Treatment of Invasive Aspergillosis with Posaconazole in Patients Who Are Refractory to or Intolerant of Conventional Therapy: An Externally Controlled Trial

Real World Posaconazole Pharmacokinetic Data in Paediatric Stem Cell Transplant Recipients

Background: Invasive fungal disease is a significant cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (alloHSCT) recipients. Posaconazole, a broad-spectrum triazole, is widely used as prophylaxis. Methods: We conducted a monocentric, retrospective study to present real-world data on posaconazole trough levels in paediatric alloHSCT patients. The main objective was to determine the required daily dose of posaconazole in paediatric patients. We analysed factors influencing posaconazole levels, and the association between posaconazole levels and breakthrough fungal infection. Results: Among 102 allogeneic HSCT recipients, we measured posaconazole plasma concentrations in 548 blood samples. The required daily doses to reach a target range of 0.7-2.0 mg/L were 15.22 (suspension), 7.52 (tablet), and 7.84 mg/kg (intravenous). Patients aged < 13 years needed higher doses to achieve the target range. The presence of enteral symptoms during prophylaxis was associated with lower plasma concentrations (p < 0.001), while co-administration of proton pump inhibitors did not (p = 0.09). Eight breakthrough infections occurred; low levels of posaconazole (<0.7 mg/L) were observed in five out of eight cases. The Cox regression model showed that higher mean plasma concentrations decreased the hazard of breakthrough infections. Conclusions: The tablet and intravenous formulations of posaconazole outperformed the suspension in terms of predictability. Our analyses on breakthrough infections and posaconazole plasma levels suggest an exposure-response relationship.

Relationship between posaconazole concentrations and clinical outcomes in paediatric cancer and haematopoietic stem cell transplant recipients

BACKGROUND

Posaconazole is used to prevent and treat invasive fungal infections (IFIs) in immunocompromised children, including those undergoing cancer treatment or HSCT. Despite differences in pharmacokinetics and IFI epidemiology between children and adults, therapeutic targets established in adult studies are often applied to children.

OBJECTIVES

This systematic review evaluated the correlation between serum posaconazole concentrations and clinical outcomes of IFI prophylaxis and treatment in children with malignancies or HSCT recipients.

METHODS

Four databases (Cochrane, Embase, MEDLINE and PubMed) were searched for studies involving children (≤18 years old) receiving cancer treatment or HSCT that reported posaconazole serum concentrations and treatment outcomes. Animal studies, those primarily in adult (>18 years old) populations, non-malignant conditions (excluding HSCT), case reports, letters, editorials, conference abstracts and narrative reviews were excluded. Bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Nineteen studies were included: 12 reported outcomes of posaconazole prophylaxis; two of treatment; and five of both. For prophylaxis, breakthrough IFIs occurred in 1%-12% of children. All but one occurred with serum concentrations of ≤0.7 mg/L. For treatment, no clear association was observed between a trough concentration of >1.0 mg/L and treatment efficacy, with poor outcomes reported for serum concentrations ranging between 0.2 and 4.8 mg/L. Overall, quality of evidence was poor (medium to high risk of bias for 18 papers, low risk for 1 paper) and there was variation in IFI definitions across studies.

CONCLUSIONS

This review supports current recommendations for posaconazole prophylaxis in paediatric oncology and HSCT recipients. The absence of a clear correlation found between serum trough concentrations and treatment efficacy highlights the need for further studies to determine optimal therapeutic targets for treatment.

Appraisal of guidelines and variations in recommendations on drug therapy for invasive aspergillosis prevention and treatment

Background

In recent years, many guidelines related to aspergillosis have been published worldwide. However, no studies have applied assessment tools to systematically evaluate the quality of these guidelines.

Objectives

This study aimed to assess the quality of clinical practice guidelines and compared their recommendations related to drug therapy for the prevention and treatment of invasive aspergillosis.

Methods

Electronic databases, guideline development organizations, and professional society websites were searched to identify clinical practice guidelines for invasive aspergillosis published between 1 January 2013, and 12 September 2023. The Appraisal of Guidelines Research and Evaluation (AGREE) II instrument was used to evaluate the quality of the guidelines. Recommendations for the drug prevention and treatment of invasive aspergillosis were extracted and descriptively analyzed.

Results

Among the 18 included clinical practice guidelines, the median scores and interquartile range for each AGREE II domain were: scope and purpose, 76.39% (69.1%, 80.21%); stakeholder involvement, 59.72% (50.35%, 67.02%); rigor of development, 64.58% (44.4%, 72.27%); clarity and presentation, 81.25% (68.06%, 91.32%); applicability, 41.67% (36.46%, 47.92%); and editorial independence, 76.05% (50%, 87.5%). Voriconazole and isavuconazole are recommended as first-line therapy for invasive aspergillosis currently. Posaconazole remains the first choice for invasive aspergillosis prophylaxis in patients with hematological malignancies.

Conclusion

The development processes and reporting of invasive aspergillosis -related clinical practice guidelines varied and their quality requires improvement. The guideline recommendations have changed since the approval of isavuconazole.

Outcome Analysis of Breakthrough Invasive Aspergillosis on Anti-Mold Azole Prophylaxis and Treatment: 30-Year Experience in Hematologic Malignancy Patients

BACKGROUND

Anti-mold azoles have improved the outcomes of invasive aspergillosis (IA) when used therapeutically, but they are extensively used as prophylaxis. There are limited data regarding the outcomes of patients with hematologic malignancy who develop breakthrough IA on anti-mold azoles. We aimed to determine whether breakthrough IA on azole prophylaxis shows worse outcomes compared to no prophylaxis.

METHODS

We compared outcomes including therapy response and mortality between antifungal regimens in hematologic malignancy patients with IA between July 1993 and July 2023.

RESULTS

Compared to an amphotericin B-containing regimen (AMB), an anti-mold azole as the primary therapy was independently associated with successful response at the end of therapy (OR = 4.38, p < 0.0001), protective against 42-day IA-associated mortality (OR = 0.51, p = 0.024) or all cause mortality (OR = 0.35, p < 0.0001), and protective against 84-day mortality, both IA-associated (OR = 0.50, p = 0.01) and all-cause mortality (OR = 0.27, p < 0.0001). Azole prophylaxis was independently associated with higher IA-associated mortality at 42 days (OR = 1.91, p = 0.012) and 84 days (OR = 2.03, p = 0.004), compared to fluconazole or no prophylaxis.

CONCLUSIONS

Patients with breakthrough IA on anti-mold azole prophylaxis show a worse prognosis than those on other or no prophylaxis, possibly related to the emergence of azole resistance due to their widespread use as prophylaxis agents. On the other hand, anti-mold azole primary therapy is superior to AMB therapy in the treatment of IA.

Controversies in the clinical management of chronic pulmonary aspergillosis

Chronic pulmonary aspergillosis has a range of manifestations from indolent nodules to semi-invasive infection. Patients may be asymptomatic or have chronic symptoms such as cough and weight loss or present with life-threatening haemoptysis. The physician can choose from a range of available therapies including medical therapy with antifungals, minimally invasive therapy with intracavitary antifungal therapy and surgery involving open thoracotomy or video-assisted thoracoscopic surgery. The patients with the most severe forms of pulmonary infection may not be surgical candidates due to their underlying pulmonary condition. The management of haemoptysis can include tranexamic acid, bronchial artery embolisation, antifungals or surgery. There are few controlled studies to inform clinicians managing complex cases, so a multidisciplinary approach may be helpful.

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.

An update on pharmacotherapy for fungal infections in allogeneic stem cell transplant recipients

INTRODUCTION

Invasive fungal diseases (IFD) constitute a major cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients.

AREAS COVERED

We describe epidemiology, causes and risk factors of IFD in allogeneic HSCT discussing prophylaxis and treatment in various HSCT phases. We present the most recent studies on this thematic area, including novel data on currently available antifungals, i.e. formulations, dosing, safety, efficacy and therapeutic drug monitoring. Finally, we present the most recent relevant recommendations published. Literature search included PubMed, Scopus, and clinicaltrials.gov between January 2014 and April 2024.

EXPERT OPINION

The antifungal agents employed for prophylaxis and therapy should be predicated on local epidemiology of IFD. Fluconazole prophylaxis remains a first-line choice before engraftment when the main pathogen is Candida spp. After engraftment, prophylaxis should be with mold-active agents (i.e. triazoles). For candidiasis, echinocandins are suggested as first-line treatment, whereas aspergillosis responds well to mold-active azoles and liposomal amphotericin B (L-AmB). For mucormycosis, treatment of choice includes L-AmB and isavuconazole. Choice between fever-driven and diagnostics-driven strategies remains equivocal. Open research topics remain: 1) optimization of tools to ensure prompt and accurate IFD diagnosis to avoid unnecessary exposure to antifungals, drug interactions and cost; 2) refinement of treatment for resistant/refractory strains.

Dosing of IV posaconazole to treat critically ill patients with invasive pulmonary aspergillosis: a population pharmacokinetics modelling and simulation study

BACKGROUND

Posaconazole is used for the prophylaxis and treatment of invasive fungal infections in critically ill patients. Standard dosing was shown to result in adequate attainment of the prophylaxis Cmin target (0.7 mg/L) but not of the treatment Cmin target (1.0 mg/L).

OBJECTIVES

To provide an optimized posaconazole dosing regimen for IV treatment of patients with invasive pulmonary aspergillosis in the ICU.

METHODS

A population pharmacokinetics (popPK) model was developed using data from the POSA-FLU PK substudy (NCT03378479). Monte Carlo simulations were performed to assess treatment Cmin and AUC0-24 PTA. PTA ≥90% was deemed clinically acceptable. PopPK modelling and simulation were performed using NONMEM 7.5.

RESULTS

Thirty-one patients with intensive PK sampling were included in the PK substudy, contributing 532 posaconazole plasma concentrations. The popPK of IV posaconazole was best described by a two-compartment model with linear elimination. Interindividual variability was estimated on clearance and volume of distribution in central and peripheral compartments. Posaconazole peripheral volume of distribution increased with bodyweight. An optimized loading regimen of 300 mg q12h and 300 mg q8h in the first two treatment days achieved acceptable PTA by Day 3 in patients <100 kg and ≥100 kg, respectively. A maintenance regimen of 400 mg q24h ensured ≥90% Cmin PTA, whereas the standard 300 mg q24h was sufficient to achieve the AUC0-24 target throughout 14 days, irrespective of bodyweight.

CONCLUSIONS

We have defined a convenient, optimized IV posaconazole dosing regimen that was predicted to attain the treatment target in critically ill patients with invasive aspergillosis.

Antifungal Susceptibility and Genotypic Analysis of cyp51A Mutations in Aspergillus fumigatus Isolates in Malaysia

Purpose

Azole resistance in Aspergillus fumigatus poses a significant challenge in the management of invasive aspergillosis. This study aimed to investigate the antifungal susceptibility and cyp51A mutation profiles of A. fumigatus isolates in Malaysia.

Patients and Methods

Sixty clinical A. fumigatus isolates were collected and subjected to antifungal susceptibility testing (AFST) and molecular analysis. The antifungal susceptibility testing was performed according to CLSI M38 guideline. The geometric mean (GM) minimum inhibitory concentration (MIC), MIC50/MIC90 for voriconazole, itraconazole, posaconazole, amphotericin B, and isavuconazole against A. fumigatus in non-invasive cases and invasive cases were calculated. In addition, the presence of cyp51A mutations was also identified.

Results

The present study revealed an overall resistance rate of 6.7% among the isolates. In non-invasive cases, isavuconazole and posaconazole demonstrated the lowest GM MIC of 0.08 µg/mL. Following them were itraconazole, voriconazole, and amphotericin B with concentrations of 0.15µg/mL, 0.16µg/mL and 0.90µg/mL, respectively. Similarly, in invasive cases, isavuconazole and posaconazole exhibited the lowest GM MIC of 0.09µg/mL. Following them were itraconazole, voriconazole, and amphotericin B with concentrations of 0.14µg/mL, 0.17µg/mL and 0.80µg/mL, respectively. Genotypic analysis revealed various cyp51A mutations, including F46Y, M172V, N248K, R34L, V244A, V244S, and E427K. However, not all mutations corresponded to antifungal resistance.

Conclusion

The majority of clinical Aspergillus fumigatus isolates demonstrated susceptibility to the antifungal agents tested, with isavuconazole and posaconazole demonstrating the lowest MIC values. However, cyp51A mutations were discovered without a consistent correlation to antifungal resistance, emphasising the need for additional research.

Personalized Antifungal Therapy Through Model-Informed Precision Dosing of Posaconazole

BACKGROUND AND OBJECTIVE

Posaconazole is a pharmacotherapeutic pillar for prophylaxis and treatment of invasive fungal diseases. Dose individualization is of utmost importance as achieving adequate antifungal exposure is associated with improved outcome. This study aimed to select and evaluate a model-informed precision dosing strategy for posaconazole.

METHODS

Available population pharmacokinetic models for posaconazole administered as a solid oral tablet were extracted from the literature and evaluated using data from a previously published prospective study combined with data collected during routine clinical practice. External evaluation and selection of the most accurate and precise model was based on graphical goodness-of-fit and predictive performance. Measures for bias and imprecision included mean percentage error (MPE) and normalized relative root mean squared error (NRMSE), respectively. Subsequently, the best-performing model was evaluated for its a posteriori fit-for-purpose and its suitability in a limited sampling strategy.

RESULTS

Seven posaconazole models were evaluated using 764 posaconazole plasma concentrations from 143 patients. Multiple models showed adequate predictive performance illustrated by acceptable goodness-of-fit and MPE and NRMSE below ± 10% and ± 25%, respectively. In the fit-for-purpose analysis, the selected model showed adequate a posteriori predictive performance. Bias and imprecision were lowest in the presence of two prior measurements. Additionally, this model showed to be useful in a limited sampling strategy as it adequately predicted total posaconazole exposure from one (non-)trough concentration.

CONCLUSION

We validated an MIPD strategy for posaconazole for its fit-for-purpose. Thereby, this study is an important first step towards MIPD-supported posaconazole dosage optimization with the goal to improve antifungal treatment in clinical practice.

Therapeutic drug monitoring of antifungal therapies: do we really need it and what are the best practices?

INTRODUCTION

Despite advancements, invasive fungal infections (IFI) still carry high mortality rates, often exceeding 30%. The challenges in diagnosis, coupled with limited effective antifungal options, make managing IFIs complex. Antifungal drugs are essential for IFI management, but their efficacy can be diminished by drug-drug interactions and pharmacokinetic variability. Therapeutic Drug Monitoring (TDM), especially in the context of triazole use, has emerged as a valuable strategy to optimize antifungal therapy.

AREAS COVERED

This review provides current evidence regarding the potential benefits of TDM in IFI management. It discusses how TDM can enhance treatment response, safety, and address altered pharmacokinetics in specific patient populations.

EXPERT OPINION

TDM plays a crucial role in achieving optimal therapeutic outcomes in IFI management, particularly for certain antifungal agents. Preclinical studies consistently show a link between therapeutic drug levels and antifungal efficacy. However, clinical research in mycology faces challenges due to patient heterogeneity and the diversity of fungal infections. TDM's potential advantages in guiding Echinocandin therapy for critically ill patients warrant further investigation. Additionally, for drugs like Posaconazole, assessing whether serum levels or alternative markers like saliva offer the best measure of efficacy is an intriguing question.

Population pharmacokinetics of posaconazole in allogeneic haematopoietic stem cell transplant patients

BACKGROUND

Invasive fungal disease (IFD) in the early post-allogeneic HSCT (alloHCT) period is associated with increased likelihood of catastrophic outcomes. The utility of oral modified release (MR) posaconazole tablets is limited by reduced drug absorption from gastrointestinal toxicity induced by cytotoxic chemotherapy, necessitating a switch to the IV posaconazole formulation.

OBJECTIVES

To describe the population pharmacokinetics of posaconazole for oral MR and IV formulations in alloHCT patients and determine dosing regimens likely to achieve therapeutic exposures.

METHODS

We performed a prospective observational pharmacokinetic study in adult patients in the early post-alloHCT period requiring a change in posaconazole formulation (oral to IV). Samples were analysed using a validated LC-MS/MS method. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using Pmetrics for R.

RESULTS

Twenty patients aged between 21 and 70 years were included in the study. A two-compartment model, incorporating mucositis/diarrhoea to modify the bioavailability for oral administration best described the data. To achieve ≥90% PTA, simulations showed that higher than currently recommended doses of oral MR posaconazole were required for prophylaxis Cmin targets (≥0.5 and ≥0.7 mg/L), while increased doses of both formulations were required for IFD treatment PK/PD targets, with patients experiencing oral mucositis/diarrhoea unlikely to achieve these.

CONCLUSIONS

Increased doses of posaconazole should be considered for both prophylaxis and treatment of IFD to increase the proportion of alloHCT patients achieving therapeutic exposures, particularly the oral formulation in patients with mucositis and/or diarrhoea. Posaconazole therapeutic drug monitoring should be considered for all formulations in this setting.

Antifungal Therapies for Aspergillus spp.: Present and Future

Currently available and recommended options for the treatment of pulmonary aspergillosis include the triazoles, echinocandins, and amphotericin B products. These therapies have significant limitations. Only the azoles are available orally, but their use is often limited by toxicities, drug-drug interactions, pharmacokinetic variability, and emerging resistance. While the echinocandins are safe agents and may have a role in combination therapy, they are unproven as monotherapy. Amphotericin B preparations are toxic and require intensive monitoring. Finally, aspergillosis continues to be a disease conferring substantial morbidity and mortality, and clinical trials have not identified a therapeutic approach clearly associated with improved outcomes. As a result, there is a great need for new options in the treatment of invasive aspergillosis. Ideally, such options would be safe, have high oral bioavailability, have favorable pharmacokinetics to sequestered sites and retain activity against azole-resistant isolates. Reassuringly, there is a robust pipeline of novel therapies in development. Rezafungin (a once-weekly dosed echinocandin) and ibrexafungerp (oral agent with same mechanism of action as echinocandins) will likely be reserved for combination therapy or refractory/intolerance scenarios with no other options. Inhaled opelconazole is an attractive option for combination therapy and prophylaxis of pulmonary aspergillosis. Development of an oral form of amphotericin B that avoids nephrotoxicity and electrolyte disturbances is an exciting development. Finally, olorofim and fosmanogepix, two agents with novel mechanisms of action and oral formulations, hold significant potential to challenge the triazole antifungals place as preferred therapies. However, many questions remain regarding these novel agents, and at the time of this writing, none of these agents have been robustly studied in Phase III studies of aspergillosis, and so their promise remains investigational.

COVID-19-associated pulmonary aspergillosis in intensive care unit: A real-life experience

Since 2020, cases of COVID-19-associated pulmonary aspergillosis (CAPA) have been frequently described, representing an important cause of mortality, especially among patients admitted to intensive care unit (ICU). A predisposition to invasive infection caused by Aspergillus spp. in SARS-CoV-2 infected patients can be ascribed either to the direct viral-mediated damage of the respiratory epithelium or to the dysregulated immunity associated with COVID-19. In this case series we have collected the clinical, laboratory and radiological data of 10 patients admitted to the ICU with diagnosis of probable CAPA, according to the recent expert consensus statement, from March 2020 to December 2022 in the Teaching Hospital of Catanzaro in Italy. Overall, 249 patients were admitted to the COVID-19-ICU from March 2020 to December 2022; out of these, 4% developed a probable CAPA. Most of patients were male with a mean age of 62 years. Only two patients had an underlying immunocompromising condition. The observed mortality was 70%. In our institution, all COVID-19 patients requiring invasive mechanical ventilation systematically underwent bronchoscopy with bronchoalveolar lavage for an early evaluation of bacterial and/or fungal co- or super-infections, including galactomannan test. Patients were re-evaluated by an infectious diseases consultant team every 24-48 hours and the galactomannan test was systematically repeated based on patient's clinical course. Even though the numbers in this study are very small, we report our experience about the role of early diagnosis and careful choice of antifungal therapy, considering the fragility of these patients, and its relationship with outcomes. Despite a systemic approach allowing early diagnosis and initiation of anti-fungal therapy, the mortality rate turned out to be very high (70%).

Preclinical Pharmacokinetic/Pharmacodynamic Studies and Clinical Trials in the Drug Development Process of EMA-Approved Antifungal Agents: A Review

Antifungal drug development is essential as invasive fungal disease is still associated with a very high mortality rate and the emergence of resistant species in the last decade. In Europe, the European Medical Agency (EMA) approves antifungals and publishes the European Public Assessment Report (EPAR) including the information leading up to the authorisation. We looked at EMA-approved antifungals and their reports within the last 23 years. We focused primarily on the role of pharmacokinetic/pharmacodynamic indices in antifungal development and the level of information depicted in their corresponding report. Furthermore, we investigated guidelines applicable to the development process at the time and compared the content with a focus on pharmacokinetic/pharmacodynamic studies and preclinical requirements. Since 2000, six new antifungal substances have been authorised. Most were authorised for treatment of Candida infections or Aspergillus infections but also included rarer pathogens. Pharmacokinetic/pharmacodynamic indices were scarcely investigated and/or mentioned in the report. Current antifungal EMA guidelines started emphasising investigating pharmacokinetic/pharmacodynamic indices in 2010 and then again in 2016. It remains to be seen how this translates into the authorisation process for new antifungals.

Triazole Antifungal Quantification for Therapeutic Drug Monitoring in Serum by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS): Posaconazole, Voriconazole, Itraconazole, and Hydroxyitraconazole

Antifungal therapy with triazole drugs including posaconazole, voriconazole, itraconazole, and its active metabolite hydroxyitraconazole is routinely accompanied by therapeutic drug monitoring to ensure optimal dosing. The method presented here simultaneously quantitates these compounds in serum by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Specimen preparation includes protein precipitation with a methanol and acetonitrile mixture, centrifugation, and filtration. Analyte separation is achieved by reverse-phase chromatography using a dC18 column and a linear gradient of methanol in water. Analytes are detected by multiple reaction monitoring mass spectrometry and quantitated by comparison to a standard curve.

Single-Dose Crossover Comparative Bioavailability Study of Two Different Posaconazole 100 mg Gastro-Resistant Tablets Under Fasted and Fed Conditions in Healthy Volunteers

Objective

This study aimed to compare the bioavailability of two different gastro-resistant oral tablet formulations of posaconazole under fasted and fed conditions and to evaluate a potential food effect on the bioavailability of each formulation.

Materials and Methods

Healthy volunteers randomly assigned to receive a test product (Posagil® 100 mg gastro-resistant tablet) or reference product (Noxafil® 100 mg gastro-resistant tablet) were included in this single-center, randomized, four-period (days 1, 15, 29 and 43), four-sequence crossover comparative bioavailability study. Data on posaconazole plasma concentrations and related pharmacokinetic profile (the maximum observed plasma concentration [Cmax] from time 0 to the time of last observed quantifiable plasma concentration [AUC0-T] and from time zero to infinity [AUC0-∞]) were recorded to evaluate efficacy of the test product in relation to the reference product under both fasted and fed conditions, based on bioequivalence (T-fasted vs. R-fasted and T-fed vs. R-fed) and food effect (T-fasted vs. T-fed and R-fasted vs. R-fed) assessments. Safety was evaluated through assessment of adverse events (AEs), standard laboratory evaluations, and vital signs.

Results

The bioequivalence criteria were met under fed conditions (T-fed vs. R-fed: geometric LSMean ratios of Cmax, AUC0-T, and AUC0-∞ of posaconazole were 97.41%, 97.45%, and 97.08%, respectively; all within the range of 80% to 125%) but not under fasted conditions. There was a food effect on the reference product (R-fed vs. R-fasted: geometric LSMean ratios of Cmax, AUC0-T, and AUC0-∞ of posaconazole were 145.32%, 138.84%, and 138.46%, respectively) but not on the test product. No safety concerns were identified.

Conclusions

Our findings suggest that the pharmacokinetic profile of Posagil® is similar to the pharmacokinetic profile of Noxafil®. The generic Posagil® seems to have similarly high bioavailability under fed and fasted conditions, offering a higher posaconazole exposure than the original Noxafil® in the fasted state. Hence, Posagil® may be considered a value-added generic product that offers adequate posaconazole exposure under fasted state and fed state, regardless of the concomitant high-fat meal intake.

Meta-pharmacokinetic analysis of posaconazole following dosing of oral suspension, delayed-release tablet, and intravenous infusion in patients vs. healthy volunteers: Impact of clinical characteristics and race

OBJECTIVES

To investigate the potential impact of clinical characteristics and the Chinese race on posaconazole pharmacokinetics in patients using an integrated population pharmacokinetic model for posaconazole oral suspension (SUS), delayed-release tablet (DR-tablet), and intravenous (IV) infusion that was developed in healthy volunteers (HV).

METHODS

1046 concentrations from 105 prospectively studied Caucasian patients receiving either of the three posaconazole formulations were pooled with 3898 concentrations from 182 HV. Clinical characteristics were tested for significance. The impact of Chinese race was assessed using 292 opportunistic samples from 80 Chinese patients receiving SUS.

RESULTS

Bioavailability of SUS (Fsus) in patients decreased from 38.2% to 24.6% when the dose was increased from 100 mg to 600 mg. Bioavailability of DR-tablet (Ftab) was 59% regardless of dose. Mucositis, diarrhoea, administration through a nasogastric tube, and concomitant use of proton pump inhibitors or metoclopramide reduced Fsus by 61%, 36%, 44%, 48%, and 29%, respectively, putting patients with these characteristics at increased risk of inadequate exposure. Clearance decreased from 7.0 to 5.1 L/h once albumin levels were <30 g/L. Patients showed an 84.4% larger peripheral volume of distribution (Vp) and 67.5% lower intercompartmental clearance (Q) compared with HV. No racial difference could be identified.

CONCLUSIONS

Pharmacokinetics of posaconazole in patients differ considerably to those in HV, with altered Fsus that is also impacted by clinical covariates, an Ftab similar to fasted conditions in HV, and altered parameters for clearance, Vp, and Q. There was no evidence to indicate that Chinese patients require a different dose to Caucasian patients.

Effect of Mycetoma in Lung Transplant Patients - a Single Center Experience

BACKGROUND

Mycetomas are uncommon in lung transplant recipients. Prior studies have shown increased mortality associated with mycetoma in lung transplant recipients (LTR). We reviewed our center's experience in outcome of LTRs with pre -or post-transplant mycetoma.

METHODS

We retrospectively reviewed electronic health records of LTRs performed at our institute between January 1, 2013 to December 31, 2020.

RESULTS

Mycetoma was present in less than 1 percent of LTR patients (7/1086). Mean age at the time of the transplant was 65 years. Idiopathic pulmonary fibrosis (5/7), interstitial lung disease (1/7), and sarcoidosis (1/7) were underlying pulmonary diagnoses. Seventy-one percent (5/7) received single lung transplant and 29% received double lung transplant. Seventy-one percent had negative serum galactomannan vs 29% (2/7) of patients who had positive serum galactomannan (one post and one pre). Fifty-seven percent had positive bronchoalveolar aspergillus galactomannan (23% had negative). A total of 42% (3/7) were found to have mycetoma before transplant and 58% (4/7) had mycetoma post transplant. Chest computed tomography findings in all patients were consistent with mycetoma.

CONCLUSIONS

In our cohort of patients, mycetoma was not found to be the primary cause of death if diagnosed pre transplant. Transplant recipients with mycetoma pre transplant did not develop invasive fungal infection or mycetoma post transplant. Careful evaluation of lung transplant candidates with mycetoma is critical. Further studies are needed to determine optimal duration of antifungal therapy and to determine if surgical resection may be needed to manage post-lung transplant mycetoma.

Invasive pulmonary aspergillosis in the intensive care unit: current challenges and best practices

The prevalence of invasive pulmonary aspergillosis (IPA) is growing in critically ill patients in the intensive care unit (ICU). It is increasingly recognized in immunocompetent hosts and immunocompromised ones. IPA frequently complicates both severe influenza and severe coronavirus disease 2019 (COVID-19) infection. It continues to represent both a diagnostic and therapeutic challenge and can be associated with significant morbidity and mortality. In this narrative review, we describe the epidemiology, risk factors and disease manifestations of IPA. We discuss the latest evidence and current published guidelines for the diagnosis and management of IPA in the context of the critically ill within the ICU. Finally, we review influenza-associated pulmonary aspergillosis (IAPA), COVID-19-associated pulmonary aspergillosis (CAPA) as well as ongoing and future areas of research.

Pharmacokinetic and Exposure Response Analysis of the Double-Blind Randomized Study of Posaconazole and Voriconazole for Treatment of Invasive Aspergillosis

BACKGROUND AND OBJECTIVE

A double-blind phase 3 study was conducted to compare posaconazole 300 mg intravenously (IV)/300 mg orally once daily (twice daily day 1) with voriconazole 4 mg/kg IV twice daily/200 mg orally twice daily (6 mg/kg day 1) for treatment of invasive aspergillosis. This analysis was conducted to summarize the pharmacokinetics and exposure-response relationships of posaconazole and voriconazole using plasma trough concentration (Ctrough) as a surrogate for exposure from the double-blind phase 3 study.

METHODS

The pharmacokinetic evaluable population included all intention-to-treat (ITT) participants with at least one plasma concentration during the treatment period. Treatment blinding was maintained without therapeutic drug monitoring. Ctrough sampling occurred throughout treatment; efficacy and safety were evaluated using quartiles determined by mean Ctrough concentrations. Exposure efficacy variables included day 42 all-cause mortality (primary study endpoint) and global clinical response. Exposure safety variables included all adverse events and treatment-related adverse events.

RESULTS

The pharmacokinetic analysis population included 506 of 575 ITT participants (437 with Ctrough concentrations: 228 posaconazole, 209 voriconazole). No trend was seen across quartiles of posaconazole Ctrough for the key efficacy endpoint of all-cause mortality through day 42. Participants in the highest quartile of voriconazole Ctrough had higher all-cause mortality through day 42 than participants in the lower three quartiles of voriconazole Ctrough. Similar findings were observed for global clinical response and Ctrough. No clear exposure safety trend by quartile was seen for posaconazole or voriconazole.

CONCLUSIONS

A strong exposure-response relationship was not observed across the range of exposure from the administered doses and formulations for posaconazole or voriconazole.

TRIAL REGISTRATION

NCT01782131; registered January 30, 2013.

Food and Drug Administration Public Workshop Summary-Development Considerations of Antifungal Drugs to Address Unmet Medical Need

Pressing challenges in the treatment of invasive fungal infections (IFIs) include emerging and rare pathogens, resistant/refractory infections, and antifungal armamentarium limited by toxicity, drug-drug interactions, and lack of oral formulations. Development of new antifungal drugs is hampered by the limitations of the available diagnostics, clinical trial endpoints, prolonged trial duration, difficulties in patient recruitment, including subpopulations (eg, pediatrics), and heterogeneity of the IFIs. On 4 August 2020, the US Food and Drug Administration convened a workshop that included IFI experts from academia, industry, and other government agencies to discuss the IFI landscape, unmet need, and potential strategies to facilitate the development of antifungal drugs for treatment and prophylaxis. This article summarizes the key topics presented and discussed during the workshop, such as incentives and research support for drug developers, nonclinical development, clinical trial design challenges, lessons learned from industry, and potential collaborations to facilitate antifungal drug development.

Therapeutic drug monitoring-guided dosing for pediatric cystic fibrosis patients: recent advances and future outlooks

INTRODUCTION

Medicine use in children with cystic fibrosis (CF) is complicated by inconsistent pharmacokinetics at variance with the general population, a lack of research into this and its effects on clinical outcomes. In the absence of established dose regimens, therapeutic drug monitoring (TDM) is a clinically relevant tool to optimize drug exposure and maximize therapeutic effect by the bedside. In clinical practice though, use of this is variable and limited by a lack of expert recommendations.

AREAS COVERED

We aimed to review the use of TDM in children with CF to summarize recent developments, current recommendations, and opportunities for future directions. We searched PubMed for relevant publications using the broad search terms "cystic fibrosis" in combination with the specific terms "therapeutic drug monitoring (TDM)" and "children." Further searches were undertaken using the name of identified drugs combined with the term "TDM."

EXPERT OPINION

Further research into the use of Bayesian forecasting and the relationship between exposure and response is required to personalize dosing, with the opportunity for the development of expert recommendations in children with CF. Use of noninvasive methods of TDM has the potential to improve accessibility to TDM in this cohort.

Evolution of antifungals for invasive mold infections in immunocompromised hosts, then and now

INTRODUCTION

The current armamentarium of antifungal agents for invasive mold infections (IMI) has dramatically improved over the last 50 years. Existing therapies are, however, associated with toxicities, drug interactions, and in some cases, therapeutic failures. Novel antifungals are needed to address the increasing prevalence of IMI and the growing threat of antifungal resistance.

AREAS COVERED

We review the history and development of the most commonly used antifungals. We discuss the current consensus guidelines and supporting data for treatment of invasive mold infection (IMI), the role of susceptibility testing, and the niche that novel antifungals could fill. We review the current data for aspergillosis, mucormycosis, and hyalohyphomycosis.

EXPERT OPINION

Robust clinical trial data demonstrating the relative effectiveness of our current antifungal agents for treating IMI outside of A. fumigatus remains limited. Clinical trials are urgently needed to delineate the relationship between MICs and clinical outcomes for existing agents and to better evaluate the invitro and in-vivo aspects of antifungal synergy. Continued international multicenter collaboration and standardized clinical endpoints for trials evaluating both existing and new agents is necessary to advance the field.

Model-Informed Dose Justifications of Posaconazole in Japanese Patients for Prophylaxis and Treatment Against Fungal Infection

Posaconazole is a globally approved broad-spectrum triazole antifungal compound. In Japanese patients, posaconazole has identical dosing regimens as those approved globally for both tablet and intravenous formulations. This article aims to describe a model-informed approach for dose justification of posaconazole in the Japanese population as either high-risk patients with fungal infections (prophylaxis patients) or patients with fungal infections (treatment patients). A simultaneous population pharmacokinetic (PK) model for tablet and intravenous formulation was developed on the basis of a data set including Japanese data from healthy participants and treatment patients. The PK profiles and exposure distributions in Japanese patients were predicted and compared against foreign patients, that is, patients outside of Japan. Relationships between the post hoc posaconazole exposures and frequently observed clinical adverse events were evaluated. Although clinical trials for Japanese prophylaxis patients were not conducted, PK profiles in Japanese prophylaxis patients were predicted using the population PK model and demographic covariate information obtained from the published literature. Based upon the globally approved dosing regimen, posaconazole exposure distribution was predicted to be the highest in Japanese treatment patients, and generally similar between Japanese and foreign prophylaxis patients. Exposures in Japanese patients exceeded the efficacy target level (500 ng/mL). Safety profiles in Japanese treatment patients with the highest exposures were clinically acceptable without specific concerns to Japanese patients and appeared to have no relationship with posaconazole exposures. From PK, safety, and efficacy perspectives, the use of the same dosing regimen as in foreign patients was justified in Japanese prophylaxis and treatment patients.

Invasive aspergillosis in liver transplant recipients

BACKGROUND

Liver transplantation is increasing worldwide with underlying pathologies dominated by metabolic and alcoholic diseases in developed countries.

METHODS

We provide a narrative review of invasive aspergillosis (IA) in liver transplant (LT) recipients. We searched PubMed and Google Scholar for references without language and time restrictions.

RESULTS

The incidence of IA in LT recipients is low (1.8%), while mortality is high (∼50%). It occurs mainly early (<3 months) after LT. Some risk factors have been identified before (corticosteroid, renal, and liver failure), during (massive transfusion and duration of surgical procedure), and after transplantation (intensive care unit stay, re-transplantation, re-operation). Diagnosis can be difficult and therefore requires full radiological and clinicobiological collaboration. Accurate identification of Aspergillus species is recommended due to the cryptic species, and susceptibility testing is crucial given the increasing resistance of Aspergillus fumigatus to azoles. It is recommended to reduce the dose of tacrolimus (50%) and to closely monitor the trough level when introducing voriconazole, isavuconazole, and posaconazole. Surgery should be discussed on a case-by-case basis. Antifungal prophylaxis is recommended in high-risk patients. Environmental preventative measures should be implemented to prevent outbreaks of nosocomial aspergillosis in LT recipient units.

CONCLUSION

IA remains a very serious disease in LT patients and should be promptly sought and, if possible, prevented by clinicians when risk factors are identified.

Aspergillus infection in chronic obstructive pulmonary diseases

Chronic obstructive pulmonary disease (COPD) is a chronic airway non-specific inflammatory disease characterised by airway obstruction and alveolar destruction. In recent years, due to the extensive use of antibiotics, glucocorticoids, immunosuppressants and other drugs, pulmonary fungal infection in patients with AECOPD, especially aspergillus infection, has gradually increased. The forms of aspergillus infection present in COPD patients include sensitisation, chronic pulmonary aspergillosis (CPA) and invasive pulmonary aspergillosis (IPA). This review will summarise diagnostic and treatment of aspergillus in COPD patients.

Invasive Pulmonary Aspergillosis

Invasive pulmonary aspergillosis is growing in incidence, as patients at risk are growing in diversity. Outside the classical context of neutropenia, new risk factors are emerging or newly identified, such as new anticancer drugs, viral pneumonias and hepatic dysfunctions. Clinical signs remain unspecific in these populations and the diagnostic work-up has considerably expanded. Computed tomography is key to assess the pulmonary lesions of aspergillosis, whose various features must be acknowledged. Positron-emission tomography can bring additional information for diagnosis and follow-up. The mycological argument for diagnosis is rarely fully conclusive, as biopsy from a sterile site is challenging in most clinical contexts. In patients with a risk and suggestive radiological findings, probable invasive aspergillosis is diagnosed through blood and bronchoalveolar lavage fluid samples by detecting galactomannan or DNA, or by direct microscopy and culture for the latter. Diagnosis is considered possible with mold infection in lack of mycological criterion. Nevertheless, the therapeutic decision should not be hindered by these research-oriented categories, that have been completed by better adapted ones in specific settings. Survival has been improved over the past decades with the development of relevant antifungals, including lipid formulations of amphotericin B and new azoles. New antifungals, including first-in-class molecules, are awaited.

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.

Therapeutic Approaches for Combating Aspergillus Associated Infection

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

A Review of Population Pharmacokinetic Models of Posaconazole

Posaconazole is often used for the prophylaxis and treatment of invasive fungal infections (IFI). However, intra- and inter-individual differences and drug interactions affect the efficacy and safety of posaconazole. Precision dosing of posaconazole based on the population pharmacokinetic (PopPK) model may assist in making significant clinical decisions. This review aimed to comprehensively summarize the published PopPK models of posaconazole and analyze covariates that significantly influence posaconazole exposure. Articles published until May 2022 for PopPK analysis of posaconazole were searched in PubMed and EMBASE databases. Demographic characteristics, model characteristics, and results of PopPK analysis were extracted from the selected articles. In addition, the steady-state pharmacokinetic profiles of posaconazole were simulated at different covariate levels and dosing regimens. Out of the 13 studies included in our review, nine studies included adults, three included children, and one included both adults and children. All oral administration models were one-compartment models, and all intravenous administration models were two-compartment models. Body weight, proton pump inhibitors, and incidence of diarrhea were found to be important covariates. Clinically, the potential impact of factors such as patient physiopathologic characteristics and comorbid medications on posaconazole pharmacokinetics should be considered. Dose adjustment in combination with TDM or replacement with a tablet or intravenous formulation with higher exposure may be an effective way to ensure drug efficacy as well as to reduce fungal resistance. Meanwhile, published models require further external evaluation to examine extrapolation.

Challenges in the Treatment of Invasive Aspergillosis in Immunocompromised Children

Invasive aspergillosis (IA) is associated with significant morbidity and mortality. Voriconazole remains the drug of choice for the treatment of IA in children; however, the complex kinetics of voriconazole in children make dosing challenging and therapeutic drug monitoring (TDM) essential for treatment success. The overarching goal of this review is to discuss the role of voriconazole, posaconazole, isavuconazole, liposomal amphotericin B, echinocandins, and combination antifungal therapy for the treatment of IA in children. We also provide a detailed discussion of antifungal TDM in children.

Multicenter Registry of Patients Receiving Systemic Mold-Active Triazoles for the Management of Invasive Fungal Infections

Introduction

‘Real-world’ data for mold-active triazoles (MATs) in the treatment of invasive fungal infections (IFIs) are lacking. This study evaluated usage of MATs in a disease registry for the management of IFIs.

Methods

Data were collected for this multicenter, observational, prospective study from 55 US centers, between March 2017 and April 2020. Eligible patients received isavuconazole, posaconazole, or voriconazole as MAT monotherapy (one MAT) or multiple/sequenced MAT therapy (more than one MAT) for prophylaxis or treatment. Patients were enrolled within 60 days of MAT initiation. The primary objective was to characterize patients receiving a MAT and their patterns of therapy. The full analysis set (FAS) included eligible patients for the relevant enrollment protocol, and the safety analysis set (SAF) included patients who received ≥ 1 MAT dose.

Results

Overall, 2009 patients were enrolled in the SAF. The FAS comprised 1993 patients (510 isavuconazole; 540 posaconazole; 491 voriconazole; 452 multiple/sequenced MAT therapies); 816 and 1177 received treatment and prophylaxis at study index/enrollment, respectively. Around half (57.8%) of patients were male, and median age was 59 years. Among patients with IFIs during the study, the most common pathogens were Aspergillus fumigatus in the isavuconazole (18.2% [10/55]) and voriconazole (25.5% [12/47]) groups and Candida glabrata in the posaconazole group (20.9% [9/43]); the lungs were the most common infection site (58.2% [166/285]). Most patients were maintained on MAT monotherapy (77.3% [1541/1993]), and 79.4% (1520/1915) completed their MAT therapies. A complete/partial clinical response was reported in 59.1% (591/1001) of patients with a clinical response assessment. Breakthrough IFIs were reported in 7.1% (73/1030) of prophylaxis patients. Adverse drug reactions (ADRs) were reported in 14.7% (296/2009) of patients (3.9% [20/514] isavuconazole; 11.3% [62/547] posaconazole; 14.2% [70/494] voriconazole).

Conclusions

In this ‘real-world’ study, most patients remained on their initial therapy and completed their MAT therapy. Over half of patients receiving MATs for IFIs had a successful response, and most receiving prophylaxis did not develop breakthrough IFIs. ADRs were uncommon.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00661-5.

Therapeutic Drug Monitoring of Antifungal Agents in Critically Ill Patients: Is There a Need for Dose Optimisation?

Invasive fungal infections are an important cause of morbidity and mortality, especially in critically ill patients. Increasing resistance rates and inadequate antifungal exposure have been documented in these patients, due to clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) alterations, leading to treatment failure. Physiological changes such as third spacing (movement of fluid from the intravascular compartment to the interstitial space), hypoalbuminemia, renal failure and hepatic failure, as well as common interventions in the intensive care unit, such as renal replacement therapy and extracorporeal membrane oxygenation, can lead to these PK and PD alterations. Consequently, a therapeutic target concentration that may be useful for one patient may not be appropriate for another. Regular doses do not take into account the important PK variations in the critically ill, and the need to select an effective dose while minimising toxicity advocates for the use of therapeutic drug monitoring (TDM). This review aims to describe the current evidence regarding optimal PK/PD indices associated with the clinical efficacy of the most commonly used antifungal agents in critically ill patients (azoles, echinocandins, lipid complexes of amphotericin B, and flucytosine), provide a comprehensive understanding of the factors affecting the PK of each agent, document the PK parameters of critically ill patients compared to healthy volunteers, and, finally, make recommendations for therapeutic drug monitoring (TDM) of antifungals in critically ill patients.

Early Postoperative Management of Lung Transplant Recipients

The early postoperative period after lung transplantation is a critical time. Prompt recognition and treatment of primary graft dysfunction can alter long-term allograft function. Cardiovascular, gastrointestinal, renal, and hematologic derangements are common and require close management to limit their negative sequelae.

Phase 1b/3 Pharmacokinetics and Safety Study of Intravenous Posaconazole in Adult Asian Participants at High Risk for Invasive Fungal Infections

Introduction

Antifungal prophylaxis in patients at high risk for invasive fungal infections (IFIs), such as those with acute myeloid leukemia or myelodysplastic syndromes, continues to be underused in Asia, despite the fact that it reduces IFI-related death and increases IFI-free survival. We characterized the pharmacokinetics (PK) and safety of the intravenous (IV) formulation of posaconazole in adult Asian participants at high risk for IFI.

Methods

Participants received posaconazole IV 300 mg twice on day 1, posaconazole IV 300 mg once daily on days 2–10, and posaconazole IV 300 mg once daily or oral suspension 200 mg 3 times daily for up to 18 days for a maximum of 28 days. There were two PK sampling groups: intensive and sparse. Sparse trough PK sampling was collected from all participants on days 3, 6, 10, 15, 22, and 28/end of treatment. The intensive PK group had additional sampling performed over 24 h on day 10. Primary end points were steady state average concentration (C_avg,ss) and percentage of participants with C_avg,ss ≥ 500 ng/mL. Safety was assessed up to day 30/end of treatment.

Results

Seventy participants with acute myelogenous leukemia were enrolled, 30 in the intensive PK group and 40 in the sparse PK group; 57 participants completed the study, 26 in the intensive PK group and 31 in the sparse PK group. On day 10, arithmetic mean C_avg,ss was 2986 ng/mL [coefficient of variation (%CV), 36%; range, 1409–5930 ng/mL]; 100% of participants in the intensive PK group (n/N = 27/27) had C_avg,ss ≥ 500 ng/mL. Arithmetic mean (%CV) C_min was 2474 (50.4%) and 2466 ng/mL (42.4%) in the intensive and sparse PK groups on day 10, respectively. Safety was similar to that of previous posaconazole formulations.

Conclusion

In Asian participants at high risk for IFIs, IV posaconazole achieved the target exposure associated with efficacy that was previously established for supporting global registration of posaconazole for IV administration and was generally well tolerated.

Clinical trial registration

ClinicalTrials.gov, NCT03336502.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-02012-1.

Novel 1, 2, 4-Triazoles as Antifungal Agents

The development of innovative antifungal agents is essential. Some fungicidal agents are no longer effective due to resistance development, various side effects, and high toxicity. Therefore, the synthesis and development of some new antifungal agents are necessary. 1,2,4-Triazole is one of the most essential pharmacophore systems between five-membered heterocycles. The structure-activity relationship (SAR) of this nitrogen-containing heterocyclic compound showed potential antifungal activity. The 1,2,4-triazole core is present as the nucleus in a variety of antifungal drug categories. The most potent and broad activity of triazoles have confirmed them as pharmacologically significant moieties. The goal of this review is to highlight recent developments in the synthesis and SAR study of 1,2,4-triazole as a potential fungicidal compound. In this study, we provide the results of a biological activity evaluation using various structures and figures. Literature investigation showed that 1, 2, 4-triazole derivatives reveal the extensive span of antifungal activity. This review will assist researchers in the development of new potential antifungal drug candidates with high effectiveness and selectivity.

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.

Evaluating posaconazole, its pharmacology, efficacy and safety for the prophylaxis and treatment of fungal infections

INTRODUCTION

Invasive fungal diseases (IFDs) are a significant cause of morbidity and mortality among immunocompromised patients. Safe and effective antifungal medications used for prophylaxis and treatment are pivotal in their management. Posaconazole is a promising triazole antifungal agent.

AREAS COVERED

The authors discuss the pharmacological properties of posaconazole, including pharmacokinetics/pharmacodynamics, safety and tolerability profile, together with efficacy data for prophylaxis and treatment as well as its use in special populations based on current literature.

EXPERT OPINION

Posaconazole has a favorable safety and tolerability profile; however, caution is advised when co-administered with agents that are CYP3A4 inhibitors, because their concentration may significantly increase, and their levels should be closely monitored. It has an extended spectrum of activity against yeasts and filamentous fungi. It is successfully used as prophylaxis for patients with acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and post-hematopoietic cell transplantation (HCT) with graft-versus-host disease (GVHD). It is the first line treatment for oropharyngeal candidiasis and is also used as a salvage treatment for refractory IFDs. Currently available formulations include the oral suspension, delayed-release tablets and solution for intravenous infusion, all with different PK/PD properties and indications. Its use in children and adolescents is currently being examined in Phase-II clinical trials.

Future Directions for Clinical Respiratory Fungal Research

There has been a growing appreciation of the importance of respiratory fungal diseases in recent years, with better understanding of their prevalence as well as their global distribution. In step with the greater awareness of these complex infections, we are currently poised to make major advances in the characterization and treatment of these fungal diseases, which in itself is largely a consequence of post-genomic technologies which have enabled rational drug development and a path towards personalized medicines. These advances are set against a backdrop of globalization and anthropogenic change, which have impacted the world-wide distribution of fungi and antifungal resistance, as well as our built environment. The current revolution in immunomodulatory therapies has led to a rapidly evolving population at-risk for respiratory fungal disease. Whilst challenges are considerable, perhaps the tools we now have to manage these infections are up to this challenge. There has been a welcome acceleration of the antifungal pipeline in recent years, with a number of new drug classes in clinical or pre-clinical development, as well as new focus on inhaled antifungal drug delivery. The "post-genomic" revolution has opened up metagenomic diagnostic approaches spanning host immunogenetics to the fungal mycobiome that have allowed better characterization of respiratory fungal disease endotypes. When these advances are considered together the key challenge is clear: to develop a personalized medicine framework to enable a rational therapeutic approach.

Supratherapeutic Posaconazole Concentration in a Pediatric Transplant Patient With Confirmed Rhizopus Infection

There are a limited number of studies that guide dosing of posaconazole delayed-release (DR) tablets for the pediatric population. Current FDA-approved doses are only recommended for patients 13 years and older. For younger patients, providers are faced with the challenge of recommending posaconazole doses extrapolated from adult studies or choosing an alternative agent. We report on a case of a 10-year-old patient who experienced a supratherapeutic trough serum concentration and transaminitis after receiving the extrapolated adult dosage of posaconazole DR tablets (300 mg twice daily for the first day, followed by 300 mg daily) for 7 days. In the end, the patient required a smaller dose of 200 mg daily to achieve the desired trough target concentration for the treatment of a Rhizopus neck infection. Our findings highlight the need for additional studies to determine the optimal dosing of posaconazole DR tablets for children.

When to change treatment of acute invasive aspergillosis: an expert viewpoint

Invasive aspergillosis (IA) is an acute infection affecting patients who are immunocompromised, as a result of receiving chemotherapy for malignancy, or immunosuppressant agents for transplantation or autoimmune disease. Whilst criteria exist to define the probability of infection for clinical trials, there is little evidence in the literature or clinical guidelines on when to change antifungal treatment in patients who are receiving prophylaxis or treatment for IA. To try and address this significant gap, an advisory board of experts was convened to develop criteria for the management of IA for use in designing clinical trials, which could also be used in clinical practice. For primary treatment failure, a change in antifungal therapy should be made: (i) when mycological susceptibility testing identifies an organism from a confirmed site of infection, which is resistant to the antifungal given for primary therapy, or a resistance mutation is identified by molecular testing; (ii) at, or after, 8 days of primary antifungal treatment if there is increasing serum galactomannan, or galactomannan positivity in serum, or bronchoalveolar lavage fluid when the antigen was previously undetectable, or there is sudden clinical deterioration, or a new clearly distinct site of infection is detected; and (iii) at, or after, 15 days of primary antifungal treatment if the patient is clinically stable but with ≥2 serum galactomannan measurements persistently elevated compared with baseline or increasing, or if the original lesions on CT or other imaging, show progression by >25% in size in the context of no apparent change in immune status.

Clinical pharmacokinetics and dose recommendations for posaconazole gastroresistant tablets in children with cystic fibrosis

Objectives

To investigate the population pharmacokinetics of posaconazole gastroresistant tablets in children with cystic fibrosis (CF) and perform simulations to recommend optimal doses.

Patients and methods

Children from a paediatric CF centre who had received posaconazole tablets and underwent therapeutic drug monitoring were identified from pharmacy records. Relevant clinical data were collated from case notes and electronic patient records and used to develop an allometrically scaled population pharmacokinetic model. A stepwise covariate model-building exercise evaluated the influence of interacting medicines and liver function.

Results

One hundred posaconazole serum concentrations were collected from 37 children with a median age of 14 years (range 7–17). Posaconazole pharmacokinetics were adequately described by a one-compartment model with inter-individual variability on clearance. Dose simulations demonstrated a 77%–83% probability of attaining a trough target of 1 mg/L with a dose of 300 mg every 12 h for two doses then 300 mg once daily (OD) in children aged 6–11 years; and 86%–88% with a dose of 400 mg every 12 h for two doses then 400 mg OD in adolescents aged 12–17 years. This dose scheme also yielded a 90% probability of achieving an AUC of 30 mg·h/L. AUC and trough concentration were highly correlated (r² = 0.98). Simulations showed that trough concentrations of >0.75 mg/L would exceed an AUC of 30 mg·h/L in 90% of patients.

Conclusions

A starting dose of 300 mg OD in those aged 6–11 years and 400 mg OD in those aged 12–17 years (following loading doses) yields a 90% probability of attaining an AUC of 30 mg·h/L.

Managing uncertainty in antifungal dosing: antibiograms, therapeutic drug monitoring and drug-drug interactions

PURPOSE OF REVIEW

A number of pharmacokinetic and pharmacodynamic factors in critically ill or severely immunosuppressed patients influence the effectiveness of antifungal therapy making dosing less certain. Recent position papers from infectious diseases societies and working groups have proposed methods for dosage individualization of antibiotics in critically ill patients using a combination of population pharmacokinetic models, Monte-Carlo simulation and therapeutic drug monitoring (TDM) to guide dosing. In this review, we examine the current limitations and practical issues of adapting a pharmacometrics-guided dosing approaches to dosing of antifungals in critically ill or severely immunosuppressed populations.

RECENT FINDINGS

We review the current status of antifungal susceptibility testing and challenges in incorporating TDM into Bayesian dose prediction models. We also discuss issues facing pharmacometrics dosage adjustment of newer targeted chemotherapies that exhibit severe pharmacokinetic drug-drug interactions with triazole antifungals.

SUMMARY

Although knowledge of antifungal pharmacokinetic/pharmacodynamic is maturing, the practical application of these concepts towards point-of-care dosage individualization is still limited. User-friendly pharmacometric models are needed to improve the utility of TDM and management of a growing number of severe pharmacokinetic antifungal drug-drug interactions with targeted chemotherapies.

Pharmacokinetics and target attainment of intravenous posaconazole in critically ill patients during extracorporeal membrane oxygenation

BACKGROUND

Posaconazole is an antifungal drug used for prophylaxis and treatment of invasive fungal infections. Severe influenza has been identified as a risk factor for invasive pulmonary aspergillosis in critically ill patients. In this population, extracorporeal membrane oxygenation (ECMO) is used as rescue therapy, although little is known about the pharmacokinetics (PK) of posaconazole during ECMO.

OBJECTIVES

To determine the PK and target attainment of six patients treated with IV posaconazole under ECMO and to develop a population PK model that can be used to simulate the PTA.

METHODS

Critically ill patients treated with posaconazole and ECMO were included in this study. Plasma samples were collected at several timepoints within one dosing interval on two occasions: an early (Day 2-3) and a late (Day 4-7) sampling day. Daily trough concentrations were measured.

RESULTS

The median (IQR) AUC0-24, CL and Vd were 34.3 (28.3-37.7) mg·h/L, 8.7 (8.0-10.6) L/h and 389 (314-740) L, if calculated with non-compartmental analysis based on the observed concentrations. All measured trough concentrations were ≥0.7 mg/L and 11/16 were ≥1 mg/L, which are the haematological thresholds for prophylaxis and treatment of invasive aspergillosis, respectively. The targeted PTA (>90%) was attained for prophylaxis but not for treatment.

CONCLUSIONS

ECMO does not appear to influence posaconazole exposure compared with haematology patients. However, some trough levels were below the lower limit for treatment. An a priori dose adjustment does not appear to be necessary but drug monitoring is recommended.