Efficacy of Cochleated Amphotericin B in Mouse and Human Mucocutaneous Candidiasis

Invasive fungal disease and antifungal prophylaxis in children with acute leukaemia: a multicentre retrospective Australian cohort study

Background

Invasive fungal disease (IFD) is a significant complication for children receiving treatment for leukaemia, contributing to morbidity and mortality. Recent regional paediatric epidemiological IFD data are lacking. Additionally uncertainty remains regarding the optimal prophylactic approach in this context.

Methods

In a multi-centre Australian cohort study of children diagnosed with de novo acute leukaemia between 1st January 2017 and 30th June 2020, we characterised antifungal prophylaxis prescribing and IFD prevalence. Impact of antifungal prophylaxis was assessed using Kaplan Meier curves and Cox-proportional hazards regression adjusting for known IFD risk factors.

Findings

A total of 434 children were included (47.2% female; median age 5.0 years, median follow-up 240 days). This cohort included 351 children with ALL (214 high-risk [HR-ALL]; 137 standard-risk [SR-ALL]), and 73 with AML. The prevalence of proven/probable IFD was 6.8% for AML, 14.0% for HR-ALL and 4.4% for SR-ALL. A mould was implicated as the causative pathogen in almost two thirds of cases. Antifungal prophylaxis was prescribed in 98.7% of chemotherapy cycles for AML, 56.7% for HR-ALL and 14.9% for SR-ALL. A mould-active agent was used in 77.4% of AML cycles and 21.2% of HR-ALL cycles. Mould-active prophylaxis was associated with a lower risk of IFD overall and increased IFD-free survival in AML.

Interpretation

These data demonstrate the persistent high regional burden of IFD in children with HR-ALL, and the potential for mould-active prophylaxis to ameliorate this. Strategies to increase uptake of appropriate prophylaxis are required in this cohort.

Funding

This study was supported by a Perth Children's Hospital Foundation grant (PCHF9973).

Pulsatilla suppository prevents recurrent vulvovaginal candidiasis in a rat model via the TLR/MyD88/NLRP3 signaling pathway

Fungal infection caused by Candida albicans is a serious health problem, and as drug resistance worsens, new sources for therapeutic compounds are needed. Traditional Chinese medicine represents a wealth of such sources, and can be designed as suppositories for the treatment of recurrent vulvovaginal candidiasis (RVVC). This study aimed to develop a Pulsatilla suppository containing the n-butanol extract of Pulsatilla decoction (BEPD) to treat RVVC. A Pulsatilla suppository containing BEPD was prepared, and its performance, weight, drug content, dissolution time and percentage, stability, toxicology, and pharmacodynamics were evaluated. Biological compatibility tests and clinical evaluations were performed in female Sprague-Dawley rats. The Pulsatilla suppository melted completely within 30 min. In vitro anti-C. albicans activity, stability changes, and toxicology tests indicated stability and safety in the rats. Compared with RVVC model rats, high-dose BEPD suppository (40, 60 mg/kg) can significantly reduce the vaginal fungal load of rats, relieve neutrophil infiltration, reduce the content of TLR/MyD88 pathway-related proteins, and reduce the expression of inflammatory factors such as NLRP3, demonstrating the efficacy of the Pulsatilla suppository in RVVC.

Successful Treatment of Refractory Cutaneous Protothecosis With MAT2203, an Oral Lipid Nanocrystal Formulation of Amphotericin B

Prototheca wickerhamii is a rare cause of cutaneous and systemic infection that requires long treatment courses with potentially toxic medications. We describe a patient with cutaneous protothecosis refractory to triazole monotherapy who experienced clinical and radiographic improvement with the novel oral lipid nanocrystal formulation of amphotericin B without experiencing toxicity.

Oral Lipid Nanocrystal Amphotericin B (MAT2203) for the Treatment of Invasive Fungal Infections

Amphotericin B (AmB) has broad fungicidal activity against many fungi, but the high incidence of adverse events, particularly nephrotoxicity, and the need for intravenous administration restrict its use for many patients. MAT2203, an investigational oral AmB formulation available under a compassionate use program, uses a lipid nanocrystal bilayer structure to deliver AmB with lower toxicity. We present a synopsis of clinical characteristics, treatment course, and outcomes for 5 patients who were treated with MAT2203. Outcomes were positive, with cure of infection noted in 4 patients and improvement in 1 patient who remains on therapy. MAT2203 was well tolerated with only modest gastrointestinal adverse effects. This new oral formulation might provide a safer treatment option for patients requiring extended courses of AmB.

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.

Advancements and challenges in antifungal therapeutic development

Over recent decades, the global burden of fungal disease has expanded dramatically. It is estimated that fungal disease kills approximately 1.5 million individuals annually; however, the true worldwide burden of fungal infection is thought to be higher due to existing gaps in diagnostics and clinical understanding of mycotic disease. The development of resistance to antifungals across diverse pathogenic fungal genera is an increasingly common and devastating phenomenon due to the dearth of available antifungal classes. These factors necessitate a coordinated response by researchers, clinicians, public health agencies, and the pharmaceutical industry to develop new antifungal strategies, as the burden of fungal disease continues to grow. This review provides a comprehensive overview of the new antifungal therapeutics currently in clinical trials, highlighting their spectra of activity and progress toward clinical implementation. We also profile up-and-coming intracellular proteins and pathways primed for the development of novel antifungals targeting their activity. Ultimately, we aim to emphasize the importance of increased investment into antifungal therapeutics in the current continually evolving landscape of infectious disease.

Pipeline of Novel Antifungals for Invasive Fungal Disease in Transplant Recipients: A Pediatric Perspective

Invasive fungal disease (IFD) remains a significant cause of morbidity and mortality in children undergoing transplantation. There is a growing armamentarium of novel antifungal agents recently approved for use or in late stages of clinical development. The overarching goal of this review is to discuss the mechanisms of action, spectrum of activity, stage of development, and pediatric-specific data for the following agents: encochleated amphotericin B deoxycholate, fosmanogepix, ibrexafungerp, isavuconazole, olorofim, opelconazole, oteseconazole, and rezafungin. Additionally, key drug attributes of these novel agents and their potential future therapeutic roles in pediatric transplant recipients are discussed.

Candida albicans Infection Disrupts the Metabolism of Vaginal Epithelial Cells and Inhibits Cellular Glycolysis

Vulvovaginal candidiasis (VVC) is a common gynecologic disorder caused by fungal infections of the vaginal mucosa, with the most common pathogen being Candida albicans (C. albicans). Exploring metabolite changes in the disease process facilitates further discovery of targets for disease treatment. However, studies on the metabolic changes caused by C. albicans are still lacking. In this study, we used C. albicans-infected vaginal epithelial cells to construct an in vitro model of VVC, analyzed the metabolites by UHPLC-Q-Exactive MS, and screened the potential metabolites based on metabolomics. The results showed that C. albicans infection resulted in significant up-regulation of D-arabitol, palmitic acid, adenosine, etc.; significant down-regulation of lactic acid, nicotinamide (NAM), nicotinate (NA), etc.; and disruption of amino acid metabolism, and that these significantly altered metabolites might be potential therapeutic targets of VVC. Further experiments showed that C. albicans infection led to a decrease in glycolytic enzymes in damaged cells, inhibiting glycolysis and leading to significant alterations in glycolytic metabolites. The present study explored the potential metabolites of VVC induced by C. albicans infection based on metabolomics and verified the inhibitory effect of C. albicans on vaginal epithelial cell glycolysis, which is valuable for the diagnosis and treatment of VVC.

Progress in molecular diagnosis and treatment of chronic mucocutaneous candidiasis

Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent or persistent infections with Candida of the skin, nails, and mucous membrane. It is a rare and severe disease resulting from autoimmune defects or immune dysregulations. Nonetheless, the diagnosis and treatment of CMC still pose significant challenges. Erroneous or delayed diagnoses remain prevalent, while the long-term utility of traditional antifungals often elicits adverse reactions and promotes the development of acquired resistance. Furthermore, disease relapse can occur during treatment with traditional antifungals. In this review, we delineate the advancements in molecular diagnostic and therapeutic approaches to CMC. Genetic and biomolecular analyses are increasingly employed as adjuncts to clinical manifestations and fungal examinations for accurate diagnosis. Simultaneously, a range of therapeutic interventions, including Janus kinase (JAK) inhibitors, hematopoietic stem cell transplantation (HSCT), cytokines therapy, novel antifungal agents, and histone deacetylase (HDAC) inhibitors, have been integrated into clinical practice. We aim to explore insights into early confirmation of CMC as well as novel therapeutic options for these patients.

Natural Polyketides Act as Promising Antifungal Agents

Invasive fungal infections present a significant risk to human health. The current arsenal of antifungal drugs is hindered by drug resistance, limited antifungal range, inadequate safety profiles, and low oral bioavailability. Consequently, there is an urgent imperative to develop novel antifungal medications for clinical application. This comprehensive review provides a summary of the antifungal properties and mechanisms exhibited by natural polyketides, encompassing macrolide polyethers, polyether polyketides, xanthone polyketides, linear polyketides, hybrid polyketide non-ribosomal peptides, and pyridine derivatives. Investigating natural polyketide compounds and their derivatives has demonstrated their remarkable efficacy and promising clinical application as antifungal agents.

Chronic Mucocutaneous Candidiasis: A Case Report

Chronic mucocutaneous candidiasis (CMC) is a rare infectious skin disease. This study reported a case of CMC in a child with clinical manifestations of oral mucosal leukoplakia and erythema and crust-like thick scabs on the skin of the face and upper limbs. Microscopic fungal examination revealed a large amount of pseudohyphae, and the fungal culture indicated Candida albicans. A drug sensitivity test indicated that it was sensitive to itraconazole and nystatin. Laboratory tests did not show significant immunodeficiency or endocrine abnormalities, and gene sequencing did not identify DNA gene mutations in the coiled-coil domain (CCD) or the DNA-binding domain (DBD) of signal transducer and activator of transcription 1 (STAT1). The skin lesions subsided after oral administration of itraconazole but relapsed 6 months later, and hypoparathyroidism occurred 1 year later. Patients with repeated superficial fungal infection should be alert to the possibility of CMC. CMC has numerous complications and a poor prognosis that requires the attention of clinicians. In this case, STAT1 mutation was not found, and parathyroid dysfunction was rare, providing reference for clinical diagnosis and treatment of CMC.

Inborn Errors of Immunity Causing Pediatric Susceptibility to Fungal Diseases

Inborn errors of immunity are a heterogeneous group of genetically determined disorders that compromise the immune system, predisposing patients to infections, autoinflammatory/autoimmunity syndromes, atopy/allergies, lymphoproliferative disorders, and/or malignancies. An emerging manifestation is susceptibility to fungal disease, caused by yeasts or moulds, in a superficial or invasive fashion. In this review, we describe recent advances in the field of inborn errors of immunity associated with increased susceptibility to fungal disease.

Review of Novel Oral Amphotericin B Formulations for the Treatment of Parasitic Infections

Amphotericin B (AmpB) is a polyene macrolide antibiotic used in the treatment of blood-borne parasitic and fungal infections. However, its use, particularly in the developing world, has been limited by dose-dependent kidney toxicity, other systemic-related toxicity issues following injection, the inconvenience of parenteral administration, and accessibility. Oral formulation approaches have focused on the dual problem of solubility and permeability of AmpB, which is poorly water soluble, amphoteric and has extremely low oral bioavailability. Therefore, to enhance oral absorption, researchers have employed micellar formulations, polymeric nanoparticles, cochleates, pro-drugs, and self-emulsifying drug delivery systems (SEDDS). This paper will highlight current uses of AmpB against parasitic infections such as leishmaniasis, preclinical and clinical formulation strategies, applications in veterinary medicine and the importance of developing a cost-effective and safe oral AmpB formulation.