Effect of FB301 on Vaginal Bacterial Profile in Women With Asymptomatic Vaginal Dysbiosis Undergoing a Mock Frozen Embryo Transfer Cycle

Conditions

• Vaginal Dysbiosis

Eligibility Criteria

Sex

FEMALE

Age

18 Years - 40 Years

Healthy Volunteers

Not accepted

Interventions

• FB-301 — DRUG
  FB301 capsule
• Placebo — DRUG
  FB301 Placebo capsule
• Chlorhexidine (0.5%) Vaginal Cleanse — OTHER
  Vaginal cleanse with 0.5% Chlorhexidine solution prior to first IP administration
• Sham vaginal cleanse (saline) — OTHER
  Vaginal cleanse with saline solution prior to first IP administration.

Study Details

The goal of this clinical trial is to evaluate FB301 during a mock frozen embryo transfer (FET) cycle in pre-menopausal women aged 18 to 40 years with a prior failed FET and a defined vaginal bacterial imbalance (dysbiosis). The main question it aims to answer is: • Does treatment with FB301 during a mock FET cycle change the proportion of participants who meet the predefined vaginal bacterial threshold compared with placebo? Researchers will compare: * FB301 given after an initial vaginal cleansing with chlorhexidine (an antiseptic solution), * FB301 given after an initial vaginal cleansing with saline (saltwater), and * A placebo capsule given after an initial vaginal cleansing with saline to determine whether these approaches affect vaginal bacterial composition and pregnancy outcomes. Participants will take study treatment for 15 days during a "mock" FET cycle. In a mock cycle, participants receive the hormones needed to prepare the uterus for embryo transfer, but no embryo is transferred. After completing the mock cycle, participants will proceed with their planned frozen embryo transfer and will be followed during pregnancy until birth. Participants will: * Undergo a vaginal cleansing before receiving the first dose of FB301 or placebo * Provide vaginal swab samples at up to 5 study visits * Attend the study centre for up to 8 visits and participate in up to 4 follow-up phone calls * Complete a mock FET cycle before proceeding with their planned frozen embryo transfer cycle Participants who become pregnant will be followed until birth.

Key Dates

Start date

Apr 15, 2026

Status verified

Mar 2026

Primary completion

Oct 31, 2026

Completion

Sep 30, 2027

Study Design

Enrollment

30 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Experimental: FB301 / Chlorhexidine
• Experimental: FB301 / Sham
• Placebo Comparator: Placebo / Sham

Primary Outcome Measure

Proportion of participants with ≥90% combined relative abundance of Lactobacillus crispatus, L. jensenii, L. mulieris, L. gasseri, and L. paragasseri as measured by metagenomic sequencing. [ Time Frame: Baseline to Day 16 (Mock FET cycle) ]

Locations (1)

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