A Phase 3 Study of Micafungin Versus Amphotericin B Deoxycholate in Infants With Invasive Candidiasis

Combination of Systemic and Lock-Therapies with Micafungin Eradicate Catheter-Based Biofilms and Infections Caused by Candida albicans and Candida parapsilosis in Neutropenic Rabbit Models

Vascular catheter-related infections, primarily caused by Candida albicans and Candida parapsilosis, pose significant challenges due to the formation of biofilms on catheters, leading to refractory disease and considerable morbidity. We studied the efficacy of micafungin in systemic and lock therapies to eliminate catheter-based biofilms and deep tissue infections in experimental central venous catheter (CVC)-related candidemia in neutropenic rabbits. Silastic CVCs in rabbits were inoculated with 1 × 103 CFU/mL of C. albicans or C. parapsilosis, establishing catheter-based biofilm, and subjected to various treatments. Neutropenic rabbits treated with a combination of lock therapy and systemic micafungin demonstrated the most significant reduction in fungal burden, from 5.0 × 104 to 1.8 × 102 CFU/mL of C. albicans and from 5.9 × 104 to 2.7 × 102 CFU/mL of C. parapsilosis (p ≤ 0.001), in the CVC after 24 h, with full clearance of blood cultures after 72 h from treatment initiation. The combination of lock and systemic micafungin therapy achieved eradication of C. albicans from all studied tissues (0.0 ± 0.0 log CFU/g) vs. untreated controls (liver 7.5 ± 0.22, spleen 8.3 ± 0.25, kidney 8.6 ± 0.07, cerebrum 6.3 ± 0.31, vena cava 6.6 ± 0.29, and CVC wash 2.3 ± 0.68 log CFU/g) (p ≤ 0.001). Rabbits treated with a combination of lock and systemic micafungin therapy demonstrated a ≥2 log reduction in C. parapsilosis in all treated tissues (p ≤ 0.05) except kidney. Serum (1→3)-β-D-glucan levels demonstrated significant decreases in response to treatment. The study demonstrates that combining systemic and lock therapies with micafungin effectively eradicates catheter-based biofilms and infections caused by C. albicans or C. parapsilosis, particularly in persistently neutropenic conditions, offering promising implications for managing vascular catheter-related candidemia and providing clinical benefits in cases where catheter removal is not feasible.

Physicochemical Characteristics of Antimicrobials and Practical Recommendations for Intravenous Administration: A Systematic Review

Most antimicrobial drugs need an intravenous (IV) administration to achieve maximum efficacy against target pathogens. IV administration is related to complications, such as tissue infiltration and thrombo-phlebitis. This systematic review aims to provide practical recommendations about diluent, pH, osmolarity, dosage, infusion rate, vesicant properties, and phlebitis rate of the most commonly used antimicrobial drugs evaluated in randomized controlled studies (RCT) till 31 March 2023. The authors searched for available IV antimicrobial drugs in RCT in PUBMED EMBASE®, EBSCO® CINAHL®, and the Cochrane Controlled Clinical trials. Drugs' chemical features were searched online, in drug data sheets, and in scientific papers, establishing that the drugs with a pH of <5 or >9, osmolarity >600 mOsm/L, high incidence of phlebitis reported in the literature, and vesicant drugs need the adoption of utmost caution during administration. We evaluated 931 papers; 232 studies were included. A total of 82 antimicrobials were identified. Regarding antibiotics, 37 reach the "caution" criterion, as well as seven antivirals, 10 antifungals, and three antiprotozoals. In this subgroup of antimicrobials, the correct vascular access device (VAD) selection is essential to avoid complications due to the administration through a peripheral vein. Knowing the physicochemical characteristics of antimicrobials is crucial to improve the patient's safety significantly, thus avoiding administration errors and local side effects.

Plasma and Cerebrospinal Fluid Concentrations of Micafungin Administered at High Doses in Critically Ill Infants with Systemic Candidiasis: A Pooled Analysis of Two Studies

Background: Neonates may require higher doses of micafungin than adults to reach the therapeutic effect for increased plasma clearance. Only poor and inconclusive data are available still now to support this hypothesis, especially with regard to central nervous system micafungin concentrations. To assess the pharmacokinetics of increased doses (8 to 15 mg/kg/day) of micafungin in preterm and term neonates with invasive candidiasis and to complete previously presented results, we analyzed the pharmacokinetic data on a total of 53 newborns treated with micafungin, whereby 3 of them had Candida meningitis and hydrocephalus. Methods: Fifty-three neonates with systemic candidiasis, three of them with meningitis, were treated for at least 14 days with intravenous micafungin (Mycamine^®) at a dosage ranging from 8 to 15 mg/kg/day. Plasma and cerebrospinal fluid (CSF) concentrations of micafungin were measured before the drug administration and at 1, 2, and 8 h after the end of the infusion using high-performance liquid chromatography (HPLC). Systemic exposure was assessed according to AUC_0-24, plasma clearance (CL), and half-life measured in 52/53 patients, divided by chronological age. Results and conclusions: The mean micafungin clearance is higher in neonates than in older infants (0.036 L/h/kg before 28 days of life versus 0.028 L/h/kg after 120 days). The drug half-life is shorter in neonates than in older patients (13.5 h before 28 days of life versus 14.4 h after 120 days). With doses ranging between 8 and 15 mg/kg/day, micafungin crosses the blood-brain barrier reaching therapeutic levels in CSF.

Amphotericin B in Pediatrics: Analysis by Age Stratification Suggests a Greater Chance of Adverse Events from 13 Months of Age Onwards

BACKGROUND AND OBJECTIVE

Amphotericin B deoxycholate (AMB-D) remains an antifungal agent with great therapeutic value in pediatric patients. The currrent consensus is that its use in neonates is safer than in older children. However, childhood presents different periods of development that deserve to be evaluated more precisely. Our goal was to assess the usage profile of AMB-D in stratified pediatric age groups, adapted according to the National Institute of Child Health and Human Development classification.

METHODS

This retrospective cross-sectional observational study was conducted at a Brazilian tertiary children's hospital between January 2014 and December 2019.  Data of patients who received at least two doses of intravenous AMB-D while hospitalized were extracted from electronic health files. Information on patient demographics, underlying diseases and comorbidities, laboratory examinations, fungal infection diagnosis, and AMB-D use were gathered following specific criteria. Nonparametric tests were applied, such as the chi-square test to compare proportions and Fisher's exact test to assess the association between categorical variables or contingency tables.

RESULTS

One hundred and twenty-seven (127) medical records were stratified as preterm neonatal (birth <37 weeks postmenstrual age), term neonatal (birth-27 days), infants (28 days-12 months), toddlers (13 months-2 years), early childhood (3-5 years), middle childhood (6-11 years), and early adolescence (12-18 years). The criteria for the indication of AMB-D followed empirical use as the main indication (n = 74; 58.26%), proven and probable fungal infection (n = 39; 30.71%), and medical suspicion (n = 14; 11.02%). Candida spp. was the main etiologic agent isolated in cultures, with the highest frequency of C. albicans (n = 18; 40%), followed by Candida parapsilosis (n = 14; 31.11%), and Candida tropicalis (n = 6; 13.33%). Very few acute infusion-related adverse effects were observed during the administration of AMB-D in pediatric patients. We found an unfavorable impact of AMB-D use in patients from 13 months of age onwards suggesting this group as a turning point for a greater chance of adverse events, and not soon after the neonatal period.

CONCLUSIONS

Clinical or observational studies based on age stratification are essential to accurately elucidate whether potentially toxic drugs can be used safely in the pediatric population. Our search for a turning point was shown to contribute to the accuracy of the study, as it provided data on the impact of D-AMB in specific pediatric age groups.

Updates in the Pharmacologic Prophylaxis and Treatment of Invasive Candidiasis in the Pediatric and Neonatal Intensive Care Units

Purpose of review

The goal of this review was to provide an update on the prevention and treatment options for invasive candidiasis (IC) in the neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU).

Recent findings

Studies have further validated the use of fluconazole for IC prophylaxis among high-risk patients in the NICU. It remains unclear if prophylaxis leads to resistance development and the ideal dosage regimen is still not clear. Recent studies have been published comparing caspofungin and micafungin to amphotericin B and illustrated similar efficacy outcomes in the NICU. Micafungin now has approval from the United States Food and Drug Administration (FDA) for use in infants < 4 months of age. Prophylactic strategies in the PICU could include zinc and vitamin D. Anidulafungin has recent non-comparative data supporting use in pediatric patients older than 1 month of age and also has a recent FDA approval for use in children 1 month of age and older.

Summary

Fluconazole prophylaxis remains a reasonable strategy in select NICU patients, although further analyses of resistance and the optimal dosage regimen are needed. Echinocandins are potential therapeutic options for non-meningitis or urinary tract infections in both the neonatal and pediatric population.

Pharmacodynamics of Meropenem and Tobramycin for Neonatal Meningoencephalitis: Novel Approaches to Facilitate the Development of New Agents to Address the Challenge of Antimicrobial Resistance

Neonatal sepsis is an underrecognized burden on health care systems throughout the world. Antimicrobial drug resistance (AMR) is increasingly prevalent and compromises the use of currently recommended first-line agents. The development of new antimicrobial agents for neonates and children is mandated by regulatory agencies. However, there remains uncertainty about suitable development pathways, especially because of the propensity of premature babies to develop meningoencephalitis as a complication of neonatal sepsis and difficulties studying this disease in clinical settings. We developed a new platform and approach to accelerate the development of antimicrobial agents for neonatal bacterial meningoencephalitis using Pseudomonas aeruginosa as the challenge organism. We defined the pharmacodynamics of meropenem and tobramycin in these models. The percentage of partitioning of meropenem and tobramycin into the cerebrospinal fluid was comparable at 14.3 and 13.7%, respectively. Despite this similarity, there were striking differences in their pharmacodynamics. Meropenem resulted in bactericidal activity in both the cerebrospinal fluid and cerebrum, whereas tobramycin had minimal antibacterial activity. A hollow fiber infection model (HFIM) using neonatal CSF concentration time profiles yielded pharmacodynamics comparable to those observed in the rabbit model. These new experimental models can be used to estimate the pharmacodynamics of currently licensed agents and those in development and their potential efficacy for neonatal bacterial meningoencephalitis.

Micafungin injection for the treatment of invasive candidiasis in pediatric patients under 4 months of age

INTRODUCTION

Neonates and young infants with invasive candidiasis are particularly at increased risk of dissemination including hematogenous Candida meningoencephalitis. The echinocandins including micafungin have emerged as a preferred agent in most cases of candidemia and invasive candidiasis but data in pediatric patients under 4 months of age are limited.

AREAS COVERED

In this report, we review the micafungin use in infants younger than 4 months of age. Animal studies as well as clinical data that support its use in neonatal candidiasis are reviewed. In addition, the status of FDA approval and the rationale of micafungin dosing recommendations in infants <4 months are discussed.

EXPERT OPINION

A dose of 4 mg/kg was approved for treatment of candidemia, Candida peritonitis and abscesses excluding meningoencephalitis or ocular involvement in patients younger than 4 months of age. However, because of the risk of central nervous system dissemination as well as the difficulty in establishing this diagnosis, this dose is inadequate to treat ill infants with candidemia. More studies are needed to establish the safety and efficacy of micafungin daily dose of at least 10 mg/kg in infants younger than 4 months of age when hematogenous Candida meningoencephalitis or ocular involvement cannot be excluded.

Methodological and reporting quality of non-inferiority randomized controlled trials comparing antifungal therapies: a systematic review

BACKGROUND

Detailed reporting is essential in non-inferiority randomized controlled trials (NI-RCTs) to assess evidence quality, as these trials inform standards of care.

OBJECTIVES

The primary objective was to evaluate the methodological and reporting quality of antifungal NI-RCTs.

DATA SOURCES

Medline, EMBASE, the Cochrane CENTRAL and the United States Federal Drug Administration (FDA) drugs database were searched to 9 September 2020.

STUDY ELIGIBILITY CRITERIA

NI-RCTs differing by antifungal formulation, type, dose, administration and/or duration were included. Articles were independently assessed in duplicate using quality indicators developed by the Consolidated Standards of Reporting Trials (CONSORT) group.

PARTICIPANTS

Patients enrolled in antifungal trials for prophylactic and therapeutic use.

METHODS

The Cochrane RoB 2.0 tool was used to assess risk of bias. Descriptive statistics were used; all statistical tests were two sided.

RESULTS

Of 32 included studies, 22 (68.7%) did not justify the NIM. Handling of missing data was not described in 20 (62.5%). Intention-to-treat (ITT) and per-protocol (PP) analyses were both reported in 12/32 (37.5%) studies. Eleven of 32 studies (34.3%) reported potentially misleading conclusions. Industry-financed studies were more likely to report only the ITT analysis (n = 14/27, 51.9%). Methodological and reporting quality was unaffected by publication year; risk of bias from missing data changed over time. Overall risk of bias across included studies was moderate to high, with high risk in randomization process (n = 8/32, 25%), missing outcome data (n = 5/32, 15.6%), and selection of reported result (n = 9/32, 28.1%).

CONCLUSIONS

Justification of the non-inferiority margin, reporting of ITT and PP analyses, missing data handling description, and ensuring conclusions are consistent with reported data is necessary to improve CONSORT adherence. Small sample size and overall risk of bias are study limitations. (Systematic Review Registration Number PROSPERO CRD42020219497).

Are antifungal non-inferiority trials at risk of eroding effectiveness because of bio-creep? A secondary analysis of a systematic review

Non-inferiority randomized controlled trial (RCT) effectiveness may erode when results favour the active control over time, and when a decreasingly effective control arm is used in serial trials. We analyzed 32 antifungal noninferiority RCTs (NI-RCTs) for these scenarios in this secondary analysis of a systematic review. Our exploratory analysis suggests that the erosion risk in the effectiveness of antifungal non-inferiority trials is uncommon. Findings are limited by small sample size, and overall risk of bias.

Ceftolozane/Tazobactam in Neonates and Young Infants: The Challenges of Collecting Pharmacokinetics and Safety Data in This Vulnerable Patient Population

OBJECTIVE

New treatments are needed for multidrug-resistant (MDR) gram-negative infections in neonates. Ceftolozane/tazobactam is a β-lactam/β-lactamase inhibitor combination that has broad-spectrum activity against most common gram-negative bacteria, including MDR strains. We evaluated pharmacokinetics (PK) and safety of ceftolozane/tazobactam in term and premature neonates and young infants.

STUDY DESIGN

This is a subgroup analysis of a phase 1, noncomparative, open-label, multicenter study that characterized the PK, safety, and tolerability of a single intravenous (IV) dose of ceftolozane/tazobactam in pediatric patients with proven/suspected gram-negative infection or receiving perioperative prophylaxis.

RESULTS

Seven patients were enrolled in Group A (birth [7 days postnatal] to < 3 months, > 32 weeks gestation) and six patients were enrolled in Group B (birth [7 days postnatal] to < 3 months, ≤ 32 weeks gestation). PK profiles in neonates and young infants were generally comparable to those of older children receiving a single IV dose of ceftolozane/tazobactam. No serious adverse events (AEs), treatment-related AEs, severe AEs, or clinically significant laboratory abnormalities were reported.

CONCLUSION

Among term and premature neonates and young infants, PK was comparable to older children and ceftolozane/tazobactam was generally well tolerated. An adaptable and flexible study design is necessary for enrollment in neonatal PK trials.

Efficacy and Pharmacokinetics of Fosmanogepix (APX001) in the Treatment of Candida Endophthalmitis and Hematogenous Meningoencephalitis in Nonneutropenic Rabbits

Candida endophthalmitis is a serious sight-threatening complication of candidemia that may occur before or during antifungal therapy. Hematogenous Candida meningoencephalitis (HCME) is also a serious manifestation of disseminated candidiasis in premature infants, immunosuppressed children, and immunocompromised adults. We evaluated the antifungal efficacy and pharmacokinetics of the prodrug fosmanogepix (APX001) in a rabbit model of endophthalmitis/HCME. Manogepix (APX001A), the active moiety of prodrug fosmanogepix, inhibits the fungal enzyme Gwt1 and is highly active in vitro and in vivo against Candida spp., Aspergillus spp., and other fungal pathogens. Plasma pharmacokinetics of manogepix after oral administration of fosmanogepix on day 6 at 25, 50, and 100 mg/kg resulted in maximum concentration of drug in plasma (C _max) of 3.96 ± 0.41, 4.14  ± 1.1, and 11.5 ± 1.1 μg/ml, respectively, and area under the concentration-time curve from 0 to 12 h (AUC_0-12) of 15.8 ± 3.1, 30.8 ± 5.0, 95.9 ± 14 μg·h/ml, respectively. Manogepix penetrated the aqueous humor, vitreous, and choroid with liquid-to-plasma ratios ranging from 0.19 to 0.52, 0.09 to 0.12, and 0.02 to 0.04, respectively. These concentrations correlated with a significant decrease in Candida albicans burden in vitreous (>10¹ to 10³ log CFU/g) and choroid (>10¹ to 10³ log CFU/g) (P ≤ 0.05 and P ≤ 0.001, respectively). The aqueous humor had no detectable C. albicans in treatment and control groups. The tissue/plasma concentration ratios of manogepix in meninges, cerebrum, cerebellum, and spinal cord were approximately 1:1, which correlated with a >10² to 10⁴ decline of C. albicans in tissue versus control (P ≤ 0.05). Serum and cerebrospinal fluid (CSF) (1→3)-β-d-glucan levels demonstrated significant declines in response to fosmanogepix treatment. These findings provide an experimental foundation for fosmanogepix in treatment of Candida endophthalmitis and HCME and derisk the clinical trials of candidemia and invasive candidiasis.

Review of Fluconazole Treatment and Prophylaxis for Invasive Candidiasis in Neonates

Invasive candidiasis accounts for approximately 10% of nosocomial infections in preterm infants, with an incidence of 1% to 4% among neonatal intensive care unit (NICU) admissions and a mortality as high as 20% to 30%. These outcomes warrant improved treatment and prevention strategies for infants at highest risk. The Infectious Diseases Society of America provides guidelines on antifungal medications for the prophylaxis and treatment of candidiasis in NICUs; however, there are still variations in practice on the use of fluconazole for prophylaxis and treatment of invasive candidiasis. This review provides specific information regarding fluconazole activity, pharmacokinetics, and a literature evaluation of dosing strategies and comparisons to other treatments in the neonatal population.

A Regulatory Review Approach for Evaluation of Micafungin for Treatment of Neonatal Candidiasis

Pathogenesis of neonatal candidiasis (NC) is distinct from systemic candidiasis in adults and older pediatric patients due to the significant incidence of central nervous system (CNS) involvement in neonates. Thus, although adequate and well-controlled trials in NC are often unfeasible due to difficulty enrolling patients, extrapolation of efficacy from antifungal drug trials in adults is generally not appropriate. However, treatment of NC is an area of great unmet need. We describe a regulatory review approach that combined the assessment of limited clinical efficacy, pharmacokinetics, and safety data from neonates and young infants along with microbiology outcomes and pharmacokinetic data from relevant nonclinical models of candidemia/invasive candidiasis to inform the use of micafungin in pediatric patients younger than 4 months of age, while communicating areas of remaining uncertainty in labeling.

Administration and Dosing of Systemic Antifungal Agents in Pediatric Patients

Neonates and immunosuppressed/immunocompromised pediatric patients are at high risk of invasive fungal diseases. Appropriate antifungal selection and optimized dosing are imperative to the successful prevention and treatment of these life-threatening infections. Conventional amphotericin B was the mainstay of antifungal therapy for many decades, but dose-limiting nephrotoxicity and infusion-related adverse events impeded its use. Despite the development of several new antifungal classes and agents in the past 20 years, and their now routine use in at-risk pediatric populations, data to guide the optimal dosing of antifungals in children are limited. This paper reviews the spectra of activity for approved antifungal agents and summarizes the current literature specific to pediatric patients regarding pharmacokinetic/pharmacodynamic data, dosing, and therapeutic drug monitoring.

Echinocandins vs. amphotericin B against invasive candidiasis in children and neonates: A meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this meta-analysis was to assess the efficacy and safety of treatment with echinocandins compared with amphotericin B in paediatric patients with invasive candidiasis.

METHODS

PubMed, Embase and Cochrane databases were searched up to August 2018. Only randomized controlled trials (RCTs) evaluating echinocandins and amphotericin B in the treatment of paediatric patients with invasive candidiasis were included. The outcomes were clinical responses and adverse effects.

RESULTS

Five RCTs of 354 patients (191 patients in the echinocandins group and 163 patients in the amphotericin B group) were included in this study. Overall, no significant differences in clinical response were found between echinocandins and amphotericin B (odds ratio [OR], 1.38; 95% confidence interval [CI], 0.68-2.80; I² = 39%). Similar results were also observed in the high-risk group (OR, 3.10; 95% CI, 0.10-97.23; I² = 76%), the low-risk group (OR, 1.29; 95% CI, 0.36-4.62; I² = 21%) and the neutropenia group (OR, 1.56; 95% CI, 0.75-3.26; I² = 0%). The risk of discontinuing treatment because of adverse effects was significantly lower in the echinocandins group than in the amphotericin B group (OR, 0.30, 95% CI, 0.12-0.76; I² = 0%).

CONCLUSIONS

There were no differences in efficacy between the echinocandins group and the amphotericin B group in the treatment of invasive candidiasis in paediatric patients. However, the echinocandins group had a significantly lower risk of discontinuing treatment than the amphotericin B group.

Invasive Candidiasis in Infants and Children: Recent Advances in Epidemiology, Diagnosis, and Treatment

This paper reviews recent advances in three selected areas of pediatric invasive candidiasis: epidemiology, diagnosis, and treatment. Although the epidemiological trends of pediatric invasive candidiasis illustrate a declining incidence, this infection still carries a heavy burden of mortality and morbidity that warrants a high index of clinical suspicion, the need for rapid diagnostic systems, and the early initiation of antifungal therapy. The development of non-culture-based technologies, such as the T2Candida system and (1→3)-β-d-glucan detection assay, offers the potential for early laboratory detection of candidemia and CNS candidiasis, respectively. Among the complications of disseminated candidiasis in infants and children, hematogenous disseminated Candida meningoencephalitis (HCME) is an important cause of neurological morbidity. Detection of (1→3)-β-d-glucan in cerebrospinal fluid serves as an early diagnostic indicator and an important biomarker of therapeutic response. The recently reported pharmacokinetic data of liposomal amphotericin B in children demonstrate dose–exposure relationships similar to those in adults. The recently completed randomized clinical trial of micafungin versus deoxycholate amphotericin B in the treatment of neonatal candidemia provides further safety data for an echinocandin in this clinical setting.

Advances in the Treatment of Mycoses in Pediatric Patients

The main indications for antifungal drug administration in pediatrics are reviewed as well as an update of the data of antifungal agents and antifungal policies performed. Specifically, antifungal therapy in three main areas is updated as follows: a) Prophylaxis of premature neonates against invasive candidiasis; b) management of candidemia and meningoencephalitis in neonates; and c) prophylaxis, empiric therapy, and targeted antifungal therapy in children with primary or secondary immunodeficiencies. Fluconazole remains the most frequent antifungal prophylactic agent given to high-risk neonates and children. However, the emergence of fluconazole resistance, particularly in non-albicans Candida species, should be considered during preventive or empiric therapy. In very-low birth-weight neonates, although fluconazole is used as antifungal prophylaxis in neonatal intensive care units (NICU's) with relatively high incidence of invasive candidiasis (IC), its role is under continuous debate. Amphotericin B, primarily in its liposomal formulation, remains the mainstay of therapy for treating neonatal and pediatric yeast and mold infections. Voriconazole is indicated for mold infections except for mucormycosis in children >2 years. Newer triazoles-such as posaconazole and isavuconazole-as well as echinocandins, are either licensed or under study for first-line or salvage therapy, whereas combination therapy is kept for refractory cases.