New Antifungals for Vulvovaginal Candidiasis: What Is Their Role?

New antifungals, ibrexafungerp and oteseconazole, are now available for treatment of vulvovaginal candidiasis. Both have novel antimicrobial and pharmacokinetic properties and advantages over fluconazole, although comparative trials have involved only placebo. In the absence of allergy, intolerance, and resistance, it is unclear whether these antifungals will replace fluconazole.

State of the Art for Diagnosis of Bacterial Vaginosis.

Bacterial vaginosis (BV) is the most common cause of vaginal discharge among reproductive-age women. It is associated with multiple adverse health outcomes, including increased risk of acquisition of HIV and other sexually transmitted infections (STIs), in addition to adverse birth outcomes. While it is known that BV is a vaginal dysbiosis characterized by a shift in the vaginal microbiota from protective Lactobacillus species to an increase in facultative and strict anaerobic bacteria, its exact etiology remains unknown. The purpose of this minireview is to provide an updated overview of the range of tests currently used for the diagnosis of BV in both clinical and research settings. This article is divided into two primary sections: traditional BV diagnostics and molecular diagnostics. Molecular diagnostic assays, particularly 16S rRNA gene sequencing, shotgun metagenomic sequencing, and fluorescence in situ hybridization (FISH), are specifically highlighted, in addition to multiplex nucleic acid amplification tests (NAATs), given their increasing use in clinical practice (NAATs) and research studies (16S rRNA gene sequencing, shotgun metagenomic sequencing, and FISH) regarding the vaginal microbiota and BV pathogenesis. We also provide a discussion of the strengths and weaknesses of current BV diagnostic tests and discuss future challenges in this field of research.

A longitudinal study on fluconazole resistance in Candida albicans vaginal isolates.

BACKGROUND: Recurrent vulvovaginal candidiasis (RVVC), despite its worldwide prevalence, has limited treatment options; and a long-term prophylactic regimen utilising fluconazole is the dominant choice. OBJECTIVES: An increase in fluconazole resistance is reported, and little information is available about the reversibility of resistance status following the withdrawal of fluconazole. METHODS: Repeated antifungal susceptibility tests (ASTs) for fluconazole at a median interval of 3 months between them were evaluated in women with refractory or recurrent VVC patients at the Vaginitis clinic from 2012 to 2021 (10 years) and performed at pH 7 and pH 4.5 using the broth microdilution tests based on the CLSI M27-A4 reference method. RESULTS: Of 38 patients with long-term follow-up with repeat ASTs, 13 patients (13/38, 34.2%) tested at pH 7.0 remained susceptible to fluconazole with MIC ≤2 µg/mL. Nineteen patients (19/38, 50%) remained resistant to fluconazole with MIC ≥8 µg/mL, whereas four (4/38, 10.5%) changed from susceptible to resistant and two (2/38, 5.2%) changed from resistant to susceptible over time. At pH 4.5, among the 37 patients with repeated MIC values, nine (9/37, 24.3%) remained susceptible to fluconazole and 22 (22/37, 59.5%) remained resistant. Three isolates (3/37, 8.1%) changed from susceptible to resistant, while 3 (3/37, 8.1%) changed from resistant to susceptible over time. CONCLUSION: Fluconazole susceptibility in Candida albicans vaginal isolates obtained longitudinally in women with RVVC remains stable with rare reversal of resistance despite azole avoidance.

Vulvovaginal Candidiasis: A Review of the Evidence for the 2021 Centers for Disease Control and Prevention of Sexually Transmitted Infections Treatment Guidelines.

BACKGROUND: Vulvovaginal candidiasis (VVC) is a common cause of vulvovaginal itching and discharge. This article discusses the latest CDC STI Treatment Guidelines for VVC. METHODS: A literature search of relevant topics was performed, and a team of experts was convened to discuss (1) diagnosis/testing modalities; treatment of (2) uncomplicated VVC , (3) complicated VVC, and (4) VVC caused by non-albicans yeast; (5) alternative treatment regimens; (6) susceptibility testing of yeast; Special Populations: (7) pregnancy and (8) HIV and VVC. RESULTS: Yeast culture remains the gold standard for diagnoses. Newer molecular assays have been developed for the diagnosis of VVC and perform well. Azole antifungals remain the treatment of choice for uncomplicated VVC. Two new drugs, TOL-463 and recently FDA-approved ibrexafungerp, appeared promising in clinical trials. For recurrent VVC, oteseconazole, not yet commercially available, may represent a new option. For non-albicans yeast infections in symptomatic patients, boric acid appears useful. No evidence supports the use of alternative treatments, including probiotics. Fluconazole during pregnancy may be associated with spontaneous abortion and craniofacial and heart defects. In women with HIV infection, lower CD4+ T-cell counts are associated with increased rates of VVC, and VVC is associated with increased viral shedding. Treatment measures in women with HIV infection are identical to those women without HIV infection. CONCLUSIONS: There has been significant new knowledge generated about VVC since the 2015 CDC Guidelines which have led to changing recommendations.

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.

Phase 2 Randomized Study of Oral Ibrexafungerp Versus Fluconazole in Vulvovaginal Candidiasis.

BACKGROUND: Vulvovaginal candidiasis affects approximately 75% of women in their lifetime. Approved treatment options are limited to oral or topical azoles. Ibrexafungerp, a novel, first-in-class oral triterpenoid glucan synthase inhibitor, has demonstrated broad fungicidal Candida activity and a favorable tolerability profile. The primary objective of this dose-finding study was to identify the optimal dose of oral ibrexafungerp in patients with acute vulvovaginal candidiasis. METHODS: Patients with vulvovaginal signs and symptoms score ≥7 were randomized equally to 6 treatments groups: 5 treatment doses of oral ibrexafungerp or oral fluconazole 150 mg. The primary endpoint was the percentage of patients with a clinical cure (complete resolution of vulvovaginal signs and symptoms) at the test-of-cure visit (day 10). RESULTS: Overall, 186 patients were randomized into the 6 treatment groups. Results, using the modified intent-to-treat population (baseline positive culture), are reported for ibrexafungerp 300 mg twice daily (BID) for 1 day (n = 27), which was the dose selected for phase 3 studies, and fluconazole 150 mg for 1 day (n = 24). At day 10, the clinical cure rates for ibrexafungerp and fluconazole were 51.9% and 58.3%, respectively; at day 25, patients with no signs or symptoms were 70.4% and 50.0%, respectively. During the study ibrexafungerp patients required less antifungal rescue medications compared with fluconazole (3.7% vs 29.2%, respectively). Ibrexafungerp was well tolerated, with the most common treatment-related adverse events being mild gastrointestinal events. CONCLUSIONS: Ibrexafungerp is a well-tolerated novel antifungal with comparable efficacy to fluconazole in the treatment of acute vulvovaginal candidiasis. CLINICAL TRIALS REGISTRATION: NCT03253094.

Ibrexafungerp Versus Placebo for Vulvovaginal Candidiasis Treatment: A Phase 3, Randomized, Controlled Superiority Trial (VANISH 303).

BACKGROUND: Current treatment of vulvovaginal candidiasis (VVC) is largely limited to azole therapy. Ibrexafungerp is a first-in-class triterpenoid antifungal with broad-spectrum anti-Candida fungicidal activity. The objective of this study was to evaluate the efficacy and safety of ibrexafungerp compared with placebo in patients with acute VVC. METHODS: Patients were randomly assigned 2:1 to receive ibrexafungerp (300 mg twice for 1 day) or placebo. The primary endpoint was the percentage of patients with a clinical cure (complete resolution of vulvovaginal signs and symptoms [VSS] = 0) at test-of-cure (day 11 ± 3). Secondary endpoints included the percentage of patients with mycological eradication, overall success (clinical cure and mycological eradication), clinical improvement (VSS ≤ 1) at test-of-cure, and symptom resolution at follow-up (day 25 ± 4). RESULTS: Patients receiving ibrexafungerp had significantly higher rates of clinical cure (50.5% [95/188] vs 28.6% [28/98]; P = .001), mycological eradication (49.5% [93/188] vs 19.4% [19/98]; P < .001), and overall success (36.0% [64/178] vs 12.6% [12/95]; P < .001) compared with placebo. Symptom resolution was sustained and further increased with ibrexafungerp compared with placebo (59.6% [112/188] vs 44.9% [44/98]; P = .009) at follow-up. Post hoc analysis showed similar rates of clinical cure and clinical improvement at test-of-cure for Black patients (54.8% [40/73] and 63.4% [47/73], respectively) and patients with a body mass index >35 (54.5% [24/44] and 68.2% [30/44], respectively) compared with overall rates. Ibrexafungerp was well tolerated. Adverse events were primarily gastrointestinal and mild in severity. CONCLUSIONS: Ibrexafungerp provides a promising safe and efficacious oral treatment that mechanistically differs from current azole treatment options for acute VVC.

Cell wall protein variation, break-induced replication, and subtelomere dynamics in Candida glabrata.

Candida glabrata is an opportunistic pathogen of humans, responsible for up to 30% of disseminated candidiasis. Adherence of C. glabrata to host cells is mediated by adhesin-like proteins (ALPs), about half of which are encoded in the subtelomeres. We performed a de novo assembly of two C. glabrata strains, BG2 and BG3993, using long single-molecule real-time (SMRT) reads, and constructed high-quality telomere-to-telomere assemblies of all 13 chromosomes to assess differences between C. glabrata strains. We documented variation between strains, and in agreement with earlier studies, found high (~0.5%-1%) frequencies of SNVs across the genome, including within subtelomeric regions. We documented changes in ALP gene structure and complement: there are large length differences in ALP genes in different strains, resulting from copy number variation in tandem repeats. We compared strains to characterize chromosome rearrangement events including within the poorly characterized subtelomeric regions. We show that rearrangements within the subtelomere regions all affect ALP-encoding genes, and 14/16 involve just the most terminal ALP gene. We present evidence that these rearrangements are mediated by break-induced replication. This study highlights the constrained nature of subtelomeric changes impacting ALP gene complement and subtelomere structure.

Determining Susceptibility in Candida Vaginal Isolates.

Antifungal drug susceptibility tests (AST) for Candida albicans are increasingly demanded for women with refractory or recurrent Candida vaginitis due to fluconazole resistance. Given reduced activity of azole drugs at pH levels found in women with Candida vaginitis, it is proposed that AST be performed at pH 4.5, since testing at only the recommended pH 7.0 is likely to miss a significant number of clinically relevant azole-resistant C. albicans vaginal isolates.

Vulvovaginal candidiasis: An overview of mycological, clinical, and immunological aspects.

AIM: To provide an overview of clinical, immunological, and mycological aspects of vulvovaginal candidiasis (VVC). METHODS: A literature search was conducted to find relevant articles about different aspects of VVC. Related data from retrieved articles were summarized in different headings. RESULTS: VVC has a global distribution and Candida albicans is the leading cause of infection except for specific patient groups like postmenopausal, diabetic, or immunocompromised women. VVC has a range of clinical presentations, accordingly, its diagnosis should be based on clinical examination coupled with laboratory investigations. The best therapeutic regimen depends on the patient's conditions and the causative agent. Moreover, factors like drug resistance of the causative agents and different mutations in the immunity-related genes could affect the treatment outcome. CONCLUSION: As a globally distributed disease, VVC needs further attention, especially in areas related to the treatment failure and recurrence of the disease.

Lower Genital Tract Microbiome-A Work in Progress.

ABSTRACT: The lower genital tract microbiome is composed of millions upon millions of microbes colonizing this unique anatomical niche reflecting the influence of genetic, biologic, and behavioral factors. Over the last decade, as a result of ever advancing technology and research investment, our knowledge of this complex microbiome ecosystem has grown enormously. All too often such progress remains invisible to practitioners. In this special issue, clinical scientists, in a unique contribution, have bridged the ever-increasing distance between vaginal microbiota science and clinical disease. Approaching a myriad of pathologic entities, authors describe the clinical application of recent molecular laboratory findings encouraging diagnostic, prognostic, and therapeutic advances. Nevertheless, challenges are recognized and the authors outline vulvovaginal disease management opportunities. Above all, exposing the dynamism of vaginal microbiota affords a better understanding of pathogenesis of lower genital tract disease.

Mixed Vaginitis Due to Bacterial Vaginosis and Candidiasis.

OBJECTIVE: The aim of the study was to review recent clinic cases with mixed vaginitis due to bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) with reference to demographics, clinical presentation, diagnosis, and treatment. MATERIALS AND METHODS: This is a retrospective chart review of patients defined with mixed vaginitis due to BV and VVC in academic vaginitis clinic over 3 years (2018-2021). RESULTS: Thirty-eight women, mean age 32.6 years, met mixed vaginitis definition criteria. Diagnosis was invariably suspected clinically and rapidly confirmed using standard point of care diagnostic tests. Most patients (>90%) had a history of long-standing recurrent vaginitis both BV and VVC. Condom use was infrequent at 30% and 100% of yeast isolates were Candida albicans. Dual antimicrobial therapy achieved short term therapeutic success in 66.7% with failure in part due to fluconazole resistant C. albicans strains. CONCLUSIONS: Mixed vaginitis is not uncommon and serves as a significant therapeutic challenge requiring initial dual antimicrobial therapy and additional consideration for long-term antimicrobial therapy.

A Randomized Phase 2 Study of VT-1161 for the Treatment of Acute Vulvovaginal Candidiasis.

BACKGROUND: Acute vulvovaginal candidiasis (VVC) is common among women, but current azole antifungal treatments are often associated with safety and resistance issues. VT-1161 (oteseconazole) is an oral agent with increased selectivity for fungal CYP51. In this phase 2 clinical study, we evaluated the efficacy and safety of VT-1161 vs fluconazole in participants with moderate to severe acute VVC. METHODS: Participants presenting with an acute episode of VVC (n = 55) were randomized to receive VT-1161 300 mg once daily (q.d.) for 3 days, 600 mg q.d. for 3 days, or 600 mg twice daily (b.i.d.) for 3 days or to receive a single dose of fluconazole 150 mg (FDA-approved dose to treat acute VVC). Participants were followed for 6 months. The primary outcome was the proportion of participants with therapeutic (clinical and mycological) cure at day 28. RESULTS: A larger proportion of participants in the per-protocol population experienced therapeutic cure in the VT-1161 300 mg q.d. (75.0%), VT-1161 600 mg q.d. (85.7%), and VT-1161 600 mg b.i.d. (78.6%) groups vs the fluconazole group (62.5%); differences were not statistically significant. At 3 and 6 months, no participants in the VT-1161 groups vs 28.5% and 46.1% in the fluconazole group, respectively, had evidence of mycological recurrence. No serious adverse events or treatment-emergent adverse events leading to discontinuation were reported. CONCLUSIONS: The majority of participants across all treatment groups achieved therapeutic cure at day 28. VT-1161 was well tolerated at all dose levels through 6 months of follow-up. CLINICAL TRIALS REGISTRATION: NCT01891331.

Treatment of Male Sexual Partners of Women With Bacterial Vaginosis: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: We aimed to determine if treatment of male sexual partners of women with recurrent bacterial vaginosis (BV) with oral metronidazole 2×/day for 7 days (ie, multidose metronidazole) significantly decreased BV recurrence rates in the female. METHODS: This was a multicenter, 2-arm, double-blind, placebo-controlled study. Women with recurrent BV and current diagnosis of BV by Amsel and Nugent were enrolled. Multidose metronidazole for 7 days was dispensed to women. Male partners were randomized to placebo versus multidose metronidazole for 7 days and asked to refrain from unprotected sex for 14 days. Female follow-up visits were conducted at day 21 and 8 and 16 weeks. Male follow-up visits occurred at days 14-21. BV cure was defined as 0-2 Amsel criteria and Nugent score 0-6 in the female partner with the primary endpoint at 16 weeks. RESULTS: 214 couples were enrolled. In the intent-to-treat population, there was no significant difference between treatment arms for the primary outcome. BV treatment failure occurred in 81% and 80% of women in the metronidazole and placebo arms through the third follow-up visit, respectively (P > .999). However, women whose male partners adhered to study medication were less likely to fail treatment (adjusted relative risk, .85; 95% CI, .73-.99; P = .035). This finding persisted in post hoc comparisons in the metronidazole arm. CONCLUSIONS: Overall, this study did not find that male partner treatment with multidose metronidazole significantly reduces BV recurrence in female partners, although women whose partners adhered to multidose metronidazole were less likely to fail treatment. CLINICAL TRIALS REGISTRATION: (NCT02209519).

In Vitro pH Activity of Ibrexafungerp against Fluconazole-Susceptible and -Resistant Candida Isolates from Women with Vulvovaginal Candidiasis.

The vaginal environment with candidiasis has a pH of 3.8 to 4.5 and this has a negative effect on the activity of antifungals. Ibrexafungerp was evaluated against 187 Candida isolates, including fluconazole-sensitive and -resistant Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, and Candida tropicalis with the media adjusted to pH 7.0 and pH 4.5. Ibrexafungerp MIC values were not adversely affected when tested at pH 4.5. Ibrexafungerp exhibited significant activity against all isolates at pH 4.5.

Vaginal Isolates of Candida glabrata Are Uniquely Susceptible to Ionophoric Killer Toxins Produced by Saccharomyces cerevisiae.

Compared to other species of Candida yeasts, the growth of Candida glabrata is inhibited by many different strains of Saccharomyces killer yeasts. The ionophoric K1 and K2 killer toxins are broadly inhibitory to all clinical isolates of C. glabrata from patients with recurrent vulvovaginal candidiasis, despite high levels of resistance to clinically relevant antifungal therapeutics.

Bacterial vaginosis: drivers of recurrence and challenges and opportunities in partner treatment.

Bacterial vaginosis (BV) is the most common vaginal dysbiosis to affect women globally, yet an unacceptably high proportion of women experience BV recurrence within 6 months of recommended antibiotic therapy. The low rate of sustained cure highlights our limited understanding of the pathogenesis of BV recurrence, which has been attributed to possible persistence and re-emergence of BV-associated bacteria (BVAB) or a BV-associated biofilm following antimicrobials and/or reinfection occurring from sexual partners.There is a robust body of evidence to support the exchange of bacteria between partners during sexual activity, and while the hypothesis that women treated for BV are subsequently reinfected with BVAB following sex with an untreated sexual partner is not new, failure of past partner treatment trials has eroded confidence in this concept. If reinfection is a key driver of recurrence, current antimicrobial regimens directed to women alone are unlikely to achieve a high level of sustained cure, and the approach of partner treatment to reduce reinfection is justified. In this manuscript, we present the molecular and epidemiological evidence that underlies the hypothesis that BV is sexually transmitted, and summarise why research that continues to consider sexual partnerships is necessary. We also outline the significant barriers and challenges that we have identified while undertaking partner treatment studies, and we discuss the factors that impact on our ability to determine their effectiveness.Ultimately, the pathogenesis of BV recurrence is likely to be multifaceted and not attributable to a single mechanism in all women. If we are to achieve sustained cure for women, it is likely that combined and individualised approaches to eradicate BVAB, support an optimal vaginal microbiome, and prevent reinfection from partners will be required.

Recurrent Bacterial Vaginosis: An Unmet Therapeutic Challenge. Experience With a Combination Pharmacotherapy Long-Term Suppressive Regimen.

BACKGROUND: Recurrence of bacterial vaginosis (RBV) is a major challenge to effective therapy. Women experiencing intractable and frequent recurrences are ill-served by available treatment options, such as both antimicrobial and use of probiotics. METHODS: One hundred five women with RBV failing all recommended regimens seen in the clinic were prescribed combination oral nitroimidazole 500 mg twice a day for 7 days and simultaneous boric acid 600 mg daily per vagina therapy for 30 days; thereafter, they were prescribed twice-weekly vaginal metronidazole gel for 5 months in an attempt to prevent recurrence and followed by a 6-month observation period. Results reflect standard of clinic care in this uncontrolled retrospective cohort analysis. RESULTS: An initial regimen of nitroimidazole and simultaneous but prolonged vaginal boric acid achieved a satisfactory response (BV cure ≤2 Amsel criteria) in 92 of 93 available patients. Thereafter, a maintenance metronidazole gel prevented symptomatic BV recurrence in 69.6% of compliant patients at 6-month follow-up. Long-term cure at a 12-month follow-up was demonstrated in almost 69% of women reaching the 6-month observation phase. Vaginal candidiasis frequently complicated prolonged antibiotic prophylaxis requiring frequent antifungal rescue or prophylaxis. Frequent loss to follow-up in this long-term study influenced efficacy evaluation. CONCLUSIONS: In the absence of new antimicrobials or proven probiotic regimens, women with RBV may benefit from a prolonged drug-intensive antimicrobial regimen incorporating antibiofilm activity until newer measures are available. Additional randomized, control studies are needed.

Data on Safety of Intravaginal Boric Acid Use in Pregnant and Nonpregnant Women: A Narrative Review.

ABSTRACT: Intravaginal boric acid (IBA) represents one of the only options available to treat azole-resistant vulvovaginal candidiasis (VVC) and is included as part of multiple national guidelines (including the United Kingdom and the United States) for the treatment of VVC or recurrent bacterial vaginosis. Novel products using IBA are under development for treatment and suppression of VVC and bacterial vaginosis. Use of over-the-counter or clinician-prescribed IBA in reproductive-aged women is already widespread and may increase further if drug resistance in VVC rises. However, IBA is not a Food and Drug Administration-approved drug, and safety data are sparse. Given these factors, it is important to understand the currently available data on the safety of IBA use. Herein, we set out to synthesize human and animal data (converting, where appropriate, dose and serum values to standard units to facilitate comparison) to answer 2 key questions: (1) What are the data on the safety of IBA use for women? and (2) What are the data on the safety of IBA use in pregnancy? We find that, despite gaps, available data suggest IBA use is safe, at least when used in doses commonly described in the literature as being prescribed by clinicians. Information on harms in pregnancy is limited, and data remain insufficient to change current guidelines, which recommend IBA avoidance in pregnancy.

Use of a Novel Couples' Verification Tool in a Male Partner Treatment Study of Women With Recurrent Bacterial Vaginosis.

Verification of relationship status beyond self-report is an important aspect in sexually transmitted infection research, including partner treatment studies where primary sexual partners are targeted for enrollment. This exploratory study describes the use of a novel couples' verification tool in a male partner treatment study of women with recurrent bacterial vaginosis.