Oral Ibrexafungerp: an investigational agent for the treatment of vulvovaginal candidiasis

The Role of Novel Antifungals in the Management of Candidiasis: A Clinical Perspective

Mucosal and invasive candidiasis can be challenging to treat in the setting of drug intolerance, antifungal resistance, drug-drug interactions, or host immune status. Antifungals with novel mechanisms of action and distinct pharmacokinetic/pharmacodynamic properties have been developed in recent years. Rezafungin is an echinocandin with high-tissue penetration and an extended half-life that allows for once-weekly administration, making it a convenient treatment option for invasive candidiasis while obviating the need for central catheter placement. Ibrexafungerp is an oral glucan synthase inhibitor that is active against most echinocandin-resistant Candida species. At present, it is approved for the treatment of acute vulvovaginal candidiasis and is under investigation as an oral step-down therapy following initial treatment with an echinocandin for cases of invasive candidiasis. Oteseconazole is a long-acting tetrazole that exhibits a higher affinity for the fungal enzyme CYP51, resulting in a potentially lower risk of drug-drug interactions and side effects compared to other azoles. It is currently approved for the treatment of recurrent vulvovaginal candidiasis. Fosmanogepix has a novel mechanism of action and potent activity against several Candida strains resistant to other antifungals. Due to its considerable bioavailability and tissue penetration, it holds promise as a potential treatment option in patients with invasive candidiasis, including those with chorioretinitis or meningitis. Results from clinical trials and observational studies will further delineate the role of these agents in the management of candidiasis. As the usage of these novel antifungals becomes widespread, we expect to acquire a greater understanding of their efficacy and potential benefits.

Molecular association of Candida albicans and vulvovaginal candidiasis: focusing on a solution

Candida albicans-mediated vulvovaginal candidiasis (VVC) is a significant challenge in clinical settings, owing to the inefficacy of current antifungals in modulating virulence, development of resistance, and poor penetration into the biofilm matrix. Various predisposition factors are molecular drivers that lead to the dysbiosis of normal microflora of the vagina, upregulation of central metabolic pathways, morphogenesis, hyphal extension, adhesion, invasion, and biofilm formation leading to chronic infection and recurrence. Hence, it is crucial to understand the molecular mechanism behind the virulence pathways driven by those drivers to decode the drug targets. Finding innovative solutions targeting fungal virulence/biofilm may potentiate the antifungals at low concentrations without affecting the recurrence of resistance. With this background, the present review details the critical molecular drivers and associated network of virulence pathways, possible drug targets, target-specific inhibitors, and probable mode of drug delivery to cross the preclinical phase by appropriate in vivo models.

Artemisinins inhibit oral candidiasis caused by Candida albicans through the repression on its hyphal development

Candida albicans is the most abundant fungal species in oral cavity. As a smart opportunistic pathogen, it increases the virulence by switching its forms from yeasts to hyphae and becomes the major pathogenic agent for oral candidiasis. However, the overuse of current clinical antifungals and lack of new types of drugs highlight the challenges in the antifungal treatments because of the drug resistance and side effects. Anti-virulence strategy is proved as a practical way to develop new types of anti-infective drugs. Here, seven artemisinins, including artemisinin, dihydroartemisinin, artemisinic acid, dihydroartemisinic acid, artesunate, artemether and arteether, were employed to target at the hyphal development, the most important virulence factor of C. albicans. Artemisinins failed to affect the growth, but significantly inhibited the hyphal development of C. albicans, including the clinical azole resistant isolates, and reduced their damage to oral epithelial cells, while arteether showed the strongest activities. The transcriptome suggested that arteether could affect the energy metabolism of C. albicans. Seven artemisinins were then proved to significantly inhibit the productions of ATP and cAMP, while reduced the hyphal inhibition on RAS1 overexpression strain indicating that artemisinins regulated the Ras1-cAMP-Efg1 pathway to inhibit the hyphal development. Importantly, arteether significantly inhibited the fungal burden and infections with no systemic toxicity in the murine oropharyngeal candidiasis models in vivo caused by both fluconazole sensitive and resistant strains. Our results for the first time indicated that artemisinins can be potential antifungal compounds against C. albicans infections by targeting at its hyphal development.

Treatment of Vulvovaginal Candidiasis-An Overview of Guidelines and the Latest Treatment Methods

Vulvovaginal candidiasis (VVC) is a common condition associated with discomfort in affected women. Due to the presence of different forms of the disease, diverse treatment regimens are developed; the newest ones include oteseconazole and ibrexafungerp. Here, we focus on the most up-to-date recommendations regarding VVC treatment, as well as novel treatment options. Topical and oral azoles are the drugs of choice in uncomplicated mycosis. The efficacy of probiotics and substances such as TOL-463 and chlorhexidine is indicated as satisfactory; however, there are no relevant guidelines. Although the majority of researchers agree that the treatment of non-albicans VVC should be long-lasting, the recommendations are inconsistent. Another clinical problem is the treatment of VVC with azole intolerance or resistance, for which literature proposes the use of several drugs including oteseconazole, ibrexafungerp, and voriconazole. The treatment schedules for recurrent VVC include mainly fluconazole; however, alternative options such as immunotherapeutic vaccine (NDV-3A) or designed antimicrobial peptides (dAMPs) were also described. We also focused on VVC affecting pregnant women, which is a substantial challenge in clinical practice, also due to the heterogeneous relevant guidelines. Thus far, few precise recommendations are available in the literature. Future studies should focus on atypical VVC forms to elucidate the inconsistent findings.

Public Health Research Priorities for Fungal Diseases: A Multidisciplinary Approach to Save Lives

Fungal infections can cause severe disease and death and impose a substantial economic burden on healthcare systems. Public health research requires a multidisciplinary approach and is essential to help save lives and prevent disability from fungal diseases. In this manuscript, we outline the main public health research priorities for fungal diseases, including the measurement of the fungal disease burden and distribution and the need for improved diagnostics, therapeutics, and vaccines. Characterizing the public health, economic, health system, and individual burden caused by fungal diseases can provide critical insights to promote better prevention and treatment. The development and validation of fungal diagnostic tests that are rapid, accurate, and cost-effective can improve testing practices. Understanding best practices for antifungal prophylaxis can optimize prevention in at-risk populations, while research on antifungal resistance can improve patient outcomes. Investment in vaccines may eliminate certain fungal diseases or lower incidence and mortality. Public health research priorities and approaches may vary by fungal pathogen.

Candidiasis: From cutaneous to systemic, new perspectives of potential targets and therapeutic strategies

Candidiasis is an infection caused by fungi from a Candida species, most commonly Candida albicans. C. albicans is an opportunistic fungal pathogen typically residing on human skin and mucous membranes of the mouth, intestines or vagina. It can cause a wide variety of mucocutaneous barrier and systemic infections; and becomes a severe health problem in HIV/AIDS patients and in individuals who are immunocompromised following chemotherapy, treatment with immunosuppressive agents or after antibiotic-induced dysbiosis. However, the immune mechanism of host resistance to C. albicans infection is not fully understood, there are a limited number of therapeutic antifungal drugs for candidiasis, and these have disadvantages that limit their clinical application. Therefore, it is urgent to uncover the immune mechanisms of the host protecting against candidiasis and to develop new antifungal strategies. This review synthesizes current knowledge of host immune defense mechanisms from cutaneous candidiasis to invasive C. albicans infection and documents promising insights for treating candidiasis through inhibitors of potential antifungal target proteins.

Repurposing Disulfiram as an Antifungal Agent: Development of a New Disulfiram Vaginal Mucoadhesive Gel

Alternative formulations need to be developed to improve the efficacy of treatments administered via the vaginal route. Mucoadhesive gels with disulfiram, a molecule that was originally approved as an antialcoholism drug, offer an attractive alternative to treat vaginal candidiasis. The aim of the current study was to develop and optimize a mucoadhesive drug delivery system for the local administration of disulfiram. Such formulations were composed of polyethylene glycol and carrageenan to improve the mucoadhesive and mechanical properties and to prolong the residence time in the vaginal cavity. Microdilution susceptibility testing showed that these gels had antifungal activity against Candida albicans, Candida parapsilosis, and Nakaseomyces glabratus. The physicochemical properties of the gels were characterized, and the in vitro release and permeation profiles were investigated with vertical diffusion Franz cells. After quantification, it was determined that the amount of the drug retained in the pig vaginal epithelium was sufficient to treat candidiasis infection. Together, our findings suggest that mucoadhesive disulfiram gels have the potential to be an effective alternative treatment for vaginal candidiasis.

Microbiome and Vulvovaginitis

Vulvovaginitis occurs in mostly reproductive aged women. Recurrent vaginitis affects overall quality of life, with a large financial burden on the patient, family, and health system. This review discusses a clinician's approach to vulvovaginitis with specific attention to the 2021 updated Center for Disease Control and Prevention guidelines. The authors discuss the role of the microbiome in vaginitis and evidence-based approaches for diagnosis and treatment of vaginitis. This review also provides updates on new considerations, diagnosis, management, and treatment of vaginitis. Desquamative inflammatory vaginitis and genitourinary syndrome of menopause are discussed as differential diagnosis of vaginitis symptoms.

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.

Ibrexafungerp for the Treatment of Vulvovaginal Candidiasis: Design, Development and Place in Therapy

Vulvovaginal candidiasis (VVC) is experienced by an estimated 75% of women at least once in their lifetime and is recurrent, defined as three or more infections per year (RVVC) in 5-9%. Candida albicans is the most common causative agent, but up to 19% of infections may be related to non-albicans species. Available treatment options for VVC have consisted of oral and topical azoles (except for topical nystatin, a polyene). Oral polyenes are not absorbed and therefore not effective for VVC. Fluconazole is the only oral medication FDA approved for VVC. None of these treatments are FDA approved for RVVC. Ibrexafungerp, a triterpenoid fungicidal agent, was FDA approved in 2021, becoming the first oral non-azole agent for VVC. Ibrexafungerp reaches concentrations up to 9-fold higher in vaginal tissues versus plasma. In Phase 2 clinical trials, ibrexafungerp had a clinical cure rate comparable to fluconazole at day 10, but significantly better at day 25. In Phase 3 clinical trials, ibrexafungerp had both a higher clinical and mycologic cure rate versus placebo at both days 10 and 25. In December 2022, Ibrexafungerp received FDA approval for once monthly dosing to decrease the incidence of RVVC. This approval was based on data from the CANDLE STUDY, which showed 65.4% resolution of symptoms and culture negative success through week 24, compared to 53.1% of placebo. Ibrexafungerp provides an alternative oral option for treatment of acute, severe VVC. It is the only FDA approved antifungal for RVVC. Currently, the population likely to benefit from this drug are those with azole allergy, non-albicans or azole resistant albicans species, or other azole contraindications such as drug interactions (like statins or tricyclics). Side effects are mostly gastrointestinal and mild in nature. Ibrexafungerp, like fluconazole, should be used with caution in women who are or may become pregnant.

Oral Ibrexafungerp for Vulvovaginal Candidiasis Treatment: An Analysis of VANISH 303 and VANISH 306

Background: Ibrexafungerp is a novel antifungal treatment for acute vulvovaginal candidiasis (VVC). Using pooled data from two phase three studies (VANISH 303 and 306) in the treatment of acute VVC, this analysis sought to determine the effectiveness of ibrexafungerp in various patient subgroups that may impact outcomes. Materials and Methods: Data from VANISH 303 (NCT03734991) and VANISH 306 (NCT03987620) evaluating ibrexafungerp 300 mg twice daily (BID) for 1 day versus placebo, were pooled and analyzed to determine clinical cure rate, clinical improvement, and mycological cure at the test-of-cure visit (day 11 ± 3) and symptom resolution at the follow-up visit (day 25 ± 4) in the overall population. Patient subgroups analyzed included race, body mass index (BMI), baseline vulvovaginal signs and symptoms (VSS) score, and Candida species. Results: At the test-of-cure visit, patients receiving ibrexafungerp, compared with those who received placebo, had significantly higher rates of clinical cure (56.9% [214/376 patients] vs. 35.7% [65/182 patients]), clinical improvement (68.4% [257/376 patients] vs. 45.1% [82/182 patients]), and mycological cure (54.0% [203/376 patients] vs. 24.2% [44/182 patients]; all p < 0.0001). At the follow-up visit, patients receiving ibrexafungerp had sustained responses with higher symptom resolution rates (66.8% [251/376 patients]) versus placebo (48.4% [88/182 patients]; p < 0.0001). Race, BMI, baseline VSS score (including VSS severity score 13-18), and Candida species infection did not adversely affect clinical cure rates. Safety analysis results were consistent with the individual studies. Conclusions: Ibrexafungerp provides a safe and well-tolerated first-in-class fungicidal, 1-day oral treatment for patients with acute VVC, the first new therapy in >20 years. Clinical Trial Registration Number: NCT03734991.

Therapeutic Approaches for Combating Aspergillus Associated Infection

Now-a-days fungal infection emerges as a significant problem to healthcare management systems due to high frequency of associated morbidity, mortality toxicity, drug-drug interactions, and resistance of the antifungal agents. Aspergillus is the most common mold that cause infection in immunocompromised hosts. It's a hyaline mold that is cosmopolitan and ubiquitous in nature. Aspergillus infects around 10 million population each year with a mortality rate of 30-90%. Clinically available antifungal formulations are restricted to four classes (i.e., polyene, triazole, echinocandin, and allylamine), and each of them have their own limitations associated with the activity spectrum, the emergence of resistance, and toxicity. Consequently, novel antifungal agents with modified and altered chemical structures are required to combat these invasive fungal infections. To overcome these limitations, there is an urgent need for new antifungal agents that can act as potent drugs in near future. Currently, some compounds have shown effective antifungal activity. In this review article, we have discussed all potential antifungal therapies that contain old antifungal drugs, combination therapies, and recent novel antifungal formulations, with a focus on the Aspergillus associated infections.

Similarities and Differences among Species Closely Related to Candida albicans: C. tropicalis, C. dubliniensis, and C. auris

Although Candida species are widespread commensals of the microflora of healthy individuals, they are also among the most important human fungal pathogens that under certain conditions can cause diseases (candidiases) of varying severity ranging from mild superficial infections of the mucous membranes to life-threatening systemic infections. So far, the vast majority of research aimed at understanding the molecular basis of pathogenesis has been focused on the most common species—Candida albicans. Meanwhile, other closely related species belonging to the CTG clade, namely, Candida tropicalis and Candida dubliniensis, are becoming more important in clinical practice, as well as a relatively newly identified species, Candida auris. Despite the close relationship of these microorganisms, it seems that in the course of evolution, they have developed distinct biochemical, metabolic, and physiological adaptations, which they use to fit to commensal niches and achieve full virulence. Therefore, in this review, we describe the current knowledge on C. tropicalis, C. dubliniensis, and C. auris virulence factors, the formation of a mixed species biofilm and mutual communication, the environmental stress response and related changes in fungal cell metabolism, and the effect of pathogens on host defense response and susceptibility to antifungal agents used, highlighting differences with respect to C. albicans. Special attention is paid to common diagnostic problems resulting from similarities between these species and the emergence of drug resistance mechanisms. Understanding the different strategies to achieve virulence, used by important opportunistic pathogens of the genus Candida, is essential for proper diagnosis and treatment.

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.

Drug Resistance and Novel Therapeutic Approaches in Invasive Candidiasis

Candida species are the leading cause of invasive fungal infections worldwide and are associated with acute mortality rates of ~50%. Mortality rates are further augmented in the context of host immunosuppression and infection with drug-resistant Candida species. In this review, we outline antifungal drugs already in clinical use for invasive candidiasis and candidaemia, their targets and mechanisms of resistance in clinically relevant Candida species, encompassing not only classical resistance, but also heteroresistance and tolerance. We describe novel antifungal agents and targets in pre-clinical and clinical development, including their spectrum of activity, antifungal target, clinical trial data and potential in treatment of drug-resistant Candida. Lastly, we discuss the use of combination therapy between conventional and repurposed agents as a potential strategy to combat the threat of emerging resistance in Candida.

Pharmacokinetics and Pharmacodynamics of Ibrexafungerp

On 2 June, 2021, the US Food and Drug Administration approved ibrexafungerp (formerly MK-3118 and SCY-078) for the treatment of vulvovaginal candidiasis, also known as vaginal yeast infection. Ibrexafungerp is the first drug approved in a novel antifungal class in more than two decades, and the Food and Drug Administration’s decision was based on positive results from two pivotal phase III studies in which oral ibrexafungerp proved both safe and effective in patients with vulvovaginal candidiasis. The decision was also based on substantial preclinical and clinical work in both the pharmacokinetics and pharmacodynamics of ibrexafungerp. This paper reviews that research and looks ahead to explore how this novel antifungal agent may be used in the future to address the expanding problem of drug-resistant mycotic infections.

The rise in cases of mucormycosis, candidiasis and aspergillosis amidst COVID19

The Coronavirus outbreak globally has changed the medical system and also led to a shortage of medical facilities in both developing and underdeveloped countries. The COVID19 disease, being novel in nature along with high infectivity and frequent mutational rate, has been termed to be fatal across the globe. The advent of infection by SARS-CoV-2 has brought a myriad of secondary complications and comorbidities resulting in additional challenges to the health care system induced by novel therapeutic procedures. The emerging variant with respect to the Indian subcontinent and the associated genetic mutations have worsened the situation at hand. Proper clinical management along with epidemiological studies and clinical presentations in scientific studies and trials is necessary in order to combat the simultaneous waves of emerging strains. This article summarizes three of the major fungal outbreaks in India namely mucormycosis, candidiasis and aspergillosis, and elaborates their subtypes, pathogenesis, symptoms and treatment and detection techniques. A detail of future therapeutics under consideration are also elaborated along with a general hypothesis on how COVID19 is related to immunological advances leading to major widespread fungal infection in the country. The factors that contribute in promoting virus proliferation and invasive fungal infections include cell-mediated immunity, associated immunocompromised conditions and treatment protocols that slows down immune mechanisms. To better comprehend a fungal or bacterial outbreak, it is very important to conduct audits mediated through multicenter national and state research teams for recognizing patterns and studying current cases of fungal infection in both healthy and comorbid groups of COVID19 patients.

Oteseconazole: an advance in treatment of recurrent vulvovaginal candidiasis

Recurrent vulvovaginal candidiasis (RVVC) has significant disease, financial and quality-of-life burdens, affects women from all strata of society worldwide, and lacks an approved therapeutic solution. Fluconazole emerged in 2004 as an antifungal for RVVC; it provides symptom control and has been accepted worldwide as a first-line treatment. Its limitations include the development of resistance and a high rate of vulvovaginal candidiasis recurrence after therapy cessation. There is now an improved treatment option on the horizon: oteseconazole - a novel, oral, selective fungal cytochrome P450 enzyme 51 inhibitor, designed to avoid off-target toxicities. In clinical studies to date, oteseconazole has demonstrated impressive efficacy, a positive tolerability profile and hope for a superior RVVC treatment option.

Efficacy and safety of oral ibrexafungerp for the treatment of acute vulvovaginal candidiasis: a global phase 3, randomised, placebo-controlled superiority study (VANISH 306)

Objective

To evaluate the efficacy and safety of ibrexafungerp versus placebo for acute vulvovaginal candidiasis (VVC) treatment.

Design

Global phase 3, randomised, placebo‐controlled superiority study.

Setting

Study sites in the USA (n = 19) and Bulgaria (n = 18).

Population

Female patients aged ≥12 years with acute VVC and a vulvovaginal signs and symptoms (VSS) score ≥4 at baseline.

Methods

Patients were randomly assigned 2:1 to ibrexafungerp (300 mg twice for 1 day) or placebo.

Main outcome measures

The primary endpoint was the percentage of patients with a clinical cure (VSS = 0) at the test‐of‐cure visit (day 11 ± 3). Secondary endpoints included percentages of patients with mycological eradication, clinical cure and mycological eradication (overall success), clinical improvement (VSS ≤1) at test‐of‐cure visit, and complete resolution of symptoms at follow‐up visit (day 25 ± 4).

Results

At the test‐of‐cure visit, patients receiving ibrexafungerp had significantly higher rates of clinical cure (63.3% [119/188] versus 44.0% [37/84]; P = 0.007), mycological eradication (58.5% [110/188] versus 29.8% [25/84]; P < 0.001), overall success (46.1% [82/188] versus 28.4% [23/84]; P = 0.022) and clinical improvement (72.3% [136/188] versus 54.8% [46/84]; P = 0.01) versus those receiving placebo. Symptom resolution was sustained and further increased with ibrexafungerp (73.9%) versus placebo (52.4%) at follow‐up (P = 0.001). Ibrexafungerp was generally well tolerated. Adverse events were primarily gastrointestinal and were mild to moderate in severity.

Conclusions

Ibrexafungerp demonstrated statistical superiority over placebo for the primary and secondary endpoints. Ibrexafungerp is a promising novel, well‐tolerated and effective oral 1‐day treatment for acute VVC.

Tweetable abstract

Ibrexafungerp is statistically superior to placebo for the treatment of vulvovaginal candidiasis.

Ibrexafungerp is statistically superior to placebo for the treatment of vulvovaginal candidiasis.

Linked article This article is commented on by KSJ Olah, p. 421–422 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471-0528.17000.

Virulence Factors as Promoters of Chronic Vulvovaginal Candidosis: A Review

INTRODUCTION

The vast majority of the species of the genus Candida spp. is commensal in humans; however, some are opportunistic pathogens that can cause infection, called candidosis. Among the different types of candidosis, we highlight the vulvovaginal (VVC) which can occur in two main clinical variants: chronic (cVVC) and episodic or sporadic. The incidence of cVVC has been worrying the scientific community, promoting the research on genotypic and phenotypic causes of its occurrence. We summarize important findings on factors that favor chronic vulvovaginal candidosis with respect to molecular epidemiology and the expression of various virulence factors, while clarifying the terminology involving these infections.

AIM AND METHODOLOGY

The aim of this review was to gather research that linked virulence factors to VVC and its persistence and recurrence, using two databases (Pubmed and Google Scholar). Predisposing factors in women for the occurrence of cVVC and some studies that refer new preventive and alternative therapies were also included, where appropriate.

RESULTS AND DISCUSSION

Several studies have been shedding light on the increasing number of persistence and recurrences of VVC. The expression of virulence factors has been related to both chronic forms of VVC and antifungal resistance. Other studies report mutations occurring in the genome of Candida spp. during the infection phase which may be important indications for new therapies. The introduction of preventive therapies and new therapies has revealed great importance and is also highlighted here.

Phase 2 randomized study of oral ibrexafungerp vs 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.

How urgent is the need for new antifungals?

Introduction: Invasive fungal infection carries a high morbidity, mortality and economic cost. In recent times, a rising incidence of fungal infection and antifungal resistance is occurring which has prompted the development of novel antifungal agents.Areas covered:In this perspective, the authors describe the current status of registered antifungals and their limitations in the treatment of invasive fungal infection. They also go on to describe the new antifungal agents that are in the clinical stage of development and how they might be best utilized in patient care in the future.Expert opinion: The antifungal drug development pipeline has responded to a growing need for new agents to effectively treat fungal disease without concomitant toxicity or issues with drug tolerance. Olorofim (F901318), ibrexafungerp (SCY-078), fosmanogepix (APX001), rezafungin (CD101), oteseconazole (VT-1161), encochleated amphotericin B (MAT2203), nikkomycin Z (NikZ) and ATI-2307 are all in the clinical stage of development and offer great promise in offering clinicians better agents to treat these difficult infections.

Emerging Prospects for Combating Fungal Infections by Targeting Phosphatidylinositol Transfer Proteins

The emergence of fungal “superbugs” resistant to the limited cohort of anti-fungal agents available to clinicians is eroding our ability to effectively treat infections by these virulent pathogens. As the threat of fungal infection is escalating worldwide, this dwindling response capacity is fueling concerns of impending global health emergencies. These developments underscore the urgent need for new classes of anti-fungal drugs and, therefore, the identification of new targets. Phosphoinositide signaling does not immediately appear to offer attractive targets due to its evolutionary conservation across the Eukaryota. However, recent evidence argues otherwise. Herein, we discuss the evidence identifying Sec14-like phosphatidylinositol transfer proteins (PITPs) as unexplored portals through which phosphoinositide signaling in virulent fungi can be chemically disrupted with exquisite selectivity. Recent identification of lead compounds that target fungal Sec14 proteins, derived from several distinct chemical scaffolds, reveals exciting inroads into the rational design of next generation Sec14 inhibitors. Development of appropriately refined next generation Sec14-directed inhibitors promises to expand the chemical weaponry available for deployment in the shifting field of engagement between fungal pathogens and their human hosts.

Antifungals in Clinical Use and the Pipeline

Over the past 15 years, there has been an increase in the development and utilization of newer antifungal agents. The ideal antifungal, however, in regard to spectrum of activity, pharmacokinetic/pharmacodynamic properties, development of resistance, safety, and drug interaction profile remains elusive. This article reviews pharmacologic aspects of Food and Drug Administration-approved polyenes, flucytosine, azoles, and echinocandins as well as promising pipeline antifungal agents. Unique properties of these newer agents are highlighted. The clinical role of established and investigational antifungal agents as treatment and/or prevention of invasive fungal infections is discussed.

An overview of current and emerging antifungal pharmacotherapy for invasive fungal infections

Introduction: Invasive fungal infections (IFIs) remain a significant cause of morbidity and mortality despite significant advancements in currently available therapy. With a flush pipeline of investigational antifungals, the clinician must identify appropriate roles of currently available therapies, potential advantages of emerging antifungals, and shortcomings in the evolving clinical evidence.Areas covered: Standard and developing treatment approaches for IFIs with currently available antifungals are summarized with a focus on invasive candidiasis and invasive aspergillosis. Emerging investigational antifungals are discussed in depth, including mechanisms of action, fungal activity, clinical evidence, and ongoing research. An opinion on the impact and potential role of therapy for emerging antifungals of interest is also provided.Expert opinion: Despite advances and clinical studies optimizing antifungal use, current therapies fall short in preventing IFI morbidity and mortality. Further optimization of currently available antifungals may improve outcomes; however, novel agents are required for historically difficult-to-treat infections, transitions to oral treatment, minimizing adverse drug effects, decreasing drug interactions, and ultimately improving patient quality of life. Emerging antifungals may positively revolutionize the treatment of IFIs.

An evaluation of ibrexafungerp for the treatment of invasive candidiasis: the evidence to date

INTRODUCTION

Invasive fungal infections, especially candidemia and invasive candidiasis, cause significant morbidity and mortality. The epidemiology of candida infections have changed dramatically due to an increase in risk factors associated with the development of infection and the emergence of resistant isolates such as C. glabrata and C. auris. This has prompted the search for novel and effective antifungals.

AREAS COVERED

The results of in vitro studies evaluating the activity of ibrexafungerp against Candida species are reviewed and the pharmacokinetic/pharmacodynamic properties are highlighted. Available results and safety data from limited clinical studies are discussed.

EXPERT OPINION

Ibrexafungerp demonstrates potent in vitro activity against susceptible and resistant Candida species, including echinocandin-resistant C. glabrata and multidrug-resistant C. auris. It also offers the flexibility of a parenteral and an oral preparation, minimal adverse effects, and low drug-drug interactions. In Phase 2/3 clinical trials, ibrexafungerp appears to have excellent clinical activity in patients with candidemia, invasive candidiasis, and mucosal candidiasis. Although there are several ongoing clinical trials, ibrexafungerp appears to be a promising agent and an important addition to the antifungal armamentarium necessary to treat emerging and resistant pathogens, including several of the Candida species.

Ibrexafungerp: A First-in-Class Oral Triterpenoid Glucan Synthase Inhibitor

Ibrexafungerp (formerly SCY-078 or MK-3118) is a first-in-class triterpenoid antifungal or “fungerp” that inhibits biosynthesis of β-(1,3)-D-glucan in the fungal cell wall, a mechanism of action similar to that of echinocandins. Distinguishing characteristics of ibrexafungerp include oral bioavailability, a favourable safety profile, few drug–drug interactions, good tissue penetration, increased activity at low pH and activity against multi-drug resistant isolates including C. auris and C. glabrata. In vitro data has demonstrated broad and potent activity against Candida and Aspergillus species. Importantly, ibrexafungerp also has potent activity against azole-resistant isolates, including biofilm-forming Candida spp., and echinocandin-resistant isolates. It also has activity against the asci form of Pneumocystis spp., and other pathogenic fungi including some non-Candida yeasts and non-Aspergillus moulds. In vivo data have shown IBX to be effective for treatment of candidiasis and aspergillosis. Ibrexafungerp is effective for the treatment of acute vulvovaginal candidiasis in completed phase 3 clinical trials.

In vitro activity of ibrexafungerp and comparators against Candida albicans genotypes from vaginal samples and blood cultures

OBJECTIVES

Emergence of azole resistance may contribute to recurrences of vulvovaginal candidiasis. Thus, new drugs are needed to improve the therapeutic options. We studied the in vitro activity of ibrexafungerp and comparators against Candida albicans isolates from vaginal samples and blood cultures. Furthermore, isolates were genotyped to study compartmentalization of genotypes and the relationship between genotype and antifungal susceptibility.

METHODS

Candida albicans unique patient isolates (n = 144) from patients with clinical suspicion of vulvovaginal candidiasis (n = 72 isolates) and from patients with candidaemia (n = 72) were studied. Antifungal susceptibility to amphotericin B, fluconazole, voriconazole, posaconazole, isavuconazole, clotrimazole, miconazole, micafungin, anidulafungin and ibrexafungerp was tested (EUCAST 7.3.2). Mutations in the erg11 gene were analysed and isolates genotyped.

RESULTS

Ibrexafungerp showed high activity (MICs from 0.03 mg/L to 0.25 mg/L) against the isolates, including those with reduced azole susceptibility, and regardless of their clinical source. Fluconazole resistance rate was 7% (n = 5/72) and 1.4% (n = 1/72) in vaginal and blood isolates, respectively. Some amino acid substitutions in the Erg11 protein were observed exclusively in phenotypically fluconazole non-wild type. Population structure analysis suggested two genotype populations, one mostly involving isolates from blood samples (66.3%) and the mostly from vaginal samples (69.8%). The latter group hosted all fluconazole non-wild-type isolates.

DISCUSSION

Ibrexafungerp shows good in vitro activity against Candida albicans from vaginal samples including phenotypically fluconazole non-wild-type isolates. Furthermore, we found a certain population structure where some genotypes show reduced susceptibility to fluconazole.

Current and promising pharmacotherapeutic options for candidiasis

Introduction: Candida spp. are commensal yeasts capable of causing infections such as superficial, oral, vaginal, or systemic infections. Despite medical advances, the antifungal pharmacopeia remains limited and the development of alternative strategies is needed.Areas covered: We discuss available treatments for Candida spp. infections, highlighting advantages and limitations related to pharmacokinetics, cytotoxicity, and antimicrobial resistance. Moreover, we present new perspectives to improve the activity of the available antifungals, discussing their immunomodulatory potential and advances on drug delivery carriers. New therapeutic approaches are presented including recent synthesized antifungal compounds (Enchochleated-Amphotericin B, tetrazoles, rezafungin, enfumafungin, manogepix and arylamidine); drug repurposing using a diversity of antibacterial, antiviral and non-antimicrobial drugs; combination therapies with different compounds or photodynamic therapy; and innovations based on nano-particulate delivery systems.Expert opinion: With the lack of novel drugs, the available assets must be leveraged to their best advantage through modifications that enhance delivery, efficacy, and solubility. However, these efforts are met with continuous challenges presented by microbes in their infinite plight to resist and survive therapeutic drugs. The pharmacotherapeutic options in development need to focus on new antimicrobial targets. The success of each antimicrobial agent brings strategic insights to the next phased approach in treatingCandida spp. infections.