Comparative phase I randomized open-label pilot clinical trial of Gynophilus(®) (Lcr regenerans(®)) immediate release capsules versus slow release muco-adhesive tablets

Gynophilus(®) (Lcr regenerans(®)) is a live biotherapeutic product (LBP) that contains the live biotherapeutic microorganism Lactobacillus rhamnosus Lcr35(®), which is indicated to restore vaginal health. The aim of the study was to compare the safety, ease of use, and compliance of two formulations (immediate release: IR capsule and slow release: SR muco-adhesive tablets) as well as the colonization of Lcr35(®) in healthy women. This phase I study (Comprigel) is a parallel, randomized, 4-arm, and open-label clinical trial evaluating an IR daily capsule formulation vs. a SR tablet administered every 3, 4, or 5 days for 21 days. Self-collected vaginal swabs were used to quantify Lcr35(®) and characterize the composition and structure of the vaginal microbiota. Both LBPs were well-tolerated, and no severe adverse effects were reported. All groups had Lcr35(®) vaginal concentrations over 10(7) colony forming unit per milliliter of vaginal secretion on each day in the study. The new Gynophilus(®) slow release tablets administered either every 3, 4, or 5 days provided vaginal concentrations that were not significantly different from those of classic Gynophilus(®) (capsule) once-a-day regimen. The LBPs and the different regimens did not adversely influence the abundance of native Lactobacillus spp. and indeed tended to favor their growth and reduce colonization by non-Lactobacillus spp. This study illustrates that the SR muco-adhesive LBP tablet (Gynophilus(®) SR) administered every 3 or 4 days as a safe, well-tolerated, and efficacious alternative to a more demanding IR daily capsule and could protect women’s healthy vaginal microbiome by promoting endogenous Lactobacillus spp. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10096-018-3321-8) contains supplementary material, which is available to authorized users.