In short
FB301 is an investigational live biotherapeutic product being studied for bacterial vaginosis (BV), a common vaginal infection caused by an imbalance in the vaginal microbiome. It is given vaginally as a hard capsule and is currently being tested in one authorised Phase 2 trial involving 120 participants. The trial is investigating whether FB301, with or without pre-treatment using chlorhexidine or metronidazole, can increase the abundance of beneficial Lactobacillus bacteria in the vagina.
Key points
- FB301 is an investigational live biotherapeutic product, not yet authorised as a medicine.
- It is being studied for bacterial vaginosis, a condition caused by an imbalance in vaginal bacteria.
- The active substance is given vaginally as a hard capsule.
- One Phase 2 trial is authorised, planning to enrol 120 participants.
- The trial measures the change in Lactobacillus crispatus and jensenii abundance in the vaginal microbiome.
- The study includes pre-treatment with chlorhexidine and/or metronidazole before FB301 administration.
What is FB301?
FB301 is an investigational live biotherapeutic product, which means it contains live microorganisms intended to restore a healthy balance of bacteria in the body. It is being developed for use in bacterial vaginosis, a condition where the normal vaginal microbiome is disrupted. The product is given as a hard vaginal capsule and is administered directly into the vagina. In the product records, the active substance is also referred to under the registry names FRE01, FRE02, FRE03 and FRE04, and the product name is FB301. The company responsible for the product records is Freya Biosciences ApS. No marketing authorisation exists for FB301 in these records, so it remains an investigational substance.
How does FB301 work?
FB301 is a live biotherapeutic product designed to deliver beneficial bacteria, specifically Lactobacillus species, into the vagina. The trial aims to assess whether giving FB301 after pre-treatment with chlorhexidine vaginal antisepsis and/or oral metronidazole can increase the relative abundance of combined Lactobacillus crispatus and Lactobacillus jensenii species in the vaginal microbiome. These Lactobacillus species are considered important for maintaining a healthy vaginal environment and protecting against bacterial vaginosis. The primary outcome measures this change from baseline to week 3 using metagenomic sequencing of vaginal samples.
Which conditions is it used or studied for?
- Bacterial vaginosis — a common vaginal condition caused by an overgrowth of certain bacteria and a reduction in protective Lactobacillus species. FB301 is being studied to see if it can help restore a healthier vaginal microbiome in women with this condition.
How is FB301 given?
FB301 is given vaginally as a hard capsule. The trial records state that the product is administered as a vaginal capsule containing 10 million colony forming units (CFU) of the live biotherapeutic. The route of administration is vaginal use. In the study, FB301 is given after pre-treatment with chlorhexidine vaginal antisepsis (0.5%) and/or oral metronidazole, which are used to reduce the existing bacterial load before the live biotherapeutic is introduced.
What do the clinical trials show?
One Phase 2 interventional trial is authorised for FB301, with a planned enrolment of 120 participants. The trial is investigating the impact of chlorhexidine vaginal antisepsis and/or oral metronidazole pre-treatment followed by administration of FB301 in women with bacterial vaginosis. The primary outcome is the change in vaginal microbiome composition, specifically the relative abundance of combined Lactobacillus crispatus and jensenii species, measured by metagenomic sequencing of vaginal samples from baseline (visit 2) to week 3 (visit 3). The trial is currently authorised, meaning it has received regulatory approval to proceed but has not yet reported results.
Who can take part in these trials?
The trial enrols women with bacterial vaginosis. The study design involves pre-treatment with chlorhexidine and/or metronidazole before FB301 administration, so participants must be eligible to receive these pre-treatments. The trial is interventional, meaning participants are assigned to receive specific treatments and are then monitored over time. The planned enrolment is 120 participants. Further details about specific inclusion and exclusion criteria can be found in the trial registry record.
What side effects are known?
No side effect information for FB301 is provided in the available sources. As an investigational live biotherapeutic product, its safety profile is still being evaluated in the Phase 2 trial. The trial will collect safety data alongside the microbiome measurements, but no specific adverse events are reported in the registry data.