The study will look at whether FB301 (the investigational medicinal product being studied) can change the balance of certain vaginal bacteria in women with bacterial vaginosis (BV). FB301 is being developed as a drug for the treatment of BV. Researchers will measure two types of bacteria, Lactobacillus crispatus and Lactobacillus jensenii, during the study to assess how the vaginal bacterial balance changes following treatment.

You may be eligible for this study if you meet the following criteria.

Inclusion Criteria:

• Women ages 18-45
• Have symptoms of bacterial vaginosis (BV)
• Have not received treatment for current BV symptoms
• Have regular menstrual cycles or have not had a period for 3+ months due to birth control
• Willing to answer questions about reproductive and sexual health
• Willing to complete study procedures, including vaginal swabs and treatment at home
• Able to attend five outpatient study visits in Berlin over approximately 3 months

If you qualify and decide to join, you will:

1. Complete a screening: You will first have a phone interview. If you may qualify, you will visit the study center for an exam and vaginal sample.
2. Attend study visits: You will have up to 6 visits at the study center over about 3 months.
3. Give samples: You will provide vaginal swab samples during your visits. You may also collect vaginal fluid using a menstrual disc. Blood samples will also be taken.
4. Receive study treatment: You will be randomly placed into a treatment group. Depending on your group, you may receive chlorhexidine, metronidazole, or both before receiving FB301.
5. Use the study treatment: You will use the study treatment during two menstrual cycles. Some treatments will be taken or used at home as instructed by the study team.
6. Complete follow-up visits: You will return to the study center so researchers can check your health and collect samples.

The study will last about 3 months, from the first exam through the final visit.

You may receive up to 1550 € for taking part in the study. This includes payment for the screening visit, five outpatient visits, exams and sample collection, and the two treatment cycles. Travel expenses are also included.

Payment is usually made after your final study visit if you complete all required visits and follow the study instructions. If you do not complete the entire study, your payment will be based on the number of visits you complete.

There is no cost for you to participate in our research study.