Phase 1 dose-ranging safety trial of Lactobacillus crispatus CTV-05 for the prevention of bacterial vaginosis.

Background: Bacterial vaginosis is a very common vaginal infection. The lack of endogenous lactobacilli and overgrowth of pathogens facilitate numerous gynecological complications.

Methods: A phase I dose-ranging safety trial tested the safety, tolerability, and acceptability of Lactobacillus crispatus CTV-05 (LACTIN-V) administered by vaginal applicator. Twelve healthy volunteers were enrolled in 3 blocks of 4 (5 x 10, 1 x 10, and 2 x 10 cfu/dose). Each block was randomized in a 3:1 ratio of active product to placebo. Participants used study product for 5 consecutive days, returned for follow-up on days 7 and 14, and had phone interviews on days 2 and 35.

Results: All 12 participants took 5 doses and completed study follow-up.Overall, 45 adverse events (AEs) occurred, of which 31 (69%) were genitourinary (GU) AEs. GU AEs appeared evenly distributed between the 3 treatment blocks and between LACTIN-V and placebo arms. The most common GU AEs were vaginal discharge in 5 subjects (42%), abdominal pain in 4 subjects (33%), metrorrhagia in 4 subjects (33%), vulvovaginitis in 4 subjects (33%), vaginal candidiasis in 3 subjects (25%), and vaginal odor in 3 subjects (25%). Forty-one (91%) AEs were mild (grade 1) in severity. All 4 moderate AEs (grade 2) were unrelated to product use. No grade 3 or 4 AEs or serious adverse events (SAE) occurred. Laboratory parameters and colposcopy findings were within normal limits or clinically insignificant. The product was well-tolerated and accepted.

Conclusion: All 3 dose levels of LACTIN-V appeared to be safe and acceptable in healthy volunteers.