The POLARIS study: Protocol for a multicentre, open-label, non-controlled international clinical trial with a 10-month follow up in recurrent bacterial vaginosis (Preprint)

BACKGROUND Medical literature has evidenced in recurrent bacterial vaginosis a relapse rate of 35% within 3 months and 60% within 12 months after antibiotic administration. The products able to create a barrier effect against the biofilm produced by Gardnerella vaginalis could play a role in improving the results of bacterial vaginosis treatment. OBJECTIVE This protocol aimed to test the performance and the safety of a medical device containing polycarbophil, lauryl glucoside, and glycerides (PLGG) in reducing the rate of recurrence of BV. METHODS The trial included two phases: in the first one (according to an open-label, non-controlled design) the treatment with PLGG was administered for three cycles and it was followed by a 1-month of follow-up without treatment. In the second phase of the study a 9-month follow-up period was envisaged. This entailed that, for each patient, a 10-months follow-up period without treatment was planned. Bacterial vaginosis diagnosis should be performed using Amsel criteria. The 55 planned patients were enrolled in five centres (two in Italy and three in România). RESULTS We calculated a sample size of 44 pairs to achieve a power of 80% and a one-sided significance of 5% for detecting, in comparison with the mean recurrence rate of bacterial vaginosis reported in medical literature, a difference of 0.25 between marginal proportions. Estimating a potential drop-out rate of 20%, and so we decided to enroll 55 patients (one group Chi-square test). The study received ethics approval in 2016 in Romania and one year later in Italy. The recruitment started on September 2016. An interim analysis was performed in 2019 and the results of the full study analysis should be available by the end of 2022. CONCLUSIONS The tested medical device PLGG could modify the mechanisms involved in the pathogenesis of bacterial vaginosis and, thanks to the acidifying effect on the vaginal pH could improve the microbiological parameters. We believe that our article could be useful as a tool for other Investigators who want to test different products against the BVR using a standardized protocol and procedures. CLINICALTRIAL Clinical Trials.gov NCT 02863536; https://clinicaltrials.gov/ct2/show/NCT02863536?term=NCT+02863536&draw=2&rank=1