Experience with caspofungin in the treatment of persistent fungemia in neonates

Candidemia in Brazilian neonatal intensive care units: risk factors, epidemiology, and antifungal resistance

Candidemia is responsible for substantial morbidity and mortality in neonatal intensive care units and represents a challenge due to the complexity of hospitalized neonates, the deficiency in approved and precise diagnostic techniques, and the increasing number of species resistant to antifungal agents. Thus, the objective of this study was to detect candidemia among neonates evaluating the risk factors, epidemiology, and antifungal susceptibility. Blood samples were obtained from neonates with suspected septicemia, and the mycological diagnosis was based on yeast growth in culture. The fungal taxonomy was based on classic identification, automated system, and proteomic, when necessary molecular tools were used. The in vitro susceptibility tests were performed according to the broth microdilution method from Clinical and Laboratory Standards Institute. Statistical analysis was performed using the R software version R-4.2.2. The prevalence of neonatal candidemia was 10.97%. The major risk factors involved were previous use of parenteral nutrition, exposure to broad-spectrum antibiotics, prematurity, and prior use central venous catheter, but only this last was statistically associated with mortality risk. Species from Candida parapsilosis complex and C. albicans were the most frequent. All isolates were susceptible to amphotericin B, except C. haemulonii that also exhibited elevated MICs to fluconazole. C. parapsilosis complex and C. glabrata exhibit the highest MICs to echinocandins. Considering these data, we emphasize that an effective management strategy to reduce the impact of neonatal candidemia should involve the knowledge of risk factors, rapid and precise mycological diagnostic, and tests of antifungal susceptibility to help in the selection of an appropriate treatment.

Antifungal Combinations against Candida Species: From Bench to Bedside

Candida spp. is the major causative agent of fungal infections in hospitalized patients and the fourth most common cause of nosocomial bloodstream infection (BSI). The availability of standardized methods for testing the in vitro activity of antifungals along with the expanding of antifungal armamentarium, the rising of drug-resistance and the persistence of a high mortality rate in systemic candidiasis have led to an increased interest in combination therapy. Therefore, we aimed to review the scientific literature concerning the antifungal combinations against Candida. A literature search performed in PubMed yielded 92 studies published from 2000 to 2021: 29 articles referring to in vitro studies, six articles referring to either in vitro and in vivo (i.e., animal models) studies and 57 clinical articles. Pre-clinical studies involved 735 isolates of Candida species and 12 unique types of antifungal combination approaches including azoles plus echinocandins (19%), polyenes plus echinocandins (16%), polyenes plus azoles (13%), polyenes plus 5-flucytosine ([5-FC], 13%), azoles plus 5-FC (11%) and other types of combinations (28%). Results varied greatly, often being species-, drug- and methodology-dependent. Some combinatorial regimens exerted a synergistic effect against difficult-to-treat Candida species (i.e., azoles plus echinocandins; polyenes plus 5-FC) or they were more effective than monotherapy in prevent or reducing biofilm formation and in speeding the clearance of infected tissues (i.e., polyenes plus echinocandins). In 283 patients with documented Candida infections (>90% systemic candidiasis/BSI), an antifungal combination approach could be evaluated. Combinations included: azoles plus echinocandins (36%), 5-FC-combination therapies (24%), polyenes plus azoles (18%), polyenes plus echinocandins (16%) and other types of combination therapy (6%). Case reports describing combination therapies yielded favorable response in most cases, including difficult-to-treat fungal infections (i.e., endocarditis, osteoarticular infections, CNS infections) or difficult-to-treat fungal pathogens. The only randomized trial comparing amphotericin-B deoxycholate (AMB) plus FLU vs. AMB alone for treatment of BSI in nonneutropenic patients showed that the combination trended toward improved success and more-rapid clearance from the bloodstream. In summary, antifungal combinations against Candida have produced great interest in the past two decades. To establish whether this approach can become a reliable treatment option, additional in vitro and clinical data are warranted.

A randomized, double-blind trial investigating the efficacy of caspofungin versus amphotericin B deoxycholate in the treatment of invasive candidiasis in neonates and infants younger than 3 months of age

Objectives

Investigate the efficacy of caspofungin in participants <3 months of age with invasive Candida infection (ICI).

Methods

This multicentre, randomized, double-blind, comparator-controlled, Phase 2 study (protocol MK0991-064; NCT01945281) enrolled participants <3 months of age with culture-confirmed ICI within 96 h of study entry. Participants were randomly assigned 2:1 to once-daily intravenous 2 mg/kg caspofungin or intravenous 1 mg/kg amphotericin B deoxycholate (dAMB). The primary endpoint was fungal-free survival (FFS) 2 weeks after treatment in the full-analysis-set (FAS) population, defined as participants with culture-confirmed ICI who received ≥1 dose of therapy. Planned enrolment was 90 participants.

Results

Fifty-one participants were enrolled; 49 received treatment (caspofungin, n=33; dAMB, n=16); 2 additional participants did not have confirmed infections at study entry. The study was terminated after ∼ 3.5 years because of low enrolment. Forty-seven participants were included in the FAS population (caspofungin, n=31; dAMB, n=16). FFS rate at 2 weeks after treatment was 71.0% (22/31) in the caspofungin arm and 68.8% (11/16) in the dAMB arm [difference, stratified by weight, − 0.9% (95% CI, − 24.3%–27.7%)]. Adverse events developed in 84.8% (28/33) of participants in the caspofungin arm and 100% (16/16) in the dAMB arm.

Conclusions

Among neonates and infants with confirmed ICI, FFS at 2 weeks was similar in the caspofungin and dAMB treatment arms. A smaller proportion of participants who received caspofungin experienced adverse events.

Antifungal Drugs for Invasive Candida Infections (ICI) in Neonates: Future Perspectives

Fungal infections may complicate the neonatal clinical course, and the spectrum of therapies for their treatment in the perinatal period is limited. Polyenes, Azoles and Echinocandins represent the three classes of antifungal drugs commonly used in the neonatal period. The present review provides an overview about the most recent therapeutic strategies for the treatment of fungal infections in neonates.

Echinocandins in antifungal pharmacotherapy

Objectives

Echinocandins are the newest addition of the last decade to the antifungal armamentarium, which, owing to their unique mechanism of action, selectively target the fungal cells without affecting mammalian cells. Since the time of their introduction, they have come to occupy an important niche in the antifungal pharmacotherapy, due to their efficacy, safety, tolerability and favourable pharmacokinetic profiles. This review deals with the varying facets of echinocandins such as their chemistry, in-vitro and in-vivo evaluations, clinical utility and indications, pharmacokinetic and pharmacodynamic profiles, and pharmacoeconomic considerations.

Key findings

Clinical studies have demonstrated that the echinocandins – caspofungin, micafungin and anidulafungin – are equivalent, if not superior, to the mainstay antifungal therapies involving amphotericin B and fluconazole. Moreover, echinocandin regimen has been shown to be more cost-effective and economical. Hence, the echinocandins have found favour in the management of invasive systemic fungal infections.

Conclusions

The subtle differences in echinocandins with respect to their pharmacology, clinical therapy and the mechanisms of resistance are emerging at a rapid pace from the current pool of research which could potentially aid in extending their utility in the fungal infections of the eye, heart and nervous system.

Persistent Candida conglobata bloodstream infection in a preterm neonate successfully treated by combination therapy with amphotericin B and caspofungin

Fungemia due to uncommon/rare Candida species is an emerging problem of global clinical significance. Here, we describe a case of Candida conglobata bloodstream infection in a preterm neonate. The diagnosis was established by repeated isolation of C. conglobata in blood cultures and by detection of rDNA of the fungus in serum samples. The identity of the isolate as C. conglobata was confirmed by sequencing of ITS region and D1/D2 domains of rDNA. Despite initial treatment with a liposomal amphotericin B (AmBisome) for 7 days, the blood culture remained positive. The neonate was successfully treated by combination therapy with caspofungin for 25 days. To the best of our knowledge, this is the first proven report unequivocally proving the etiologic role of C. conglobata in bloodstream infection.

Advances in the treatment of invasive neonatal candidiasis

INTRODUCTION

Invasive candidiasis is responsible for ∼ 10% of nosocomial sepsis in very-low-birth-weight infants and is associated with substantial morbidity and mortality. Over the last two decades, the antifungal armamentarium against Candida spp. has increased; however, efficacy and safety studies in this population are lacking.

AREAS COVERED

We reviewed the medical literature and extracted information on clinical and observational studies evaluating the use of antifungal agents in neonates with invasive candidiasis.

EXPERT OPINION

Efficacy and safety data for antifungals in neonates are lacking, and the majority of studies conducted to date have concentrated on pharmacokinetic/pharmacodynamic evaluations. Unlike other anti-infective agents, efficacy data in the setting of neonatal candidiasis cannot be extrapolated from adult studies due to differences in the pathophysiology of the disease in this population relative to older children and adults. Data for amphotericin B deoxycholate, fluconazole, and micafungin suggest that these are the current agents of choice for this disease in neonates until data for newer antifungal agents become available. For prophylaxis, data from fluconazole randomized controlled trials will be submitted to the regulatory agencies for labeling. Ultimately, the field of therapeutics for neonatal candidiasis will require multidisciplinary collaboration given the numerous challenges associated with conducting clinical trials in neonates.

Pharmacokinetics and pharmacodynamics of antifungals in children: clinical implications

Invasive fungal disease (IFD) remains life threatening in premature infants and immunocompromised children despite the recent development of new antifungal agents. Optimal dosing of antifungals is one of the few factors clinicians can control to improve outcomes of IFD. However, dosing in children cannot be extrapolated from adult data because IFD pathophysiology, immune response, and drug disposition differ from adults. We critically examined the literature on pharmacokinetics (PK) and pharmacodynamics (PD) of antifungal agents and highlight recent developments in treating pediatric IFD. To match adult exposure in pediatric patients, dosing adjustment is necessary for almost all antifungals. In young infants, the maturation of renal and metabolic functions occurs rapidly and can significantly influence drug exposure. Fluconazole clearance doubles from birth to 28 days of life and, beyond the neonatal period, agents such as fluconazole, voriconazole, and micafungin require higher dosing than in adults because of faster clearance in children. As a result, dosing recommendations are specific to bracketed ranges of age. PD principles of antifungals mostly rely on in vitro and in vivo models but very few PD studies specifically address IFD in children. The exposure-response relationship may differ in younger children compared with adults, especially in infants with invasive candidiasis who are at higher risk of disseminated disease and meningoencephalitis, and by extension severe neurodevelopmental impairment. Micafungin is the only antifungal agent for which a specific target of exposure was proposed based on a neonatal hematogenous Candida meningoencephalitis animal model. In this review, we found that pediatric data on drug disposition of newer triazoles and echinocandins are lacking, dosing of older antifungals such as fluconazole and amphotericin B products still need optimization in young infants, and that target PK/PD indices need to be clinically validated for almost all antifungals in children. A better understanding of age-specific PK and PD of new antifungals in infants and children will help improve clinical outcomes of IFD by informing dosing and identifying future research areas.

Successful caspofungin treatment of persistent candidemia in extreme prematurity at 23 and 24 weeks' gestation

Systemic fungal infection continues to be a major cause of mortality in extremely low-birth-weight premature infants. Amphotericin B has been recommended as the primary treatment; however, its use is limited due to drug-induced nephrotoxicity and amphotericin B-resistant candidemia. Caspofungin therapy was initiated in seven extremely premature infants at 23 and 24 weeks' gestation with persistent systemic candidiasis despite liposomal amphotericin B treatment. The gestational age was 23(+1)-24(+6) weeks, and birth weight was 530-825 g. Of the seven patients, the peripheral blood cultures of six patients were positive for Candida parapsilosis and one had positive culture for Candida albicans. The dosage of caspofungin was 2 mg/kg/day, and the mean treatment duration was 14 days. All of the persistent candidemia resolved on caspofungin therapy. There was no recurrent candidemia after discontinuing caspofungin. There were no adverse effects, hepatotoxicity, nephrotoxicity, anemia, or thrombocytopenia. Caspofungin successfully treated persistent candidemia in extremely premature infants at 23 and 24 weeks' gestational age.

Recommendations for the management of candidemia in neonates in Latin America. Latin America Invasive Mycosis Network

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the management of candidemia in neonates in Latin America', was written to provide guidance to healthcare professionals on the management of neonates who have, or who are at risk of, candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the management of candidemia in neonates in Latin America' includes prophylaxis, empirical therapy, therapy for proven candidemia, patient work-up following diagnosis of candidemia, central venous catheter management, and management of complications. This manuscript is the fourth of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the diagnosis of candidemia in Latin America', 'Recommendations for the management of candidemia in adults in Latin America', and 'Recommendations for the management of candidemia in children in Latin America'.

[Recommendations for the management of candidemia in neonates in Latin America. Grupo Proyecto Épico]

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the management of candidemia in neonates in Latin America', was written to provide guidance to healthcare professionals on the management of neonates who have, or who are at risk of, candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the management of candidemia in neonates in Latin America' includes prophylaxis, empirical therapy, therapy for proven candidemia, patient work-up following diagnosis of candidemia, central venous catheter management, and management of complications. This manuscript is the fourth of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the diagnosis of candidemia in Latin America', 'Recommendations for the management of candidemia in adults in Latin America', and 'Recommendations for the management of candidemia in children in Latin America'.

Antifungal therapy in children: an update

Invasive fungal infections are a common problem in children affected by primary or secondary immunodeficiencies. Thanks to an increased knowledge about their mechanisms of action and their pharmacokinetic and toxicity profiles, the use of these drugs in common and uncommon invasive infections in immunocompromised children has improved over the last decades. Choosing the most appropriate antifungal drug is a serious challenge for any clinician, also considering that, in most cases, therapy has to be started before cultures are available, the choice being driven by clinical symptoms and statistical criteria only. In this study, we performed a systematic review of literature, providing antifungal treatment recommendations for paediatric patients which can help clinicians find the most suitable treatment for each specific case. Principal antifungal drugs-ranging from first-generation antimycotics to the latest molecules-are classified according to their targets, and of each group, the pharmacokinetic profile, clinical indications and side effects are extensively described.

A review of clinical experience with newer antifungals in children

Fungal infections are a significant cause of morbidity and mortality in immunocompromised children. Since the beginning of the 21st century, many new antifungals including the echinocandins (i.e., caspofungin, micafungin, anidulafungin) and the newer generation triazoles (i.e., voriconazole and posaconazole) have received Food and Drug Administration approval. Unfortunately, despite making great strides in the adult arena, these agents are not currently approved in the pediatric population. However, pharmacokinetic data and clinical experiences with these agents in infants, children, and adolescents are mounting. As such, this review will discuss key concepts in pediatric pharmacology and clinical use of these newer antifungal agents.

Antifungal therapy for newborn infants with invasive fungal infection

BACKGROUND

A variety of antifungal drugs, drug preparations and drug combinations are available to treat newborn infants with suspected or confirmed invasive fungal infection. There is a need to assess their relative merits.

OBJECTIVES

To assess the effect of treatment with different antifungal drugs, drug preparations or drug combinations on mortality and morbidity in newborn infants with suspected or confirmed invasive fungal infection.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2012, Issue 2), MEDLINE, EMBASE, CINAHL (to March 2012), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised control trials comparing one antifungal agent or combination of agents with another in newborn infants with suspected or confirmed invasive fungal infection.

DATA COLLECTION AND ANALYSIS

We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author, and synthesis of data using risk ratio and risk difference.

MAIN RESULTS

We identified only one small trial in which 24 newborn infants participated. This trial compared the use of fluconazole versus amphotericin B (plus 5-fluorocytosine if fungal meningitis present). The trial did not detect a statistically significant effect on mortality (risk ratio 0.73; 95% confidence interval 0.26 to 2.05).

AUTHORS' CONCLUSIONS

There are insufficient data to inform practice. Large randomised controlled trials are required to compare antifungal drugs, drug preparations or drug combinations for treating newborn infants with invasive fungal infection.

Caspofungin for the treatment of immunocompromised and severely ill children and neonates with invasive fungal infections

Caspofungin is the first member of the echinocandin class of antifungals to receive an indication for the use in infants, children, and adolescents from the United States Food and Drug Administration. Daily doses of 50 mg/m(2) result in pharmacokinetic parameters that are similar to those observed in adults. Although fewer data are available, the response rates in pediatric patients who received caspofungin either as treatment or empiric therapy in clinical trials are similar to those reported in adults. In addition, caspofungin appears to be generally safe and well tolerated in this population. This represents a significant step forward in the treatment of invasive fungal infections within this population, as caspofungin is associated with few clinically significant drug-interactions and toxicities compared to other antifungals, such as the azoles and amphotericin B.

Strategies for the prevention of neonatal candidiasis

Invasive fungal infections represent the third-leading cause of late-onset sepsis in very-low-birth-weight infants (VLBWI) and have a high rate of infection-associated mortality. The infants at high risk for fungal sepsis are VLBWI with presence of additional risk factors that contribute to increased colonization and concentration of fungal organisms. Colonization with Candida spp. in neonates is secondary to either maternal vertical transmission or nosocomial acquisition in the nursery. Multiple sites may become colonized and a direct correlation between fungal colonization and subsequent progression to invasive candidemia was determined. Randomized, single and multiple-center, placebo-controlled trials found intravenous fluconazole prophylaxis to be effective in decreasing fungal colonization and sepsis for at-risk preterm infants <1500 g birth weight. The prophylactic use of fluconazole was found to be safe with no significant development of fungal resistance. Fluconazole prophylaxis administered to preterm neonates with birth weight <1000 g and/or 27 weeks' gestation or less has the potential of reducing and potentially eliminating invasive fungal infections and Candida-related mortality.

The use of antifungal therapy in neonatal intensive care

Invasive fungal infections remain a significant cause of infection-related mortality and morbidity in preterm infants. Central nervous system involvement is the hallmark of neonatal candidiasis, differentiating the disease's impact on young infants from that among all other patient populations. Over the past decade, the number of antifungal agents in development has grown, but most are not labeled for use in newborns. We summarize the findings of several antifungal studies that have been completed to date, emphasizing those including infant populations. We conclude that more studies are required for antifungals to be used safely and effectively in infants.

Epidemiology, risk factors and therapy of candidemia in pediatric hematological patients

Invasive fungal infections (IFI) are an important cause of morbidity, increased hospitalization and healthcare costs in critically ill or immunocompromised children. The mortality is comprised between 5 and 20%. In the last 2 decades, the epidemiology of candidemia has changed with an increase of episodes caused by non-Candida albicans species. Central venous catheter, diagnosis of malignancy, and receipt of either vancomycin or antimicrobials with activity against anaerobic organisms for >3 days have been associated with the development of candidemia in the pediatric intensive care unit (PICU). Additional risk factors found in hematological patients were the diagnosis of aplastic anemia, performing an unrelated bone marrow or cord blood transplant, the occurrence of a graft versus host disease and the use of steroids. Early antifungal treatment is recommended to reduce mortality. In neutropenic patients, liposomal amphotericin B, an echinocandin (caspofungin, micafungin), and voriconazole are considered the best option especially for C. glabrata and C. krusei. Fluconazole remains a valid option for infection by Candida albicans in patients not exposed to fluconazole prophylaxis. Amphotericn B deoxy-cholate is generally not recommended because of its nephrotoxicity.

Echinocandin use in the neonatal intensive care unit

OBJECTIVE

To evaluate the literature regarding the use of echinocandins to treat invasive fungal infections caused by Candida spp. in patients in the neonatal intensive care unit.

DATA SOURCES

Literature retrieval was accessed through MEDLINE (Jan 2000-September 2011) using the search terms echinocandin, caspofungin, micafungin, anidulafungin, and neonate with limits for age group (ie, birth to 1 month). Reference citations from identified articles were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant information on the pharmacokinetics, efficacy, and safety of echinocandins in neonates was selected. Prospective studies, retrospective studies, and case series in English identified from MEDLINE were evaluated.

DATA SYNTHESIS

Neonates, especially preterm neonates, have many risk factors that predispose them for invasive fungal infections caused by Candida spp. To date, the only antifungals recommended for use in neonates for treatment of candidiasis are amphotericin B (deoxycholate or a lipid formulation) and fluconazole; however, the toxicities associated with amphotericin B and resistance of certain Candida spp. to fluconazole limit their use in neonates. There is a need for a broad-spectrum antifungal agent with limited toxicity for use in this patient population. The echinocandins may represent such a class of antifungals. To date, micafungin is the most studied echinocandin in the neonatal population, followed by caspofungin; however, studies evaluating their efficacy and pharmacokinetic parameters in neonates are few.

CONCLUSIONS

Although studies suggest that the echinocandins may have a favorable safety profile, the lack of pharmacokinetic data and standardized study designs limit current recommendations of use of echinocandins as first-line agents in neonates in the treatment of fungal infections. However, if an echinocandin is to be used in this population, the data presented in this review suggest the use of micafungin over the other echinocandins, and higher doses of micafungin (10-15 mg/kg/day) should be used when central nervous system involvement is suspected.

Neonatal intensive care unit candidemia: epidemiology, risk factors, outcome, and critical review of published case series

Evaluation of epidemiological trends, risk factors, and clinical outcome associated with candidemia at a neonatal intensive care unit is reported. From January 2005 to December 2009, forty candidemia cases were identified. C. albicans and C. parapsilosis were the most common species recovered (69 and 24%, respectively). All C. parapsilosis strains were susceptible to antifungals, whereas, C. albicans exhibited higher resistance rates to azoles. Low birth weight, low gestational age, presence of central lines, endotracheal intubation, total parenteral nutrition, previous use of antibiotics, steroids, previous episode(s) of bacteremia and prolonged stay in intensive care unit were common features associated with candidemia. C. albicans was most often isolated from extremely low birth weight neonates as compared to non-albicans Candida (P < 0.01). Mortality rate was 35.7% and was associated with low gestational age (P < 0.01), low birth weight (P < 0.01), and presence of renal failure (P < 0.05). Furthermore, a critical review of recent published case series is presented.

Caspofungin therapy in immunocompromised children and neonates

The prevalence of invasive fungal infections is increasing and the infections are becoming a major problem in immunocompromised children and neonates. Fortunately, there has been a recent surge in the development of new antifungal agents. Caspofungin, the first licensed echinocandin, is a novel class of antifungal and is approved for use in children 3 months of age or older for the treatment of invasive candidiasis, salvage therapy for invasive aspergillosis and as empirical therapy for febrile neutropenia. This article reviews the published data on the use of caspofungin in immunocompromised children and neonates with invasive fungal infections.

Echinocandins: A ray of hope in antifungal drug therapy

Invasive fungal infections are on the rise. Amphotericin B and azole antifungals have been the mainstay of antifungal therapy so far. The high incidence of infusion related toxicity and nephrotoxicity with amphotericin B and the emergence of fluconazole resistant strains of Candida glabrata egged on the search for alternatives. Echinocandins are a new class of antifungal drugs that act by inhibition of β (1, 3)-D- glucan synthase, a key enzyme necessary for integrity of the fungal cell wall.

Caspofungin was the first drug in this class to be approved. It is indicated for esophageal candidiasis, candidemia, invasive candidiasis, empirical therapy in febrile neutropenia and invasive aspergillosis. Response rates are comparable to those of amphotericin B and fluconazole. Micafungin is presently approved for esophageal candidiasis, for prophylaxis of candida infections in patients undergoing hematopoietic stem cell transplant (HSCT) and in disseminated candidiasis and candidemia. The currently approved indications for anidulafungin are esophageal candidiasis, candidemia and invasive candidiasis.

The incidence of infusion related adverse effects and nephrotoxicity is much lower than with amphotericin B. The main adverse effect is hepatotoxicity and derangement of serum transaminases. Liver function may need to be monitored. They are, however, safer in renal impairment. Even though a better pharmacoeconomical choice than amphotericin B, the higher cost of these drugs in comparison to azole antifungals is likely to limit their use to azole resistant cases of candidial infections and as salvage therapy in invasive aspergillosis rather than as first line drugs.

[Echinocandins in children]

Echinocandins are a new class of antifungal agents with a specific mechanism of action. These drugs inhibit the enzyme 1,3β-D-glucan synthetase which is responsible for the formation of 1,3β-D-glucan, an essential fungal cell wall component. They have a good activity against Candida species and Aspergillus. Three agents are available at the present time or under development : caspofungin, micafungin and anidulafungin. These drugs require intravenous administration. Efficacy, safety, rare drugs interactions and specificity of action are advantages for therapy of invasive fungal infections. In France, micafungin and caspofungin are approved for a pediatric use.

Efficacy of caspofungin in a juvenile mouse model of central nervous system candidiasis

Neonatal candidiasis is an increasingly common occurrence causing significant morbidity and mortality and a higher risk of dissemination to the central nervous system (CNS) than that seen with older patients. The current understanding of optimal antifungal therapy in this setting is limited. We have developed a model of disseminated candidiasis with CNS involvement in juvenile mice to assess the efficacy of the echinocandin caspofungin relative to amphotericin B (AmB). Juvenile mice were inoculated intravenously with 5.64 × 10(4) CFU of Candida albicans MY1055. Treatment with caspofungin at 1, 2, 4, and 8 mg/kg of body weight/day, AmB at 1 mg/kg/day, or a vehicle control (VC) was initiated 30 h after infection and continued for 7 days. Pharmacokinetic parameters for caspofungin were also determined. Culture and histology showed evidence of disseminated candidiasis with multifocal encephalitis at the start of antifungal therapy. Survival was 100% in all treated groups, while mortality was 100% in the VC by day 11 after infection. By day 5, all mice in the caspofungin treatment (four doses) groups showed reductions in kidney and brain burden relative to the VC, while AmB treatment reduced kidney burden but gave no reduction of brain fungal burden. Systemic levels of caspofungin were similar in infected and uninfected mice, while brain levels were higher in infected animals. In this juvenile mouse model, caspofungin demonstrated dose-dependent activity, equivalent to or better than that of AmB at 1 mg/kg, against disseminated candidiasis with CNS involvement.

Efficacy and safety of antifungals in pediatric patients

Invasive fungal infections (IFIs) constitute an important cause for morbidity and mortality in immunocompromised pediatric patients [1]. Despite substantial achievements, the prevention and treatment of IFIs are still limited by the facts that not all antifungal agents are approved in the pediatric population, the appropriate dosage of these drugs has not been established for all age groups, and postmarketing data providing information on the safety and efficacy of approved agents under real-life circumstances are scant. In this article, we 1) briefly review the principles of drug development, 2) discuss safety and approved indications of antifungal agents, and 3) provide a summary of current options for treatment of invasive fungal infections in pediatric patient populations.

Role of echinocandins in the management of fungal infections in neonates

As the incidence rates of neonatal systemic fungal infections (SFI) have been increasing over the last years, research efforts have been addressed towards identifying both effective preventative strategies, and efficacious and well-tolerated antifungal drugs. Historically, the first options in treatment of neonatal SFI have been &#x2013; and currently are &#x2013; fluconazole and amphotericin B. However, these two drugs carry limitations both in efficacy and in putative toxicity. Recently, new therapeutic alternatives have drawn the neonatologists' attention. Echinocandins are a new class of antifungal drugs with characteristics that might better meet the needs of this particular population of patients. Caspofungin (CSP), micafungin (MICA), and anidulafungin have inherent good activities both against biofilms, and against natively fluconazole-resistant strains of Candida spp, thus overcoming two of the major weaknesses of the commonly used antifungal drugs in nurseries. CSP and MICA have been recently studied in neonatal populations. The kinetics and appropriate dosing of this agent in premature and term infants have been described, but ongoing further studies are needed to better address this area. Case-report series show clinical efficacy and tolerability in critical neonatal patients given CSP and MICA. In addition, extrapolation of data from randomized trials conducted in pediatric and adult patients showed through a subgroup analysis that both CSP and MICA are effective and well tolerated also in neonates. Further studies properly designed for neonatal populations will better address long-term safety and ecological issues related to echinocandin use in neonates.

Challenging issues in neonatal candidiasis

In an era of quality improvement and 'getting to zero (infections and/or related mortality),' neonatal candidiasis is ripe for evidence-based initiatives. Knowledge of each institution's invasive Candida infection (ICI) incidence and infection-related mortality is critical to evaluate disease burden and effective interventions. Evidenced-based interventions include: antifungal prophylaxis, starting with appropriate dosing, and prompt removal of central venous catheters (CVC). There is A-I evidence supporting antifungal prophylaxis with fluconazole, and it should be considered in every neonatal intensive care unit (NICU). The literature supports targeting infants <1000 g and/or <or=27 weeks, because this group has high infection-related mortality and neurodevelopmental impairment in 57% of survivors. Antifungal prophylaxis has been shown to nearly eliminate infection-related mortality. Interventions start with prenatal initiatives, with women being treated for vaginal candidiasis, especially with preterm labor or complications. Targeting modifiable risk factors, including restriction policies for use of third- and fourth-generation cephalosporins, carbapenems, H2-antagonists, proton pump inhibitors, and postnatal steroids; guidelines for CVC care and removal; and feeding practices, with promotion of early feedings and breast milk, may also reduce risk. A few studies have emerged on empiric antifungal therapy with sepsis evaluations for preterm infants <1500 g and other high-risk patients that have shown favorable effects of eliminating mortality, but these have not been compared to appropriate antifungal therapy and central line removal. Further study of empiric therapy, prospective treatment studies with higher targeted dosing of amphotericin B preparations, fluconazole, and new antifungals with prompt CVC removal may contribute to a 100% survival rate for those infants >1000 g and >or=28 weeks not receiving antifungal prophylaxis. Evaluation of ICI incidence and mortality by gestational age and birth week should be followed in each NICU, to evaluate infection control and prevention.

Use of Antifungal Combination Therapy: Agents, Order, and Timing

Given the substantial morbidity and mortality related to invasive fungal infections, treatment with a combination of antifungal agents is often considered. A growing body of literature from in vitro studies, animal models, and clinical experience provides data evaluating this approach. This review describes combination antifungal strategies for the management of cryptococcal meningitis, invasive candidiasis, invasive aspergillosis, and rare mold infections. The potential effects that sequencing and timing have on the efficacy of such approaches are discussed, with a focus on recent clinical data in this arena.

Clinical aspects of invasive candidiasis in paediatric patients

Candida infections in paediatric patients are an important issue. They are associated with significant mortality, particularly in newborns and those with congenital immunodeficiencies. At present, there is limited knowledge regarding factors associated with an increased risk of developing invasive candidiasis in newborns and those with congenital immunodeficiencies, although there have been a number of studies conducted to characterize these risk factors. These studies have suggested that, in neonates, the most important of these factors is colonization, whereas in paediatric patients with congenital immunodeficiencies, risk factors may differ according to the specific deficiency present. Regarding treatment of invasive candidiasis in paediatric patients, fluconazole is considered an appropriate choice, although the method for determining treatment strategies for each patient should be the same as that used for such decisions in adult patients.

Pediatric antifungal agents

PURPOSE OF REVIEW

In immunocompromised hosts, invasive fungal infections are common and fatal. In the past decade, the antifungal armamentarium against invasive mycoses has expanded greatly. The purpose of the present report is to review the most recent literature addressing the use of antifungal agents in children.

RECENT FINDINGS

Most studies evaluating the safety and efficacy of antifungal agents are limited to adults. However, important progress has been made in describing the pharmacokinetics and safety of newer antifungal agents in children, including the echinocandins.

SUMMARY

Dosage guidelines for newer antifungal agents are currently based on adult and limited pediatric data. Because important developmental pharmacology changes occur throughout childhood impacting the pharmacokinetics of these agents, antifungal studies specifically designed for children are necessary.

A Clinical Review of Echinocandins in Pediatric Patients

OBJECTIVE

To identify and evaluate available data on pediatric echinocandin use.

DATA SOURCES

A PubMed search, limited to English-language articles, was conducted (1990-August 2009) using the search terms echinocandin, pediatric, child, pharmacokinetics, caspofungin, micafungin, and anidulafungin. Additional articles were retrieved from citations of selected references.

STUDY SELECTION AND DATA EXTRACTION

Relevant information on the pharmacology, pharmacokinetics, efficacy, and safety of echinocandins in children was selected. Clinical trials, retrospective reviews, and case series were identified and evaluated. Data from these sources were included in this review.

DATA SYNTHESIS

Caspofungin is the only echinocandin approved by the Food and Drug Administration for use in children. Pediatric pharmacokinetics has been evaluated with all 3 echinocandins but is limited with anidulafungin. Micafungin is the most well-studied agent in prospective clinical trials for antifungal prophylaxis in stem cell transplantation and treatment of invasive fungal infections. Caspofungin has been studied prospectively for febrile neutropenia and treatment of invasive fungal infections, but most published data are from retrospective reviews or case reports. One case report of anidulafungin for neonatal candidiasis has been published. The role of echinocandins in the management of invasive pediatric fungal infections has expanded. Micafungin and caspofungin are recommended as primary or alternative treatment of candidemia and esophageal or invasive candidiasis, and as salvage therapy for invasive aspergillosis. Micafungin is recommended for neutropenic prophylaxis in stem cell transplantation, while caspofungin may be used in febrile neutropenia as an alternative to azoles. Dosing has been well established for caspofungin only in children 3 months of age and above. Anidulafungin should be avoided in children until more pharmacokinetic and clinical data become available.

CONCLUSIONS

Further comparative trials are needed to more clearly define the role of echinocandins, either as monotherapy or in combination for difficult-to-treat infections, in the pediatric population.

Refractory neonatal candidemia and high-dose micafungin pharmacotherapy

OBJECTIVE

Preterm neonates with candidemia frequently have persistently positive blood cultures, despite the use of conventional antifungal therapy. Our institutional treatment protocol for invasive candidiasis incorporates lipid complex amphotericin B as initial therapy with the sequential addition of fluconazole and high-dose micafungin (10 mg kg(-1)) every 48 to 72 h, if cultures from a sterile site remain positive. Our study objectives were to compare the clinical profiles and outcomes of preterm neonates with candidemia that responded to or were refractory to conventional antifungals. We further evaluate the clinical efficacy of high-dose micafungin pharmacotherapy of refractory candidemia.

STUDY DESIGN

A chart review was performed on preterm infants (n=29) with invasive candidiasis and demographic, microbiologic and outcome data abstracted. Proportions and continuous variables were compared between the groups using Fisher's exact two-tailed test and t-test.

RESULT

The refractory (n=19) candidemia and early responder (n=10) groups had comparable mean (+/-s.d.) gestation, 27(+/-3.1) vs 27.8 (+/-2.7) weeks. The refractory group was administered antibiotics for a longer duration, 14.5 (+/-10.3) vs 7.1 (+/-5) days, had a preponderance of non-albicans infections, 11 (57.9%) vs 1 (10%) and were on enteral feeds > 20 ml kg(-1) day(-1) significantly less often (21 vs 70%). Mortality was significantly higher (53 vs 20%) and fungal clearance rates lower (63.1 vs 90%), with a longer duration to clearance in the group with refractory candidemia. Mean aspartate aminotransferase (AST) showed a statistically significant increase following micafungin treatment, although clinical significance remains unclear.

CONCLUSION

Candidemia refractory to conventional antifungals is associated with prolonged antibiotic use, lack of enteral nutritive feeds and non-albicans infection. Despite high-dose micafungin pharmacotherapy in combination with conventional antifungals, infants with refractory candidemia had high mortality and poor fungal clearance.

Successful treatment of Candida albicans septicemia in a preterm infant with severe congenital ichthyosis (Harlequin baby)

Candida infections are a major cause of fungal septicemia in neonates and are associated with marked morbidity and mortality. Despite the spectrum of antifungal drugs being dramatically extended during the last decade, invasive fungal infections remain a serious challenge for neonatologists. Amphotericin B and its lipid formulations are the drugs of choice for the treatment of systemic candidiasis in neonates. The combination of antifungal drugs with different sites of action, like caspofungin and amphotericin B, may improve antifungal efficacy. Severe congenital ichthyosis often leads to death within the neonatal period. Main causes of death are dehydration, electrolyte disturbances, and respiratory or systemic infections. We report the case of a preterm infant with severe congenital ichthyosis and sepsis caused by Candida albicans. The infection did not improve despite proper liposomal amphotericin B treatment. After addition of caspofungin, the baby recovered. To our best knowledge, a case of a preterm infant suffering from severe congenital ichthyosis and Candida albicans sepsis, who survived, has not been previously described.

Neonatal liver abscesses due to Candida infection effectively treated with caspofungin

Candidiasis is relatively frequent in neonatal and pediatric intensive care units (ICUs), particularly in preterm infants less than 28 weeks of gestational age. Neonatal candidiasis shows high mortality and is often associated to poor neurodevelopmental prognosis in survivor patients. Amphotericin B and fluconazole are the first choice drugs for the treatment of neonatal candidiasis. Caspofungin is an alternative antifungal agent, which is recommended for invasive candidiasis in adults, but has been poorly experienced in neonates and infants as far as now. We report the first two infants with Candida liver abscesses treated with caspofungin. In the first infant bloodstream and liver lesions were cleared by combination therapy with fluconazole, liposomal amphotericin and caspofungin, while in the second one by caspofungin alone.

CONCLUSION

Our observations confirm the efficacy and tolerability of caspofungin in the treatment of neonatal candidiasis refractory to conventional antifungal drugs. More extensive data are recommended in order to asses a specific neonatal schedule.

Therapeutic strategies for invasive fungal infections in neonatal and pediatric patients

Invasive Candida and Aspergillus infections are the most commonly encountered fungal infections. They appear to be life threatening in the setting of profound immunosuppression, whereas cases that are resistant to antifungal therapy are occasionally encountered. Novel antifungal triazole and echinocandin agents appear to exhibit good activity as first-line or salvage therapy, whereas the use of amphotericin B formulations is particularly valuable in neonates. Significant differences in toxicity have been demonstrated among various antifungal agents with in vitro activity from available comparative data on fungal infections in children: however, no clear difference in treatment efficacy has been demonstrated. However, very little data are available about neonates. Host factors and responsible fungal species most frequently guide the choice of therapy.

Pharmacokinetics and safety of caspofungin in neonates and infants less than 3 months of age

Candida infections represent a major threat in neonatal intensive care units. This is the first prospective study to obtain caspofungin plasma levels and safety data for neonates and very young infants. Patients of <3 months of age receiving intravenous amphotericin B for documented or highly suspected candidiasis were enrolled in a single-dose (n = 6) or subsequent multiple-dose (n = 12) panel; all received caspofungin at 25 mg/m(2) once daily as a 1-hour infusion. Caspofungin plasma levels were measured by high-performance liquid chromatography and compared to historical data from adults. Patient chronological ages ranged from 1 to 11 weeks, and weights ranged from 0.68 to 3.8 kg. Gestational ages ranged from 24 to 41 weeks. Geometric mean (GM) peak (C(1 h)) and trough (C(24 h)) caspofungin levels were 8.2 and 1.8 microg/ml, respectively, on day 1, and 11.1 and 2.4 microg/ml, respectively, on day 4. GM ratios for C(1 h) and C(24 h) for neonates/infants relative to adults receiving caspofungin at 50 mg/day were 1.07 and 1.36, respectively, on day 1, and 1.18 and 1.21, respectively, on day 4. Clinical and laboratory adverse events occurred in 17 (94%) and 8 (44%) patients, respectively. Five patients (28%) had serious adverse events, none of which were considered drug related. Caspofungin at 25 mg/m(2) once daily was well tolerated in this group of neonates/infants of <3 months of age and appears to provide relatively similar plasma exposure to that obtained in adults receiving 50 mg/day. However, the small number of patients studied precludes any definitive recommendations about caspofungin dosing for this group comprising a broad range of ages and weights.