Phase 2 randomized study of oral ibrexafungerp vs fluconazole in vulvovaginal candidiasis

Efficacy and safety of oral ibrexafungerp in Chinese patients with vulvovaginal candidiasis: a phase III, randomized, double-blind study

PURPOSE

To evaluate the efficacy and safety of oral ibrexafungerp (HS-10366) versus placebo in Chinese patients with vulvovaginal candidiasis (VVC).

METHODS

A double-blind, placebo-controlled, randomized, multicenter phase III study was conducted in symptomatic VVC patients. Patients received (2:1) twice-daily oral ibrexafungerp 300 mg or matching placebo for 1 day. The primary endpoint was clinical cure (vulvovaginal signs and symptoms [VSS] score = 0) at test-of-cure (TOC) on day 11 ± 3. The secondary endpoints included mycological eradication, overall response, and clinical improvement (VSS score ≤ 1) at TOC, and vulvovaginal symptom resolution at follow-up on day 25 ± 4.

RESULTS

In total, 360 patients were included in the modified intention-to-treat set (defined as positive Candida cultured and receiving at least one study drug; 239 for ibrexafungerp, 121 for placebo). Compared with placebo, patients receiving ibrexafungerp had a significantly higher proportion of clinical cure (51.0% vs. 25.6%), mycological eradication (55.6% vs. 18.2%), overall response (33.9%, vs. 8.3%) at TOC and complete symptom resolution (74.5% vs. 39.7%, all P < 0.001) at follow-up. Subgroup analysis of clinical cure indicated that patients with C. albicans could benefit from ibrexafungerp over placebo. A similar benefit trend was also observed in those with non-albicans Candida by post-hoc analysis. Further analyses revealed similar efficacy of ibrexafungerp between patients with fluconazole non-susceptible C. albicans and fluconazole susceptible C. albicans regarding clinical cure and mycological eradication. Ibrexafungerp was generally well tolerated. Adverse events were primarily gastrointestinal and were mainly mild in severity.

CONCLUSIONS

As a first-in-class antifungal agent, ibrexafungerp demonstrated promising efficacy and favorable safety for VVC treatment in Chinese patients. CHINADRUGTRIALS.ORG.

CN REGISTRY NUMBER

CTR20220918.

A review of the fernane-type triterpenoids as anti-fungal drugs

Human fungal pathogens could cause a broad plethora of infections in both the immunocompetent and immunocompromised host. Fungal infections have become important causes of morbidity and mortality in recent years, the current arsenal of anti-fungal therapies was restricted. Ibrexafungerp was a novel, highly bioavailable glucan synthase inhibitor formulated for both intravenous and oral administration being developed by Scynexis; it was also the first novel anti-fungal drug class approved in more than 20 years. Ibrexafungerp was one semi-synthetic derivative of enfumafungin, a natural product isolated from fungi. This review reported the discovery of enfumafungin and ibrexafungerp, their anti-fungal mechanism, summed up 63 fernane-type triterpenoids from natural products, including 49 from plants, 9 from fungi and 5 from lichen. In addition, the review summarized the progress of enzymes responsible for the biosynthesis of type II fernane triterpenoid (enfumafungin skeleton) and type I fernane triterpenoid (polytolypin skeleton). The good example kept our confidence up for searching for new leading compounds and discovering drugs from fungi.

Pharmacokinetic evaluation of ibrexafungerp for the treatment of vulvovaginal candidiasis and beyond

INTRODUCTION

Ibrexafungerp is a new triterpenoid antifungal agent with activity against a variety of fungal species, including Aspergillus spp. and echinocandin-resistant Candida spp.

AREAS COVERED

This evaluation will summarize currently available clinical evidence on the use of ibrexafungerp in the treatment/prevention of vulvovaginal candidiasis (VVC) and detail the mechanism of action, pharmacokinetic/pharmacodynamic parameters, and ongoing/latest research involving ibrexafungerp.

EXPERT OPINION

The evidence involving the utilization of ibrexafungerp for the treatment of VVC shows that it is superior when compared to placebo and has comparable clinical cure rates when compared with fluconazole. Ibrexafungerp demonstrates reliable coverage against several Candida spp. including echinocandin-resistant strains, Candida auris, and Aspergillus spp. For VVC, a dose of 300 mg (two 150 mg tablets) twice daily is recommended and does not require dose adjustments based on renal or hepatic function. The use of ibrexafungerp outside of VVC is currently under study with several ongoing trials showing promising interim data.

Assessment and Treatment of Vaginitis

Vaginitis is the presenting symptom at millions of office visits each year in the United States. Although treatment of sporadic cases is often straightforward, recurrent cases present both diagnostic and treatment challenges. Molecular diagnostic tests are likely superior to in-office microscopy for most clinicians and most cases. In both recurrent bacterial vaginosis and recurrent vulvovaginal candidiasis, national treatment guidelines recommend an extended treatment duration with one of the first-line agents. In cases in which such treatment is not successful, vaginal boric acid is likely the cheapest and easiest alternative option. New antifungal medications offer additional but limited treatment options. Probiotics are not recommended for prevention of vulvovaginal candidiasis; however, vaginal products containing Lactobacillus crispatus may have promise for recurrent bacterial vaginosis. Trichomoniasis should be treated with a 1-week course of metronidazole; this is the only sexually transmitted infection for which treatment recommendations vary by sex. In cases in which patients do not respond to initial treatment, the diagnosis should be reconsidered, and other potential causes such as desquamative inflammatory vaginitis, genitourinary syndrome of menopause, or vulvodynia should be considered.

Novel antifungals and treatment approaches to tackle resistance and improve outcomes of invasive fungal disease

SUMMARYFungal infections are on the rise, driven by a growing population at risk and climate change. Currently available antifungals include only five classes, and their utility and efficacy in antifungal treatment are limited by one or more of innate or acquired resistance in some fungi, poor penetration into "sequestered" sites, and agent-specific side effect which require frequent patient reassessment and monitoring. Agents with novel mechanisms, favorable pharmacokinetic (PK) profiles including good oral bioavailability, and fungicidal mechanism(s) are urgently needed. Here, we provide a comprehensive review of novel antifungal agents, with both improved known mechanisms of actions and new antifungal classes, currently in clinical development for treating invasive yeast, mold (filamentous fungi), Pneumocystis jirovecii infections, and dimorphic fungi (endemic mycoses). We further focus on inhaled antifungals and the role of immunotherapy in tackling fungal infections, and the specific PK/pharmacodynamic profiles, tissue distributions as well as drug-drug interactions of novel antifungals. Finally, we review antifungal resistance mechanisms, the role of use of antifungal pesticides in agriculture as drivers of drug resistance, and detail detection methods for antifungal resistance.

Heterologous expression of the insect SVWC peptide WHIS1 inhibits Candida albicans invasion into A549 and HeLa epithelial cells

Candida albicans (C. albicans), a microbe commonly isolated from Candida vaginitis patients with vaginal tract infections, transforms from yeast to hyphae and produces many toxins, adhesins, and invasins, as well as C. albicans biofilms resistant to antifungal antibiotic treatment. Effective agents against this pathogen are urgently needed. Antimicrobial peptides (AMPs) have been used to cure inflammation and infectious diseases. In this study, we isolated whole housefly larvae insect SVWC peptide 1 (WHIS1), a novel insect single von Willebrand factor C-domain protein (SVWC) peptide from whole housefly larvae. The expression pattern of WHIS1 showed a response to the stimulation of C. albicans. In contrast to other SVWC members, which function as antiviral peptides, interferon (IFN) analogs or pathogen recognition receptors (PRRs), which are the prokaryotically expressed MdWHIS1 protein, inhibit the growth of C. albicans. Eukaryotic heterologous expression of WHIS1 inhibited C. albicans invasion into A549 and HeLa cells. The heterologous expression of WHIS1 clearly inhibited hyphal formation both extracellularly and intracellularly. Furthermore, the mechanism of WHIS1 has demonstrated that it downregulates all key hyphal formation factors (ALS1, ALS3, ALS5, ECE1, HWP1, HGC1, EFG1, and ZAP1) both extracellularly and intracellularly. These data showed that heterologously expressed WHIS1 inhibits C. albicans invasion into epithelial cells by affecting hyphal formation and adhesion factor-related gene expression. These findings provide new potential drug candidates for treating C. albicans infection.

Ibrexafungerp: A narrative overview

Ibrexafungerp (IBX) is a new antifungal drug that recently entered the antifungal landscape. It disrupts fungal cell wall synthesis by non-competitive inhibition of the β-(1,3)-D-glucan (BDG) synthase enzyme. It has demonstrated activity against a range of pathogens including Candida and Aspergillus spp., as well as retaining its activity against azole-resistant and echinocandin-resistant strains. It also exhibits anti-biofilm properties. Pharmacokinetic (PK) studies revealed favorable bioavailability, high protein binding, and extensive tissue distribution with a low potential for CYP-mediated drug interactions. It is characterized by the same mechanism of action of echinocandins with limited cross-resistance with other antifungal agents. Resistance to this drug can arise from mutations in the FKS genes, primarily FKS2 mutations in Nakaseomyces glabrata. In vivo, IBX was found to be effective in murine models of invasive candidiasis (IC) and invasive pulmonary aspergillosis (IPA). It also showed promising results in preventing and treating Pneumocystis jirovecii infections. Clinical trials showed that IBX was effective and non-inferior to fluconazole in treating vulvovaginal candidiasis (VVC), including complicated cases, as well as in preventing its recurrence. These trials positioned it as a Food and Drug Administration (FDA)-approved option for the treatment and prophylaxis of VVC. Trials showed comparable responses to standard-of-care in IC, with favorable preliminary results in C. auris infections in terms of efficacy and tolerability as well as in refractory cases of IC. Mild adverse reactions have been reported including gastrointestinal symptoms. Overall, IBX represents a significant addition to the antifungal armamentarium, with its unique action, spectrum of activity, and encouraging clinical trial results warranting further investigation.

A Mini-Review of In Vitro Data for Candida Species, Including C. auris, Isolated during Clinical Trials of Three New Antifungals: Fosmanogepix, Ibrexafungerp, and Rezafungin

This mini-review summarizes the clinical outcomes and antifungal susceptibility results, where available, for three new antifungals, including fosmanogepix, ibrexafungerp, and rezafungin, against Candida isolates cultured from patients in clinical trials. When reported, most of the data were generated by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method or by both the CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodologies. For fosmanogepix, we summarize the in vitro data for C. auris isolates from 9 patients and for Candida spp. cultured from 20 patients in two clinical trials. Ibrexafungerp has also been evaluated in several clinical trials. From conference proceedings, a total of 176 Candida isolates were evaluated in the FURI and CARES studies, including 18 C. auris isolates (CARES study). However, MIC data are not available for all clinical isolates. Results from the ReSTORE rezafungin phase 3 clinical study also included in vitro results against Candida spp., but no patients with C. auris infections were included. In conclusion, this mini-review summarizes insights regarding clinical outcomes and the in vitro activity of three new antifungals against Candida spp. cultured from patients in clinical trials.

Efficacy and safety of ibrexafungerp in the treatment of vulvovaginal candidiasis: A meta-analysis of randomized controlled trials

Background

This study aims to evaluate the efficacy and safety associated with ibrexafungerp in the treatment of vulvovaginal candidiasis infection patients.

Methods

We conducted a comprehensive search of the PubMed, Embase, Cochrane Library, and Clinical Trials databases up to December 25, 2022. The primary outcomes were clinical cure rate and mycological eradication rate, whereas the secondary outcomes were the risk of an adverse events.

Results

In total of four studies encompassing 880 patients diagnosed with vulvovaginal candidiasis (VVC) were included in the analysis. The findings demonstrated that ibrexafungerp exhibited superior clinical cure ratio (RR = 1.33 [1.07, 1.66]), mycological eradication rate (RR = 1.72 [1.00, 2.95]), and overall success ratio (RR = 1.64 [0.92, 2.92]) when compared to the fluconazole/placebo in the treatment of VVC. Furthermore, patients treated with ibrexafungerp demonstrated significantly higher clinical cure rates, mycological eradication, and overall success ratio compared to those receiving other treatments for vulvovaginal candidiasis caused by C. albicans. When ibrexafungerp was compared to fluconazole/placebo, the duration of any treatment-related treatment-emergent adverse events (TEAE), nausea, and diarrhea during therapy was significantly longer.

Conclusion

In summary, the use of ibrexafungerp was linked to superior clinical cure ratio, and mycological eradication when compared to fluconazole/placebo.

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.

Antifungal chemotherapies and immunotherapies for the future

Human fungal pathogens cause a broad plethora of infections, spanning cutaneous dermatophytoses to invasive infections in immunocompromised hosts. As eukaryotic pathogens are capable of morphotype switching, they present unique challenges both for drug development and the immunological response. Whilst current antifungal therapies are limited to the orally available triazoles, intravenous echonocandins and polyenes, and flucytosine and terbinafine, there has been recent significant progress in the antifungal armamentorium with ibrexafungerp, a novel orally available terpanoid that inhibits 1,3-beta-D-glucan-approved by Food and Drug Administration in 2021, and fosmanogepix, an orally available pro-drug of manogepix, which targets glycosylphosphatidylinositol-anchored protein maturation entering Phase 3 studies for candidaemia. A number of further candidates are in development. There has been significant use of existing immunotherapies such as recombinant interferon-γ and G-CSF for fungal disease in immunocompromised patients, and there are emerging opportunities for monoclonal antibodies targeting TH2 inflammation. Omalizumab, an anti-IgE monoclonal antibody in asthma, is now used routinely for the treatment of allergic bronchopulmonary aspergillosis, and further agents targeting IL-4 and IL-5 are being evaluated. In addition, T-cell CAR therapy is showing early promise for fungal disease. Thus, we are likely to see rapid advances to our approach to the management of fungal disease in the near future.

Ibrexafungerp in the Treatment of Vulvovaginal Candidiasis

OBJECTIVE

To review the pharmacology, efficacy, and safety of ibrexafungerp in the management of vulvovaginal candidiasis (VVC).

DATA SOURCES

Literature was sought using PubMed (1966-February 2022) and EMBASE (1973-February 2022), and clinicaltrials.gov. Search terms included ibrexafungerp, SCY-078, and VVC.

STUDY SELECTION AND DATA EXTRACTION

All studies including humans and published in English with data assessing the efficacy and safety of ibrexafungerp for the treatment of VVC were evaluated.

DATA SYNTHESIS

A phase 2 dose-finding study found ibrexafungerp had similar efficacy to fluconazole in the clinical cure of VVC (51.9% vs 58.3%, respectively). Two phase 3 clinical trials demonstrated ibrexafungerp had statistical superiority over placebo for clinical cure in moderate to severe VVC (P < 0.001 and P = 0.023, respectively). The most frequently reported adverse reactions in the clinical trials were gastrointestinal-related symptoms. To date, data comparing efficacy of ibrexafungerp and topical imidazoles in the treatment of VVC are nonexistent.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Topical imidazoles and oral fluconazole are effective for the treatment of uncomplicated VVC. Due to increased resistance, limited fluconazole coverage for non-Candida albicans species, and potential for significant drug interactions associated with fluconazole use, alternative treatments for VVC are needed. Ibrexafungerp is a new oral triterpenoid antifungal agent indicated for the treatment of VVC. Additional clinical trials are needed to evaluate long-term safety data as well as efficacy and safety in specialty populations.

CONCLUSION

Ibrexafungerp, a recently approved triterpenoid antifungal agent, is an effective and well-tolerated option for the treatment of VVC.

Outcomes and experiences of using oral voriconazole with or without concomitant topical agents to treat refractory vulvovaginal yeast infections

BACKGROUND

We describe 11 cases of refractory vulvovaginal yeast infections (RVVYI) treated using oral voriconazole with or without concomitant topical agents.

METHODS

Retrospective case-note review of all women prescribed oral voriconazole to treat RVVYI in five Sexual Health Clinics from Jan 2010-March 2020. Demographic details, clinical features, diagnostic results and treatment outcomes were collected.

RESULTS

11 women with vulvovaginal symptoms for a median of 1 year were treated with voriconazole. RVVYI was diagnosed clinically and confirmed on microscopy and culture with speciation. 10/11 isolates were fluconazole resistant, 1 intermediately sensitive, 10/11 were either fully or intermediately sensitive to voriconazole. All had received prior fluconazole and clotrimazole and 10/11 had used at least 2-weeks of one or more second-line antifungals with non-clearance of the yeast. Oral voriconazole 400 mg BD day-1, then 200 mg BD 13-days was prescribed and 10/11 women completed the course. Concomitant topical treatment was used by 6/11. Liver and renal function were monitored at 0, 7, 14 days. One woman stopped voriconazole after 5-days due to perioral tingling. Other transient side-effects were nausea (n = 2), photosensitivity, muscle aches, hair thinning (all n = 1), peripheral visual disturbance (n = 2). 8/11 experienced both symptom reduction and yeast clearance. Two women had an initial partial response but experienced resolution of symptoms following a second course of voriconazole.

CONCLUSIONS

Our observational data adds to the limited evidence to support voriconazole treatment for RVVYI. A 2-week course of voriconazole was tolerated and completed by 10/11 women. Eight women, five using concomitant topical agents, achieved mycological cure.

Ibrexafungerp: A new triterpenoid antifungal

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

The pharmacology, microbiology, pharmacokinetics, pharmacodynamics, efficacy, safety, and role of ibrexafungerp in the treatment of fungal infections are reviewed.

SUMMARY

Ibrexafungerp is the first triterpenoid antifungal. Similarly to echinocandins, it inhibits the synthesis of 1,3-β-d-glucan. However, it binds to a different site on the enzyme than echinocandins, resulting in limited cross-resistance. Ibrexafungerp exerts concentration-dependent fungicidal activity against Candida species and retains in vitro activity against most fluconazole-resistant strains. It is also active against Aspergillus species. Ibrexafungerp has been shown to be safe and effective in the treatment of vulvovaginal candidiasis caused by Candida albicans in phase 2 and phase 3 clinical trials. It is approved for vulvovaginal candidiasis in adult and postmenarchal pediatric females and is given as two 150-mg tablets orally, administered 12 hours apart. Ibrexafungerp is contraindicated in pregnancy. The most commonly reported adverse reactions were diarrhea, nausea, abdominal pain, dizziness, and vomiting. Ibrexafungerp should be avoided with strong or moderate CYP3A inducers, and the dose should be reduced with strong CYP3A inhibitors. Ibrexafungerp may be useful for patients who are not able to receive fluconazole or prefer oral therapy for the treatment of vulvovaginal candidiasis. However, it is more expensive than the 150-mg tablet of generic fluconazole, which is the current standard of care for vulvovaginal candidiasis. Clinical trials are ongoing for recurrent and complicated vulvovaginal candidiasis as well as invasive candidiasis and pulmonary aspergillosis.

CONCLUSION

Ibrexafungerp is an alternative to fluconazole for the treatment of vulvovaginal candidiasis in nonpregnant females. It has the potential to be useful for recurrent and complicated vulvovaginal candidiasis as well as certain invasive fungal infections.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.