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.