intravaginal FB301 once daily for additional 15 days starting immediately after the next menstrual cycle.

Drug: FB 301; Drug: Chlorhexidine 0.5%

single dose of 0.5% chlorhexidine solution, oral metronidazole 500 mg then intravaginal FB301

EXPERIMENTAL

Intravaginal antisepsis with a single dose of 0.5% chlorhexidine solution 1 day after menses, then oral metronidazole 500 mg twice daily for 7 days and intravaginal FB301 once daily for 15 days, followed by second intravaginal antisepsis with a single dose of 0.5% chlorhexidine solution then a second course of intravaginal FB301 once daily for additional 15 days 1 day after menses

Drug: FB 301; Drug: Chlorhexidine 0.5%; Drug: metronidazole 500 mg

FB301

EXPERIMENTAL

Intravaginal FB301 once daily for 15 days starting 1 day after menses, followed by second course of intravaginal FB301 once daily for additional 15 days 1 day after menses

Drug: FB 301

Interventions

FB 301 DRUG

FB 301 capsule

FB301; Metronidazole 500 mg plus intravaginal FB301; single dose of 0.5% chlorhexidine solution followed by intravaginal FB301; single dose of 0.5% chlorhexidine solution, oral metronidazole 500 mg then intravaginal FB301

Chlorhexidine 0.5% DRUG

Vaginal cleanse with 0.5% Chlorhexidine solution

single dose of 0.5% chlorhexidine solution followed by intravaginal FB301; single dose of 0.5% chlorhexidine solution, oral metronidazole 500 mg then intravaginal FB301

metronidazole 500 mg DRUG

Metronidazole 500 mg tablets

Metronidazole 500 mg plus intravaginal FB301; single dose of 0.5% chlorhexidine solution, oral metronidazole 500 mg then intravaginal FB301

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may not qualify if:

• Known immunodeficiency conditions, including drug induced.
• Contraindication to metronidazole or chlorhexidine.
• Any known condition requiring regular use of antibiotics, which would suggest the likely requirement for antibiotic treatment during the trial.
• Any social, medical, or psychiatric condition that in the opinion of the Investigator would make it unlikely for the participant to comply with the trial requirements or might interfere with the objectives of the trial.
• History of drug or alcohol abuse that in the opinion of the Investigator would make it unlikely for the participant to comply with the trial or would complicate interpretation of data from participation.
• History of gynecological cancers, gynecological conditions, or surgical gynecological medical history which, in the opinion of the Investigator, precludes participation.
• Abnormal finding on the physical examination or gynecological examination or any other condition which, in the opinion of the Investigator, precludes participation.
• Patients with other infectious causes of vulvovaginitis (e.g., vulvovaginal candidiasis, Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, or active Herpes simplex \[including PCR test positive\]).
• Patients with another vaginal or vulvar condition, which would confound the interpretation of clinical response.
• Participants taking prescription or non-prescription drugs (including vitamins and dietary or herbal supplements) within 2 weeks or 5 half-lives (whichever is longer) before the start of trial treatment (unless, in the opinion of the Investigator and Sponsor, the medication will not interfere with the trial).
• Receiving treatment involving investigational drugs. Any previous investigational drug must have been completed at least 30 days prior to screening in this trial.
• Systemic and/or vaginally applied antibiotic use within the last 30 days prior to screening.
• Participants who are currently receiving antibacterial therapy unrelated to BV.
• Clinical laboratory test results which are clinically unacceptable at screening. Any clinically significant abnormal urinalysis should be repeated. If then confirmed abnormal and clinically significant, participant should be excluded. Any clinically significant out of range chemistry or hematology values should exclude the participant.
• Positive serum HBsAg (other than vaccination related), HCV and HIV antibody tests at screening.

Sponsors & Collaborators

• Freya Biosciences ApS: lead
• CRS Clinical Research Services Berlin GmbH: collaborator

Study Sites (1)

CRS Clinical Research Services Berlin GmbH

Berlin, State of Berlin, 13627, Germany

Location

MeSH Terms

Conditions

Vaginosis, Bacterial

Interventions

Metronidazole

Condition Hierarchy (Ancestors)

Bacterial Infections; Bacterial Infections and Mycoses; Infections; Vaginitis; Vaginal Diseases; Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Genital Diseases

Intervention Hierarchy (Ancestors)

Nitroimidazoles; Nitro Compounds; Organic Chemicals; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 15, 2026
• First Posted: March 19, 2026
• Study Start: March 16, 2026
• Primary Completion (Estimated): March 3, 2027
• Study Completion (Estimated): April 21, 2027
• Last Updated: March 20, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1)