Randomized, double-blind, multicenter study of caspofungin versus amphotericin B for treatment of oropharyngeal and esophageal candidiases

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

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

Comparative Efficacy of Antifungal Agents Used in the Treatment of Oropharyngeal Candidiasis among HIV-Infected Adults: A Systematic Review and Network Meta-Analysis

The objective of this study was to assess the comparative efficacy and safety of different antifungal agents used for the treatment of oropharyngeal candidiasis (OPC) in adult patients with HIV. A systematic search was performed on the four major databases (Medline, Embase, CENTRAL and Scopus) to identify randomized controlled trials (RCTs) that evaluated the efficacy of antifungal agents in HIV patients with OPC. A network meta-analysis was performed from the data extracted from the selected studies. The agents were ranked according using surface under the cumulative ranking (SUCRA). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to determine the quality of evidence. A total of 15 trials were included in the quantitative analysis involving the data from a total of 2883 participants. Fluconazole was ranked as the most effective antifungal agent to achieve clinical cure (SUCRA = 0.87) in OPC followed by posaconazole and itraconazole. Posaconazole was ranked the most efficacious agent in achieving mycological cure (SUCRA = 0.81), followed by fluconazole. While nystatin was ranked the safest, the effect estimates of none of the other systemic antifungal agents were significantly higher than fluconazole. Based on the available evidence, fluconazole can be considered as the most effective drug in the treatment of OPC among HIV-infected adults and has a favorable safety profile, followed by posaconazole.

Efficacy and acceptability of different anti-fungal interventions in oropharyngeal or esophageal candidiasis in HIV co-infected adults: a pilot network meta-analysis

Background: Oropharyngeal/esophageal candidiasis are the most common opportunistic infections observed in patients with human immunodeficiency virus (HIV). While the commonly recommended treatment is fluconazole, relapse of oropharyngeal or esophageal candidiasis has been gradually increasing in recent decades.Methods: The current network meta-analysis (NMA) included randomized controlled trials (RCTs) investigating the efficacy and acceptability (i.e. drop-out rate) of different anti-fungal interventions against oropharyngeal or esophageal candidiasis in adults with HIV. All NMA procedures were conducted using the frequentist model.Results: Twenty-seven RCTs and 6277 participants were included. For oropharyngeal candidiasis, photosensitizer-based antimicrobial photodynamic therapy (aPDT) with laser irradiation plus methylene blue was associated with the highest cure rate and the lowest relapse rate among the investigated interventions [odds ratio (OR) = 6.82, 95% confidence intervals (95%CIs) = 0.19 to 244.42, p = 0.293, and OR = 0.03, 95%CIs = 0.00 to 0.77, p = 0.034, compared to fluconazole]. None of the investigated anti-fungal interventions were superior to fluconazole for esophageal candidiasis in respect of cure rates/relapse rates. All investigated anti-fungal interventions were well-accepted.Conclusions: aPDT could be the preferred strategy to manage oropharyngeal candidiasis; however the evidence for esophageal candidiasis still remained inconclusive.

Efficacy and mechanism of actions of natural antimicrobial drugs

Microbial infections have significantly increased over the last decades, and the mortality rates remain unacceptably high. The emergence of new resistance patterns and the spread of new viruses challenge the eradication of infectious diseases. The declining efficacy of antimicrobial drugs has become a global public health problem. Natural products derived from natural sources, such as plants, animals, and microorganisms, have significant efficacy for the treatment of infectious diseases accompanied by less adverse effects, synergy, and ability to overcome drug resistance. As the Chinese female scientist Youyou Tu received the Nobel Prize for the antimalarial drug artemisinin, antimicrobial drugs developed from Traditional Chinese Medicine are expected to receive increasing attention again. This review summarizes the antimicrobial agents derived from natural products approved for nearly 20 years and describes their efficacy and mode of action. The aim of this unit is to review the current status of antimicrobial drugs from natural products in order to increase the value of natural products as a source of novel drug candidates for infectious diseases.

Caspofungin Effects on Electrocardiogram of Mice: An Evaluation of Cardiac Safety

Caspofungin is an echinocandin, exhibiting efficacy against most Candida species invasive infection. Its cardiotoxicity was reported in isolated rat heart and ventricular myocytes, but in vivo and clinical studies are insufficient. Our objective was to evaluate caspofungin in vivo cardiac effects using an efficacious dose against Candida albicans. Female Swiss mice were infected with C. albicans, and treated with caspofungin, 5 or 10 mg/kg, intraperitoneal along 5 days. Survival rate and colony-forming units (CFU) into vital organs were determined. For cardiac effects study, mice were treated with caspofungin 10 mg/kg, and electrocardiogram (ECG) signal was obtained on C. albicans-infected mice, single dose-treated, and uninfected mice treated along 5 days, both groups to measure ECG intervals. Besides, ECG was also obtained by telemetry on uninfected mice to evaluate heart rate variability (HRV) parameters. The MIC for caspofungin on the wild-type C. albicans SC5314 strain was 0.3 μg/ml, indicating the susceptible. Survival rate increased significantly in infected mice treated with caspofungin compared to mice treated with vehicle. None of the survived infected mice presented positive CFU after treatment with 10 mg/kg. C. albicans infection induced prolongation of QRS, QT, and QTc intervals; caspofungin did not alter this effect. Caspofungin induced increase of PR and an additional increase of QRS after 24 h of a single dose in infected mice. No significant alterations occurred in ECG intervals and HRV parameters of uninfected mice, after caspofungin treatment. Caspofungin showed in vivo cardiac relative safety maintaining its antifungal efficacy against C. albicans.

Nephrotoxicity of Antimicrobials and Antibiotics

Medication-induced nephrotoxicity remains one of the most common causes of acute kidney injury (AKI) among hospitalized patients. Within the extensive group of medications associated with AKI, antibiotics and other antimicrobials are well recognized triggers of structural and functional renal impairment. Clinical manifestations range from mild forms of tubular injury to significant deterioration of kidney function requiring acute renal replacement therapy. Several mechanisms are described, although the most frequent are acute interstitial nephritis, acute tubular necrosis, intratubular crystal deposition, and proximal/distal tubulopathy with electrolyte wasting abnormalities. General risk factors for antimicrobial-induced AKI include pre-existing chronic kidney disease, and concomitant use of medication with nephrotoxic potential. Prevention and early recognition of AKI represent the standard approach to mitigate AKI and avoid morbidity.

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.

Clinical hepatotoxicity associated with antifungal agents

INTRODUCTION

Invasive fungal diseases (IFDs) are a leading cause of morbidity and mortality among immunocompromised patients with bone marrow failure syndromes, hematological malignancies, hematopoietic stem cell transplantation (HSCT), those admitted in intensive care units (ICUs) and those with prolonged febrile neutropenia. IFDs occur in a setting of multiple morbidities and are associated with case fatality rates between 30 and 70%. Along with the development of classes and compounds, the last two decades have seen substantial improvements in the prevention and management of these infections and an overall increased use of antifungal agents. Areas covered: All antifungal agents, including amphotericin B formulations, echinocandins and the triazoles, may cause hepatic toxicity that ranges from mild and asymptomatic abnormalities in liver function tests to substantial liver injury and fulminant hepatic failure. Expert opinion: The present article reviews incidence and severity of hepatotoxicity associated with different classes and agents to provide a better understanding of this specific end organ toxicity and safer use of antifungal agents A thorough understanding of the distribution, metabolism, elimination and drug-drug interactions of antifungal agents used for management of IFDs in combination with safety data from clinical trials, pharmacokinetic and pharmacodynamic studies may guide the use of antifungal treatment in patients at high risk for the development of hepatic dysfunction and in those with underlying liver damage due to cytotoxic therapy.

Fungal Opportunistic Infections in HIV Disease

Fungal pathogens can lead to many of the complications seen in advanced HIV disease and are commonly identified in HIV-infected populations with decreased immune function. Common fungal organisms affecting individuals with AIDS include Cryptococcus neoformans, various Candida species, and Histoplasma capsulatum. While infection with these organisms can be fatal, appropriate identification and management of the condition can result in reduced mortality and the opportunity for effectivemanagement of HIV disease with highly active antiretroviral therapy. This article describes the clinical presentation and treatment of 3 fungal infections common in the immunocompromised individual with AIDS. Current antifungal therapy for themanagement of these infections is discussed. In addition, the role of newer antifungal agents in the setting of these conditions is reviewed.

Tissue penetration of antifungal agents

Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection.

Discovery and development of first in class antifungal caspofungin (CANCIDAS®)--a case study

Covering: 1985 to 2001.This paper describes a fifteen year journey from concept to clinical discovery and development of the first in class caspofungin acetate (CANCIDAS®) a parenteral antifungal agent. Caspofungin is a semisynthetic derivative of pneumocandin B0, a naturally occurring, lipophilic cyclic peptide isolated from the fungus, Glarea lozoyensis. While the echinocandins had been previously studied for antifungal activity by several organizations, the class was dropped for a variety of reasons. Merck subsequently initiated a research program leading to the discovery and development of caspofungin. The multitude of challenges that ensued during the discovery and development process and which were successfully resolved by multi-disciplinary teams constitute the content of this article. The article consists of five sections that describe the discovery and development of caspofungin in chronological order: (i) discovery of the natural product pneumocandin B0 from fungal fermentations, (ii) fermentation development to improve the titer of pneumocandin B0 to make it commercially viable, (iii) semisynthetic modification by medicinal chemistry to successfully improve the properties of pneumocandin B0 leading to the discovery of caspofungin, (iv) development of commercial semisynthesis and purification and formulation development to improve stability and (v) clinical development and approval of CANCIDAS® as an antifungal drug which subsequently saved thousands of lives.

Anidulafungin: advantage for the newcomer?

Anidulafungin is the most recently approved compound of the echinocandin antifungal class. Its mode of action is the noncompetitive inhibition of β-(1,3)-D-glucan synthesis. Potent fungicidal activity has been demonstrated against many Candida spp., including non-albicansCandida spp. and fluconazole-resistant strains, as well as fungistatic activity against Aspergillus spp. Owing to low oral bioavailability, it can only be administered intravenously. Anidulafungin is not metabolized by the liver and renal clearance is negligible, thus rendering dosage adjustments in patients with impaired hepatic or renal function unnecessary. Due to lack of interference with the cytochrome P450 pathway, it displays minimal drug-drug interaction. Anidulafungin has been approved by the US FDA for the treatment of esophageal and invasive candidiasis after clinical trials demonstrated its noninferiority to fluconazole. In September 2007, anidulafungin gained EMEA approval for the treatment of invasive candidiasis in adult non-neutropenic patients. For those with invasive or noninvasive candidiasis with resistance or intolerance to fluconazole in particular, as well as those requiring antifungal medication, that anidulafungin does not interact with concomitant medication means it may be regarded as a safe and efficacious treatment option. Promising results from animal models and experience with the other echinocandins indicate several potential lines of investigation: invasive aspergillosis, prophylaxis and treatment of transplant patients, and empirical treatment in patients with febrile neutropenia. Significant differences in clinical efficacy or safety favoring anidulafungin over the other echinocandins are yet to be discovered.

Fluconazole for the treatment of candidiasis: 15 years experience

Candidia spp. are responsible for contributing to the increasing global prevalence of fungal infections. Fluconazole (Diflucan((R)), Pfizer) is a triazole that has established an exceptional therapeutic record for candida infections including oropharyngeal and esophageal candidiasis, vulvovaginal candidiasis, candidemia and disseminated candidiasis. It is both an oral and parenteral fungistatic agent that inhibits ergosterol synthesis in yeasts. Extensive clinical studies have demonstrated fluconazole's remarkable efficacy, favorable pharmacokinetics and reassuring safety profile, all of which have contributed to its widespread use. Fluconazole became the first antifungal with worldwide sales exceeding billions of dollars, therefore providing an incentive for the pharmaceutical industry to develop new antifungals. This review will examine the contributions and limitations of fluconazole in the treatment of superficial and invasive candidiasis syndromes.

Fungal infections in cancer patients

Invasive fungal infections (IFI) have become a leading cause of morbidity and mortality in cancer patients. Infections with these organisms are often difficult to diagnose and treat. Appropriate and timely diagnosis requires a high index of suspicion and invasive procedures, including biopsy, to confirm the diagnosis. Treatment may be difficult, secondary to variable susceptibility and difficulty with exact and specific characterization of the fungal pathogen. The pathogens that are seen range from yeasts to invasive molds. Fortunately newer, noninvasive diagnostic techniques are available to aid in the diagnosis and treatments have become better tolerated and more efficacious.

Caspofungin exposure-response relationships in adult patients with mucosal or invasive candidiasis

Caspofungin is an echinocandin antifungal agent administered once daily as an intravenous infusion. Relationships between caspofungin exposure and clinical efficacy and safety were investigated. End-of-infusion (CEOI ) and trough (C24 hours ) concentrations were obtained in 218 patients with mucosal (i.e., esophageal and/or oropharyngeal) candidiasis (MC) receiving caspofungin 35, 50, or 70 mg/day and 278 patients with invasive candidiasis (IC) receiving 50, 100, or 150 mg/day. Area under the plasma concentration-time curve (AUC0-24 hours ) was obtained in a subset of MC patients (n = 99). Odds ratios were estimated for the association between log-transformed PK and efficacy response and the occurrence of common adverse events. No pharmacokinetic or hybrid parameter (ratio of AUC:MIC, CEOI :MIC, C24 hours :MIC) was significantly correlated with overall treatment outcome in either MC or IC, although this patient population may exhibit confounding factors which masked a potential pharmacokinetic/pharmacodynamic relationship. An exploratory evaluation of MC identified significant pharmacokinetic correlations with endoscopic response, but not symptom response. Statistically significant associations were identified for IC patients with C. parapsilosis infections. Occurrence of clinical adverse events and/or laboratory abnormalities did not appear to be increased by higher caspofungin plasma concentrations. Caspofungin concentrations achieved with 50 mg/day are generally within the therapeutic window for the treatment of candidiasis.

Invasive candidiasis: update on current pharmacotherapy options and future perspectives

INTRODUCTION

Invasive candidiasis (IC), mainly candidemia, is a leading cause of morbidity and mortality among immunocompromised patients and those admitted to intensive care units. Despite the recognition of risk factors and advances in disease prevention, Candida-related hospitalizations and mortality continue to rise. For treatment, four classes of older and newer antifungal agents are currently available. Adjunctive immunotherapies and a monoclonal antibody against heat shock protein 90 (efungumab) are promising novel therapeutic approaches.

AREAS COVERED

In this article, approaches and therapeutic agents for candidemia and other forms of IC are reviewed.

EXPERT OPINION

The thorough understanding of the available antifungal agents in combination with the increasing knowledge of the mechanisms that underlie the pathogenesis of Candida infections and the development of newer approaches such as efungumab and immunotherapy with adjunctive cytokines may improve the prognosis of patients with life-threatening invasive Candida infections.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: patients with HIV infection or AIDS

Mucosal candidiasis is frequent in immunocompromised HIV-infected highly active antiretroviral (HAART) naive patients or those who have failed therapy. Mucosal candidiasis is a marker of progressive immune deficiency. Because of the frequently marked and prompt immune reconstitution induced by HAART, there is no recommendation for primary antifungal prophylaxis of mucosal candidiasis in the HIV setting in Europe, although it has been evidenced as effective in the pre-HAART era. Fluconazole remains the first line of therapy for both oropharyngeal candidiasis and oesophageal candidiasis and should be preferred to itraconazole oral solution (or capsules when not available) due to fewer side effects. For patients who still present with fluconazole-refractory mucosal candidiasis, oral treatment with any other azole should be preferred based on precise Candida species identification and susceptibility testing results in addition to the optimization of HAART when feasible. For vaginal candidiasis, topical therapy is preferred.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT)

Fungal diseases still play a major role in morbidity and mortality in patients with haematological malignancies, including those undergoing haematopoietic stem cell transplantation. Although Aspergillus and other filamentous fungal diseases remain a major concern, Candida infections are still a major cause of mortality. This part of the ESCMID guidelines focuses on this patient population and reviews pertaining to prophylaxis, empirical/pre-emptive and targeted therapy of Candida diseases. Anti-Candida prophylaxis is only recommended for patients receiving allogeneic stem cell transplantation. The authors recognize that the recommendations would have most likely been different if the purpose would have been prevention of all fungal infections (e.g. aspergillosis). In targeted treatment of candidaemia, recommendations for treatment are available for all echinocandins, that is anidulafungin (AI), caspofungin (AI) and micafungin (AI), although a warning for resistance is expressed. Liposomal amphotericin B received a BI recommendation due to higher number of reported adverse events in the trials. Amphotericin B deoxycholate should not be used (DII); and fluconazole was rated CI because of a change in epidemiology in some areas in Europe. Removal of central venous catheters is recommended during candidaemia but if catheter retention is a clinical necessity, treatment with an echinocandin is an option (CII(t) ). In chronic disseminated candidiasis therapy, recommendations are liposomal amphotericin B for 8 weeks (AIII), fluconazole for >3 months or other azoles (BIII). Granulocyte transfusions are only an option in desperate cases of patients with Candida disease and neutropenia (CIII).

Population pharmacokinetics of escalating doses of caspofungin in a phase II study of patients with invasive aspergillosis

Caspofungin (CAS) is approved for second-line management of proven or probable invasive aspergillosis at a dose of 50 mg once daily (QD). Preclinical and limited clinical data support the concept of the dose-dependent antifungal efficacy of CAS with preservation of its favorable safety profile. Little is known, however, about the pharmacokinetics (PKs) of higher doses of CAS in patients. In a formal multicenter phase II dose-escalation study, CAS was administered as a 2-h infusion at doses ranging from 70 to 200 mg QD. CAS PK sampling (n = 468 samples) was performed on day 1 and at peak and trough time points on days 4, 7, 14, and 28 (70 mg, n = 9 patients; 100 mg, n = 8 patients; 150 mg, n = 9 patients; 200 mg, n = 20 patients; total, n = 46 patients). Drug concentrations in plasma were measured by liquid chromatography tandem mass spectroscopy. Population pharmacokinetic analysis (PopPK) was performed using NONMEM (version 7) software. Model evaluation was performed using bootstrap analysis, prediction-corrected visual predictive check (pcVPC), as well as standardized visual predictive check (SVPC). The four investigated dose levels showed no difference in log-transformed dose-normalized trough levels of CAS (analysis of variance). CAS concentration data fitted best to a two-compartment model with a proportional-error model, interindividual variability (IIV) fitted best on clearance (CL), central and peripheral volume of distribution (V(1) and V(2), respectively) covariance fitted best on CL and V(1), interoccasion variability (IOV) fitted best on CL, and body weight fitted best as a covariate on CL and V(1) (CL, 0.411 liters/h ± 29% IIV; IOV on CL, 16%; V(1), 5.785 liters ± 29% IIV; intercompartmental clearance, 0.843 liters/h; V2, 6.53 liters ± 67% IIV). None of the other examined covariates (dose level, gender, age, serum bilirubin concentration, creatinine clearance) improved the model further. Bootstrap results showed the robustness of the final PopPK model. pcVPC and SVPC showed the predictability of the model and further confirmed the linear PKs of CAS over the dosage range of 70 to 200 mg QD. On the basis of the final model, geometric mean simulated peak plasma levels at steady state ranged from 13.8 to 39.4 mg/liter (geometric coefficient of variation, 31%), geometric mean trough levels ranged from 4.2 to 12.0 mg/liter (49%), and geometric mean areas under the concentration-time curves ranged from 170 to 487 mg · h/liter (34%) for the dosage range of 70 to 200 mg QD. CAS showed linear PKs across the investigated dosage range of 70 to 200 mg QD. Drug exposure in the present study population was comparable to that in other populations. (This study has been registered with the European Union Drug Regulating Authorities Clinical Trials website under registration no. 2006-001936-30 and at ClinicalTrials.gov under registration no. NCT00404092.).

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.

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.

Efficacy and safety of caspofungin in obese patients

Safety and efficacy outcomes were retrospectively compared for obese versus non-obese patients who received standard caspofungin doses for different clinical conditions in nine clinical trials within the Merck caspofungin database. Favorable outcomes were as defined in specific protocols. Safety was assessed based on drug-related adverse experiences (AEs). The proportion of obese patients in the esophageal candidiasis and invasive aspergillosis studies was lower than seen in the invasive candidiasis and empirical therapy studies. The proportions of patients with a favorable response were generally similar in non-obese and obese patients with invasive candidiasis (73% versus 77%) or patients receiving empirical therapy (33% versus 40%). The efficacy analysis in patients with invasive aspergillosis or esophageal candidiasis was limited due to the small number of obese patients. The proportion of favorable responses in these two infections was similar among normal/underweight patients as compared to obese/overweight patients, i.e., esophageal candidiasis 81% versus 88% and invasive aspergillosis 48% versus 44%, respectively. AEs related to caspofungin occurred in similar proportions with non-obese and obese patients across all and within the four clinical conditions. The proportion of obese patients with serious drug-related AEs (1%) or caspofungin discontinuations due to toxicity (5%) was low. In the post-hoc analysis, caspofungin appeared to be as efficacious and well-tolerated in obese patients as in non-obese patients.

Fungal infections: their diagnosis and treatment in transplant recipients

Systemic fungal infections typically occur in individuals who are seriously ill with recognized risk factors such as those frequently found in transplant recipients. Unfortunately, they are often diagnosed late, when the efficacy of the available treatments is low, often less than 50%, and the cost in terms of lives lost, hospital length of stay, and total hospital costs is substantially increased. The application of antifungal therapies associated with reported efficacy rates greater than 50% are those used prophylactically. When used prophylactically, these infections are reduced in greater than 95% of the expected cases. The choice of a prophylactic agent should be based upon its ease of administration, lack of adverse effects, reduced likelihood of potential drug interactions, and its efficacy in patients with established risk factors and comorbid disease processes that include renal, hepatic, and chronic pulmonary disease. The indications for the use of currently available antifungal agents, their adverse effects, drug interactions, ease of dosing, and applicability in patients with preexisting disease states, and especially in liver transplant recipients, are presented in this paper.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Phase II dose escalation study of caspofungin for invasive Aspergillosis

Our objective was to evaluate the maximum tolerated dose of caspofungin for invasive aspergillosis (IA). The safety and pharmacokinetics of escalating dosages of caspofungin were investigated in IA. Eight patients each received caspofungin 70, 100, 150, or 200 mg once a day (QD). Dose-limiting toxicity (DLT) was defined as the same non-hematological treatment-related adverse event of grade ≥ 4 in 2 of 8 patients or ≥ 3 in 4 of 8 patients in a cohort. A total of 46 patients (median age, 61 years; 21 female; 89% with hematological malignancies) received caspofungin (9, 8, 9, and 20 patients in the 70-, 100-, 150-, and 200-mg cohorts) for a median of 24.5 days. Plasma pharmacokinetics were linear across the investigated dosages and followed a two-compartment model, with weight as the covariate on clearance and sex as the covariate on central volume of distribution. Simulated peak plasma concentrations at steady state ranged from 14.2 to 40.6 mg/liter (28%), trough concentrations from 4.1 to 11.8 mg/liter (58%), and area under the concentration-time curve from 175 to 500 mg/liter/h (32%) (geometric mean, geometric coefficient of variation). Treatment was well tolerated without dose-limiting toxicity. The rate of complete or partial responses was 54.3%, and the overall mortality at 12-week follow-up was 28.3%. In first-line treatment of invasive aspergillosis, daily doses of up to 200 mg caspofungin were well tolerated and the maximum tolerated dose was not reached. Pharmacokinetics was linear. Response rates were similar to those previously reported for voriconazole and liposomal amphotericin.

Comparison of echinocandin antifungals

The incidence of invasive fungal infections, especially those due to Aspergillus spp. and Candida spp., continues to increase. Despite advances in medical practice, the associated mortality from these infections continues to be substantial. The echinocandin antifungals provide clinicians with another treatment option for serious fungal infections. These agents possess a completely novel mechanism of action, are relatively well-tolerated, and have a low potential for serious drug-drug interactions. At the present time, the echinocandins are an option for the treatment of infections due Candida spp (such as esophageal candidiasis, invasive candidiasis, and candidemia). In addition, caspofungin is a viable option for the treatment of refractory aspergillosis. Although micafungin is not Food and Drug Administration-approved for this indication, recent data suggests that it may also be effective. Finally, caspofungin- or micafungin-containing combination therapy should be a consideration for the treatment of severe infections due to Aspergillus spp. Although the echinocandins share many common properties, data regarding their differences are emerging at a rapid pace. Anidulafungin exhibits a unique pharmacokinetic profile, and limited cases have shown a potential far activity in isolates with increased minimum inhibitory concentrations to caspofungin and micafungin. Caspofungin appears to have a slightly higher incidence of side effects and potential for drug-drug interactions. This, combined with some evidence of decreasing susceptibility among some strains of Candida, may lessen its future utility. However, one must take these findings in the context of substantially more data and use with caspofungin compared with the other agents. Micafungin appears to be very similar to caspofungin, with very few obvious differences between the two agents.

Anidulafungin in the treatment of invasive fungal infections

More antifungal agents have reached clinical use in the past two decades than at any other time. The echinocandins have been a welcome addition to this group, with the latest being anidulafungin. There are several lines of evidence to support anidulafungin’s role as primary therapy for the treatment of invasive candidiasis in non-neutropenic patients, and as alternative therapy to fluconazole in patients with esophageal candidiasis with azole intolerance or triazole-resistant Candida. Pharmacokinetic–pharmacodynamic studies in animals have demonstrated superior efficacy, defined as maximal microbial kill, when compared to fluconazole, regardless of the fluconazole susceptibility of the Candida species. These studies, as well as dose-effect studies in patients, also support the currently recommended dose of anidulafungin. A well designed randomized controlled trial has demonstrated anidulafungin’s efficacy in patients with invasive candidiasis. In this paper, we argue that anidulafungin may be preferable to fluconazole for the treatment of candidemia. However, as of yet, the difference between anidulafungin and the other two licensed echinocandins as first-line therapy for invasive candidiasis is unclear. On the other hand, there is insufficient evidence as of yet to support first-line use of anidulafungin in patients with neutropenia or aspergillosis.

Caspofungin: when and how? The microbiologist's view

The echinocandins are antifungal agents, which act by inhibiting the synthesis of β-(1,3)-D-glucan, an integral component of fungal cell walls. Caspofungin, the first approved echinocandin, demonstrates good in vitro and in vivo activity against a range of Candida species and is an alternative therapy for Aspergillus infections. Caspofungin provides an excellent safety profile and is therefore favoured in patients with moderately severe to severe illness, recent azole exposure and in those who are at high risk of infections due to Candida glabrata or Candida krusei. In vivo/in vitro resistance to caspofungin and breakthrough infections in patients receiving this agent have been reported for Candida and Aspergillus species. The types of pathogens and the frequency causing breakthrough mycoses are not well delineated. Caspofungin resistance resulting in clinical failure has been linked to mutations in the Fksp subunit of glucan synthase complex. European Committee for Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute need to improve the in vitro susceptibility testing methods to detect fks hot spot mutants. Caspofungin represents a significant advance in the care of patients with serious fungal infections.

Overview of treatment options for invasive fungal infections

The introduction of several new antifungals has significantly expanded both prophylaxis and treatment options for invasive fungal infections (IFIs). Relative to amphotericin B deoxycholate, lipid-based formulations of amphotericin B have significantly reduced the incidence of nephrotoxicity, but at a significant increase in drug acquisition cost. Newer, broad-spectrum triazoles (notably voriconazole and posaconazole) have added significantly to both the prevention and treatment of IFIs, most notably Aspergillus spp. (with voriconazole) and the treatment of some emerging fungal pathogens. Finally, a new class of parenteral antifungals, the echinocandins, is employed most frequently against invasive candidal infections. While the role of these newer agents continues to evolve, this review summarizes the activity, safety and clinical applications of agents most commonly employed in the treatment of IFIs.

Population pharmacokinetics and pharmacodynamics of caspofungin in pediatric patients

We describe the pharmacokinetics (PKs) of caspofungin, an echinocandin antifungal, administered once daily as a 1-hour intravenous infusion in children and adolescents (ages, 3 months to 17 years), based on pooled data from four prospective pediatric studies. Caspofungin dosing was body-surface-area (BSA) based (50 mg/m2 daily after 70 mg/m2 on day 1). The area under the concentration-time curve from time zero to 24 h (AUC0-24), the concentration at the end of infusion (1 h after the start of infusion; C1), and the trough concentration (24 h after the start of infusion; C24) were obtained for 32 pediatric patients with invasive candidiasis, 10 with invasive aspergillosis, and 82 in the setting of empirical therapy with fever and neutropenia. Exposures were modestly higher (93 to 134% for C1, 45 to 78% for C24, ∼40% for AUC0-24) in pediatric patients than in adults receiving the standard 50-mg daily dose. The potential for covariates (age, gender, weight, race, renal status, serum albumin level, and disease state) to alter PKs was evaluated with a multiple-linear-regression model. Weight and disease state had statistically significant (P<0.05) yet small effects on caspofungin PKs in pediatric patients. Concomitant use of dexamethasone (a cytochrome p450 inducer) was associated with a statistically significant reduction (44%) in C24 in a limited number of patients (n=4). Odds ratios were estimated for the association between log-transformed PKs and treatment outcome or adverse events. No PK parameter or hybrid parameter (AUC/MIC, C1/MIC, and C24/MIC) was significantly correlated with treatment outcome or adverse events in the setting of similar response levels as adults, which suggests that the concentrations examined fall within the therapeutic window for caspofungin in pediatric patients. These results support a 50-mg/m2 daily dosing regimen (after a 70-mg/m2 loading dose) in children ages 3 months to 17 years.

Candida tropicalis in human disease

Candida tropicalis is one of the more common Candida causing human disease in tropical countries; the frequency of invasive disease varies by geography causing 3--66% of candidaemia. C. tropicalis is taxonomically close to C. albicans and shares many pathogenic traits. C. tropicalis is particularly virulent in neutropenic hosts commonly with hematogenous seeding to peripheral organs. For candidaemia and invasive candidiasis amphotericin B or an echinocandin are recommended as first-line treatment, with extended-spectrum triazoles acceptable alternatives. Primary fluconazole resistance is uncommon but may be induced on exposure. Physicians in regions where C. tropicalis is common need to be mindful of this lesser-described pathogen.

Interventions for the prevention and management of oropharyngeal candidiasis associated with HIV infection in adults and children

BACKGROUND

Oral candidiasis (OC) associated with human immunodeficiency virus (HIV) infection occurs commonly and recurs frequently, often presenting as an initial manifestation of the disease. Left untreated, these lesions contribute considerably to the morbidity associated with HIV infection. Interventions aimed at preventing and treating HIV-associated oral candidal lesions form an integral component of maintaining the quality of life for affected individuals.

OBJECTIVES

To determine the effects of any intervention in preventing or treating OC in children and adults with HIV infection.

SEARCH STRATEGY

The search strategy was based on that of the Cochrane HIV/AIDS Review Group. The following electronic databases were searched for randomised controlled trials for the years 1982 to 2005: Medline, AIDSearch, EMBASE and CINAHL. The Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness, and the Cochrane Central Register of Controlled Trials (CENTRAL) were also searched through May 2005. The abstracts of relevant conferences, including the International Conferences on AIDS and the Conference on Retroviruses and Opportunistic Infections, as indexed by AIDSLINE, were also reviewed. The strategy was iterative, in that references of included studies were searched for additional references. All languages were included.The updated database search was done for the period 2005 up to 2009. The following databases were searched: Medline, EMBASE, the Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library. AIDSearch was not searched for the updated search as it ceased publication during 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of palliative, preventative or curative therapy were considered, irrespective of whether the control group received a placebo. Participants were HIV positive adults and children.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the methodological quality of the trials and extracted data. Study authors were contacted for additional data where necessary.

MAIN RESULTS

For the first publication of the review in 2006, forty studies were retrieved. Twenty eight trials (n=3225) met inclusion criteria. During the update search for the review a, further six studies were identified. Of these, five met the inclusion criteria and were included in the review. The review now includes 33 studies (n=3445): 22 assessing treatment and 11 assessing prevention of oropharyngeal candidiasis. Six studies were done in developing countries, 16 in the United States of America and the remainder in Europe.Treatment Treatment was assessed in the majority of trials looking at both clinical and mycological cures. In the majority of comparisons there was only one trial. Compared to nystatin, fluconazole favoured clinical cure in adults (1 RCT; n=167; RR 1.69; 95% CI 1.27 to 2.23). There was no difference with regard to clinical cure between fluconazole compared to ketoconazole (2 RCTs; n=83; RR 1.27; 95% CI 0.97 to 1.66), itraconazole (2 RCTs; n=434; RR 1.05; 95% CI 0.94 to 1.16), clotrimazole (2 RCTs; n=358; RR 1.14; 95% CI 0.92 to 1.42) or posaconazole (1 RCT; n=366; RR1.32; 95% CI 0.36 to 4.83). Two trials compared different dosages of fluconazole with no difference in clinical cure. When compared with clotrimazole, both fluconazole (2 RCTs; n=358; RR 1.47; 95% CI 1.16 to 1.87) and itraconazole (1 RCT; n=123; RR 2.20; 95% CI 1.43 to3.39) proved to be better for mycological cure. Both gentian violet (1 RCT; n=96; RR 5.28; 95% CI 1.23 to 22.55) and ketoconazole (1 RCT; n=92; RR 5.22; 95% CI 1.21 to 22.53) were superior to nystatin in bringing about clinical cure. A single trial compared gentian violet with lemon juice and lemon grass with no significant difference in clinical cure between the groups. Prevention Successful prevention was defined as the prevention of a relapse while receiving prophylaxis. Fluconazole was compared with placebo in five studies (5 RCTs; n=599; RR 0.61; 95% CI 0.5 to 0.74) and with no treatment in another (1 RCT; n=65; RR 0.16; 95% CI 0.08 to 0.34). In both instances the prevention of clinical episodes was favoured by fluconazole. Comparing continuous fluconazole treatment with intermittent treatment (2 RCTs; n=891; RR 0.65; 95% CI 0.23 to 1.83), there was no significant difference between the two treatment arms. Chlorhexidine was compared with normal saline in a single study with no significant difference between the treatment arms.

AUTHORS' CONCLUSIONS

Five new studies were added to the review, but their results do not alter the final conclusion of the review.Implications for practice Due to there being only one study in children, it is not possible to make recommendations for treatment or prevention of OC in children. Amongst adults, there were few studies per comparison. Due to insufficient evidence, no conclusion could be made about the effectiveness of clotrimazole, nystatin, amphotericin B, itraconazole or ketoconazole with regard to OC prophylaxis. In comparison to placebo, fluconazole is an effective preventative intervention. However, the potential for resistant Candida organisms to develop, as well as the cost of prophylaxis, might impact the feasibility of implementation. No studies were found comparing fluconazole with other interventions. The direction of findings suggests that ketoconazole, fluconazole, itraconazole and clotrimazole improved the treatment outcomes.Implications for research It is encouraging that low-cost alternatives are being tested, but more research needs to be on in this area and on interventions like gentian violet and other less expensive anti-fungal drugs to treat OC. More well-designed treatment trials with larger samples are needed to allow for sufficient power to detect differences in not only clinical, but also mycological, response and relapse rates. There is also a strong need for more research to be done on the treatment and prevention of OC in children as it is reported that OC is the most frequent fungal infection in children and adolescents who are HIV positive. More research on the effectiveness of less expensive interventions also needs to be done in resource-poor settings. Currently few trials report outcomes related to quality of life, nutrition, or survival. Future researchers should consider measuring these when planning trials. Development of resistance remains under-studied and more work must be done in this area. It is recommended that trials be more standardised and conform more closely to CONSORT.

Optimal management of oropharyngeal and esophageal candidiasis in patients living with HIV infection

Mucocutaneous candidiasis is frequently one of the first signs of human immunodeficiency virus (HIV) infection. Over 90% of patients with AIDS will develop oropharyngeal candidiasis (OPC) at some time during their illness. Although numerous antifungal agents are available, azoles, both topical (clotrimazole) and systemic (fluconazole, itraconazole, voriconazole, posaconazole) have replaced older topical antifungals (gentian violet and nystatin) in the management of oropharyngeal candidiasis in these patients. The systemic azoles, are generally safe and effective agents in HIV-infected patients with oropharyngeal candidiasis. A constant concern in these patients is relapse, which is dependent on the degree of immunosuppression commonly seen after topical therapy, rather than with systemic azole therapy. Candida esophagitis (CE) is also an important concern since it occurs in more than 10% of patients with AIDS and can lead to a decrease in oral intake and associated weight loss. Fluconazole has become the most widely used antifungal in the management of mucosal candidiasis. However, itraconazole and posaconazole have similar clinical response rates as fluconazole and are also effective alternative agents. In patients with fluconazole-refractory mucosal candidiasis, treatment options now include itraconazole solution, voriconazole, posaconazole, and the newer echinocandins (caspofungin, micafungin, and anidulafungin).

Drug interactions and adverse events associated with antimycotic drugs used for invasive aspergillosis in hematopoietic SCT

The aim of this study was to assess the frequency of potential drug-drug interactions (pDDIs) and adverse drug events (ADEs) associated with antimycotics in hospitalized patients with hematopoietic SCT (HSCT). Of the 120 HSCT recipients evaluated, 36 received antimycotics. A total of 124 ADEs were recorded in 32 of the 36 patients treated, with 54 ADEs being possibly and 9 probably related to antimycotics. Of the treatments with amphotericin B, 93% were associated with one or more possible and 36% with probable ADEs. The corresponding figures for lipid-based amphotericin B were 100% and 7%, for voriconazole 68% and 11% and for caspofungin 70% and 0%. A total of 57 potentially severe DDIs associated with antimycotics were detected in 31 of the 36 patients. Of these, 14 DDIs were a possible cause of an ADE and 5 (4 times a combination of voriconazole with CYA and once a combination of CYA with conventional amphotericin B) were probably related. Although the prevalence of pDDIs and ADEs is high in HSCT patients, ADEs related with a high probability to treatment with antimycotics are rare. Regarding the high prevalence of pDDIs, our findings underscore the importance of close monitoring of laboratory and clinical parameters, as well as dose adjustment for critical drugs, in patients with HSCT.

Assessment of the in vitro kinetic activity of caspofungin against Candida glabrata

Echinocandins have become the drug of choice in infections caused by Candida glabrata. The objective of this study was to evaluate the in vitro activity of caspofungin alone and in combination against C. glabrata. In vitro assays demonstrated that caspofungin alone showed excellent fungicidal activity against C. glabrata, including fluconazole-resistant strains. The combination of caspofungin and azole antifungals showed potential synergy against C. glabrata. Overall, caspofungin demonstrated excellent in vitro activity, alone and in combination, against strains of C. glabrata.

Echinocandins: The Newest Class of Antifungals

Objective:

To review the mechanism of action, antifungal spectrum of activity, pharmacodynamics, pharmacokinetics, clinical efficacy, and safety of the echinocandins.

Data Sources:

A MEDLINE search (1982–May 2009) was conducted for articles published in the English language using the key words caspofungin, micafungin, anidulafungin, and echinocandins.

Study Selection and Data Extraction:

Medicinal chemistry, in vitro, and animal studies, as well as human trials were reviewed for information on the pharmacodynamics, pharmacokinetics, efficacy, and safety of each echinocandin. Clinical trials were reviewed and included to compare and contrast the available echinocandins.

Data Synthesis:

Three echinocandin antifungal agents are currently approved for use in the US: caspofungin, micafungin, and anidulafungin. The echinocandins have a unique mechanism of action, inhibiting β-(1,3)-d-glucan synthase, an enzyme that is necessary for the synthesis of an essential component of the cell wall of several fungi. The echinocandins display fungistatic activity against Aspergillus spp. and fungicidal activity against most Candida spp., including strains that are fluconazole-resistant. The echinocandins have been shown to be efficacious for the treatment of esophageal candidiasis, candidemia, and invasive candidiasis. In addition, caspofungin has demonstrated efficacy as empiric treatment of febrile neutropenia and salvage therapy for the treatment of invasive aspergillosis, and it is the only echinocandin approved for use in pediatric patients. Micafungin is the only echinocandin approved for use as prophylaxis against Candida infections in patients undergoing hematopoietic stem cell transplantation. Overall, resistance to echinocandins is still rare, and all agents are well tolerated, with similar adverse effect profiles and few drug–drug interactions.

Conclusions:

Echinocandins, the newest addition to the arsenal of antifungals, offer potential advantages over other classes of agents. Clinicians should assess their distinguishing characteristics, including route of metabolism, drug interaction profile, and approved indications for use, when determining which agent to include on a formulary.

Recent approaches to antifungal therapy for invasive mycoses

Invasive fungal infections with primary and opportunistic mycoses have become increasingly common in recent years and pose a major diagnostic and therapeutic challenge. They represent a major area of concern in today's medical fraternity. The occurrence of invasive fungal diseases, particularly in AIDS and other immunocompromised patients, is life-threatening and increases the economic burden. Apart from the previously known polyenes and imidazole-based azoles, newly discovered triazoles and echinocandins are more effective in terms of specificity, yet some immunosuppressed hosts are difficult to treat. The main reasons for this include antifungal resistance, toxicity, lack of rapid and microbe-specific diagnoses, poor penetration of drugs into sanctuary sites, and lack of oral or intravenous preparations. In addition to combination antifungal therapy, other novel antimycotic treatments such as calcineurin signaling pathway blockers and vaccines have recently emerged. This review briefly summarizes recent developments in the pharmacotherapeutic treatment of invasive fungal infections.