Efficacy and Safety of Single Oral Dosing of Secnidazole for Trichomoniasis in Women: Results of a Phase 3, Randomized, Double-Blind, Placebo-Controlled, Delayed-Treatment Study.

BACKGROUND Trichomonas vaginalis is the most prevalent non-viral sexually transmitted infection. We evaluated the efficacy and safety of secnidazole vs. placebo in women with trichomoniasis. METHODS Women with trichomoniasis, confirmed by a positive T. vaginalis culture, were randomized to single-dose oral secnidazole 2g or placebo. The primary endpoint was microbiological test of cure (TOC) by culture 6-12 days after dosing. At the TOC visit, participants were given the opposite treatment. They were followed for resolution of infection afterward and offered treatment at subsequent visits, if needed. Fifty patients per group (N=100) provided ~95% power to detect a statistically significant difference between treatment groups. RESULTS Between April 2019 and March 2020, 147 women enrolled at 10 US sites. The modified intent-to-treat (mITT) population included 131 randomized patients (64/67, in secnidazole/placebo). Cure rates were significantly higher in the secnidazole vs. placebo group (92.2% [95% CI: 82.7-97.4] vs. 1.5% [95% CI: 0.0-8.0]) for the mITT population and for the per-protocol population (94.9% [95% CI: 85.9-98.9]) vs. 1.7% [95% CI: 0.0-8.9]). Cure rates were 100% (4/4) in women with HIV and 95.2% (20/21) in women with bacterial vaginosis (BV). Secnidazole was generally well tolerated. The most frequently reported treatment-emergent adverse events (TEAEs) were vulvovaginal candidiasis and nausea (each 2.7%). No serious TEAEs were observed. CONCLUSION A single oral 2g dose of secnidazole was associated with significantly higher microbiological cure rates vs. placebo, supporting a role for secnidazole in treating women with trichomoniasis, including those with HIV and/or BV.