A Phase 3, Multicenter, Randomized, Double-Blind, Vehicle-Controlled Study Evaluating the Safety and Efficacy of Metronidazole Vaginal Gel 1.3% in the Treatment of Bacterial Vaginosis

Resident microbes shape the vaginal epithelial glycan landscape

Epithelial cells are covered in carbohydrates (glycans). This glycan coat or "glycocalyx" interfaces directly with microbes, providing a protective barrier against potential pathogens. Bacterial vaginosis (BV) is a condition associated with adverse health outcomes in which bacteria reside in direct proximity to the vaginal epithelium. Some of these bacteria, including Gardnerella, produce glycosyl hydrolase enzymes. However, glycans of the human vaginal epithelial surface have not been studied in detail. Here, we elucidate key characteristics of the "normal" vaginal epithelial glycan landscape and analyze the impact of resident microbes on the surface glycocalyx. In human BV, glycocalyx staining was visibly diminished in electron micrographs compared to controls. Biochemical and mass spectrometric analysis showed that, compared to normal vaginal epithelial cells, BV cells were depleted of sialylated N- and O-glycans, with underlying galactose residues exposed on the surface. Treatment of primary epithelial cells from BV-negative women with recombinant Gardnerella sialidases generated BV-like glycan phenotypes. Exposure of cultured VK2 vaginal epithelial cells to recombinant Gardnerella sialidase led to desialylation of glycans and induction of pathways regulating cell death, differentiation, and inflammatory responses. These data provide evidence that vaginal epithelial cells exhibit an altered glycan landscape in BV and suggest that BV-associated glycosidic enzymes may lead to changes in epithelial gene transcription that promote cell turnover and regulate responses toward the resident microbiome.

Formulation and Characterization of Pressure-Assisted Microsyringe 3D-Printed Scaffolds for Controlled Intravaginal Antibiotic Release

Bacterial vaginosis (BV) is a highly recurrent vaginal condition linked with many health complications. Topical antibiotic treatments for BV are challenged with drug solubility in vaginal fluid, lack of convenience and user adherence to daily treatment protocols, among other factors. 3D-printed scaffolds can provide sustained antibiotic delivery to the female reproductive tract (FRT). Silicone vehicles have been shown to provide structural stability, flexibility, and biocompatibility, with favorable drug release kinetics. This study formulates and characterizes novel metronidazole-containing 3D-printed silicone scaffolds for eventual application to the FRT. Scaffolds were evaluated for degradation, swelling, compression, and metronidazole release in simulated vaginal fluid (SVF). Scaffolds retained high structural integrity and sustained release. Minimal mass loss (<6%) and swelling (<2%) were observed after 14 days in SVF, relative to initial post-cure measurements. Scaffolds cured for 24 hr (50°C) demonstrated elastic behavior under 20% compression and 4.0 N load. Scaffolds cured for 4 hr (50°C), followed by 72 hr (4°C), demonstrated the highest, sustained, metronidazole release (4.0 and 27.0 µg/mg) after 24 hr and 14 days, respectively. Based upon daily release profiles, it was observed that the 24 hr timepoint had the greatest metronidazole release of 4.08 μg/mg for scaffolds cured at 4 hr at 50°C followed by 72 hr at 4°C. For all curing conditions, release of metronidazole after 1 and 7 days showed >4.0-log reduction in Gardnerella concentration. Negligible cytotoxicity was observed in treated keratinocytes comparable to untreated cells, This study shows that pressure-assisted microsyringe 3D-printed silicone scaffolds may provide a versatile vehicle for sustained metronidazole delivery to the FRT.

Sexually Transmitted Infection Treatment Guidelines for Adolescent Health Providers: What's New in 2021?

The Centers for Disease Control and Prevention's Sexually Transmitted Infections Treatment Guidelines, 2021 contain new recommendations for the treatment of gonococcal, chlamydial, and trichomonas infections, as well as pelvic inflammatory disease. Providers are encouraged to broaden their screening practices by considering incorporating rectal and pharyngeal testing when indicated, as well as opt-out testing for adolescent females. The discussion of testing and counseling for genital herpes infections has been expanded.

Diagnosis and Management of Bacterial Vaginosis: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

In preparation for the 2021 Centers for Disease Control and Prevention (CDC) sexually transmitted infections (STIs) treatment guidelines, the CDC convened an advisory group in 2019 to examine recent literature addressing updates in the epidemiology, diagnosis, and management of STIs. This article summarizes recent data in each of these key topic areas as they pertain to bacterial vaginosis (BV), the most common cause of vaginal discharge. The evidence reviewed primarily focused on updates in the global epidemiology of BV, risk factors for BV, data supportive of sexual transmission of BV-associated bacteria, BV molecular diagnostic tests, and novel treatment regimens. Additionally, recent literature on alcohol abstinence in the setting of 5-nitroimidazole use was reviewed.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11–14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

Astodrimer gel for treatment of bacterial vaginosis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Bacterial vaginosis is a frequent source of vaginal infection among reproductive-aged women. Astodrimer gel is a novel drug which demonstrated favourable outcomes for treatment of patients with bacterial vaginosis.

AIM

We attempted to conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) which examined the efficacy and safety of astodrimer gel in patients with bacterial vaginosis.

METHODS

We searched four databases from inception to August 15, 2020, using relevant keywords. We identified all RCTs which surveyed the efficacy and safety of astodrimer gel in treating patients with bacterial vaginosis. We appraised the quality of the included RCTs using the Cochrane risk of bias assessment tool. We pooled dichotomous outcomes as numbers and totals and reported them as risk ratios (RR) with 95% confidence intervals (95% CI) under random- or fixed-effects meta-analysis models depending on heterogeneity.

RESULTS

Three eligible studies comprising four independent RCTs and 1165 patients were identified (614 and 551 patients received astodrimer gel and placebo, respectively). For efficacy outcomes (n = 320 astodrimer gel versus n = 260 placebo), astodrimer gel was significantly superior to placebo for all pooled efficacy outcomes, including clinical cure rate (at 9-12 and 21-30 days), microbiological Nugent cure rate (at 9-12 and 21-30 days), patient self-reported absence of vaginal odor/discharge (at 9-12 and 21-30 days), resolution of Amsel criteria (at 9-12 days) and percentage of patients who did not receive rescue therapy during study. With respect to safety outcomes (n = 614 astodrimer gel versus n = 551 placebo), astodrimer gel demonstrated equal tolerability to placebo for all pooled safety endpoints, expect unfavourably for vulvovaginal candidiasis and treatment-related vulvovaginal candidiasis.

CONCLUSIONS

Astodrimer gel is effective in treating bacterial vaginosis and corroborated by clinical (Amsel criteria) and microbiological (Nugent score) measurements as well as patient-reported symptoms. Moreover, astodrimer gel is largely safe and associated with marginal rate of vulvovaginal candidiasis.

Current and emerging pharmacotherapy for recurrent bacterial vaginosis

INTRODUCTION

Given the frequency of recurrent bacterial vaginosis (RBV), enhancing treatment and preventing recurrence have become the central target of pharmacotherapy today. Antimicrobial failure is occurring at a time when knowledge of pathogenesis of bacterial vaginosis (BV) and RBV is incomplete, limiting rational treatment modification.

AREAS COVERED

The current manuscript reviews pathogenesis of RBV and the performance of available antimicrobials as well as attempts employed to enhance activity and pharmacologic strategies to reduce BV recurrence and refractory vaginal disease. The authors also provide their expert perspectives on the subject area, including their outlook for the future.

EXPERT OPINION

In the face of an empty pipeline of new antibiotics, strategies have emerged to enhance existing antibiotic efficacy, which include modifying drug dose, treatment duration, long-term prophylactic regimens, and use of biofilm disrupting agents. It is likely that future effective therapy will include several simultaneous and consecutive treatment components, including combinations of antibiotics, antibiofilm agents, and probiotics. Measures to prevent sexual transmission and reinfection are also essential.

Antimicrobial Susceptibility Testing of Metronidazole and Clindamycin against Gardnerella vaginalis in Planktonic and Biofilm Formation

Background

Bacterial vaginosis (BV), one of the most common vaginal ecosystem-related microbiologic syndromes, is the most common disorder in women of reproductive age. Gardnerella (G.) vaginalis is the predominant species causing this infection. Our aim was to compare the antimicrobial susceptibilities of metronidazole and clindamycin against G. vaginalis at planktonic and biofilm levels.

Methods

From September 2019 to October 2019, we recruited a total of 10 patients with BV who underwent gynecological examinations at Beijing Obstetrics and Gynecology Hospital. G. vaginalis isolates were obtained from the vagina and identified using their characteristic colony morphology. Sequence data of clinical G. vaginalis isolates were confirmed by comparing 16S rDNA sequences. Subsequently, clinical isolates were evaluated for antimicrobial susceptibilities in vitro to metronidazole and clindamycin at planktonic and biofilm levels. The minimum inhibitory concentration (MIC) for metronidazole and clindamycin was evaluated by antimicrobial susceptibility testing. The minimum biofilm eradication concentration (MBEC) was evaluated by the biofilm inhibition assay.

Results

Planktonic clinical isolates showed a significantly higher susceptibility rate (76.67%) and lower resistance rate (23.33%) to clindamycin than to metronidazole (susceptibility rate: 38.24%; resistance rate: 58.82%; P < 0.05 for both). Furthermore, in comparison to planktonic isolates, the minimum inhibitory concentration (MIC) of metronidazole was significantly higher for biofilm-forming isolates (7.3 ± 2.6 μg/mL vs. 72.4 ± 18.3 μg/mL; P=0.005); the resistance rate was 27.3%, and the minimum biofilm eradication concentration (MBEC) was >128 μg/mL. Moreover, the MIC of clindamycin was higher too for biofilm-forming isolates (0.099 ± 0.041 μg/mL vs. 23.7 ± 9.49 μg/mL; P=0.034); the resistance rate was 27.3%, and the MBEC of clindamycin was 28.4 ± 6.50 μg/mL.

Conclusion

Our results indicate that in comparison to metronidazole, clindamycin seems to be a better choice to tackle G. vaginalis as it exhibits a relatively higher susceptibility rate and lower resistance rate.

A phase 2, double-blind, multicenter, randomized, placebo-controlled, dose‑ranging study of the efficacy and safety of Astodrimer Gel for the treatment of bacterial vaginosis

Background

Astodrimer Gel contains a novel dendrimer intended to treat and prevent bacterial vaginosis. We assessed the efficacy and safety of Astodrimer Gel for treatment of bacterial vaginosis.

Methods

132 women with bacterial vaginosis were randomized 1:1:1:1 to Astodrimer 0.5% (N = 34), 1% (N = 33), or 3% (N = 32) Gel or hydroxyethyl cellulose placebo gel (N = 33) at a dose of 5 g vaginally once daily for 7 days at 6 centers in the United States. The primary endpoint was clinical cure (no bacterial vaginosis vaginal discharge and no more than one of 1) vaginal pH ≥4.5; 2) ≥20% clue cells; or 3) positive whiff test) at study days 21–30. Secondary analyses included clinical cure at study days 9–12, patient-reported symptoms, acceptability and adverse events.

Results

The Astodrimer 1% Gel dose was superior to placebo for the primary and selected secondary efficacy measures in the modified intent-to-treat population. Clinical cure rates at day 9–12 were superior to placebo for the Astodrimer 3%, 1% and 0.5% Gel groups (62.5% [15/24; P = .002], 74.1% [20/27; P < .001], and 55.2% [16/29; P = .001], respectively, vs. 22.2% [6/27]). At day 21–30, clinical cure rates were 46.2% (12/26) for the 1% dose vs. 11.5% for placebo (3/26; P = .006). A greater proportion of patients reported absence of vaginal discharge and vaginal odor at day 9–12 and day 21–30 for Astodrimer Gel groups compared with placebo. Adverse events considered potentially treatment-related occurred in only 25% of Astodrimer Gel-treated patients vs. 22% of placebo patients.

Conclusion

Astodrimer Gel once daily for 7 days was superior to placebo for treatment of bacterial vaginosis and was well-tolerated. The 1% dose consistently showed the strongest efficacy across endpoints. These results support a role for Astodrimer Gel, 1%, as an effective treatment for bacterial vaginosis.

Safety and Efficacy of a Novel Vaginal Anti-infective, TOL-463, in the Treatment of Bacterial Vaginosis and Vulvovaginal Candidiasis: A Randomized, Single-blind, Phase 2, Controlled Trial

BACKGROUND

Bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) present serious reproductive health risks and management challenges, with poor control attributed to survival of treatment-resistant biofilm communities. Boric acid is used in various regimens for non-albicans VVC and recurrent BV. We investigated safety and efficacy of a novel boric acid-based vaginal anti-infective with enhanced antibiofilm activity (TOL-463) in treating BV and VVC.

METHODS

In this phase 2 randomized, investigator-blinded trial conducted at 2 sexual health clinics, women with BV or VVC were randomly assigned (1:1) to 7 nights of TOL-463 vaginal gel or insert. The primary test of cure (TOC) was clinical cure at day 9-12; safety was assessed at TOC and day 21-30.

RESULTS

One hundred six participants (53 with BV, 36 VVC, 17 both) were enrolled; most were African American (69%). Clinical cure rate of BV at TOC was 59% (95% confidence interval [CI], 41%-75%) for TOL-463 insert and 50% (95% CI, 31%-69%) for TOL-463 gel, and for VVC, 92% (95% CI, 67%-99%) for TOL-463 insert and 81% (95% CI, 57%-93%) for TOL-463 gel. Both products were safe and well tolerated with no secondary cases of VVC; vulvovaginal burning was the most common adverse event (9.6%).

CONCLUSIONS

TOL-463, especially in vaginal insert form, is effective and safe in treating BV and VVC. Future studies should assess the potential role of TOL-463 as a biofilm disrupter in enhancing likelihood of cure relative to approved therapies, reducing recurrence rates, and combined with traditional antimicrobials.

CLINICAL TRIALS REGISTRATION

NCT02866227.

The Effect of Prangos Ferulacea Vaginal Cream on Accelerating the Recovery of Bacterial Vaginosis: A Randomized Controlled Clinical Trial

BACKGROUND

The present study was conducted on the effect of prangos ferulacea vaginal cream on accelerating the recovery of bacterial vaginosis.

METHODS

This randomized controlled clinical trial was conducted on 100 non-pregnant women referring to health centers affiliated to Lorestan University of Medical Sciences in 2016 with the diagnosis of bacterial vaginosis based on the patient's complaints, Amsel's clinical criteria, and the Nugent microscopic criteria. The women were randomly divided into two groups of 50. One group was treated with oral metronidazole plus Prangos ferulacea vaginal cream and the other with oral metronidazole plus a placebo vaginal cream for seven days. The patient's complaints, Amsel's clinical criteria and the Nugent microscopic criteria were assessed seven days after treatment. The data were analyzed using SPSS, version 20, with a significance level of 0.05.

RESULTS

The response to oral metronidazole plus Prangos ferulacea vaginal cream treatment was 94% according to Amsel's clinical criteria and 88% according to the Nugent microscopic criteria. The response to oral metronidazole plus placebo vaginal cream treatment was 94% according to Amsel's criteria and 86% according to the Nugent criteria. The analysis of the patients' complaints, Amsel's clinical criteria and the Nugent microscopic criteria showed significant differences in each group before and after the treatment.

CONCLUSION

This trial showed that Prangos ferulacea vaginal cream accelerated the recovery of bacterial vaginosis of patients with bacterial vaginosis. It can be used effectively as a complementary treatment with oral metronidazole in cases of medication resistance and also in people wishing to use herbal remedies Trial Registration Number: IRCT2016042327534N1.

Susceptibility of bacterial vaginosis (BV)-associated bacteria to secnidazole compared to metronidazole, tinidazole and clindamycin

Secnidazole, a 5-nitroimidazole with a longer half-life, is structurally related to metronidazole and tinidazole. For treatment of bacterial vaginosis (BV), secnidazole is a suitable single-dose oral drug having a longer serum half-life than metronidazole. The objective of this study was to evaluate the antimicrobial susceptibility of vaginal isolates of facultative and anaerobic bacteria to secnidazole, metronidazole, tinidazole and clindamycin. A total of 605 unique BV-related bacteria and 108 isolates of lactobacilli recovered from the human vagina of US women during the years 2009-2015 were tested for antimicrobial susceptibility by the agar dilution CLSI reference method to determine the minimal inhibitory concentration (MIC). The MIC₉₀ (μg/mL) for secnidazole was similar to metronidazole and tinidazole for Anaerococcus tetradius (secnidazole: MIC₉₀ 2; metronidazole: MIC₉₀ 2; tinidazole: MIC₉₀ 4), Atopobium vaginae (32; >128; 128), Bacteroides species (2; 2; 2), Finegoldia magna (2; 2; 4), Gardnerella vaginalis (128; 64; 32), Mageeibacillus indolicus (2; 2; 2), Megasphaera-like bacteria (0.5; 0.25; 0.5), Mobiluncus curtisii (128; >128; >128) and Mobiluncus mulieris (>128; >128; >128), Peptoniphilus lacrimalis (4; 4; 4) and Peptoniphilus harei (2; 2; 4), Porphyromonas species (0.25; 0.5; 0.25), Prevotella bivia (8; 8; 8), Prevotella amnii (2; 1; 2) and Prevotella timonensis (2; 2; 2). In this evaluation, 14 (40%) of 35 P. bivia, 5 (14%) of 35 P. amnii and 21 (58%) of 36 P. timonensis isolates were resistant to clindamycin with MIC values of >128 μg/mL. Secnidazole, like metronidazole, was superior to clindamycin for Prevotella spp., Bacteroides spp., Peptoniphilus spp., Anaerococcus tetradius and Finegoldia magna. Clindamycin had greater activity against Atopobium vaginae, Gardnerella vaginalis and Mobiluncus spp. compared to the nitroimidazoles. All 27 Lactobacillus crispatus, 26 (96%) of 27 L. jensenii, 5 (19%) of 27 L. gasseri and 18 (67%) of 27 L. iners isolates were susceptible to clindamycin (MIC ≤2) while the MIC₉₀ for all lactobacilli tested was >128 μg/mL for secnidazole, metronidazole and tinidazole. Secnidazole has similar in vitro activity against the range of microorganisms associated with BV compared to metronidazole or tinidazole. Further, secnidazole spares lactobacilli, a characteristic which is desirable in drugs used to treat bacterial vaginosis.

Bacterial Vaginosis Biofilms: Challenges to Current Therapies and Emerging Solutions

Bacterial vaginosis (BV) is the most common genital tract infection in women during their reproductive years and it has been associated with serious health complications, such as preterm delivery and acquisition or transmission of several sexually transmitted agents. BV is characterized by a reduction of beneficial lactobacilli and a significant increase in number of anaerobic bacteria, including Gardnerella vaginalis, Atopobium vaginae, Mobiluncus spp., Bacteroides spp. and Prevotella spp.. Being polymicrobial in nature, BV etiology remains unclear. However, it is certain that BV involves the presence of a thick vaginal multi-species biofilm, where G. vaginalis is the predominant species. Similar to what happens in many other biofilm-related infections, standard antibiotics, like metronidazole, are unable to fully eradicate the vaginal biofilm, which can explain the high recurrence rates of BV. Furthermore, antibiotic therapy can also cause a negative impact on the healthy vaginal microflora. These issues sparked the interest in developing alternative therapeutic strategies. This review provides a quick synopsis of the currently approved and available antibiotics for BV treatment while presenting an overview of novel strategies that are being explored for the treatment of this disorder, with special focus on natural compounds that are able to overcome biofilm-associated antibiotic resistance.