Bacterial Vaginosis (BV) is a common infectious disorder and is characterized by a disturbance in the vaginal microbiological milieu. Anaerobic bacteria, such as Gardnerella vaginalis and Atopobium vaginae overgrow the physiologic vaginal flora which is dominated by Lactobacilli. BV can arise and remit spontaneously but often presents as a recurrent disease.

New findings indicate that the presence of an adherent bacterial biofilm on the vaginal mucosa seems to be the reason for the recurrence of BV as well as the overgrowth condition by anaerobic bacteria. Biofilms are defined as a structured consortium of bacteria embedded in a matrix of extracellular polymeric substances (EPS).

The purpose of this study is to achieve substantial results with respect to tolerability and safety, and to gain further knowledge on the clinical efficacy of Vaginal suppository WO3191, the investigation will be performed in a parallel-design, double-blind, randomised, controlled manner.

This investigation is a multicentre, parallel-group, double-blind, controlled trial with an open Follow-up Phase of 12 weeks. It is conducted to gain clinical experience and further knowledge about the certified medical device Vaginal suppository WO3191 in women with bacterial vaginosis.

In this investigation the Investigational Medical Device (IMD) will be used as post-treatment following standard therapy with oral metronidazole for BV. IMD will be applied 2 times a week for 3 weeks.

The primary purpose is the evaluation of the safety and local tolerability of WO3191, therefore all adverse events (AEs) and adverse device effects (ADEs) will be documented. Furthermore, patients will be asked for possibly arising subjective vaginal symptoms (burning, itching, bleeding, pain, dryness) and will be examined for possibly arising objective vaginal findings (redness, petechial bleeding, dryness, swelling).

The secondary purpose of this investigation is to gain clinical experience and further knowledge about Vaginal suppository WO3191 with respect to the efficacy in the post-treatment of bacterial vaginosis.

In addition pH-values and microbiological data shall be examined.

Furthermore, the difference between Vaginal suppository WO3191 (Group A) and the comparator (Vagisan® Lactic Acid, group B) with respect to the safety, tolerability and the efficacy in the post-treatment of bacterial vaginosis shall be evaluated exploratively.

Patients who have completed all regular visits (Visit 1 - 4; Visit 1 - Screening, Visit 2 - Randomization, Start of application of IMD; Visit 3 - one week after Visit 2; Visit 4 - two weeks after Visit 3, End of application of IMD) of the investigation shall attend an observational Follow-up Phase of 12 weeks with a final Visit 5. At Visit 5 recurrences of BV as well as the sustainability of the efficacy of Vaginal suppository WO3191 will be evaluated.

Inclusion Criteria:

• Signed declaration of consent and signed data protection declaration after having been informed about the nature, relevance and the scope of the investigation and about the expected desired and undesired effects of the IMD
• Premenopause, age 18 to 50 years (incl. patients with Intrauterine device, e.g. Mirena® with amenorrhoea)
• Acute BV (at least 3 of 4 Amsel's Criteria fulfilled and Nugent Score > 6)
• Existing bacterial biofilm in the vagina, verified by positive EPS of bacterial biofilm and by microscopy
• Requirement of oral treatment of metronidazole for BV

Exclusion Criteria:

• Postmenopause (no menses in the last six months prior to enrolment)
• Positive Herpes simplex infection
• Positive Candida spp. infection
• Positive Trichomonas spp. infection
• Pathologic PAP (III, III D-V) within the last 3 months
• Chronic immunosuppressive diseases (i.e. HIV) or treatment (i.e. transplantation)
• Malignant conditions of CIN, VIN or VAIN, currently and / or within the past 6 months
• Presence or history (within the last 5 years) of any other malignancy
• Previous chemotherapy (within 6 months before start of this investigation)
• Current vaginal or systemic treatment with antibiotics or corticosteroids, systemic treatment with NSAIDs (nonsteroidal anti-inflammatory drugs) within the last two weeks prior to start of this investigation (except metronidazole for the treatment of BV: prescription of metronidazole before investigation entry; except NSAIDs taken in a single dose in case of need, e.g. for headache)
• Use of not permitted contraception or not willing to use contraception (Allowed contraception: oral hormonal contraceptives, intrauterine device, surgical, sexual abstinence; Not permitted contraception: condoms, local spermicides, intravaginal contraceptive measures)
• Pregnancy or lactation
• Active Smokers (more than 5 cigarettes per day)
• Use of any other intravaginal medicinal product or medical device (including all intravaginal contraceptive measures (e.g. NuvaRing®, local spermicides)
• Known hypersensitivity to one or more of the active and / or inactive ingredients of the antibiotic treatment (metronidazole: mandatory for inclusion)
• Known hypersensitivity to one or more of the ingredients of the IMD (test product and/or comparator)