Comparison of posaconazole serum concentrations from haematological cancer patients on posaconazole tablet and oral suspension for treatment and prevention of invasive fungal infections

Factors Influencing Serum Posaconazole Concentrations in Patients With Hematologic Malignancies Receiving Delayed-Release Tablets

BACKGROUND

Posaconazole (PCZ) plays a crucial role in the prophylaxis and treatment of invasive fungal infections in hematologic malignancies. PCZ concentrations reportedly vary among patients receiving delayed-release tablets (DRT). However, the factors influencing these concentrations remain insufficiently elucidated. Therefore, this study aimed to evaluate the factors influencing PCZ concentrations and their effect on the probability of target attainment (PTA) using a population pharmacokinetic (PPK) approach. We also explored the relationship between PCZ exposure and hepatotoxicity.

METHODS

This retrospective study included adult patients with hematologic malignancies who received PCZ DRT. A PPK model was developed based on observational data for 130 concentrations in 28 patients. Simulation analyses were performed to assess the PTA at standard doses of 0.7 and 1.0 mg/L for prophylaxis and treatment, respectively. Estimated concentrations were used to evaluate the correlation between PCZ exposure and hepatotoxicity.

RESULTS

Significant factors influencing PCZ concentrations included body weight, serum total protein levels, and diarrhea. Diarrhea correlated with decreased PCZ concentrations resulting in up to 26% lower PTA compared with that without diarrhea. Moreover, PTA declined markedly as the total protein levels decreased from 6.6 g/dL to 4.4 g/dL. The incidence of hepatotoxicity was 17.4% (4/23); no significant relationship could be established between the PCZ concentrations and hepatotoxicity ( P = 0.188).

CONCLUSIONS

We identified the factors affecting PCZ exposure, which could not be detected by PPK analysis using data from clinical trials. Our results suggest that the generally recommended dose of PCZ causes underexposure in patients with hematologic malignancies characterized by high body weight, hypoproteinemia, or concurrent diarrhea. Therapeutic drug monitoring for DRT may be recommended, especially in patients with these risk factors.

Updated antimicrobial dosing recommendations for obese patients

The prevalence of obesity has increased considerably in the last few decades. Pathophysiological changes in obese patients lead to pharmacokinetic (PK) and pharmacodynamic (PD) alterations that can condition the correct exposure to antimicrobials if standard dosages are used. Inadequate dosing in obese patients can lead to toxicity or therapeutic failure. In recent years, additional antimicrobial PK/PD data, extended infusion strategies, and studies in critically ill patients have made it possible to obtain data to provide a better dosage in obese patients. Despite this, it is usually difficult to find information on drug dosing in this population, which is sometimes contradictory. This is a comprehensive review of the dosing of different types of antimicrobials (antibiotics, antifungals, antivirals, and antituberculosis drugs) in obese patients, where the literature on PK and possible dosing strategies in obese adults was critically assessed.

Evaluation of Posaconazole Serum Concentrations Achieved With Delayed-release Tablets and Oral Suspension in Patients Undergoing Intensive Chemotherapy for Acute Myeloid Leukemia and Myelodysplastic Syndrome

Data on posaconazole serum levels of patients on prophylaxis with delayed-release tablets or oral suspension during intensive chemotherapy for acute myeloid leukemia and myelodysplastic syndrome are scarce. In this analysis, the proportion of patients with acute myeloid leukemia/myelodysplastic syndrome achieving posaconazole target concentrations with delayed-release tablets was higher than with oral suspension.

Subtherapeutic concentrations of posaconazole tablet: determining risk factors and effectiveness of a standardized dose adjustment in hematology inpatients

Posaconazole is indicated for antifungal prophylaxis in hematology patients at high-risk of invasive fungal infections (IFI). Consensus guidelines recommend maintaining steady-state trough concentrations above 0.7 mg/L; however, upto one-third of patients return subtherapeutic concentrations which is associated with breakthrough IFI. This retrospective observational study of 496 concentrations from 90 hematology inpatients prescribed posaconazole tablet (PCZ-tab) between May 2017 and May 2019 identified 24% (n = 121) of posaconazole concentrations were subtherapeutic after the dosage of 300 mg daily. On multivariable analyses, diarrhea (p = 0.002), male gender (p = 0.018), and concurrent regular metoclopramide (p = 0.002) were significantly associated with subtherapeutic posaconazole concentrations. Eighty-nine percent of patients (n = 16) who underwent dose adjustment to 200 mg twice daily successfully achieved target posaconazole concentrations at first steady-state measurement. This study confirms that therapeutic drug monitoring of posaconazole remains necessary as subtherapeutic posaconazole concentrations are relatively common, and that dose adjustment of 200 mg twice daily, safely enabled achievement of therapeutic concentrations.

New Perspectives on Antimicrobial Agents: Isavuconazole

Isavuconazole is the newest of the clinically available advanced generation triazole antifungals and is active against a variety of yeasts, molds, and dimorphic fungi. Its current FDA-approved indications include the management of invasive aspergillosis as well as mucormycosis, though the latter indication is supported by limited clinical data. Isavuconazole did not achieve noninferiority to caspofungin for the treatment of invasive candidiasis and therefore lacks an FDA-approved indication for this invasive disease. Significant advantages of isavuconazole, primarily over voriconazole but in some circumstances posaconazole as well, make it an appealing option for the management of complex patients with invasive fungal infections. These potential advantages include lack of QTc interval prolongation, more predictable pharmacokinetics, a less complicated drug interaction profile, and improved tolerability, particularly when compared to voriconazole. This review discusses these topics in addition to addressing the in vitro activity of the compound against a variety of fungi and provides insight into other distinguishing factors among isavuconazole, voriconazole, and posaconazole. The review concludes with an opinion section in which the authors provide the reader with a framework for the current role of isavuconazole in the antifungal armamentarium and where further data are required.

Update on the Epidemiology, Diagnosis, and Treatment of Coccidioidomycosis

Coccidioidomycosis is a fungal infection caused by Coccidioides immitis and Coccidioides posadasii. The dimorphic fungi live in the soils of arid and semi-arid regions of the western United States, as well as parts of Mexico, Central America, and South America. Incidence of disease has risen consistently in recent years, and the geographic distribution of Coccidioides spp. appears to be expanding beyond previously known areas of endemicity. Climate factors are predicted to further extend the range of environments suitable for the growth and dispersal of Coccidioides species. Most infections are asymptomatic, though a small proportion result in severe or life-threatening forms of disease. Primary pulmonary coccidioidomycosis is commonly mistaken for community-acquired pneumonia, often leading to inappropriate antibacterial treatment and unnecessary healthcare costs. Diagnosis of coccidioidomycosis is challenging and often relies on clinician suspicion to pursue laboratory testing. Advancements in diagnostic tools and antifungal therapy developments seek to improve the early detection and effective management of infection. This review will highlight recent updates and summarize the current understanding of the epidemiology, diagnosis, and treatment of coccidioidomycosis.

Hepatic safety of the antifungal triazole agent posaconazole: characterization of adverse event reports in a manufacturer's safety database

BACKGROUND

Second-generation triazoles including posaconazole are efficacious for prophylaxis and salvage treatment of life-threatening invasive fungal diseases but have been associated with hepatic adverse events (AEs). This report evaluated hepatic AEs in posaconazole-treated patients.

RESEARCH DESIGN AND METHODS

Hepatobiliary AEs with posaconazole exposure in the company's global safety database were analyzed to characterize underlying medical conditions and concomitant drug exposure.

RESULTS

As of October 2019, 516 cases (168 from clinical trials, 348 from postmarketing use) containing 618 hepatobiliary AEs were reported regardless of causality. Frequently reported terms were hyperbilirubinemia, hepatic failure, and hepatic function abnormal (clinical trials reports) and hepatotoxicity, hepatocellular injury, and hepatic function abnormal (postmarketing reports). Cases reporting concurrent medications associated with drug-induced liver injury (DILI) included 8% with verified severe DILI (vMost-DILI) concern, 24% with verified mild to moderate DILI (vLess-DILI) concern, and 37% received both vMost-DILI and vLess-DILI-concern medications in the DILIrank data set.

CONCLUSIONS

Use of concomitant medications with known risks for hepatic injury appears to be an important contributor for the development of hepatotoxicity in patients treated with posaconazole.

Posaconazole bioavailability of the solid oral tablet is reduced during severe intestinal mucositis

OBJECTIVES

To describe the absolute oral bioavailability of the solid oral formulation of posaconazole and the impact of severe intestinal mucositis in haematology patients. Further, to describe posaconazole protein binding in haematology patients.

METHODS

A pharmacokinetic study was performed where patients receiving induction chemotherapy or a haematopoietic cell transplantation were randomized to receive 7 days of intravenous posaconazole therapy followed by 9 days of oral therapy or vice versa. Patients received posaconazole licensed dose until day 12, thereafter a reduced once daily dose of 200 mg was given. At days 7, 12, and 16 blood samples were obtained for pharmacokinetic curves, trough samples were collected on all other days. Total and unbound posaconazole pharmacokinetics were analysed by population pharmacokinetic modelling. The presence of severe intestinal mucositis was assessed by plasma citrulline levels and analysed as a binary covariate using 10 μmol/L as cut-off. Monte Carlo simulations were performed to simulate posaconazole exposure at steady state.

RESULTS

Twenty-three patients were included for analysis with 581 total posaconazole concentrations and 91 paired unbound concentrations. Absolute bioavailability in the final model was estimated at 51.4% (%relative standard error (RSE) 56.5) and 67.6% (%RSE 75.0) in patients with and without severe intestinal mucositis, respectively. Posaconazole unbound fraction was estimated at 2.7% (%RSE 3.9).

CONCLUSIONS

Posaconazole bioavailability is reduced in haematological patients with severe intestinal mucositis, requiring an increase in oral posaconazole dose to 400 mg twice daily on day 1 followed by 400 mg once daily or a switch to intravenous therapy.

Antifungal Drugs TDM: Trends and Update

PURPOSE

The increasing burden of invasive fungal infections results in growing challenges to antifungal (AF) therapeutic drug monitoring (TDM). This review aims to provide an overview of recent advances in AF TDM.

METHODS

We conducted a PubMed search for articles during 2016-2020 using "TDM" or "pharmacokinetics" or "drug-drug-interaction" with "antifungal," consolidated for each AF. Selection was limited to English language articles with human data on drug exposure.

RESULTS

More than 1000 articles matched the search terms. We selected 566 publications. The latest findings tend to confirm previous observations in real-life clinical settings. The pharmacokinetic variability related to special populations is not specific but must be considered. AF benefit-to-risk ratio, drug-drug interaction (DDI) profiles, and minimal inhibitory concentrations for pathogens must be known to manage at-risk situations and patients. Itraconazole has replaced ketoconazole in healthy volunteers DDI studies. Physiologically based pharmacokinetic modeling is widely used to assess metabolic azole DDI. AF prophylactic use was studied more for Aspergillus spp. and Mucorales in oncohematology and solid organ transplantation than for Candida (already studied). Emergence of central nervous system infection and severe infections in immunocompetent individuals both merit special attention. TDM is more challenging for azoles than amphotericin B and echinocandins. Fewer TDM requirements exist for fluconazole and isavuconazole (ISZ); however, ISZ is frequently used in clinical situations in which TDM is recommended. Voriconazole remains the most challenging of the AF, with toxicity limiting high-dose treatments. Moreover, alternative treatments (posaconazole tablets, ISZ) are now available.

CONCLUSIONS

TDM seems to be crucial for curative and/or long-term maintenance treatment in highly variable patients. TDM poses fewer cost issues than the drugs themselves or subsequent treatment issues. The integration of clinical pharmacology into multidisciplinary management is now increasingly seen as a part of patient care.

Consensus guidelines for optimising antifungal drug delivery and monitoring to avoid toxicity and improve outcomes in patients with haematological malignancy and haemopoietic stem cell transplant recipients, 2021

Antifungal agents can have complex dosing and the potential for drug interaction, both of which can lead to subtherapeutic antifungal drug concentrations and poorer clinical outcomes for patients with haematological malignancy and haemopoietic stem cell transplant recipients. Antifungal agents can also be associated with significant toxicities when drug concentrations are too high. Suboptimal dosing can be minimised by clinical assessment, laboratory monitoring, avoidance of interacting drugs, and dose modification. Therapeutic drug monitoring (TDM) plays an increasingly important role in antifungal therapy, particularly for antifungal agents that have an established exposure-response relationship with either a narrow therapeutic window, large dose-exposure variability, cytochrome P450 gene polymorphism affecting drug metabolism, the presence of antifungal drug interactions or unexpected toxicity, and/or concerns for non-compliance or inadequate absorption of oral antifungals. These guidelines provide recommendations on antifungal drug monitoring and TDM-guided dosing adjustment for selected antifungal agents, and include suggested resources for identifying and analysing antifungal drug interactions. Recommended competencies for optimal interpretation of antifungal TDM and dose recommendations are also provided.

Leveraging Oral Drug Development to a Next Level: Impact of the IMI-Funded OrBiTo Project on Patient Healthcare

A thorough understanding of the behavior of drug formulations in the human gastrointestinal (GI) tract is essential when working in the field of oral drug development in a pharmaceutical company. For orally administered drug products, various GI processes, including disintegration of the drug formulation, drugrelease, dissolution, precipitation, degradation, dosage form transit and permeation, dictate absorption into the systemic circulation. These processes are not always fully captured in predictive in vitro and in silico tools, as commonly applied in the pre-clinical stage of formulation drug development. A collaborative initiative focused on the science of oral biopharmaceutics was established in 2012 between academic institutions and industrial companies to innovate, optimize and validate these in vitro and in silico biopharmaceutical tools. From that perspective, the predictive power of these models can be revised and, if necessary, optimized to improve the accuracy toward predictions of the in vivo performance of orally administered drug products in patients. The IMI/EFPIA-funded "Oral Bioavailability Tools (OrBiTo)" project aimed to improve our fundamental understanding of the GI absorption process. The gathered information was integrated into the development of new (or already existing) laboratory tests and computer-based methods in order to deliver more accurate predictions of drug product behavior in a real-life setting. These methods were validated with the use of industrial data. Crucially, the ultimate goal of the project was to set up a scientific framework (i.e., decision trees) to guide the use of these new tools in drug development. The project aimed to facilitate and accelerate the formulation development process and to significantly reduce the need for animal experiments in this area as well as for human clinical studies in the future. With respect to the positive outcome for patients, high-quality oral medicines will be developed where the required dose is well-calculated and consistently provides an optimal clinical effect. In a first step, this manuscript summarizes the setup of the project and how data were collected across the different work packages. In a second step, case studies of how this project contributed to improved knowledge of oral drug delivery which can be used to develop improved products for patients will be illustrated.

Current and promising pharmacotherapeutic options for candidiasis

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

A Collaborative Tale of Diagnosing and Treating Chronic Pulmonary Aspergillosis, from the Perspectives of Clinical Microbiologists, Surgical Pathologists, and Infectious Disease Clinicians

Chronic pulmonary aspergillosis (CPA) refers to a spectrum of Aspergillus-mediated disease that is associated with high morbidity and mortality, with its true prevalence vastly underestimated. The diagnosis of CPA includes characteristic radiographical findings in conjunction with persistent and systemic symptoms present for at least three months, and evidence of Aspergillus infection. Traditionally, Aspergillus infection has been confirmed through histopathology and microbiological studies, including fungal culture and serology, but these methodologies have limitations that are discussed in this review. The treatment of CPA requires an individualized approach and consideration of both medical and surgical options. Most Aspergillus species are considered susceptible to mold-active triazoles, echinocandins, and amphotericin B; however, antifungal resistance is emerging and well documented, demonstrating the need for novel therapies and antifungal susceptibility testing that correlates with clinical response. Here, we describe the clinical presentation, diagnosis, and treatment of CPA, with an emphasis on the strengths and pitfalls of diagnostic and treatment approaches, as well as future directions, including whole genome sequencing and metagenomic sequencing. The advancement of molecular technology enables rapid and precise species level identification, and the determination of molecular mechanisms of resistance, bridging the clinical infectious disease, anatomical pathology, microbiology, and molecular biology disciplines.

Tablets or oral suspension for posaconazole in lung transplant recipients? Consequences for trough concentrations of tacrolimus and everolimus

AIMS

A new formulation of posaconazole (PCZ), delayed-release tablets (PCZ-tab), increases PCZ bioavailability and plasma trough concentrations (C_min ) over those achieved with an oral suspension (PCZ-susp). PCZ is an inhibitor of cytochrome P450 3A4 and P-glycoprotein. We therefore investigated the impact of PCZ-tab treatment on blood C_min and doses of tacrolimus (TAC) and everolimus (EVR).

METHODS

Eighteen lung transplant patients receiving TAC (n = 13) or TAC + EVR (n = 5) between June 2015 and March 2016 were retrospectively included. Ten of these patients received both PCZ-tab and PCZ-susp (i.e. switched patients); the other 8 received only PCZ-tab. Plasma C_min of PCZ (n = 64), blood C_min of TAC (n = 299) and EVR (n = 80) were determined during routine therapeutic drug monitoring by liquid chromatography-tandem mass spectrometry.

RESULTS

PCZ C_min on PCZ-tab treatment (n = 48) was 2.5 times higher than that on PCZ-susp therapy (n = 16), for both PCZ patients (P < .0001) and for switched patients (P = .003). PCZ initiation, regardless of galenic form, increased TAC and EVR C_min adjusted for dose (D), 3-fold and 3.5-fold, respectively (P < .0001 for both). PCZ-tab treatment was associated with a higher TAC C_min /D (PCZ-tab vs PCZ-susp: 0.004 ± 0.004 L^-1 vs 0.009 ± 0.006 L^-1 , P < .0001) and lower TAC daily dose than PCZ-susp (PCZ-tab vs PCZ-susp: 1.08 ± 0.92 vs 2.32 ± 1.62 mg d^-1 , P < .0001). EVR C_min /D was higher and EVR dose tended to be lower on PCZ-tab than on PCZ-susp.

CONCLUSION

The greater PCZ exposure achieved during PCZ-tab treatment increased drug-drug interactions with TAC and EVR, resulting in greater exposure, potentially exposing patients to higher risks of adverse effects.

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.

Pharmacokinetics and Safety of Posaconazole Tablet Formulation in Chinese Participants at High Risk for Invasive Fungal Infection

INTRODUCTION

This study characterized the multidose pharmacokinetic (PK) characteristics of posaconazole tablets used as prophylactic antifungal therapy in Chinese patients with acute myelogenous leukemia (AML) at risk for invasive fungal infection (IFI).

METHODS

Participants in this open-label, single-arm, phase 1b study received posaconazole 300 mg twice daily on day 1 and then once daily for up to 28 days. In the intensive PK sampling subgroup, posaconazole was administered under fasting conditions on days 1 and 8, and blood samples were regularly collected over 24 h. Trough PK sampling was conducted in all participants on days 1, 2, 3, 8, 14, 21, and 28 without regard for food intake. Population PK characteristics were predicted using PK modeling. Primary endpoints were steady-state average concentration (C_avg) and percentage of participants with steady-state C_avg (predicted and observed) > 500 ng/ml. Treatment safety and efficacy were secondary endpoints.

RESULTS

Sixty-five adult Chinese participants were enrolled. On day 8, steady-state arithmetic mean C_avg was 1610 ng/ml (% coefficient of variation [%CV] 42.8%) in the intensive PK subgroup (n = 20). All participants achieved a steady-state C_avg > 500 ng/ml. Predicted C_avg (pC_avg) was 1770 ng/ml (%CV 33.7%) in the total population (n = 64); 92.2% of participants had pC_avg values ≥ 500 ng/ml (n = 59). The posaconazole tablet safety profile was consistent with that of the oral formulation, and the IFI rate was 3%.

CONCLUSION

In Chinese AML patients, the posaconazole 300-mg tablet provided PK data comparable with those of previous studies and was generally well tolerated and efficacious.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02387983.

Treatment by Posaconazole Tablets, Compared to Posaconazole Suspension, Does Not Reduce Variability of Posaconazole Trough Concentrations

The delayed-release tablet formulation of posaconazole (POS-tab) results in higher plasma POS trough concentrations (C_min) than the oral suspension (POS-susp), which raises the question of the utility of therapeutic drug monitoring (TDM). We aimed to compare the variability of the POS C_min for the two formulations and identify determinants of the POS-tab C_min and its variability. Demographic, biological, and clinical data from 77 allogeneic hematopoietic stem cell transplant patients (874 C_min) treated with POS-tab (n = 41), POS-susp (n = 29), or both (n = 7) from January 2015 to December 2016 were collected retrospectively. Interpatient and within-subject coefficients of variation (CVs) of the C_min adjusted to dose (D) were calculated for each formulation. Between-group comparisons were performed using a linear mixed effects model. The POS C_min was higher for the tablet than for the suspension (median [25th-75th percentile]: 1.8 [1.2-2.4] mg/liter versus 1.2 [0.7-1.6] mg/liter, P < 0.0001). Interpatient CVs for the tablet and suspension were 60.8 versus 63.5% (P = 0.7), whereas within-subject CVs were 39.7 and 44.9%, respectively (P = 0.3). Univariate analysis showed that age and treatment by POS-tab were significantly and positively associated with the POS C_min, whereas diarrhea was associated with a diminished POS C_min Multivariate analysis identified treatment with POS-tab and diarrhea as independent factors of the POS C_min, with a trend toward a lower impact of diarrhea during treatment with POS-tab (P = 0.07). Despite increased POS exposure with the tablet formulation, the variability of the POS C_min was not significantly lower than that of the suspension. This suggests that TDM may still be useful to optimize tablet POS therapy.

Using State Transition Models to Explore How the Prevalence of Subtherapeutic Posaconazole Exposures Impacts the Clinical Utility of Therapeutic Drug Monitoring for Posaconazole Tablets and Oral Suspension

Therapeutic drug monitoring (TDM) has been recommended in guidelines for patients receiving posaconazole oral suspension, but its utility in patients receiving posaconazole tablet, which has an improved bioavailability, remains unclear. We used state transition models with first-order Monte Carlo microsimulation to re-examine the posaconazole exposure-response relationships reported in two Phase III clinical trials (prophylaxis with posaconazole oral suspension - Models 1 & 2) and a third multicenter observational TDM study (Model 3). We simulated the impact of TDM-guided interventions to improve initial average posaconazole concentrations (C_avg) to reduce clinical failure (in Models 1 & 2) and breakthrough invasive fungal disease (bIFD) in Model 3. Simulations were then repeated using posaconazole tablet C_avg distributions in place of the oral suspension formulation. In all three models with posaconazole oral suspension, TDM interventions associated with maximal improvement in posaconazole C_avg reduced absolute rates of subtherapeutic exposures (C_avg < 700 ng/mL) by 25-49%. Predicted reductions in absolute clinical failure rates were 11% in Model 1 and 6.5% in Model 2, and a 12.6% reduction in bIFD in Model 3. With the tablet formulation, maximally-effective TDM interventions reduced subtherapeutic exposures by approximately 5% in all three models and absolute clinical failure rates by 3.9% in Model 1, and 1.6% in Model 2; and a 1.6% reduction in bIFD in Model 3. Our modeling suggests that routine TDM during prophylaxis with posaconazole tablets may have limited clinical utility unless populations with higher prevalence (>10%) of subtherapeutic exposures can be identified based on clinical risk factors.

The Rise of Coccidioides: Forces Against the Dust Devil Unleashed

Coccidioidomycosis (Valley fever) is a fungal disease caused by the inhalation of Coccidioides posadasii or C. immitis. This neglected disease occurs in the desert areas of the western United States, most notably in California and Arizona, where infections continue to rise. Clinically, coccidioidomycosis ranges from asymptomatic to severe pulmonary disease and can disseminate to the brain, skin, bones, and elsewhere. New estimates suggest as many as 350,000 new cases of coccidioidomycosis occur in the United States each year. Thus, there is an urgent need for the development of a vaccine and new therapeutic drugs against Coccidioides infection. In this review, we discuss the battle against Coccidioides including the development of potential vaccines, the quest for new therapeutic drugs, and our current understanding of the protective host immune response to Coccidioides infection.

Isavuconazole to prevent invasive fungal infection in immunocompromised adults: Initial experience at an academic medical centre

OBJECTIVE

To evaluate clinical and economic outcomes associated with the use of isavuconazole as antifungal prophylaxis in high-risk immunocompromised patients.

PATIENTS/METHODS

Retrospective, single-centre cohort study of patients who received isavuconazole prophylaxis. Outcomes assessed included breakthrough IFI, early discontinuation of isavuconazole for any reason and antifungal prophylaxis prescribed at discharge. The impact on inpatient drug expenditure was evaluated using current isavuconazole and posaconazole drug costs per observed isavuconazole days of therapy (DOT) during the study period.

RESULTS

One hundred thirty-eight courses of isavuconazole prophylaxis were administered to 98 inpatients (2193 DOT). Relapsed/refractory acute myelogenous leukaemia was the indication for prophylaxis in over half (59.4%) of patients. Breakthrough IFI occurred in 8 (5.8%) courses. Suspected drug-related toxicities led to early discontinuation in 6 (4.3%) courses (five hepatotoxicity, one drug rash). At discharge, 24 (17.4%) courses lacked insurance coverage for isavuconazole. The formulary switch to isavuconazole prophylaxis resulted in an estimated mean drug cost savings of $128.25 per DOT relative to estimated posaconazole costs (P < 0.001).

CONCLUSION

Isavuconazole may be an option for antifungal prophylaxis in high-risk immunocompromised adults and has the potential to produce significant inpatient drug cost savings. Further studies are needed to confirm the clinical efficacy and cost-effectiveness of isavuconazole in this role.

Auditing fungal disease in leukemia patients in a tertiary care center: opportunities and challenges for an antifungal stewardship program

Invasive fungal disease (IFD) is responsible for significant morbidity and mortality in patients with acute leukemia. Antifungal stewardship (AFS) programs are utilized in this patient group but have been infrequently evaluated in clinical practice. Adults diagnosed with acute leukemia at an Australian tertiary center over two years were identified, with subsequent auditing of IFD prophylaxis and treatment, and identification of further opportunities for AFS activities. Proven or probable IFD occurred in 6% of cases, including 14% of acute lymphoblastic leukemia (ALL) patients and 6% of acute myeloid leukemia (AML) patients. Mold-active antifungal prophylaxis was used in 84% of cases overall, including in 94% of AML cases and 23% of ALL cases. Local auditing identified target areas for AFS in this complex patient cohort, including modification of clinical guidelines, enhanced patient screening, improved access to fungal diagnostics and therapeutic drug monitoring, and the establishment of a specialized, embedded AFS program.

Intravenous and tablet formulation of posaconazole in antifungal therapy and prophylaxis: A retrospective, non-interventional, multicenter analysis of hematological patients treated in tertiary-care hospitals

OBJECTIVES

Novel formulations (gastro-resistant tablet and intravenous solution) of posaconazole (POS) have been approved in prophylaxis and therapy of invasive fungal diseases (IFDs). Study aim was to analyze treatment strategies and clinical effectiveness.

METHODS

We set up a web-based registry on www.ClinicalSurveys.net for documentation of comprehensive data of patients who received novel POS formulations. Data analysis was split into two groups of patients who received novel POS formulations for antifungal prophylaxis (posaconazole prophylaxis group) and antifungal therapy (posaconazole therapy group), respectively.

RESULTS

Overall, 180 patients (151 in the posaconazole prophylaxis group and 29 in the posaconazole therapy group) from six German tertiary care centers and hospitalized between 05/2014 - 03/2016 were observed. Median age was 58 years (range: 19 - 77 years) and the most common risk factor for IFD was chemotherapy (n = 136; 76%). In the posaconazole prophylaxis group and posaconazole therapy group, median POS serum levels at steady-state were 1,068 μg/L (IQR 573-1,498 μg/L) and 904 μg/L (IQR 728-1,550 μg/L), respectively (P = 0.776). During antifungal prophylaxis with POS, nine (6%) probable/proven fungal breakthroughs were reported and overall survival rate of hospitalization was 86%. The median overall duration of POS therapy was 18 days (IQR: 7 - 23 days). Fourteen patients (48%) had progressive IFD under POS therapy, of these five patients (36%) died related to or likely related to IFD.

CONCLUSIONS

Our study demonstrates clinical effectiveness of antifungal prophylaxis with novel POS formulations. In patients treated for possible/probable/proven IFD, we observed considerable mortality in patients receiving salvage treatment and with infections due to rare fungal species.

Current Concepts and Future Directions in the Pharmacology and Treatment of Coccidioidomycosis

Coccidioidomycosis remains a significant clinical problem with substantial morbidity and mortality. The vast majority of infections are asymptomatic and the need for early primary therapy remains controversial. The use of triazole antifungals has improved tolerability of therapy but concerns about acute and long-term toxicities among available agents limit their use. In addition, recent findings of decreased in vitro fluconazole susceptibility to as many as 37% of Coccidioides spp. isolates raises concerns regarding optimal therapy for these infections as fluconazole is commonly used for therapy including central nervous system disease. Thus, new agents from novel antifungal classes are currently in preclinical and clinical development aimed at reducing toxicity and improving outcomes of these serious infections.

Clinical Outcomes of Oral Suspension versus Delayed-Release Tablet Formulations of Posaconazole for Prophylaxis of Invasive Fungal Infections

Posaconazole is used for prophylaxis for invasive fungal infections (IFIs) among patients with hematologic malignancies. We compared the incidence of breakthrough IFIs and early discontinuation between patients receiving delayed-release tablet and oral suspension formulations of posaconazole.

Posaconazole is used for prophylaxis for invasive fungal infections (IFIs) among patients with hematologic malignancies. We compared the incidence of breakthrough IFIs and early discontinuation between patients receiving delayed-release tablet and oral suspension formulations of posaconazole. This was a retrospective cohort study of patients receiving posaconazole between 1 January 2010 and 30 June 2016. We defined probable or proven breakthrough IFIs using the European Organization for Research and Treatment of Cancer (EORTC) criteria. Overall, 547 patients received 860 courses of posaconazole (53% received the oral suspension and 48% received the tablet); primary indications for prophylaxis were acute myeloid leukemia (69%), graft-versus-host disease (18%), and myelodysplastic syndrome (3%). There were no significant differences in demographics or indications between patients receiving the different formulations. The incidence and incidence rate of probable or proven IFIs were 1.6% and 3.2 per 10,000 posaconazole days, respectively. There was no significant difference in the rate of IFIs between suspension courses (2.8 per 10,000 posaconazole days) and tablet courses (3.7 per 10,000 posaconazole days) (rate ratio = 0.8, 95% confidence interval [CI] = 0.3 to 2.3). Of the 14 proven or probable cases of IFI, 8/14 had posaconazole serum concentrations measured, and the concentrations in 7/8 were above 0.7 μg/ml. Posaconazole was discontinued early in 15.5% of courses; however, the frequency of discontinuation was also not significantly different between the tablet (16.5%) and oral suspension (14.6%) formulations (95% CI for difference = −0.13 to 0.06). In conclusion, the incidence of breakthrough IFIs was low among patients receiving posaconazole prophylaxis and not significantly different between patients receiving the tablet formulation and those receiving the oral suspension formulation.

Co-administration of proton pump inhibitors and/or of steroids may be a risk factor for low trough concentrations of posaconazole delayed-released tablets in adult patients with haematological malignancies

AIMS

The aim of this study was to determine clinical variables associated with posaconazole exposure among adult patients with haematological malignancies who received posaconazole tablets for prophylaxis of invasive fungal infections (IFIs).

METHODS

The study population included adult patients with haematological malignancies who received posaconazole delayed-release tablets for prophylaxis of IFIs after induction chemotherapy for acute leukaemia or graft-versus-host-disease (GVHD) complicating hematopoietic stem cell transplantation (HSCT) in the period January 2016-December 2017.

RESULTS

Sixty-six consecutive patients with 176 posaconazole C_min were included for evaluation in the study. Subtherapeutic posaconazole concentrations (< 0.7 mg l^-1 ) were observed at least once in 33.3% of patients (22/66), and overall in 17.0% of therapeutic drug monitoring (TDM) episodes (30/176). At multilevel linear regression, use of PPIs (P = 0.008), use of intermediate or high dose steroids (>0.7 mg kg^-1 daily) (P = 0.022) and male gender (P = 0.025) were significantly associated with decreased C_min , whereas time from starting therapy (P = 0.032) was associated with increased C_min in our patient population.

CONCLUSION

Posaconazole exposure during treatment with delayed-released tablet formulation may be affected by the use of PPIs and/or of intermediate or high dose steroids.

Impact of patient education on plasma concentrations and effectiveness of posaconazole oral suspension under clinical conditions

Posaconazole prophylaxis is recommended for patients with acute myeloid leukaemia during induction chemotherapy. Although a tablet formulation with better oral bioavailability is available, some patients have to rely on the oral suspension in clinical routine. Therefore, effectiveness of posaconazole oral suspension under real-life clinical conditions and impact of patient education about the correct intake on its plasma concentrations were assessed in this study. Altogether 96 patients receiving 160 cycles of induction chemotherapy were retrospectively (40 patients) and prospectively (56 patients) analysed. Patients were assigned into two groups for each chemotherapy cycle according to the application of antifungal prophylaxis (A: posaconazole oral suspension, 200 mg three times a day ≥7 days; B: intake <7 days, fluconazole or no prophylaxis). Antifungal prophylaxis and therapy were analysed for each cycle. Additionally, plasma concentrations were determined from prospectively included subjects of group A who were intensively educated to perform a correct drug intake. Systemic antifungal therapy was statistically started less often in group A (26% vs 53%; P = 0.002). Posaconazole prophylaxis was associated with a lower risk of proven invasive fungal infection (P = 0.003). Median plasma concentration apparently increased between the first and second time of determination effected by an initial intensive on-site patient education. The clinical effectiveness of posaconazole oral suspension was confirmed. A detailed patient education at the beginning of the treatment with posaconazole oral suspensions seems to be of primary importance for efficient plasma concentrations.

Antifungal Prophylaxis with Posaconazole Delayed-Release Tablet and Oral Suspension in a Real-Life Setting: Plasma Levels, Efficacy, and Tolerability

We continuously determined posaconazole plasma concentrations (PPCs) in 61 patients with hematological malignancies receiving posaconazole (PCZ) delayed-release tablets (DRT; 48 patients; median duration of intake, 92 days) and PCZ oral solution (OS; 13 patients; median duration of intake, 124 days). PCZ DRT and OS antifungal prophylaxis was efficient and well tolerated. Thirty-four of 48 patients (71%) receiving DRT always had PPCs of >0.7 mg/liter, while 14 of 48 patients (29%) had at least one PPC of ≤0.7 mg/liter. In patients receiving OS, 4 of 13 patients (31%) always had PPCs of >0.7 mg/liter, 6 of 13 patients (46%) had at least one PPC of ≤0.7 mg/liter, and 3 (23%) patients never reached a PPC of 0.7 mg/liter. In patients with at least one determined PPC, the mean proportion of all PPCs of >0.7 mg/liter was 91% for PCZ DRT, whereas it was 52% for PCZ OS (P = 0.001). In the per sample analysis, PPCs were significantly more likely to be >0.7 mg/liter in patients receiving DRT than in patients receiving OS (PPCs were >0.7 mg/liter in 91.4% [297/325] of patients receiving DRT versus 70.3% [85/121] of patients receiving OS; P < 0.001). Patients receiving PCZ DRT had higher proportions of PPCs of >0.7 mg/liter than patients receiving OS both in the per patient and in the per sample analyses. Two patients (3%) had side effects during PCZ prophylaxis, and one (2%) had fungal breakthrough infection. Therapeutic drug monitoring enables detection of extended periods of PPCs of ≤0.7 mg/liter (e.g., due to nonadherence or graft-versus-host disease), which may also be associated with the loss of protective intracellular PCZ concentrations, regardless of the PCZ formulation.

Posaconazole Therapeutic Drug Monitoring in a Regional Hospital Setting

BACKGROUND

Posaconazole therapeutic drug monitoring (TDM) is recommended to promote effective antifungal prophylaxis, but its utility has yet to be optimized. Breakthrough invasive fungal infections have been reported with serum concentrations <700 mcg/L, but there is little evidence to determine the optimal serum concentration for efficacy or concentrations associated with toxicity. Challenges for effective monitoring are greater in settings without posaconazole TDM facilities because of the long turnaround time before receipt of results.

METHODS

Thirty-eight TDM episodes were performed on 18 patients in a regional center in Australia during a 30-month period. Australian guidelines recommend a trough serum concentration of ≥700 mcg/L. The response to concentrations below the recommendation threshold (700 mcg/L), the final serum plasma concentration for each patient, and the appropriateness of TDM were evaluated.

RESULTS

A total of 19 (50%) concentrations were recorded to be < 700 mcg/L. Of these 19 concentrations, the drug dose was increased on only 4 occasions. Eleven of 18 patients (61%) had initial concentrations <700 mcg/L, with only 3 (27%) among those achieving final concentration ≥ 700 mcg/L; 5 patients with initial concentrations <700 mcg/L did not have any further TDM testing. Nine of the 18 (50%) patients had a final concentration <700 mcg/L. Five of 7 (71%) patients with initial concentrations ≥700 mcg/L had further TDM with no reasoning documented.

CONCLUSIONS

The results demonstrate a lack of confidence and consistency in ordering, interpreting, and following up posaconazole concentrations. Therefore, the use of TDM should be carefully considered, especially in regional centers. Such settings should consider the practicalities of posaconazole TDM and try to improve the process to ensure consistency and optimization of patient care.

Evaluation of Posaconazole Serum Concentrations from Delayed-Release Tablets in Patients at High Risk for Fungal Infections

The purpose of our study was to determine the frequency of patients who achieved a therapeutic drug level after receiving posaconazole (PCZ) delayed-release tablets (DRT) for prophylaxis or treatment of invasive fungal infections (IFIs) and to examine the effect of demographic traits and treatment characteristics on PCZ serum levels. A retrospective single-center study was conducted on high-risk inpatients at the University of Washington Medical Center (UWMC) that had received PCZ and obtained PCZ serum levels for either treatment or prophylaxis between 1 August 2014 and 31 August 2015. High-risk patients were defined as those undergoing chemotherapy for a primary hematologic malignancy and those undergoing hematopoietic cell transplantation (HCT) or solid organ transplantation. Serum trough concentrations of ≥700 μg/liter and ≥1,000 μg/liter were considered appropriate for prophylaxis and treatment, respectively. The most frequent underlying medical condition was a hematological malignancy (43/53, 81%). Twenty-six of 53 patients (49%) received PCZ for prophylaxis; the rest received PCZ for treatment. A total of 37/53 (70%) patients had PCZ serum levels of ≥700 μg/liter regardless of indication, including 22/26 (85%) that received PCZ for prophylaxis. Of the patients that received PCZ for treatment, only 12/27 (44%) had PCZ serum levels of ≥1,000 μg/liter. The odds of having therapeutic PCZ serum levels were not statistically different in patients with a weight of ≥90 kg, a diarrhea grade of ≥2, a mucositis grade of ≥2, or poor dietary intake. However, the odds of having therapeutic PCZ serum levels was 5.85 times higher in patients without graft-versus-host disease (GVHD) treatment than in those with GVHD treatment. Four patients on prophylaxis (15%) developed breakthrough IFIs, one of which had a subtherapeutic level. We concluded that the use of PCZ DRT provided adequate concentrations in only 70% of our patients and that recommended dosing may lead to insufficient levels in patients treated for IFIs. Lower concentrations noted among high-risk patients with GVHD suggest a need for prospective studies evaluating therapeutic drug monitoring and/or dose adjustments among these patients.

Voriconazole and posaconazole therapeutic drug monitoring: a retrospective study

Background

Therapeutic drug monitoring (TDM) aims to minimize the clinical impact of posaconazole and voriconazole pharmacokinetic variability. However, its benefits on clinical outcomes are still being defined. Additionally, TDM data are limited for posaconazole IV and delayed-release tablet formulations among specific patient populations, including critically ill. The aim of this study was to determine the percentage of therapeutic posaconazole and voriconazole drug levels across all formulations in a real-world clinical setting and elucidate factors affecting attainment of target concentrations.

Methods

This study was a retrospective cohort study conducted at the University of Colorado Hospital between September 2006 and June 2015 that evaluated patients who received posaconazole or voriconazole TDM as part of routine care.

Results

Voriconazole (n = 250) and posaconazole (n = 100) levels were analyzed from 151 patients. Of these, 54% of voriconazole and 69% of posaconazole levels were therapeutic. For posaconazole, 14/38 (37%), 28/29 (97%) and 27/33 (82%) levels were therapeutic for the oral suspension, IV, and delayed-release tablet, respectively. Intravenous and delayed-release tablet posaconazole were 20 fold (p < 0.01) and sevenfold (p = 0.002) more likely than the oral suspension to achieve a therapeutic level. Subsequent levels were more likely to be therapeutic after dose adjustments (OR 3.31; 95% CI 1.3–8.6; p = 0.02), regardless of timing of initial non-therapeutic level. In a multivariable logistic regression analysis, no characteristics were independently predictive of therapeutic voriconazole levels and only absence of H2RA/PPI use was independently predictive of therapeutic posaconazole levels. There was no correlation between survival and therapeutic drug levels for either voriconazole (p = 0.67) or posaconazole (p = 0.50).

Conclusions

A high percentage of drug levels did not achieve TDM targets for voriconazole and posaconazole oral suspension, supporting the need for routine TDM for those formulations. The utility of TDM for the IV and delayed-release tablet formulations of posaconazole is less apparent.

In Vivo 11β-Hydroxysteroid Dehydrogenase Inhibition in Posaconazole-Induced Hypertension and Hypokalemia

We describe a case of apparent mineralocorticoid excess (AME) secondary to posaconazole therapy and suggest the biochemical mechanism. Clinical and laboratory investigation confirmed 11β-hydroxysteroid dehydrogenase inhibition and withholding therapy led to a resolution of all clinical and laboratory abnormalities. Posaconazole was later restarted at a lower dose and prevented recurrence of this syndrome. Additional studies are necessary to determine the frequency of posaconazole-induced AME and whether other azole antifungals can be associated with this phenomenon.

Real-Life Assessment of the Safety and Effectiveness of the New Tablet and Intravenous Formulations of Posaconazole in the Prophylaxis of Invasive Fungal Infections via Analysis of 343 Courses

Posaconazole is the preferred mold-active azole for prophylaxis against invasive fungal infections (IFIs) in patients with hematological malignancy. Delayed-release tablet and intravenous formulations of posaconazole have recently become available, but clinical data are limited. We sought to examine the real-world pharmacokinetics and prophylactic effectiveness of the new formulations of posaconazole given as prophylaxis for patients with hematological malignancy. A retrospective cohort of all consecutive adult inpatients with hematological malignancy who received ≥3 days of tablet or intravenous posaconazole therapy for primary IFI prophylaxis at the M. D. Anderson Cancer Center between 1 December 2013 and 31 December 2015 was established. Clinical information was collected and correlated with low posaconazole serum levels (<700 ng/ml). Rates of IFIs and safety events were assessed. A total of 1,321 courses of posaconazole were administered at the M. D. Anderson Cancer Center during the study period, of which 343 courses were assessed for prophylactic safety and effectiveness. Seventy-nine patients (23%) had posaconazole serum level measurements available for interpretation. Acute myeloid leukemia was the primary malignancy (62%), with 20% of all patients having previously received a stem cell transplant. The median posaconazole level was 1,380 ng/ml (interquartile range, 864 to 1,860 ng/ml). Low posaconazole levels (<700 ng/ml) were observed for 14 patients (18%). Proven or probable breakthrough IFIs occurred in 8 patients (2%); posaconazole therapeutic drug monitoring (TDM) was performed for 6 of those patients, all with levels above 700 ng/ml. Overall, 19% of patients experienced grade 3 or 4 liver injury, manifesting primarily as hyperbilirubinemia and being correlated with serum levels of >1,830 ng/ml. Although hepatotoxicity in a small percentage of patients is of concern, posaconazole tablets appeared to be generally safe and effective. As all breakthrough IFIs for which TDM was performed occurred in patients with levels of >700 ng/ml, and a posaconazole level of >1,830 ng/ml was correlated with grade 3 or 4 liver toxicity, further studies are needed to assess the role of TDM.

Evaluation of Serum Posaconazole Concentrations in Patients with Hematological Malignancies Receiving Posaconazole Suspension Compared to the Delayed-Release Tablet Formulation

Posaconazole (PCZ) is frequently used for prophylaxis against invasive fungal infections (IFI) in patients undergoing induction chemotherapy for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Posaconazole is commercially available as an oral suspension (PCZ-susp) and as a delayed-release tablet (PCZ-tab). Differences in absorption and bioavailability between these formulations may result in variability in serum posaconazole concentrations. The primary objective of this retrospective analysis was to compare attainment of goal serum posaconazole steady state concentrations (C_ss) ≥ 700 ng/ml in patients with AML/MDS undergoing induction chemotherapy receiving PCZ-susp 600-800 mg per day (N = 118) versus PCZ-Tablet 300 mg twice daily for one day, followed by 300 mg daily (N = 64). Sixty-two patients (97%) in the PCZ-tab group compared to 20 patients (17%) in the PCZ-susp group achieved goal C_ss  (P < 0.0001). Median posaconazole serum C_ss was 1,665 ng/ml (522-3,830 mg/ml) in the PCZ-tab group versus 390 ng/ml (51-1,870 ng/ml) in the PCZ-susp group (P < 0.0001). There was no difference in hepatotoxicity, QTc prolongation, or breakthrough IFI. Patients receiving PCZ-tab were significantly more likely to achieve goal C_ss and demonstrated higher C_ss versus patients receiving PCZ-susp. Prospective studies are needed to assess the potential correlation of serum concentrations with efficacy and toxicity.

Comparison of Plasma Concentrations of Posaconazole with the Oral Suspension and Tablet in Korean Patients with Hematologic Malignancies

The posaconazole tablet formulation was developed to have improved bioavailability compared to the oral suspension. Here, we compared posaconazole plasma concentration (PPC) with the posaconazole oral suspension versus the tablet in Korean patients undergoing remission induction chemotherapy for hematologic malignancies. PPC was measured at 3, 8, and 15 days of treatment with the oral suspension (174 patients) or the tablet (40 patients). At all time-points, mean PPC was significantly higher with the tablet compared to the oral suspension. Our findings suggest that posaconazole tablets generate an optimal PPC earlier and in more patients than the oral suspension among Korean patients.

New facets of antifungal therapy

Invasive fungal infections remain a major cause of morbidity and mortality in immunocompromised patients, and such infections are a substantial burden to healthcare systems around the world. However, the clinically available armamentarium for invasive fungal diseases is limited to 3 main classes (i.e., polyenes, triazoles, and echinocandins), and each has defined limitations related to spectrum of activity, development of resistance, and toxicity. Further, current antifungal therapies are hampered by limited clinical efficacy, high rates of toxicity, and significant variability in pharmacokinetic properties. New antifungal agents, new formulations, and novel combination regimens may improve the care of patients in the future by providing improved strategies to combat challenges associated with currently available antifungal agents. Likewise, therapeutic drug monitoring may be helpful, but its present use remains controversial due to the lack of available data. This article discusses new facets of antifungal therapy with a focus on new antifungal formulations and the synergistic effects between drugs used in combination therapy.

Posaconazole Tablet Formulation at 400 Milligrams Daily Achieves Desired Minimum Serum Concentrations in Adult Patients with a Hematologic Malignancy or Stem Cell Transplant

We describe our experience using the posaconazole 400-mg delayed-release tablet formulation once daily in 20 patients with hematologic malignancy or hematopoietic stem cell transplant who were unable to attain prespecified target minimum serum (trough) concentrations for treatment or prophylaxis of invasive fungal infection. The higher dose allowed the majority of patients to achieve prespecified target trough concentrations without incurring additional toxicities.

Optimizing antifungal strategies to improve patient survival

Report from the 26th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID 2016), 9-12 April Amsterdam, The Netherlands Invasive fungal infections are a major threat to the lives of the increasing number of immunocompromized patients, but neutropenic hemato-oncology patients are at especially high risk. Since effective antifungal treatment and prophylaxis are critical to improve survival in these patients, the emergence of antifungal drug resistance has become an increasing cause of concern. Mortality from invasive fungal infection also remains high even when patients receive appropriate and timely antifungal therapy. These important topics were among those discussed by the over 11,600 clinical microbiologists and infectious disease physicians from more than 120 countries attending the 26th European Congress of Clinical Microbiology and Infectious Diseases.

Management of neutropenic patients in the intensive care unit (NEWBORNS EXCLUDED) recommendations from an expert panel from the French Intensive Care Society (SRLF) with the French Group for Pediatric Intensive Care Emergencies (GFRUP), the French Society of Anesthesia and Intensive Care (SFAR), the French Society of Hematology (SFH), the French Society for Hospital Hygiene (SF2H), and the French Infectious Diseases Society (SPILF)

Neutropenia is defined by either an absolute or functional defect (acute myeloid leukemia or myelodysplastic syndrome) of polymorphonuclear neutrophils and is associated with high risk of specific complications that may require intensive care unit (ICU) admission. Specificities in the management of critically ill neutropenic patients prompted the establishment of guidelines dedicated to intensivists. These recommendations were drawn up by a panel of experts brought together by the French Intensive Care Society in collaboration with the French Group for Pediatric Intensive Care Emergencies, the French Society of Anesthesia and Intensive Care, the French Society of Hematology, the French Society for Hospital Hygiene, and the French Infectious Diseases Society. Literature review and formulation of recommendations were performed using the Grading of Recommendations Assessment, Development and Evaluation system. Each recommendation was then evaluated and rated by each expert using a methodology derived from the RAND/UCLA Appropriateness Method. Six fields are covered by the provided recommendations: (1) ICU admission and prognosis, (2) protective isolation and prophylaxis, (3) management of acute respiratory failure, (4) organ failure and organ support, (5) antibiotic management and source control, and (6) hematological management. Most of the provided recommendations are obtained from low levels of evidence, however, suggesting a need for additional studies. Seven recommendations were, however, associated with high level of evidences and are related to protective isolation, diagnostic workup of acute respiratory failure, medical management, and timing surgery in patients with typhlitis.

Posaconazole Plasma Concentrations on Days Three to Five Predict Steady-State Levels

Low posaconazole plasma concentrations (PPCs) have been associated with breakthrough invasive fungal infections. We assessed the correlation between pre-steady-state PPCs (obtained between days 3 and 5) and PPCs obtained during steady state in 48 patients with underlying hematological malignancies receiving posaconazole oral-solution prophylaxis. Pre-steady-state PPCs correlated significantly with PPCs obtained at steady state (Spearman r = 0.754; P < 0.001). Receiver operating characteristic (ROC) curve analysis of pre-steady-state PPCs revealed an area under the curve (AUC) of 0.884 (95% confidence interval [CI], 0.790 to 0.977) for predicting satisfactory PPCs at steady state.

Antifungal agents and liver toxicity: a complex interaction

INTRODUCTION

The number of antifungal agents has sharply increased in recent decades. Antifungals differ in their spectrum of activity, pharmacokinetic/pharmacodynamic properties, dosing, safety-profiles and costs. Risk of developing antifungal associated hepatotoxicity is multifactorial and is influenced by pre-existing liver disease, chemical properties of the drug, patient demographics, comorbidities, drug-drug interactions, environmental and genetic factors. Antifungal related liver injury typically manifests as elevations in serum aminotransferase levels, although the clinical significance of these biochemical alterations is not always clear. Incidence rates of hepatotoxicity induced by antifungal therapy range widely, occurring most frequently in patients treated with azole antifungals for documented fungal infections.

AREAS COVERED

This review provides an update regarding the hepatotoxicity profiles of the modern systemic antifungals used in treatment of invasive fungal infections. Expert commentary: Understanding the likelihood and pattern of hepatotoxicity for all suspected drugs can aid the clinician in early detection of liver injury allowing for intervention and potential mitigation of liver damage. Therapeutic drug monitoring is emerging as a potential tool to assess risk for hepatotoxicity.