Lactin-V reduces bacterial vaginosis recurrence

Treatment with Lactobacillus crispatus CTV-05 (Lactin-V) significantly reduces the incidence of bacterial vaginosis recurrence in women who were previously treated with vaginal metronidazole, according to a recent study.

“The use of Lactin-V after treatment with vaginal metronidazole for bacterial vaginosis resulted in a significantly lower incidence of recurrence of bacterial vaginosis at 12 weeks than placebo, and the benefit appeared to persist through week 24,” according to the researchers.

This phase IIb, double-blind, multicentre trial involved 228 women diagnosed with bacterial vaginosis who completed a 5-day course of vaginal 0.75% metronidazole gel within 30 days before the screening visit. Participants were randomized in a 2:1 ratio to receive either Lactin-V (2x10⁹ colony-forming units [CFU] per dose; n=152) or matching placebo (n=76) for 11 weeks. [N Engl J Med 2020;382:1906-1915]

At week 12, the incidence of bacterial vaginosis recurrence was significantly lower in the Lactin-V group compared with the placebo group (30.0 percent vs 45.0 percent; risk ratio [RR], 0.66; p=0.01).

By week 24, the incidence of bacterial vaginosis recurrence was still lower among patients treated with Lactin-V compared with placebo (12.0 percent vs 17.0 percent; RR, 0.73), although this was not significant.

A higher percentage of patients on Lactin-V than placebo had detectable L. crispatus CTV-05 at 12 weeks (79.0–84.0 percent vs 2.0–6.0 percent) and 24 weeks (48.0 percent vs 2.0 percent). The median L. crispatus CTV-05 concentration in the Lactin-V group was 1.7x10⁶–6.2x10⁶ CFU/mL at week 12 and 5.6x10⁶ CFU/mL at week 24.

Abnormal vaginal discharge, abnormal vaginal odour, external genital irritation, and genital itching were the most common solicited local adverse events (AEs) reported in both treatment groups.

The incidence of solicited or unsolicited AEs was comparable between the Lactin-V and placebo groups (87.0 percent vs 79.0 percent [solicited] and 42.0 percent vs 29.0 percent [unsolicited]). Severe grade 3 AEs occurred in four patients in the Lactin-V group and three patients in the placebo group, but none were considered treatment related.

“Lactin-V is a live biotherapeutic product that contains a naturally occurring vaginal strain of L. crispatus … [It] is designed to promote community state type (ie, microbial composition) with a predominance of L. crispatus after treatment with vaginal 0.75% metronidazole gel,” said the researchers.

“These results extend earlier findings seen with Lactin-V and support the general safety of the current formulation and dosing strategy, … although further study should be considered to assess longer-term sustainability of colonization and prevention of bacterial vaginosis,” they added.