Breakthrough fungal infections after allogeneic hematopoietic stem cell transplantation in patients on prophylactic voriconazole

The outcome and the risk factors of mucormycosis among patients with hematological diseases: a systematic and meta-analysis

Objectives

Mucorale has come into a significant pathogen over recent decades. Nonetheless, mucormycosis-related mortality rates among patients with hematological disorders remain unascertained. Thus, we conducted a meta-analysis to determine mortality rates of mucormycosis in patients with hematology-related conditions.

Methods

We scoured PubMed, Embase, and Web of Science for original papers exploring the intersection of Mucormycosis and Hematological Diseases (from 2000 to 2022). We scrutinized the overall mortality across three distinct periods, as well as differentiating between high-income and middle-income nations. We further evaluated the pooled mortality and the risk differential (RD) across several subgroups.

Results

The overall mortality rate for hematology patients with mucormycosis was 61%, within a 95% confidence interval (CI) of 0.54-0.68. A significant observation was that mortality rates were somewhat lower in high-income countries compared to middle-income countries (0.60 versus 0.64, p = 0.45). Importantly, we discovered that a combination of surgical and medical treatment significantly improved survival rates compared to medical treatment alone [mortality 0.49 versus 0.67, RD -0.19 (95%CI -0.38-0.00, I2 63.7%)]. As might be expected, disseminated mucormycosis posed a significantly higher risk of death compared to isolated mucormycosis [0.60 versus 0.57, RD death 0.16 (95%CI 0.03-0.28)]. Additionally, our analysis showed no discernible differences in survival rates between genders, between patients with and without breakthrough infection, between those who received mucor-active or mucor-inactive drugs prior to mucor infection, or between those on a multi-drug regimen and those on a single drug treatment.

Conclusion

Despite the high mortality rates associated with mucormycosis in patients with hematological disorders, those receiving both medical and surgical interventions, as well as those with isolated infection sites, exhibited improved survival outcomes. Conversely, factors such as gender, the presence of breakthrough infection, the use of mucor-active drugs before mucor infection, and multi-drug administration did not significantly influence patient outcomes.

Breakthrough Invasive Sinusitis by Hormographiella aspergillata in a Neutropenic Patient Receiving Voriconazole Therapy: A Case Report and Review of Breakthrough H. aspergillata Infections

Breakthrough invasive infections occurs during the use of antifungals both in prophylaxis and therapy, it favors the emergence of new pathogens in the fungal landscape. Hormographiella aspergillata is considered a rare but emerging pathogen in the era of broad-spectrum antifungal use in patients with hematological malignancies. Here, we present a case report of invasive sinusitis due to Hormographiella aspergillata, manifesting as a breakthrough infection in a patient with severe aplastic anemia under treatment with voriconazole for invasive pulmonary aspergilosis. Also, we make a review of H. aspergillata breakthrough infections published in the literature.

Antifungal Activity of Isavuconazole and Comparator Agents against Contemporaneous Mucorales Isolates from USA, Europe, and Asia-Pacific

Isavuconazole is the only US FDA-approved antifungal for treating invasive mucormycosis. We evaluated isavuconazole activity against a global collection of Mucorales isolates. Fifty-two isolates were collected during 2017-2020 from hospitals located in the USA, Europe, and the Asia-Pacific. Isolates were identified by MALDI-TOF MS and/or DNA sequencing and susceptibility tested by the broth microdilution method following CLSI guidelines. Isavuconazole (MIC_50/90, 2/>8 mg/L) inhibited 59.6% and 71.2% of all Mucorales isolates at ≤2 mg/L and ≤4 mg/L, respectively. Among comparators, amphotericin B (MIC_50/90, 0.5/1 mg/L) displayed the highest activity, followed by posaconazole (MIC_50/90, 0.5/8 mg/L). Voriconazole (MIC_50/90, >8/>8 mg/L) and the echinocandins (MIC_50/90, >4/>4 mg/L) had limited activity against Mucorales isolates. Isavuconazole activity varied by species and this agent inhibited at ≤4 mg/L 85.2%, 72.7%, and 25% of Rhizopus spp. (n = 27; MIC_50/90, 1/>8 mg/L), Lichtheimia spp. (n = 11; MIC_50/90, 4/8 mg/L), and Mucor spp. (n = 8; MIC₅₀, >8 mg/L) isolates, respectively. Posaconazole MIC_50/90 values against Rhizopus, Lichtheimia, and Mucor species were 0.5/8 mg/L, 0.5/1 mg/L, and 2/- mg/L, respectively; amphotericin B MIC_50/90 values were 1/1 mg/L, 0.5/1 mg/L, and 0.5/- mg/L, respectively. As susceptibility profiles varied among Mucorales genera, species identification and antifungal susceptibility testing are advised whenever possible to manage and monitor mucormycosis.

Therapeutic Drug Monitoring of Voriconazole in Children with Hematologic Malignancy and Invasive Fungal Infections: An RCT from a Tertiary Care Centre in India

INTRODUCTION

Voriconazole is a triazole anti-fungal with non-linear kinetics and a narrow therapeutic range. The objective of our study was to monitor the voriconazole serum levels in children with hematological malignancy and clinically suspected invasive fungal infections.

METHODS

The study was a prospective, randomized controlled trial conducted from June 2016 to December 2017. All children who had haematologic malignancies with clinically suspected invasive fungal infections and received voriconazole as the only anti-fungal were included in the study. The children were randomly allotted into two groups; one was the group that underwent TDM, and the other, TDM, was not done. Bioassay was the method employed for TDM. The trough levels were evaluated on a sample obtained on the fifth day of starting the drug. The institute's ethics committee approved the study.

RESULT

A total of 30 children were included in the study: 15 in the TDM group and 15 in the non-TDM group. The most common underlying malignancy was AML. Neutropenia due to chemotherapy sessions was these patients' most common risk factor. A favorable outcome was seen in 13/15 (86.7%) in the TDM group and 11/15 in the non-TDM group (73.3%).

CONCLUSION

Only five out of 15 (33.3%) children had voriconazole serum levels within the therapeutic range. Alterations in dose had to be done in the remaining to achieve the recommended serum levels. Thus, we recommend TDM for all children of hematologic malignancy receiving voriconazole for better management. Our findings also revealed that children with AML had lower than recommended levels of voriconazole on TDM evaluation, whereas those with ALL had normal to elevated levels of voriconazole.

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.

Experience of Isavuconazole as a Salvage Therapy in Chronic Pulmonary Fungal Disease

Background: Instances of resistant fungal infection are rising in pulmonary disease, with limited therapeutic options. Therapeutic drug monitoring of azole antifungals has been necessary to ensure safety and efficacy but is considered unnecessary for the newest triazole isavuconazole. Aims: To characterise the prevalence of isavuconazole resistance and use in a tertiary respiratory centre. Methods: A retrospective observational analysis (2016−2021) of adult respiratory patients analysing fungal culture, therapeutic drug monitoring, and outcome post-isavuconazole therapy. Results: During the study period, isavuconazole susceptibility testing was performed on 26 Aspergillus spp. isolates. A total of 80.8% of A. fumigatus isolates had isavuconazole (MIC > 1 mg/L, and 73.0% > 2 mg/L) with a good correlation to voriconazole MIC (r = 0.7, p = 0.0002). A total of 54 patients underwent isavuconazole therapy during the study period (median duration 234 days (IQR: 24−499)). A total of 67% of patients tolerated isavuconazole, despite prior azole toxicity in 61.8%, with increased age (rpb = 0.31; p = 0.021) and male sex (φc = 0.30; p = 0.027) being associated with toxicity. A total of 132 isavuconazole levels were performed with 94.8% > 1 mg/L and 72% > 2 mg/L. Dose change from manufacturer’s recommendation was, however, required in 9.3% to achieve a concentration of >2 mg/L. Conclusion: We describe the use of isavuconazole as a salvage therapy in a chronic pulmonary fungal disease setting with a high prevalence of azole resistance. Therapeutic concentrations at standard dosing were high; however, results reinforce antifungal stewardship for optimization.

Factors associated with breakthrough fungemia caused by Candida, Trichosporon, or Fusarium species when the breakthrough fungemia developed in patients with hematological disorders

Limited data are available on breakthrough fungemia, defined as fungemia that develops on administration of antifungal agents, in patients with hematological disorders. We reviewed the medical and microbiological records of adult patients with hematological diseases who had breakthrough fungemia between January 2008 and July 2019 at Toranomon Hospital and Toranomon Hospital Kajigaya in Japan. A total of 121 cases of breakthrough fungemia were identified. Of the 121 cases, 83, 11, 5, and 22 were receiving micafungin, voriconazole, itraconazole, and liposomal amphotericin B, respectively, when the breakthrough occurred. Of the 121 causative breakthrough fungal strains, 96 were Candida species, and the rest were 13 cases of Trichosporon species, 7 of Fusarium species, 2 of Rhodotorula mucilaginosa, and 1 each of Cryptococcus neoformans, Exophiala dermatitidis, and Magnusiomyces capitatus. The crude 14-day mortality rate of breakthrough fungemia was 36%. Significant independent factors associated with the crude 14-day mortality were age ≥60 years (P=0.011), chronic renal failure (P=0.0087), septic shock (P<0.0001), steroid administration (P=0.0085), and liposomal amphotericin B breakthrough fungemia (P=0.0011). An absolute neutrophil count >500/μL was significantly more common in candidemia in the multivariate analysis(P＝0.0065), neutropenia and non-allogeneic hematopoietic stem cell transplant recipients were significantly more common in Trichosporon fungemia (P=0.036 and P=0.033, respectively), and voriconazole breakthrough fungemia and neutropenia were significantly more common in Fusarium fungemia (P=0.016 and P=0.016, respectively). The epidemiological and clinical characteristics of breakthrough fungemia of patients with hematological disorders were demonstrated. Some useful factors to predict candidemia, Trichosporon fungemia, and Fusarium fungemia were identified.

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.

Changing Epidemiology of Invasive Fungal Disease in Allogeneic Hematopoietic Stem Cell Transplantation

Invasive fungal disease (IFD) is a common cause of morbidity and mortality in patients with hematologic malignancies, especially among those undergoing allogeneic hematopoietic stem cell transplantation (HSCT). The epidemiology of IFD in HSCT patients has been evolving over the last decades, mainly in relation to changes in HSCT therapies such as antifungal prophylaxis. A progressive decrease in Candida albicans infection has been documented, alongside a progressive increase in infections caused by non-albicans Candida species, filamentous fungi, and/or multidrug-resistant fungi. Currently, the most frequent IFD is invasive aspergillosis. In some parts of the world, especially in north Central Europe, a high percentage of Aspergillus fumigatus isolates are azole-resistant. New diagnostic techniques have documented the existence of cryptic Aspergillus species with specific characteristics. An increase in mucormycosis and fusariosis diagnoses, as well as diagnoses of other rare fungi, have also been described. IFD epidemiology is likely to continue changing further due to both an increased use of mold-active antifungals and a lengthened survival of patients with HSCT that may result in hosts with weaker immune systems. Improvements in microbiology laboratories and the widespread use of molecular diagnostic tools will facilitate more precise descriptions of current IFD epidemiology. Additionally, rising resistance to antifungal drugs poses a major threat. In this scenario, knowledge of current epidemiology and accurate IFD diagnoses are mandatory in order to establish correct prophylaxis guidelines and appropriate early treatments.

Guidelines for Infection Prophylaxis, Monitoring and Therapy in Cord Blood Transplantation

As an alternative stem cell source, cord blood (CB) has many advantages. However, delayed engraftment, lack of transferred immunity, and a significant incidence of acute graft-versus-host disease renders CB transplant (CBT) recipients at high risk of infectious complications. This guidance written by CBT and infectious disease experts outlines evidence-based recommendations for the prevention and treatment of opportunistic infections in adult patients undergoing CBT. Topics addressed include bacterial, fungal, viral, pneumocystis jirovcii and toxoplasmosis prophylaxis, suggested PCR monitoring for viruses, therapy for the most commonly encountered infections after CBT. We review key concepts including the recent important role of letermovir in the prevention of CMV reactivation. In instances where there is a paucity of data, practice recommendations are provided, including the duration of antimicrobial prophylaxis.

Invasive fungal disease and the immunocompromised host including allogeneic hematopoietic cell transplant recipients: Improved understanding and new strategic approach with sargramostim

In hosts with damaged or impaired immune systems such as those undergoing hematopoietic cell transplant (HCT) or intensive chemotherapy, breakthrough fungal infections can be fatal. Risk factors for breakthrough infections include severe neutropenia, use of corticosteroids, extended use of broad-spectrum antibiotics, and intensive care unit admission. An individual's cumulative state of immunosuppression directly contributes to the likelihood of experiencing increased infection risk. Incidence of invasive fungal infection (IFI) after HCT may be up to 5-8%. Early intervention may improve IFI outcomes, although many infections are resistant to standard therapies (voriconazole, caspofungin, micafungin, amphotericin B, posaconazole or itraconazole, as single agents or in combination). We review herein several contributing factors that may contribute to the net state of immunosuppression in recipients of HCT. We also review a new approach for IFI utilizing adjunctive therapy with sargramostim, a yeast-derived recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF).

Favorable Effects of Voriconazole Trough Concentrations Exceeding 1 μg/mL on Treatment Success and All-Cause Mortality: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined the optimal trough concentration of voriconazole for adult patients with invasive fungal infections. We used stepwise cutoffs of 0.5-2.0 μg/mL for efficacy and 3.0-6.0 μg/mL for safety. Studies were included if they reported the rates of all-cause mortality and/or treatment success, hepatotoxicity, and nephrotoxicity according to the trough concentration. Twenty-five studies involving 2554 patients were included. The probability of mortality was significantly decreased using a cutoff of ≥1.0 μg/mL (odds ratio (OR) = 0.34, 95% confidence interval (CI) = 0.15-0.80). Cutoffs of 0.5 (OR = 3.48, 95% CI = 1.45-8.34) and 1.0 μg/mL (OR = 3.35, 95% CI = 1.52-7.38) also increased the treatment success rate. Concerning safety, significantly higher risks of hepatotoxicity and neurotoxicity were demonstrated at higher concentrations for all cutoffs, and the highest ORs were recorded at 4.0 μg/mL (OR = 7.39, 95% CI = 3.81-14.36; OR = 5.76, 95% CI 3.14-10.57, respectively). Although further high-quality trials are needed, our findings suggest that the proper trough concentration for increasing clinical success while minimizing toxicity is 1.0-4.0 μg/mL for adult patients receiving voriconazole therapy.

Voriconazole efficacy against Candida glabrata and Candida krusei: preclinical data using a validated in vitro pharmacokinetic/pharmacodynamic model

BACKGROUND

Voriconazole exhibits in vitro activity against Candida glabrata and Candida krusei (EUCAST/CLSI epidemiological cut-off values 1/0.25 and 1/0.5 mg/L, respectively). Yet, EUCAST found insufficient evidence to set breakpoints for these species. We explored voriconazole pharmacodynamics (PD) in an in vitro dynamic model simulating human pharmacokinetics (PK).

METHODS

Four C. glabrata and three C. krusei isolates (voriconazole EUCAST and CLSI MICs of 0.03-2 mg/L) were tested in the PK/PD model simulating voriconazole exposures (t½ ∼6 h q12h dosing for 3 days). PK/PD breakpoints were determined calculating the PTA for exposure indices fAUC0-24/MIC associated with half-maximal activity (EI50) using Monte Carlo simulation analysis.

RESULTS

Fungal load increased from 3.60±0.35 to 8.41±0.24 log10 cfu/mL in the drug-free control, with a maximum effect of ∼1 log10 kill of C. glabrata and C. krusei isolates with MICs of 0.06 and 0.25 mg/L, respectively, at high drug exposures. The 72 h log10 cfu/mL change versus fAUC0-24/MIC relationship followed a sigmoid curve for C. glabrata (R2=0.85-0.87) and C. krusei (R2=0.56-0.76) with EI50 of 49 (32-76) and 52 (33-78) fAUC/MIC for EUCAST and 55 (31-96) and 80 (42-152) fAUC/MIC for CLSI, respectively. The PTAs for C. glabrata and C. krusei isolates with EUCAST/CLSI MICs ≤0.125/≤0.06 mg/L were >95%. Isolates with EUCAST/CLSI MICs of 0.25-1/0.125-0.5 would require trough levels 1-4 mg/L; isolates with higher MICs would not attain the corresponding PK/PD targets without reaching toxicity.

CONCLUSIONS

The in vitro PK/PD breakpoints for C. glabrata and C. krusei for EUCAST (0.125 mg/L) and CLSI (0.06 mg/L) bisected the WT populations. Trough levels of >4 mg/L, which are not clinically feasible, are necessary for efficacy against WT isolates.

The importance of mucormycosis infections on example of Rhino Orbital Cerebral Mucormycosis

Mucormycosis is an angioinvasive fungal infection, characterized by high morbidity and mortality and is strongly dependent on the patient’s general health condition, initial site of infection, and the time from diagnosis to treatment commencement. It has been reported that the occurrence of mucormycosis has increased rapidly, also among immunocompetent patients. Moreover, the rise in number is expected to continue. Among all clinical manifestations of mucormycosis, the rhino-orbital-cerebral type (ROCM) is the most common. The aim of this article is to increase the awareness of mucoral infections, especially ROCM, and to describe its first symptoms, as proper treatment requires immediate surgical and medical intervention.

Optimal trough concentration of voriconazole with therapeutic drug monitoring in children: A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis was designed to determine the optimal trough concentration of voriconazole for children with invasive fungal infections (IFIs).

METHODS

We searched electronic databases (PubMed, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and Japana Centra Revuo Medicina) for clinical studies describing the voriconazole trough concentration. We used stepwise cut-off values of 1.0-2.0 mg/L for efficacy and 3.0-6.0 mg/L for safety. The efficacy outcomes were treatment success and all-cause mortality, and the safety outcomes were hepatotoxicity, neurotoxicity and all-cause adverse events.

RESULTS

Nine studies involving 211 patients were included in the analysis. The probability of treatment success against IFIs was significantly increased at cut-off values of ≥1.0 mg/L (odds ratio [OR] = 2.65, 95% confidence interval [CI] = 1.20-5.87). Our analysis did not find any relationship between the trough concentration and survival. Concerning safety, the occurrence of any outcomes did not significantly differ according to the voriconazole trough concentrations at any cut-off value. However, in a subgroup analysis of Asian study locations, a significantly higher risk of hepatotoxicity was demonstrated at voriconazole trough cut-off values ≥ 3.0 mg/L (OR = 8.40, 95% CI = 1.36-51.92). Although a significant correlation between the voriconazole concentration and hepatotoxicity was evident in regression curve analysis, (y = 0.1198e^0.2298x), no correlation was demonstrated for neurotoxicity (y = 0.3913e^-0.008x).

CONCLUSION

Our findings suggest that the optimal trough concentration for increasing clinical success and minimizing hepatotoxicity during voriconazole therapy in children with IFIs, particularly for Asian populations, is 1.0-3.0 mg/L.

Donor-derived renal allograft mucormycosis in a combined liver and kidney transplantation: Case report and review of the literature

Mucormycosis infrequently may present with isolated renal involvement. Among solid organ transplant recipients, renal allograft mucormycosis has been most often associated with medical tourism or transplantation outside of the western world. We report a case of an HIV/HCV co-infected woman who underwent simultaneous liver and kidney transplantation with a Public Health Service increased risk donor organ. 16 days after transplant, she developed massive hematuria and was found to have renal allograft Rhizopus spp. involvement, we surmise to have been from donor-derived infection. Therapy included nephrectomy, debridement, liposomal amphotericin B, and posaconazole with survival. We reviewed PubMed indexed, English-language cases of isolated renal mucormycosis in general, in HIV/AIDS, and from donor-derived renal allograft infections.

Drug-Resistant Fungi: An Emerging Challenge Threatening Our Limited Antifungal Armamentarium

The high clinical mortality and economic burden posed by invasive fungal infections (IFIs), along with significant agricultural crop loss caused by various fungal species, has resulted in the widespread use of antifungal agents. Selective drug pressure, fungal attributes, and host- and drug-related factors have counteracted the efficacy of the limited systemic antifungal drugs and changed the epidemiological landscape of IFIs. Species belonging to Candida, Aspergillus, Cryptococcus, and Pneumocystis are among the fungal pathogens showing notable rates of antifungal resistance. Drug-resistant fungi from the environment are increasingly identified in clinical settings. Furthermore, we have a limited understanding of drug class-specific resistance mechanisms in emerging Candida species. The establishment of antifungal stewardship programs in both clinical and agricultural fields and the inclusion of species identification, antifungal susceptibility testing, and therapeutic drug monitoring practices in the clinic can minimize the emergence of drug-resistant fungi. New antifungal drugs featuring promising therapeutic profiles have great promise to treat drug-resistant fungi in the clinical setting. Mitigating antifungal tolerance, a prelude to the emergence of resistance, also requires the development of effective and fungal-specific adjuvants to be used in combination with systemic antifungals.

Effect of Therapeutic Drug Monitoring and Cytochrome P450 2C19 Genotyping on Clinical Outcomes of Voriconazole: A Systematic Review

Objectives

To examine current knowledge on the clinical utility of therapeutic drug monitoring (TDM) in voriconazole therapy, the impact of CYP2C19 genotype on voriconazole plasma concentrations, and the role of CYP2C19 genotyping in voriconazole therapy.

Data Sources

Three literature searches were conducted for original reports on (1) TDM and voriconazole outcomes and (2) voriconazole and CYP2C19 polymorphisms. Searches were conducted through EMBASE, MEDLINE/PubMed, Scopus, and Cochrane Central Register of Controlled Trials from inception to June 2020.

Study Selection and Data Extraction

Randomized controlled trials, cohort studies, and case series with ≥10 patients were included. Only full-text references in English were eligible.

Data Synthesis

A total of 63 studies were reviewed. TDM was recommended because of established concentration and efficacy/toxicity relationships. Voriconazole trough concentrations ≥1.0 mg/L were associated with treatment success; supratherapeutic concentrations were associated with increased neurotoxicity; and hepatotoxicity associations were more prevalent in Asian populations. CYP2C19 polymorphisms significantly affect voriconazole metabolism, but no relationship with efficacy/safety were found. Genotype-guided dosing with TDM was reported to increase chances of achieving therapeutic range.

Relevance to Patient Care and Clinical Practice

Genotype-guided dosing with TDM is a potential solution to optimizing voriconazole efficacy while avoiding treatment failures and common toxicities.

Conclusions

Voriconazole plasma concentrations and TDM are treatment outcome predictors, but research is needed to form a consensus target therapeutic range and dosage adjustment guidelines based on plasma concentrations. CYP2C19 polymorphisms are a predictor of voriconazole concentrations and metabolism, but clinical implications are not established. Large-scale, high-methodological-quality trials are required to investigate the role for prospective genotyping and establish CYP2C19-guided voriconazole dosing recommendations.

Voriconazole therapeutic drug monitoring in critically ill patients improves efficacy and safety of antifungal therapy

Since voriconazole plasma trough concentration (VPC) is related to its efficacy and adverse events, therapeutic drug monitoring (TDM) is recommended to perform. However, there is no report about the data of voriconazole TDM in critically ill patients in China. This retrospective study was performed to determine whether voriconazole TDM was associated with treatment response and/or voriconazole adverse events in critically ill patients, and to identify the potential risk factors associated with VPC. A total of 216 critically ill patients were included. Patients were divided into two groups: those underwent voriconazole TDM (TDM group, n = 125) or did not undergo TDM (non-TDM group, n = 91). The clinical response and adverse events were recorded and compared. Furthermore, in TDM group, multivariate logistic regression analysis was performed to identify the possible risk factors resulting in the variability in initial VPC. The complete response in the TDM group was significantly higher than that in the non-TDM group (P = .012). The incidence of adverse events strongly associated with voriconazole in the non-TDM group was significantly higher than that in the TDM group (19.8% vs 9.6%; P = .033). The factors, including age (OR 0.934, 95% CI: 0.906-0.964), male (OR 5.929, 95% CI: 1.524-23.062), serum albumin level (OR 1.122, 95% CI: 1.020-1.234), diarrhoea (OR 4.953, 95% CI: 1.495-16.411) and non-intravenous administration (OR 4.763, 95% CI: 1.576-14.39), exerted the greatest effects on subtherapeutic VPC (VPC < 1.5 mg/L) in multivariate analysis. Intravenous administration (OR 7.657, 95% CI: 1.957-29.968) was a significant predictor of supratherapeutic VPC (VPC > 4.0 mg/L). TDM can result in a favourable clinical efficacy and a lower incidence of adverse events strongly associated with voriconazole in critically ill patients. Subtherapeutic VPC was closely related to younger age, male, hyperalbuminaemia, diarrhoea and non-intravenous administration, and intravenous administration was a significant predictor of supratherapeutic VPC.

Mucormycosis in intensive care unit: surgery is a major prognostic factor in patients with hematological malignancy

Background

Mucormycosis is an invasive fungal infection, with an increasing incidence especially in patients with hematological malignancies. Its prognosis is poor because of its high invasive power and its intrinsic low susceptibility to antifungal agents. We aimed to describe the epidemiology of mucormycosis in intensive care units (ICU) and evaluate the outcomes. We performed a retrospective multi-center study in 16 French ICUs between 2008 and 2017. We compared the patients who survived in ICU and the patients who did not to identify factors associated with ICU survival. Then, we focused on the subgroup of patients with hematological malignancies.

Results

Mucormycosis was diagnosed in 74 patients during the study period. Among them, 60 patients (81%) were immunocompromised: 41 had hematological malignancies, 9 were solid organ transplant recipients, 31 received long-term steroids, 11 had diabetes, 24 had malnutrition. Only 21 patients survived to ICU stay (28.4%) with a median survival of 22 days (Q1–Q3 = 9–106) and a survival rate at day 28 and day 90, respectively, of 35.1% and 26.4%. Survivors were significantly younger (p = 0.001), with less frequently hematological malignancies (p = 0.02), and less malnutrition (p = 0.05). Median survival in patients with hematological malignancies (n = 41) was 15 days (Q1–Q3 = 5–23.5 days). In this subgroup, curative surgery was a major factor associated with survival in multivariate analysis (odds ratio = 0.71, [0.45–0.97], p < 0.001).

Conclusion

Overall prognosis of mucormycosis in ICU remains poor, especially in patients with hematological malignancies. In this subgroup of patients, a therapeutic strategy including curative surgery was the main factor associated with survival.

Antimicrobial therapeutic drug monitoring in critically ill adult patients: a Position Paper

Purpose

This Position Paper aims to review and discuss the available data on therapeutic drug monitoring (TDM) of antibacterials, antifungals and antivirals in critically ill adult patients in the intensive care unit (ICU). This Position Paper also provides a practical guide on how TDM can be applied in routine clinical practice to improve therapeutic outcomes in critically ill adult patients.

Methods

Literature review and analysis were performed by Panel Members nominated by the endorsing organisations, European Society of Intensive Care Medicine (ESICM), Pharmacokinetic/Pharmacodynamic and Critically Ill Patient Study Groups of European Society of Clinical Microbiology and Infectious Diseases (ESCMID), International Association for Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT) and International Society of Antimicrobial Chemotherapy (ISAC). Panel members made recommendations for whether TDM should be applied clinically for different antimicrobials/classes.

Results

TDM-guided dosing has been shown to be clinically beneficial for aminoglycosides, voriconazole and ribavirin. For most common antibiotics and antifungals in the ICU, a clear therapeutic range has been established, and for these agents, routine TDM in critically ill patients appears meritorious. For the antivirals, research is needed to identify therapeutic targets and determine whether antiviral TDM is indeed meritorious in this patient population. The Panel Members recommend routine TDM to be performed for aminoglycosides, beta-lactam antibiotics, linezolid, teicoplanin, vancomycin and voriconazole in critically ill patients.

Conclusion

Although TDM should be the standard of care for most antimicrobials in every ICU, important barriers need to be addressed before routine TDM can be widely employed worldwide.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06050-1) contains supplementary material, which is available to authorized users.

Mucormycosis: an unusual masquerader of an endobronchial tumour

Pulmonary mucormycosis is a life-threatening invasive fungal infection usually seen in the background of immunosuppression, haematological malignancies, or uncontrolled diabetes. Immunocompetent hosts can also be affected. Isolated endobronchial mucormycosis is rare with only a few cases reported in the literature. Here, we present a case of an endobronchial mass masquerading as a tumour that was later diagnosed as invasive mucormycosis by histopathological examination.

A phase I dose finding study of intravenous voriconazole in pediatric patients undergoing hematopoietic cell transplantation

To optimize voriconazole dosing in pediatric hematopoietic cell transplantation (HCT), we conducted a phase I study with a modified 3 + 3 dose-escalation followed by an expansion cohort at the maximum tolerated, minimum efficacious dose (MTD/MED). Patients ≤21 years who required voriconazole for prevention or treatment of an invasive fungal infection were assigned to three age groups. Of the 59 evaluable patients, 13 were <2 years, 23 were 2-11, and 23 were 12-21. Therapeutic serum voriconazole troughs (1.5-5 µg/mL) drawn at 7 days after initiation determined efficacy. The MTD/MED was 12 mg/kg/dose q12 h × 2 loading doses, then 10 mg/kg/dose q12 h in patients <2, and was 10 mg/kg/dose q12 h in patients 2-11. The 12-21 age group had no dose-limiting toxicity at 8 mg/kg/dose q12 h; however, the MED was not reached. Drug-related AEs ≥grade 3 included increased bilirubin, transaminases, and creatinine, all occurring in <10%. There was no significant association between supra-therapeutic troughs and AEs. Five of 17 patients who had supra-therapeutic troughs (29%) had an AE, compared to 8 of 42 who did not (19%, p = 0.38). Observational population pharmacokinetic analysis demonstrated that inter-individual variability on voriconazole clearance was >100% CV, and clearance increased with age.

Prospective CYP2C19-Guided Voriconazole Prophylaxis in Patients With Neutropenic Acute Myeloid Leukemia Reduces the Incidence of Subtherapeutic Antifungal Plasma Concentrations

A risk mitigation strategy was implemented to determine if a higher prophylactic voriconazole dosage in patients with CYP2C19 rapid metabolizer neutropenic acute myeloid leukemia (AML) reduces the incidence of subtherapeutic trough concentrations. Patients with AML (n = 263) were preemptively genotyped for CYP2C19*2, *3, and *17 alleles as part of a single-center prospective, interventional, quality improvement study. CYP2C19 rapid metabolizers (CYP2C19*1/*17) were recommended to receive interventional voriconazole 300 mg twice daily, ultrarapid metabolizers (CYP2C19*17/*17) were recommended to avoid voriconazole, and all others received the standard prophylactic dosage of 200 mg twice daily. In this real-world setting, 202 patients (76.8%) were prescribed prophylactic voriconazole, and of these patients 176 (87.1%) received CYP2C19-guided prophylactic dosing. Voriconazole trough concentrations were obtained for 41 of the 58 (70.7%) CYP2C19 rapid metabolizers prescribed prophylactic voriconazole. Interventional voriconazole resulted in higher plasma trough concentrations (median 2.7 μg/mL) compared with the standard prophylactic dosage (median 0.6 μg/mL; P = 0.001). Subtherapeutic concentrations were avoided in 83.8% of CYP2C19 rapid metabolizers receiving interventional dosage compared to 46.2% receiving standard dosage (P = 0.02). CYP2C19 genotyping to preemptively guide prophylactic voriconazole dosing is feasible and may be a potential strategy for reducing the risk of subtherapeutic trough concentrations that potentiate breakthrough fungal infections.

Overview and outcome of mucormycosis among children with cancer: Report from the Children's Cancer Hospital Egypt

Mucormycosis represents a real challenge in immunocompromised patients. This study aimed to describe the clinical characteristics, treatment outcome and infection-related mortality in our patients at the Children's Cancer Hospital 57357, Cairo, Egypt. This is a retrospective study during the period 2007-2017. Data analysis included demographic data, risk factors, diagnostic workup, treatment and outcome. During the study period, 45 patients developed proven mucormycosis according to EORTC/MSG criteria (2008). Ninety percentof cases were of haematological malignancies. Liposomal amphotericin B was the mainstay of treatment. Posaconazole was used as secondary prophylaxis in 35% of cases. Combination antifungal was used in three cases with progressive mucormycosis. Surgical intervention was achievable in 50% of cases. Therapy was successful in 35 patients (66%). Complications related to mucormycosis were seen in five cases with disfigurement and perforated hard palate. Chemotherapy delay with subsequent relapse of primary malignancy was reported in one case. Mucormycosis-related mortality was 33% (15 cases). Mucormycosis is a major cause of mortality among patients with haematological malignancies. Early diagnosis of Mucormycosis infection, with rapid initiation of appropriate antifungal therapy and surgical intervention, whenever feasible, is the backbone of mucormycosis treatment.

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

SCOPE

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

METHODS

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

QUESTIONS

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

Successful Mandibular Mucormycosis Treatment in the Severely Neutropenic Patient

PURPOSE

Mucormycosis is a rare opportunistic and aggressive deep fungal infection that predominantly affects immunocompromised patients, and its mortality rate has been reported as up to 80%. Typing of the infection is based mainly on clinical and anatomic presentations, with the most common being the rhinocerebral type.

MATERIALS AND METHODS

This report presents 3 patients with cancer who had successful treatment of mandibular mucormycosis. Chemotherapy was administered 13 to 30 days before diagnosis of the infection, resulting in neutropenia in all patients. Each case is thoroughly presented from initial admission through its diagnosis and treatment sequence.

RESULTS

Early surgical ablative treatment and antifungal treatment resulted in the resolution of infection in all patients. Absolute neutrophil count increased 7 to 8 days after surgical debridement.

CONCLUSIONS

Bringing patients to the post-neutropenic state tremendously increases their odds for survival.

Breakthrough Invasive Mold Infections in the Hematology Patient: Current Concepts and Future Directions

Although the widespread use of mold-active agents (especially the new generation of triazoles) has resulted in reductions of documented invasive mold infections (IMIs) in patients with hematological malignancies and allogeneic hematopoietic stem cell transplantation (HSCT), a subset of such patients still develop breakthrough IMIs (bIMIs). There are no data from prospective randomized clinical trials to guide therapeutic decisions in the different scenarios of bIMIs. In this viewpoint, we present the current status of our understanding of the clinical, diagnostic, and treatment challenges of bIMIs in high-risk adult patients with hematological cancer and/or HSCT receiving mold-active antifungals and outline common clinical scenarios. As a rule, managing bIMIs demands an individualized treatment plan that takes into account the host, including comorbidities, certainty of diagnosis and site of bIMIs, local epidemiology, considerations for fungal resistance, and antifungal pharmacological properties. Finally, we highlight areas that require future investigation in this complex area of clinical mycology.

Invasive Aspergillosis in Children: Update on Current Guidelines

Invasive aspergillosis (IA) is an important cause of infectious morbidity and mortality in immunocompromised paediatric patients. Despite improvements in diagnosis, prevention, and treatment, IA is still associated with high mortality rates. To address this issue, several international societies and organisations have proposed guidelines for the management of IA in the paediatric population. In this article, we review current recommendations of the Infectious Diseases Society of America, the European Conference on Infection in Leukaemia and the European Society of Clinical Microbiology and Infectious Diseases for the management and prevention of IA in children.

Pharmacogenetic of voriconazole antifungal agent in pediatric patients

AIM

We explored the role of SNPs within the SLCO1B3, SLCO1B1, SLC22A6, ABCB1, ABCG2, SLCO3A1, CYP2C19, ABCC2, SLC22A1, ABCB11 and NR1I2 genes on voriconazole pharmacokinetics.

PATIENTS & METHODS

233 pediatric patients were enrolled. Drug plasma C_trough was measured by a HPLC-MS method. Allelic discrimination was performed by qualitative real-time PCR.

RESULTS

SLCO1B3 rs4149117 c.334 GT/TT (p = 0.046), ABCG2 rs13120400 c.1194 + 928 CC (p = 0.029) and ABCC2 rs717620 c.-24 GA/AA (p = 0.025) genotype groups significantly influenced C_trough. ethnicity (p = 0.042), sex (p = 0.033), SLCO1B3 rs4149117 c.334 GT/TT (p = 0.041) and ABCB1 rs1045642 c.3435 TT (p = 0.016) have been retained in linear regression model as voriconazole predictor factors.

CONCLUSION

Understanding how some gene polymorphisms affect the voriconazole pharmacokinetic is essential to optimally dose this agent.

A strategy for designing voriconazole dosage regimens to prevent invasive pulmonary aspergillosis based on a cellular pharmacokinetics/pharmacodynamics model

Background

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease in immunosuppressed patients. Voriconazole is commonly used to prevent and treat IPA in the clinic, but the optimal prophylactic antifungal regimen is unknown. The objective of this study was to clarify the mechanism underlying how voriconazole prevents IPA based on a target cellular pharmacokinetics/pharmacodynamics model, with the aim of identifying a way to design an optimal prophylactic antifungal regimen.

Methods

A nystatin assay was used to establish a target-cells model for A. fumigatus infection. An inhibitory effect sigmoid E_max model was developed to explore the cellular PK/PD breakpoint, and Monte Carlo simulation was used to design the prophylactic antifungal regimen.

Results

The intracellular activity of voriconazole in the target cells varied with its concentration, with the minimum inhibitory concentration (MIC) being an important determinant. For A. fumigatus strains AF293 and AF26, voriconazole decreased the intracellular inoculum by 0.79 and 0.84 lg cfu, respectively. The inhibitory effect sigmoid E_max model showed that 84.01% of the intracellular inoculum was suppressed by voriconazole within 24 h, and that a PK/PD value of 35.53 for the extracellular voriconazole concentration divided by MIC was associated with a 50% suppression of intracellular A. fumigatus. The Monte Carlo simulation results showed that the oral administration of at least 200 mg of voriconazole twice daily was yielded estimated the cumulative fraction of response value of 91.48%. Concentration of voriconazole in the pulmonary epithelial lining fluid and the plasma of > 17.77 and > 1.55 mg/L, respectively, would ensure the PK/PD > 35.53 for voriconazole against most isolates of A. fumigatus and may will be benefit to prevent IPA in clinical applications.

Conclusions

This study used a target cellular pharmacokinetics/pharmacodynamics model to reveal a potential mechanism underlying how voriconazole prevents IPA and has provided a method for designing voriconazole prophylactic antifungal regimen in immunosuppressed patients.

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

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

Primary Oral Mucormycosis Due to Rhizopus microsporus after Allogeneic Stem Cell Transplantation

We herein report a rare case of oral mucormycosis following allogeneic hematopoietic stem cell transplantation. Oral mucormycosis due to Rhizopus microsporus manifested as localized left buccal mucositis with a 1-cm black focus before neutrophil recovery. Combination therapy with liposomal amphotericin B was initiated and surgical debridement was performed; however, the patient died due to progressive generalized mucormycosis. Considerable attention needs to be paid to the diagnosis and management of oral mucormycosis in post-transplant patients, thereby suggesting the importance of fully understanding the risk factors.

Therapeutic drug monitoring of voriconazole for treatment and prophylaxis of invasive fungal infection in children

Voriconazole therapeutic drug monitoring is not consistently recommended due to its high interpatient and intrapatient variability. Here, we aimed to describe our experience with voriconazole for treatment and prophylaxis of invasive fungal infections in paediatric patients. A fully validated high-performance liquid chromatography-mass spectrometry method was used to quantify voriconazole concentration in plasma, at the end of dosing interval. A high interindividual variability was shown. We enrolled 237 children, 83 receiving intravenous and 154 oral voriconazole. A positive correlation between drug dose and drug plasma exposure was observed. Considering intravenous route, patients with higher serum creatinine had higher voriconazole concentrations; a positive correlation was found among drug exposure and age. Sex significantly influenced drug levels: males had higher median drug concentrations than females (P < 0.001). Close voriconazole pharmacokinetics monitoring should help individualize antifungal therapy for children.

Complications of hematopoietic stem transplantation: Fungal infections

Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) are at increased risk of invasive fungal infections, especially during the early neutropenic phase and severe graft-versus-host disease. Mold-active prophylaxis should be limited to the highest risk groups. Empiric antifungal therapy for HSCT with persistent febrile neutropenia is associated with unacceptable response rates, unnecessary antifungal therapy, increased risk of toxicity, and inflated costs. Empiric therapy should not be a substitute for detailed work up to identify the cause of fever in such patients. The improved diagnostic performance of serum biomarkers such as galactomannan and β-D-glucan, as well as polymerase chain reaction assays has allowed the development of diagnostic-driven antifungal therapy strategies for high risk patients. Diagnostic-driven approaches have resulted in reduced unnecessary antifungal exposure, improved diagnosis of invasive fungal disease, and reduced costs without increased risk of mortality. The appropriateness of diagnostic-driven antifungal strategy for individual HSCT centers depends on the availability and turnaround times for diagnostics, multidisciplinary expertise, and the local epidemiology of invasive fungal infections. Echinocandins are the treatment of choice for invasive candidiasis in most HSCT recipients. Fluconazole may be used for the treatment of invasive candidiasis in hemodynamically stable patients with no prior azole exposure. The primary treatment of choice for invasive aspergillosis is voriconazole. Alternatives include isavuconazole and lipid formulations of amphotericin. Currently available evidence does not support routine primary combination antifungal therapy for invasive aspergillosis. However, combination salvage antifungal therapy may be considered in selected patients. Therapeutic drug monitoring is recommended for the majority of HSCT recipients on itraconazole, posaconazole, or voriconazole.

Voriconazole for prophylaxis of invasive fungal infections after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Invasive fungal infections (IFIs) following allogeneic hematopoietic stem cell transplantation (alloHSCT) are associated with a high mortality, and accordingly most alloHSCT recipients receive prophylaxis with antifungal agents. Despite some improvement in outcomes of IFIs over time, they continue to represent substantial clinical risk, mortality, and financial burden. Areas covered: We review the main pathogens responsible for IFIs in recipients of alloHSCT, current treatment recommendations, and discuss clinical and economic considerations associated with voriconazole prophylaxis of IFIs in these patients. Expert commentary: The clinical efficacy of voriconazole appears to be at least equivalent to other antifungal treatments, and generally well tolerated. Overall, benefit-risk balance is favorable, and findings from cost-effectiveness analyses support the use of voriconazole prophylaxis of IFIs in recipients of alloHSCT.

Safety, Efficacy, and Exposure-Response of Voriconazole in Pediatric Patients With Invasive Aspergillosis, Invasive Candidiasis or Esophageal Candidiasis

BACKGROUND

Data on safety and efficacy of voriconazole for invasive aspergillosis (IA) and invasive candidiasis/esophageal candidiasis (IC/EC) in pediatric patients are limited.

METHODS

Patients aged 2-<18 years with IA and IC/EC were enrolled in 2 prospective open-label, non-comparative studies of voriconazole. Patients followed dosing regimens based on age, weight and indication, with adjustments permitted. Treatment duration was 6-12 weeks for IA patients, ≥14 days after last positive Candida culture for IC patients and ≥7 days after signs/symptoms resolution for EC patients. Primary analysis for both the studies was safety and tolerability of voriconazole. Secondary end points included global response success at week 6 and end of treatment (EOT), all-causality mortality and time to death. Voriconazole exposure-response relationship was explored.

RESULTS

Of 53 voriconazole-treated pediatric patients (31 IA; 22 IC/EC), 14 had proven/probable IA, 7 had confirmed IC and 10 had confirmed EC. Treatment-related hepatic and visual adverse events, respectively, were reported in 22.6% and 16.1% of IA patients, and 22.7% and 27.3% of IC/EC patients. All-causality mortality in IA patients was 14.3% at week 6; no deaths were attributed to voriconazole. No deaths were reported for IC/EC patients. Global response success rate was 64.3% (week 6 and EOT) in IA patients and 76.5% (EOT) in IC/EC patients. There was no association between voriconazole exposure and efficacy; however, a slight positive association between voriconazole exposure and hepatic adverse events was established.

CONCLUSIONS

Safety and efficacy outcomes in pediatric patients with IA and IC/EC were consistent with previous findings in adult patients.

Comparative Evaluation of the Predictive Performances of Three Different Structural Population Pharmacokinetic Models To Predict Future Voriconazole Concentrations

Bayesian methods for voriconazole therapeutic drug monitoring (TDM) have been reported previously, but there are only sparse reports comparing the accuracy and precision of predictions of published models. Furthermore, the comparative accuracy of linear, mixed linear and nonlinear, or entirely nonlinear models may be of high clinical relevance. In this study, models were coded into individually designed optimum dosing strategies (ID-ODS) with voriconazole concentration data analyzed using inverse Bayesian modeling. The data used were from two independent data sets, patients with proven or suspected invasive fungal infections (n = 57) and hematopoietic stem cell transplant recipients (n = 10). Observed voriconazole concentrations were predicted whereby for each concentration value, the data available to that point were used to predict that value. The mean prediction error (ME) and mean squared prediction error (MSE) and their 95% confidence intervals (95% CI) were calculated to measure absolute bias and precision, while ΔME and ΔMSE and their 95% CI were used to measure relative bias and precision, respectively. A total of 519 voriconazole concentrations were analyzed using three models. MEs (95% CI) were 0.09 (-0.02, 0.22), 0.23 (0.04, 0.42), and 0.35 (0.16 to 0.54) while the MSEs (95% CI) were 2.1 (1.03, 3.17), 4.98 (0.90, 9.06), and 4.97 (-0.54 to 10.48) for the linear, mixed, and nonlinear models, respectively. In conclusion, while simulations with the linear model were found to be slightly more accurate and similarly precise, the small difference in accuracy is likely negligible from the clinical point of view, making all three approaches appropriate for use in a voriconazole TDM program.

Different effects of lansoprazole and rabeprazole on the plasma voriconazole trough levels in allogeneic hematopoietic cell transplant recipients

Voriconazole (VRC) is widely used as prophylaxis and in the treatment of invasive fungal disease (IFD) after allogeneic hematopoietic cell transplantation (HCT). We retrospectively examined the results of VRC therapeutic drug monitoring (TDM) in allogeneic HCT recipients. A total of 474 samples were obtained from 59 adult patients who received VRC during the first 100 days following HCT between 2009 and 2014 in our institute. Seventeen patients received VRC for prophylaxis of IFD, and 42 received VRC for the empirical or preemptive therapy for IFD. A total of 299 samples (63 %) were obtained during the administration of the intravenous form of VRC. The median VRC daily dose based on the actual body weight was 6.68 mg/kg/day (range, 1.92-10.41 mg/kg/day). The median VRC trough level was 0.99 mg/l (range, <0.09-5.45 mg/l). The multivariate analysis using a logistic regression model demonstrated significantly higher VRC trough levels (≥1.0 mg/l) in males (P < 0.001), empirical or preemptive therapy (P = 0.002), VRC daily dose based on the actual body weight ≥7 mg/kg/day (P < 0.001), and concomitant use of lansoprazole as compared to rabeprazole (P < 0.001). The concomitant use of calcineurin inhibitors and corticosteroids had no effects on VRC trough levels in multivariate analysis. These data suggest that lansoprazole and rabeprazole have different effects on the plasma VRC trough levels in the allogeneic HCT recipients.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Voriconazole pharmacokinetics following HSCT: results from the BMT CTN 0101 trial

BACKGROUND

Voriconazole is a first-line agent for the prevention and treatment of a number of invasive fungal diseases. Relatively little is known about the relationship between drug exposure and the prevention of invasive fungal infections.

PATIENTS AND METHODS

A pharmacokinetic-pharmacodynamic substudy was performed as part of the BMT CTN 0101 trial, which was a randomized clinical trial comparing voriconazole with fluconazole for the prevention of invasive fungal infections in HSCT recipients. A previously described population pharmacokinetic model was used to calculate the maximum a posteriori Bayesian estimates for 187 patients. Drug exposure in each patient was quantified in terms of the average AUC and average trough concentrations. The relationship between drug exposure and the probability of breakthrough infection was investigated using logistic regression. AUC and trough concentrations in patients with and without breakthrough infection were compared.

RESULTS

Pharmacokinetic data from each patient were readily described using the maximum a posteriori Bayesian estimates. There were only five patients that had a breakthrough infection while receiving voriconazole in the first 100 days post-HSCT. For these patients, there was no statistically significant relationship between the average AUC or average trough concentration and the probability of breakthrough infection [OR (95% CI) 1.026 (0.956-1.102) and 1.108 (0.475-2.581), respectively]. P value for these estimates was 0.474 and 0.813, respectively.

CONCLUSIONS

Given the very small number of proven/probable infections, it was difficult to identify any differences in drug exposure in HSCT recipients with and without breakthrough fungal infections.

Therapeutic drug monitoring of anti-infective agents in critically ill patients

Initial adequate anti-infective therapy is associated with significantly improved clinical outcomes for patients with severe infections. However, in critically ill patients, several pathophysiological and/or iatrogenic factors may affect the pharmacokinetics of anti-infective agents leading to suboptimal drug exposure, in particular during the early phase of therapy. Therapeutic drug monitoring (TDM) may assist to overcome this problem. We discuss the available evidence on the use of TDM in critically ill patient populations for a number of anti-infective agents, including aminoglycosides, β-lactams, glycopeptides, antifungals and antivirals. Also, we present the available evidence on the practices of anti-infective TDM and describe the potential utility of TDM to improve treatment outcome in critically ill patients with severe infections. For aminoglycosides, glycopeptides and voriconazole, beneficial effects of TDM have been established on both drug effectiveness and potential side effects. However, for other drugs, therapeutic ranges need to be further defined to optimize treatment prescription in this setting.

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

This meta-analysis showed trough concentrations of 0.5 mg/L to be the lower limit of voriconazole during treatment, whereas trough concentrations of 3.0 mg/L were associated with an increased risk of moderate to severe hepatotoxicity, particularly for the Asian population.

Objectives

The optimum trough concentration of voriconazole for clinical response and safety is controversial. The objective of this review was to determine the optimum trough concentration of voriconazole and evaluate its relationship with efficacy and safety.

Methods

MEDLINE, EMBASE, ClinicalTrials.gov, the Cochrane Library and three Chinese literature databases were searched. Observational studies that compared clinical outcomes below and above the trough concentration cut-off value were included. We set the trough concentration cut-off value for efficacy as 0.5, 1.0, 1.5, 2.0 and 3.0 mg/L and for safety as 3.0, 4.0, 5.0, 5.5 and 6.0 mg/L. The efficacy outcomes were invasive fungal infection-related mortality, all-cause mortality, rate of successful treatment and rate of prophylaxis failure. The safety outcomes included incidents of hepatotoxicity, neurotoxicity and visual disorders.

Results

A total of 21 studies involving 1158 patients were included. Compared with voriconazole trough concentrations of >0.5 mg/L, levels of <0.5 mg/L significantly decreased the rate of treatment success (risk ratio = 0.46, 95% CI 0.29–0.74). The incidence of hepatotoxicity was significantly increased with trough concentrations >3.0, >4.0, >5.5 and >6.0 mg/L. The incidence of neurotoxicity was significantly increased with trough concentrations >4.0 and >5.5 mg/L.

Conclusions

A voriconazole level of 0.5 mg/L should be considered the lower threshold associated with efficacy. A trough concentration >3.0 mg/L is associated with increased hepatotoxicity, particularly for the Asian population, and >4.0 mg/L is associated with increased neurotoxicity.