Intravenous itraconazole followed by oral itraconazole in the treatment of invasive pulmonary aspergillosis in patients with hematologic malignancies, chronic granulomatous disease, or AIDS

Fungal infections in hematopoietic stem-cell transplant patients: a review of epidemiology, diagnosis, and management

The advent of bone marrow transplant has opened doors to a different approach and offered a new treatment modality for various hematopoietic stem-cell-related disorders. Since the first bone marrow transplant in 1957, there has been significant progress in managing patients who undergo bone marrow transplants. Plasma-cell disorders, lymphoproliferative disorders, and myelodysplastic syndrome are the most common indications for hematopoietic stem-cell transplant. Despite the advances, invasive fungal infections remain a significant cause of morbidity and mortality in this high-risk population. The overall incidence of invasive fungal infection in patients with hematopoietic stem-cell transplant is around 4%, but the mortality in patients with allogeneic stem-cell transplant is as high as 13% in one study. Type of stem-cell transplant, conditioning regimen, and development of graft-versus-host disease are some of the risk factors that impact the risk and outcomes in patients with invasive fungal infections. Aspergillus and candida remain the two most common organisms causing invasive fungal infections. Molecular diagnostic methods have replaced some traditional methods due to their simplicity of use and rapid turnaround time. Primary prophylaxis has undoubtedly shown to improve outcomes even though breakthrough infection rates remain high. The directed treatment has seen a significant shift from amphotericin B to itraconazole, voriconazole, and echinocandins, which have shown better efficacy and fewer adverse effects. In this comprehensive review, we aim to detail epidemiology, risk factors, diagnosis, and management, including prophylaxis, empiric and directed management of invasive fungal infections in patients with hematopoietic stem-cell transplant.

Invasive Fungal Disease Among Pediatric and Adolescent Patients Undergoing Itraconazole Prophylaxis After Hematopoietic Stem Cell Transplantation

BACKGROUND

Invasive fungal disease (IFD) is a major cause of morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT). Itraconazole has been used for prevention of IFD, but data related to incidence and associated factors of IFD in pediatric and adolescent patients on itraconazole prophylaxis remain scarce.

OBJECTIVES

To identify incidence and risk factors associated with IFD among pediatric and adolescent patients receiving itraconazole prophylaxis after HSCT.

METHODS

Patients younger than 21 years who received itraconazole prophylaxis after HSCT from January 2007 to December 2016 were retrospectively enrolled. Incidence of IFD within 1 year and associated factors were analyzed.

RESULTS

All patients received itraconazole during the pre-engraftment period. Of 170 patients, 29 had IFD, with an incidence of 17.1% at 1 year. IFD at 1 year was significantly associated with increased mortality. Of 29 patients with IFD, only 9 developed IFD while on itraconazole prophylaxis (5.3%), all of whom had invasive pulmonary aspergillosis. No invasive candidiasis occurred during itraconazole prophylaxis. Prolonged neutropenia (hazard ratio [HR] = 1.08; 95% confidence interval [CI], 1.02-1.13), graft-versus-host disease within 100 days after transplantation (HR = 3.17; 95% CI, 1.17-8.57), and using etoposide in preconditioning regimens (HR = 21.60; 95% CI, 2.44-190.95) were significantly associated with IFD at 1 year. No patients had to discontinue itraconazole because of its adverse effects.

CONCLUSIONS

Itraconazole proffered good efficacy for prevention of candidiasis during the pre-engraftment period. Most IFD episodes occurred after the engraftment period when itraconazole had been discontinued. During this period, patients with risk factors require appropriate fungal prophylaxis.

A novel highly bio-available itraconazole formulation (SUBA®-Itraconazole) for anti-fungal prophylaxis in lung transplant recipients

BACKGROUND

Antifungal prophylaxis remains a mainstay of lung transplantation, given invasive fungal infection is a common and serious complication after lung transplantation. Choice of systemic agent to prevent invasive fungal infection varies between centers and funding of agents remains challenging. Our center has recently changed from posaconazole to a highly bioavailable formulation of itraconazole (SUBA®-itraconazole) at substantially reduced cost, but safety and toxicity require further assessment. A retrospective study of lung transplant patients receiving systemic antifungal prophylaxis from December 2016 through December 2019 following change from posaconazole to itraconazole as standard practice. 150 patients with lung transplants were managed in this time period, with 88 (59%) receiving at least 1 mold-active triazole during the study period. 48 (58%) of these patients received SUBA®-itraconazole; 68 (82%) received posaconazole and 10 (12%) received voriconazole. The average cost per patient during the study period was significantly lower on SUBA®-itraconazole (mean $1548/patient/6 month course) than posaconazole (mean $16 921.35/patient/6 month course). Target trough concentrations for prophylaxis of itraconazole > 0.5 mg/L and posaconazole > 0.7 mg/L were achieved on empiric dosing in 49% and 68% respectively. Overall trough itraconazole (0.50 vs 1.12 mg/L, P < .001) and posaconazole (1.37 vs 2.10 mg/L P < .001) concentrations were significantly lower in patients with cystic fibrosis. Calcineurin inhibitor dose changes on introduction or cessation were similar for SUBA®-itraconazole and posaconazole. Breakthrough invasive fungal infection and toxicity were rare. SUBA®-itraconazole is well-tolerated, associated with rare breakthrough invasive fungal infection, and lower cost. Prospective studies following general introduction are required to determine long-term safety, tolerability, and efficacy.

Cooperative Effects of an Antifungal Moiety and DMSO on Pore Formation over Lipid Membranes Revealed by Free Energy Calculations

Itraconazole is a triazole drug widely used in the treatment of fungal infections, and it is in clinical trials for treatment of several cancers. However, the drug suffers from poor solubility, while experiments have shown that itraconazole delivery in liposome nanocarriers improves both circulation half-life and tissue distribution. The drug release mechanism from the nanocarrier is still unknown, and it depends on several factors including membrane stability against defect formation. In this work, we used molecular dynamics simulations and potential of mean force (PMF) calculations to quantify the influence of itraconazole on pore formation over lipid membranes, and we compared the effect by itraconazole with a pore-stabilizing effect by the organic solvent dimethyl sulfoxide (DMSO). According to the PMFs, both itraconazole and DMSO greatly reduce the free energy of pore formation, by up to ∼20 kJ mol^-1. However, whereas large concentrations of itraconazole of 8 mol % (relative to lipid) were required, only small concentrations of a few mole % DMSO (relative to water) were sufficient to stabilize pores. In addition, itraconazole and DMSO facilitate pore formation by different mechanisms. Whereas itraconazole predominantly aids the formation of a partial defect with a locally thinned membrane, DMSO mainly stabilizes a transmembrane water needle by shielding it from the hydrophobic core. Notably, the two distinct mechanisms act cooperatively upon adding both itraconazole and DMSO to the membrane, as revealed by an additional reduction of the pore free energy. Overall, our simulations reveal molecular mechanisms and free energies of membrane pore formation by small molecules. We suggest that the stabilization of a locally thinned membrane as well as the shielding of a transmembrane water needle from the hydrophobic membrane core may be a general mechanism by which amphiphilic molecules facilitate pore formation over lipid membranes at sufficient concentrations.

Modeling Invasive Aspergillosis: How Close Are Predicted Antifungal Targets?

Animal model systems are a critical component of the process of discovery and development of new antifungal agents for treatment and prevention of invasive aspergillosis. The persistently neutropenic rabbit model of invasive pulmonary aspergillosis (IPA) has been a highly predictive system in identifying new antifungal agents for treatment and prevention of this frequently lethal infection. Since its initial development, the persistently neutropenic rabbit model of IPA has established a strong preclinical foundation for dosages, drug disposition, pharmacokinetics, safety, tolerability, and efficacy for deoxycholate amphotericin B, liposomal amphotericin B, amphotericin B lipid complex, amphotericin B colloidal dispersion, caspofungin, micafungin, anidulafungin, voriconazole, posaconazole, isavuconazole, and ibrexafungerp in treatment of patients with invasive aspergillosis. The findings of combination therapy with a mould-active triazole and an echinocandin in this rabbit model also predicted the outcome of the clinical trial for voriconazole plus anidulafungin for treatment of IPA. The plasma pharmacokinetic parameters and tissue disposition for most antifungal agents approximate those of humans in persistently neutropenic rabbits. Safety, particularly nephrotoxicity, has also been highly predictive in the rabbit model, as exemplified by the differential glomerular filtration rates observed in animals treated with deoxycholate amphotericin B, liposomal amphotericin B, amphotericin B lipid complex, and amphotericin B colloidal dispersion. A panel of validated outcome variables measures therapeutic outcome in the rabbit model: residual fungal burden, markers of organism-mediated pulmonary injury (lung weights and infarct scores), survival, and serum biomarkers. In selected antifungal studies, thoracic computerized tomography (CT) is also used with diagnostic imaging algorithms to measure therapeutic response of pulmonary infiltrates, which exhibit characteristic radiographic patterns, including nodules and halo signs. Further strengthening the predictive properties of the model, therapeutic response to successfully developed antifungal agents for treatment of IPA has been demonstrated over the past two decades by biomarkers of serum galactomannan and (1→3)-β-D-glucan with patterns of resolution, that closely mirror those documented responses in patients with IPA. The decision to move from laboratory to clinical trials should be predicated upon a portfolio of complementary and mutually validating preclinical laboratory animal models studies. Other model systems, including those in mice, rats, and guinea pigs, are also valuable tools in developing clinical protocols. Meticulous preclinical investigation of a candidate antifungal compound in a robust series of complementary laboratory animal models will optimize study design, de-risk clinical trials, and ensure tangible benefit to our most vulnerable immunocompromised patients with invasive aspergillosis.

Treatment of invasive fungal diseases in cancer patients-Revised 2019 Recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Invasive fungal diseases remain a major cause of morbidity and mortality in cancer patients undergoing intensive cytotoxic therapy. The choice of the most appropriate antifungal treatment (AFT) depends on the fungal species suspected or identified, the patient's risk factors (eg length and depth of granulocytopenia) and the expected side effects.

OBJECTIVES

Since the last edition of recommendations for 'Treatment of invasive fungal infections in cancer patients' of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) in 2013, treatment strategies were gradually moving away from solely empirical therapy of presumed or possible invasive fungal diseases (IFDs) towards pre-emptive therapy of probable IFD.

METHODS

The guideline was prepared by German clinical experts for infections in cancer patients in a stepwise consensus process. MEDLINE was systematically searched for English-language publications from January 1975 up to September 2019 using the key terms such as 'invasive fungal infection' and/or 'invasive fungal disease' and at least one of the following: antifungal agents, cancer, haematological malignancy, antifungal therapy, neutropenia, granulocytopenia, mycoses, aspergillosis, candidosis and mucormycosis.

RESULTS

AFT of IFDs in cancer patients may include not only antifungal agents but also non-pharmacologic treatment. In addition, the armamentarium of antifungals for treatment of IFDs has been broadened (eg licensing of isavuconazole). Additional antifungals are currently under investigation or in clinical trials.

CONCLUSIONS

Here, updated recommendations for the treatment of proven or probable IFDs are given. All recommendations including the levels of evidence are summarised in tables to give the reader rapid access to key information.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children

SCOPE

Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children.

METHODS

Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations.

QUESTIONS

Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.

Effects of Food and Omeprazole on a Novel Formulation of Super Bioavailability Itraconazole in Healthy Subjects

To address the limited bioavailability and intolerance of the conventional itraconazole (ITZ) formulations, a new formulation labeled super bioavailability (SUBA) itraconazole has been developed; however, the specific effects of food and gastric pH are unknown. This study evaluated the pharmacokinetic profile of SUBA itraconazole under fasting and fed conditions, as well as with the concomitant administration of a proton pump inhibitor. First, the effect of food was assessed in an open-label, randomized, crossover bioavailability study of 65-mg SUBA itraconazole capsules (2 65-mg capsules twice a day) in healthy adults (n = 20) under fasting and fed conditions to steady-state levels. Second, an open-label, two-treatment, fixed-sequence comparative bioavailability study in healthy adults (n = 28) under fasted conditions compared the pharmacokinetics of a single oral dose of SUBA itraconazole capsules (2 65-mg capsules/day) with and without coadministration of daily omeprazole delayed-release capsules (1 40-mg capsule/day) under steady-state conditions. In the fed and fasted states, SUBA itraconazole demonstrated similar concentrations at the end of the dosing interval, with modestly lower total and peak ITZ exposure being shown when it was administered under fed conditions than when it was administered in the fasted state, with fed state/fasted state ratios of 78.09% (90% confidence interval [CI], 74.49 to 81.86%) for the area under the concentration-time curve over the dosing interval (14,183.2 versus 18,479.8 ng · h/ml), 73.05% (90% CI, 69.01 to 77.33%) for the maximum concentration at steady state (1,519.1 versus 2,085.2 ng/ml), and 91.53% (90% CI, 86.41 to 96.96%) for the trough concentration (1,071.5 versus 1,218.5 ng/ml) being found. When dosed concomitantly with omeprazole, there was a 22% increase in the total plasma exposure of ITZ, as measured by the area under the concentration-time curve from time zero to infinity (P = 0.0069), and a 31% increase in the peak plasma exposure of ITZ, as measured by the maximum concentration (P = 0.0083).

Trough concentration of itraconazole and its relationship with efficacy and safety: a systematic review and meta-analysis

Objectives

The optimum trough concentration of itraconazole for clinical response and safty is controversial. The objective of this systematic review and meta-analysis was to determine the optimum trough concentration of itraconazole and evaluate its relationship with efficacy and safety.

Methods

We searched PubMed, EMBASE, Web of Science, the Cochrane Library, Clinical-Trials.gov, and three Chinese literature databases (CNKI, WanFang, and CBM). We included observational studies that compared clinical outcomes below or above the trough concentration cut-off value which we set as 0.25, 0.5, and 1.0 mg/L. The efficacy outcomes were rate of successful treatment, rate of prophylaxis failure and invasive fungal infection (IFI)-related mortality. The safety outcomes included incidents of hepatotoxicity and other adverse events.

Results

The study included a total of 29 studies involving 2,346 patients. Our meta-analysis showed that compared with itraconazole trough concentrations (C_trough) of ≥0.25 mg/L, levels of <0.25 mg/L significantly increased the incidence of IFI for prophylaxis (RR =3.279, 95% confidence interval [CI] 1.73–6.206). Moreover, the success rate of treatment decreased significantly at a cut-off level of 0.5 mg/L (RR =0.396, 95% CI 0.176–0.889). An itraconazole trough level of 1.0 mg/L was associated with hepatotoxicity and other adverse events in a review of many studies.

Conclusion

An itraconazole trough concentration of 0.25 mg/L should be considered as the lower threshold for prophylaxis, and a target concentration of 0.5 mg/L should be the lower limit for effective treatment. A trough level of 1.0 mg/L is associated with increased hepatotoxicity and other adverse events (using High Performance Liquid Chromatography [HPLC]).

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Pharmacokinetics of antifungal drugs: practical implications for optimized treatment of patients

Introduction

Because of the high mortality of invasive fungal infections (IFIs), appropriate exposure to antifungals appears to be crucial for therapeutic efficacy and safety.

Materials and methods

This review summarises published pharmacokinetic data on systemically administered antifungals focusing on co-morbidities, target-site penetration, and combination antifungal therapy.

Conclusions and discussion

Amphotericin B is eliminated unchanged via urine and faeces. Flucytosine and fluconazole display low protein binding and are eliminated by the kidney. Itraconazole, voriconazole, posaconazole and isavuconazole are metabolised in the liver. Azoles are substrates and inhibitors of cytochrome P450 (CYP) isoenzymes and are therefore involved in numerous drug–drug interactions. Anidulafungin is spontaneously degraded in the plasma. Caspofungin and micafungin undergo enzymatic metabolism in the liver, which is independent of CYP. Although several drug–drug interactions occur during caspofungin and micafungin treatment, echinocandins display a lower potential for drug–drug interactions. Flucytosine and azoles penetrate into most of relevant tissues. Amphotericin B accumulates in the liver and in the spleen. Its concentrations in lung and kidney are intermediate and relatively low myocardium and brain. Tissue distribution of echinocandins is similar to that of amphotericin. Combination antifungal therapy is established for cryptococcosis but controversial in other IFIs such as invasive aspergillosis and mucormycosis.

Invasive Aspergillosis in Hematological Patients

Invasive aspergillosis (IA) is still one of the leading causes of morbidity and mortality in hematological patients, although its outcome has been improving. Prolonged and profound neutropenia in patients receiving intensive chemotherapy for acute leukemia and stem cell transplantation is a major risk factor for IA. Allogeneic stem cell transplant recipients with graft-versus-host disease and corticosteroid use are also at high risk. Management in a protective environment with high efficiency particular air (HEPA) filter is generally recommended to prevent aspergillosis in patients with prolonged and profound neutropenia. Antifungal prophylaxis against Aspergillus species should be considered in patients with past history of aspergillosis or colonization of Aspergillus species, at facilities with high incidence of IA and those without a protective environment. Early diagnosis and prompt antifungal treatment is important to improve outcome. Imaging studies such as computed tomography and biomarkers such as galactomannan antigen and β-D-glucan are useful for early diagnosis. Empirical antifungal treatment based on persistent or recurrent fever during neutropenia despite broad-spectrum antibiotic therapy is generally recommended in high-risk patients. Alternatively, a preemptive treatment strategy has recently been proposed in the context of progress in the early diagnosis of IA based on the results of imaging studies and biomarkers. Voriconazole is recommended for initial therapy for IA. Liposomal amphotericin B is considered as alternative initial therapy. Combination antifungal therapy of echinocandin with voriconazole or liposomal amphotericin B could be a choice for refractory cases.

ECIL-6 guidelines for the treatment of invasive candidiasis, aspergillosis and mucormycosis in leukemia and hematopoietic stem cell transplant patients

The European Conference on Infections in Leukemia (ECIL) provides recommendations for diagnostic strategies and prophylactic, pre-emptive or targeted therapy strategies for various types of infection in patients with hematologic malignancies or hematopoietic stem cell transplantation recipients. Meetings are held every two years since 2005 and evidence-based recommendations are elaborated after evaluation of the literature and discussion among specialists of nearly all European countries. In this manuscript, the ECIL group presents the 2015-update of the recommendations for the targeted treatment of invasive candidiasis, aspergillosis and mucormycosis. Current data now allow a very strong recommendation in favor of echinocandins for first-line therapy of candidemia irrespective of the underlying predisposing factors. Anidulafungin has been given the same grading as the other echinocandins for hemato-oncological patients. The beneficial role of catheter removal in candidemia is strengthened. Aspergillus guidelines now recommend the use of either voriconazole or isavuconazole for first-line treatment of invasive aspergillosis, while first-line combination antifungal therapy is not routinely recommended. As only few new data were published since the last ECIL guidelines, no major changes were made to mucormycosis recommendations.

Successful empirical antifungal therapy of intravenous itraconazole with pharmacokinetic evidence in pediatric cancer patients undergoing hematopoietic stem cell transplantation

BACKGROUND AND OBJECTIVES

Empirical antifungal therapy prevents invasive fungal infections in patients with cancer. This study assessed the empirical efficacy of intravenous itraconazole in pediatric patients undergoing hematopoietic stem cell transplantation, and investigated the pharmacokinetics and clinical implications.

METHODS

Oral itraconazole syrup was started (2.5 mg/kg twice daily) for prophylaxis, and patients with persistent neutropenic fever for more than 2 days were switched to intravenous itraconazole (5 mg/kg twice daily for 2 days for induction and 5 mg/kg daily for maintenance) as empirical treatment. Empirical antifungal efficacy was assessed retrospectively in 159 transplantations, and a full pharmacokinetic study was prospectively conducted in six of these patients. Successful antifungal efficacy was defined as the fulfillment of all components of a five-part composite end point.

RESULTS

The overall empirical antifungal success rate fulfilling all criteria was 42.1 %. No death or drug-related serious adverse events occurred during the study. Mean trough plasma concentration of itraconazole after oral prophylaxis and intravenous induction were 577.2 and 1659.7 μg/L, respectively. Mean area under the concentration-time curve of itraconazole and its metabolite at steady state were 42,837 ± 24,746 μg·h/L and 63,094 ± 19,255 μg·h/L.

CONCLUSIONS

Intravenous itraconazole was effective and safe as an empirical antifungal agent in pediatric patients; this was due to the fast and satisfactory increase in drug concentration by switching from oral to intravenous therapy.

Optimizing azole antifungal therapy in the prophylaxis and treatment of fungal infections

PURPOSE OF REVIEW

Azole antifungals are widely used in the prophylaxis and treatment of fungal infections, but are associated with a range of pharmacokinetic challenges and safety issues that necessitate individualized therapy to achieve optimal clinical outcomes. Recent advances in our knowledge of azole exposure-response relationships, therapeutic drug monitoring and individualized dosing strategies are reviewed as follows.

RECENT FINDINGS

Recent studies have significantly improved the understanding of exposure-response relationships for efficacy and toxicity, increasing confidence in target exposure ranges for azole antifungal agents. Population pharmacokinetic modelling of voriconazole has led to studies demonstrating the feasibility of model-guided dose individualization strategies with the drug, which holds significant promise for optimizing therapy. The recent approval of a solid oral tablet formulation of posaconazole with improved bioavailability and once-daily dosing has significantly improved the clinical utility of this agent. Further clinical experience with the investigational azole isavuconazole is needed to determine the role of individualized therapy.

SUMMARY

The coordination of CYP2C19 pharmacogenomic testing with model-guided dose individualization holds significant promise for optimizing therapy with voriconazole. Pharmacokinetic challenges with itraconazole, voriconazole and posaconazole oral suspension continue to require therapeutic drug monitoring to individualize therapy and optimize treatment outcomes.

Breakpoints for antifungal agents: an update from EUCAST focussing on echinocandins against Candida spp. and triazoles against Aspergillus spp

Candida and Aspergillus infections have emerged as significant pathogens in recent decades. During this same time, broad spectrum triazole and echinocandin antifungal agents have been developed and increasingly used. One consequence of widespread use is leading to the emergence of mutants with acquired resistance mutations. Therefore, accurate susceptibility testing and appropriate clinical breakpoints for the interpretation of susceptibility results have become increasingly important. Here we review the underlying methodology by which breakpoints have been selected by EUCAST (European Committee on Antimicrobial Susceptibility Testing). Five parameters are evaluated: dosing regimens used; EUCAST MIC distributions from multiple laboratories, species and compound specific epidemiological cut off values (upper MIC limits of wild type isolates or ECOFFs), pharmacokinetic/pharmacodynamic relationships and targets associated with outcome and finally clinical data by species and MIC when available. The general principles are reviewed followed by a detailed review of the individual aspects for Candida species and the three echinocandins and for Aspergillus and the three mould-active azoles. This review provides an update of the subcommittee on antifungal susceptibility testing (AFST) of the EUCAST methodology and summarises the current EUCAST breakpoints for Candida and Aspergillus. Recommendations about applicability of antifungal susceptibility testing in the routine setting are also included.

Itraconazole (Sporanox®) in superficial and systemic fungal infections

Itraconazole (Sporanox) is a triazole antifungal agent with a broad activity spectrum and favorable pharmacokinetic and safety profiles. Numerous clinical trials have established the efficacy and safety of itraconazole in the treatment of superficial fungal infections. In this field, full exploitation of its pharmacokinetics in keratinized tissues has led to the development of intermittent (pulse) treatment regimens that allow similar efficacy with lower overall drug exposure as well as a reduction in treatment costs. The additional anti-inflammatory action of itraconazole also makes it suitable for application in difficult-to-treat inflammatory skin disorders, such as seborrheic dermatitis. Recently, a new oral liquid formulation and an intravenous formulation have been developed, extending the therapeutic application of itraconazole to systemic fungal infections. Due to its broad activity spectrum and excellent tolerability, itraconazole is a valuable addition to the antifungal armamentarium used for prophylactic and empiric treatment in immunocompromised hosts.

Itraconazole: an update on pharmacology and clinical use for treatment of invasive and allergic fungal infections

INTRODUCTION

Fungal infections are a major source of global morbidity and mortality. Itraconazole is a triazole antifungal agent that is widely used for the prevention and treatment of fungal infection. While newer antifungal agents are now available, itraconazole is an orally bioavailable agent with broad-spectrum antifungal activity. Itraconazole remains a useful drug for the management of allergic and invasive mycoses worldwide.

AREAS COVERED

This article provides a summary of the pharmacokinetics, pharmacodynamics and clinical uses of itraconazole. Additionally, the authors summarise the safety and recently described toxicodynamics and discuss the value of therapeutic drug monitoring (TDM) with itraconazole. The following search criteria were constructed in order to identify relevant literature using PubMed and Ovid-MEDLINE: itraconazole, triazole, pharmacokinetics, pharmacodynamics, toxicodynamics and TDM. Relevant abstracts and articles identified from reviewing secondary citations were additionally retrieved and included if relevant.

EXPERT OPINION

Itraconazole remains an important agent in the prevention and treatment of fungal infection. Itraconazole has a broad-spectrum of activity and is available in both an intravenous and oral form making long-term use in chronic mycoses practical. Itraconazole is widely used for the treatment of endemic fungal infections. Pharmacokinetic variability and clinically important drug interactions make TDM of itraconazole an important consideration.

Clinical analysis of 68 patients with pulmonary mycosis in China

Background

Due to the lack of specific clinical manifestations and imaging features, the diagnosis of pulmonary mycosis is difficult. This study aimed to investigate the pathogens, clinical manifestations, imaging features, diagnosis and management of pulmonary mycosis.

Methods

Data on 68 patients diagnosed as pulmonary mycosis in Xiang Ya hospital from January 2001 to December 2010 were collected and their clinical manifestations, radiographic characterization, diagnostic methods and management were analyzed.

Results

All patients were diagnosed by pathological examination. Of the 68 cases, 38 (55.9%) had pulmonary aspergillosis and 19 (27.9%) pulmonary cryptococcosis. Open-lung surgery was performed in 38 patients (55.9%), transbronchial biopsy in 15 (22.0%), and computerized tomography (CT) guided percutaneous needle biopsy in 11 (16.2%). Main symptoms were as follows: cough in 51 cases (75.0%), expectoration in 38 (55.9%), hemoptysis in 25 (37.8%), fever in 20 (29.4%), while 6 cases (11.1%) were asymptomatic. X-ray and chest CT showed masses or nodular lesions in 52 cases (76.5%), patchy lesions in 10 (14.7%), cavity formation in 15 (22.0%), and diffuse miliary nodules in 1 case. In 51 cases (75.0%) misdiagnosis before pathological examination occurred. Surgical resection was performed in 38 patients (55.9%). In 25 patients (36.7%) systemic antifungal therapy was administered, and 20 patients (29.4%) experienced complete responses or partial responses.

Conclusion

The main pathogens of pulmonary mycosis are Aspergillus, followed by cryptococcosis. Final diagnosis of pulmonary mycosis mainly depends on pathological examination. The clinical manifestations, imaging features, diagnostic methods and management differ depending on the pathogens. Satisfactory therapy can be obtained by both antifungal and surgical treatment.

Prophylaxis and treatment of invasive aspergillosis with voriconazole, posaconazole and caspofungin: review of the literature

Major progress for the management of invasive aspergillosis has come from the introduction of new antifungals since the late 1990s. Although mortality of invasive aspergillosis remains as high as 30-50%. Backbone of management are prophylaxis, early diagnosis and early initiation of antifungals for reduction of invasive aspergillosis related mortality. Randomized trials have been undertaken for the prophylaxis as well as treatment of invasive aspergillosis in the last two decades. Posaconazole is recommended for prophylaxis against aspergillosis in patients treated for acute myelogenous leukemia, myelodysplastic syndrome or patients with graft versus host disease after allogeneic transplantation. Efficacy has been shown for first-line therapy of invasive aspergillosis with voriconazole and liposomal amphotericin B. Gastrointestinal resorption for the azoles posaconazole, voriconazole and itraconazole differ considerably. While oral voriconazole resportion is reduced when taken with food, posaconazole has to be taken with fatty food for optimal intestinal resorption. Beside all advances in the management of invasive aspergillosis important questions remain unresolved. This article reviews the current state of prophylaxis and treatment of invasive aspergillosis and points out clinicians unmet needs.

Antifungal treatment strategies in patients with haematological diseases or cancer: from prophylaxis to empirical, pre-emptive and targeted therapy

Immunocompromised patients have a high risk for invasive fungal diseases (IFDs). These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Empirical treatment is regarded as the standard of care for granulocytopenic patients who remain febrile despite broad-spectrum antibiotics. However, this strategy can bear a risk of overtreatment and subsequently induce toxicities and unnecessary treatment costs. Pre-emptive antifungal therapy is now increasingly used to close the time gap between delayed initiation for proven disease and empirical treatment for anticipated infection without further laboratory or radiological evidence of fungal disease. Currently, some new non-invasive microbiological and laboratory methods, like the Aspergillus-galactomannan sandwich-enzyme immunoassay (Aspergillus GM-ELISA), 1,3-β-D-glucan assay or PCR techniques have been developed for a better diagnosis and determination of target patients. The current diagnostic approaches to fungal infections and the role of the revised definitions for invasive fungal infections, now IFDs, will be discussed in this review as well as old and emerging approaches to empirical, pre-emptive and targeted antifungal therapies in patients with haemato-oncological malignancies.

Correlation of in vitro activity and in vivo efficacy of itraconazole intravenous and oral solubilized formulations by testing Candida strains with various itraconazole susceptibilities in a murine invasive infection

OBJECTIVES

To examine whether in vitro antifungal susceptibility test results correlate with in vivo efficacy of two cyclodextrin-solubilized itraconazole formulations (intravenous and oral) against Candida in a murine model of invasive infection.

METHODS

A selected set of 12 Candida spp. strains with various itraconazole susceptibilities were tested. We studied the efficacy of intravenous and oral itraconazole administered once daily at dosages of 0.63, 2.5, 10 and 40 mg/kg body weight in mice lethally infected with each tested strain. Survival of mice in each treated group was monitored daily until the death of all control mice and compared between groups.

RESULTS

Survival of mice infected with 9 of 12 Candida strains with itraconazole MICs of ≤0.016-2.0 mg/L was significantly prolonged by treatment with intravenous itraconazole at dosages of 2.5 or 10 mg/kg and above. In contrast, the other three strains resistant to 8 mg/L itraconazole in vitro were refractory to the therapy, even at the highest itraconazole dosage (40 mg/kg). Closely similar in vivo data were obtained with the oral itraconazole therapy. The effective doses of the two itraconazole formulations increased with increasing itraconazole MICs for the infecting strains.

CONCLUSIONS

The in vivo efficacy of intravenous and oral itraconazole correlated with the in vitro susceptibility data.

Efficacy outcomes in a randomised trial of liposomal amphotericin B based on revised EORTC/MSG 2008 definitions of invasive mould disease

In 2008, the European Organisation for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) published revised definitions for diagnosing invasive fungal disease. A previous prospective trial of liposomal amphotericin B for invasive mould disease (AmBiLoad) used modified EORTC/MSG 2002 criteria. We wished to re-evaluate the response and survival based on the revised definitions to compare the outcomes of early vs. late treatment. Patients who had received an allogeneic haematopoietic stem cell transplant or who were neutropaenic (absolute neutrophil count <500 μl(-1) within 14 days of study entry) had been recruited on the basis of a halo or air crescent sign on chest computerised tomography. Originally classified as probable invasive mould disease, they were categorised as possible invasive mould disease using 2008 criteria. Patients had received liposomal amphotericin B at either 3 or 10 mg kg(-1) QD for 14 days, followed by 3 mg kg(-1) QD. Response at end of treatment and the 12-week survival were re-calculated according to 2008 definitions. Six-week survival was estimated by Kaplan-Meier analysis. Of 201 patients with invasive mould disease, 118 (59%) had a diagnosis based on halo signs (possible cases). Mycological evidence was present in 83 (41%) cases (probable/proven cases). Survival rates at 12 weeks for possible vs. probable/proven cases in the 3 mg kg(-1) QD group were 82% vs. 58% (P = 0.006), and 65% vs. 50% (P = 0.15) in the 10 mg kg(-1) QD group. At 6 weeks, rates were 87% vs. 69% in the 3 mg kg(-1) QD group (P = 0.009), and 75% vs. 61% in the 10 mg kg(-1) QD group (P = 0.01). Patients with possible invasive mould disease based on EORTC/MSG 2008 criteria had improved survival rates compared with those treated for probable/proven invasive mould disease. As possible invasive mould disease probably reflects an early-stage of disease, a better outcome might be expected when treatment with liposomal amphotericin B is started preemptively.

Current therapeutic approaches to fungal infections in immunocompromised hematological patients

Invasive fungal infections are significant causes of morbidity and mortality in patients with hematological malignancies. Patients with acute myeloid leukemia and those who have undergone allogeneic hematopoietic stem cell transplantation are at especially high risk. Various fungal agents are responsible for this complication, but Aspergillus spp. and Candida spp. are the most frequently isolated micro-organisms; less commonly, infections could be caused by Zygomycetes or other rare molds or yeasts. Several new systemically-administered antifungal agents have been approved for clinical use since 2001; these agents include liposomal amphotericin B, voriconazole, caspofungin, and posaconazole, and they represent a major advance in antifungal therapy and have improved the prognosis of patients with hematological malignancies. This review focuses on therapeutic aspects of the management of fungal infections in hematological patients.

Recent advances in antifungal prevention and treatment

Invasive fungal infections are important causes of morbidity and mortality in patients with bone marrow failure syndromes and hematological malignancies, or who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Current epidemiological trends indicate a shift toward infections by Aspergillus spp., non-albicans Candida spp., and previously uncommon fungal pathogens that have decreased susceptibility to the available antifungal agents. The last two decades have seen substantial improvements in the clinical, laboratory, and radiological diagnosis of these infections and the development of new antifungal compounds. Progress has been made in establishing disease definitions and paradigms for antifungal intervention and in the design and conduct of interventional clinical trials. Collectively, these advances have led to major but ongoing changes in the management of patients at risk of or being affected by invasive fungal infections. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in immunocompromised patients with hematological disorders and discusses novel approaches to antifungal chemotherapy and adjunctive treatments.

Approaches to the Management of Invasive Fungal Infections in Hematologic Malignancy and Hematopoietic Cell Transplantation

Patients with hematologic malignancy and hematopoietic cell transplant (HCT) recipients are at increased risk for invasive fungal infection (IFI) as a result of immunosuppression or organ damage stemming from their underlying disease, its treatment, or both. Such IFIs can cause significant morbidity and mortality, and the diagnosis and treatment of infected patients frequently are clinically challenging. This article discusses the epidemiology and risk factors for IFI in patients with hematologic malignancy and HCT recipients. The pros and cons of available antifungal agents are discussed, and evolving treatment strategies and recent prophylaxis guidelines from various professional organizations are reviewed. Finally, recommendations are offered for antifungal prophylaxis according to risk group.

Primary prophylaxis of invasive fungal infections in patients with hematologic malignancies. Recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology

There is no widely accepted standard for antifungal prophylaxis in patients with hematologic malignancies. The Infectious Diseases Working Party of the German Society for Haematology and Oncology assigned a committee of hematologists and infectious disease specialists to develop recommendations. Literature data bases were systematically searched for clinical trials on antifungal prophylaxis. The studies identified were shared within the committee. Data were extracted by two of the authors (OAC and MSi). The consensus process was conducted by email communication. Finally, a review committee discussed the proposed recommendations. After consensus was established the recommendations were finalized. A total of 86 trials were identified including 16,922 patients. Only a few trials yielded significant differences in efficacy. Fluconazole 400 mg/d improved the incidence rates of invasive fungal infections and attributable mortality in allogeneic stem cell recipients. Posaconazole 600 mg/d reduced the incidence of IFI and attributable mortality in allogeneic stem cell recipients with severe graft versus host disease, and in patients with acute myelogenous leukemia or myelodysplastic syndrome additionally reduced overall mortality. Aerosolized liposomal amphotericin B reduced the incidence rate of invasive pulmonary aspergillosis. Posaconazole 600 mg/d is recommended in patients with acute myelogenous leukemia/myelodysplastic syndrome or undergoing allogeneic stem cell recipients with graft versus host disease for the prevention of invasive fungal infections and attributable mortality (Level A I). Fluconazole 400 mg/d is recommended in allogeneic stem cell recipients until development of graft versus host disease only (Level A I). Aerosolized liposomal amphotericin B is recommended during prolonged neutropenia (Level B II).

Therapeutic drug monitoring for triazoles

PURPOSE OF REVIEW

Invasive fungal infections are a leading cause of morbidity and mortality in immunocompromised patients, and mechanisms to optimize therapeutic outcomes are urgently required. Therapeutic drug monitoring represents an important component for the routine use of the triazoles.

RECENT FINDINGS

Triazoles have revolutionized the prevention and treatment of invasive fungal infections. Increasing data suggest that this class displays important concentration-effect and concentration-toxicity relationships. There has been an increased understanding of the pharmacokinetics and pharmacodynamics of triazoles, and this has facilitated the identification of concentrations (or drug exposures) that are both effective and nontoxic. This review discusses the application of therapeutic drug monitoring to fluconazole, itraconazole, voriconazole and posaconazole.

SUMMARY

Therapeutic drug monitoring represents an important mechanism to optimize the outcome of immunocompromised patients receiving triazoles.

Efficient clearance of Aspergillus fumigatus in murine lungs by an ultrashort antimicrobial lipopeptide, palmitoyl-lys-ala-DAla-lys

Aspergillus fumigatus is an opportunistic fungal pathogen responsible for invasive aspergillosis in immunocompromised individuals. The inefficiency of antifungal agents and high mortality rate resulting from invasive aspergillosis remain major clinical concerns. Recently, we reported on a new family of ultrashort cationic lipopeptides active in vitro against fungi. Mode of action studies supported a membranolytic or a detergent-like effect. Here, we screened several lipopeptides in vitro for their anti-A. fumigatus activity. To investigate the therapeutic properties of the selected peptides in vivo, we challenged immunosuppressed C57BL/6 wild-type mice intranasally with DsRed-labeled A. fumigatus conidia and subsequently treated the animals locally with the lipopeptides. Confocal microscopic analysis revealed the degradation of DsRed-labeled hyphal forms and residual conidia in the lungs of the mice. The most efficient peptide was tested further using a survival assay and was found to significantly prolong the life of the treated animals, whereas no mice survived with the current standard antifungal treatment with amphotericin B. Moreover, as opposed to the drug-treated lungs, the peptide-treated lungs did not display any toxicity of the peptide. Our results highlight the potential of this family of lipopeptides for the treatment of pulmonary invasive aspergillosis.