Anidulafungin: a new echinocandin with a novel profile

BACKGROUND: Until recently, available treatment for serious fungal infections comprised amphotericin B and azoles, which have limitations. Renal toxicity is a major concern with amphotericin B, while drug-drug interactions, hepatotoxicity, and skin rashes are the primary concerns with the azole medications. The development of the echinocandins, including caspofungin, has helped to fill the need for more efficacious antifungals that are useful across different patient populations and have a good safety profile. Anidulafungin is an echinocandin being developed to treat mucosal and invasive fungal infections. OBJECTIVE: The aim of this report was to describe the pharmacodynamic and pharmacokinetic (PK) properties of anidulafungin. METHODS: Data were identified using MEDLINE and National Library of Medicine Gateway searches for English-language literature (key words: anidulafungin, esophageal candidiasis, echinocandin, caspofungin, ravuconazole, voriconazole, posaconazole, micafungin, and fluconazole; years: 1996-2004), and from meeting abstracts of the American Society for Blood and Marrow Transplantation (Arlington Heights, Illinois), European Congress of Clinical Microbiology and Infectious Diseases (Basel, Switzerland), International Conference on Antimicrobial Agents and Chemotherapy (Washington, DC), and Infectious Diseases Society of America (Arlington, Virginia). RESULTS: Anidulafungin has potent in vitro activity against Aspergillus and Candida spp, including those resistant to either fluconazole or amphotericin B. Results of several clinical trials imply that anidulafungin is effective in treating esophageal candidiasis (EC), candidemia, and invasive candidiasis (IC). In a Phase III, randomized, blinded clinical trial evaluating anidulafungin (50 mg/d) versus fluconazole (100 mg/d) for the treatment of EC, 97.2% and 98.9% of patients who received anidulafungin and fluconazole, respectively, showed evidence of cure or improvement (treatment difference, -1.6%; 95% CI, -4.1 to 0.8). In a Phase II study of candidasis and candidemia, anidulafungin showed success rates of 72%, 85%, and 83% in patients receiving the drug at dosages of 50, 75, or 100 mg/d, respectively. Studies evaluating the concomitant use of anidulafungin and either amphotericin, voriconazole, or cyclosporine did not show clinically significant drug-drug interactions or altered adverse-event (AE) profiles (P < 0.05). A population PK analysis showed no significant effect of age, race, concomitant medications, or renal or hepatic insufficiency on the PK properties of anidulafungin (P < 0.05). CONCLUSIONS: Anidulafungin may offer a new option to treat serious fungal infections, such as EC, azole-refractory EC, candidemia, and IC. In addition, anidulafungin has been associated with no clinically significant drug-drug interactions and few treatment-related AEs. Anidulafungin may offer a new option in the management of serious and difficult-to-treat invasive fungal infections.     

Anidulafungin: review of a new echinocandin antifungal agent

Anidulafungin (Vicuron Pharmaceuticals) is a new echinocandin antifungal with potent activity against Aspergillus and Candida spp. Anidulafungin is a noncompetitive inhibitor of (1,3)-beta-D-glucan synthase within fungal cells. The drug is rapidly distributed and steady-state concentrations are achieved after the first dose, when a loading dose of twice the daily maintenance dose is given on day 1. Drug biotransformation occurs via chemical degradation, with no hepatic metabolism or renal elimination. A favorable pharmacokinetic profile and lack of significant drug interactions suggest that patients can receive anidulafungin without dosage adjustments. These characteristics, in addition to comparable efficacy to fluconazole (Diflucan, Pfizer Ltd) in the treatment of esophageal candidiasis, support further investigation of its use in the treatment of systemic fungal infections caused by Candida and Aspergillus spp.     

Anidulafungin: review of a new echinocandin antifungal agent

Anidulafungin (Vicuron Pharmaceuticals) is a new echinocandin antifungal with potent activity against Aspergillus and Candida spp. Anidulafungin is a noncompetitive inhibitor of (1,3)-β-d-glucan synthase within fungal cells. The drug is rapidly distributed and steady-state concentrations are achieved after the first dose, when a loading dose of twice the daily maintenance dose is given on day 1. Drug biotransformation occurs via chemical degradation, with no hepatic metabolism or renal elimination. A favorable pharmacokinetic profile and lack of significant drug interactions suggest that patients can receive anidulafungin without dosage adjustments. These characteristics, in addition to comparable efficacy to fluconazole (Diflucan^®, Pfizer Ltd) in the treatment of esophageal candidiasis, support further investigation of its use in the treatment of systemic fungal infections caused by Candida and Aspergillus spp.     

棘白菌素类的新品种:米卡芬净

米卡芬净[1]于2005年通过美国FDA的审批,成为继卡泊芬净之后第2个应用于临床的棘白菌素类药物。一、体外抗菌作用米卡芬净是水溶性抗真菌药,它主要抑制真菌细胞壁的主要成分1,3-β-D-葡聚糖合成,从而破坏真菌细胞壁的合成,影响细胞形态和渗透压,导致细胞溶解死亡。米卡芬净还能     

Quinupristin-dalfopristin: a new antibiotic for severe gram-positive infections.

The steady increase in resistant organisms is related to the widespread use of antibiotics in community and hospital settings. New therapeutic options are needed, including treatments for infections caused by antibiotic-resistant gram-positive organisms. Quinupristin-dalfopristin, the first formulation of a distinct class of antibiotics known as the streptogramins, has activity against a range of gram-positive bacteria that are usually resistant to other agents, including vancomycin-resistant Enterococcus faecium. The pharmacodynamic (postantibiotic effect) and pharmacokinetic characteristics of quinupristin-dalfopristin allow dosing at eight- to 12-hour intervals. The safety profile of the formulation is generally favorable, with no demonstrable ototoxicity, nephrotoxicity, bone marrow suppression, or cardiovascular adverse effects. Reversible arthralgias, myalgias, and peripheral venous irritation are the formulation's major side effects. A potential for drug interactions exists because quinupristin-dalfopristin significantly inhibits the cytochrome P450-3A4 enzyme system. Quinupristin-dalfopristin has been shown to be effective in the management of documented severe infections caused by vancomycin-resistant E. faecium, nosocomial pneumonia, and infections related to the use of intravascular catheters.     

Gemifloxacin: a new fluoroquinolone approved for treatment of respiratory infections

OBJECTIVE: To evaluate the microbiology, pharmacokinetic parameters, drug interactions, and results of the available clinical trials of gemifloxacin for the treatment of community-acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis (AECB). DATA SOURCES: MEDLINE (1966-September 2003) was searched for primary and review articles. Data from the manufacturer were also included. Key words included adverse effects, clinical trials, drug interactions, gemifloxacin, and pharmacokinetic parameters. STUDY SELECTION AND DATA EXTRACTION: All articles and product labeling concerning gemifloxacin, a fluoroquinolone antibiotic recently approved by the Food and Drug Administration for treatment of CAP and AECB, were included for review. DATA SYNTHESIS: Compared with currently available fluoroquinolones, gemifloxacin demonstrated improved in vitro activity against Streptococcus pneumoniae (minimum inhibitory concentration for 90% eradication 0.03 microg/mL) and similar activity against gram-negative respiratory pathogens (Haemophilus influenzae, Moraxella catarrhalis) and atypical pathogens such as Chlamydia pneumoniae, Legionella pneumophila, and Mycoplasma pneumoniae. Gemifloxacin, consistent with other available fluoroquinolones, has insufficient activity against methicillin-resistant Staphylococcus aureus to allow clinical use for such infections. Gemifloxacin has adequate bioavailability and a favorable drug interaction profile. Gemifloxacin was comparable to commonly employed nonfluoroquinolone regimens for treatment of CAP and AECB, although the studies were designed to demonstrate equivalence. Gemifloxacin once daily for 5-7 days was well tolerated in controlled and uncontrolled clinical studies. Available clinical data, however, are insufficient to draw clinical or toxicologic distinctions between gemifloxacin and other fluoroquinolones. CONCLUSIONS: Gemifloxacin may be a suitable choice for empiric treatment of CAP or AECB. However, due to the significant history of fluoroquinolone-induced hepatic failure and dermatologic complications, the use of this drug should be closely monitored.     

Dalbavancin: a new option for the treatment of gram-positive infections

OBJECTIVE: To review the pharmacology, microbiology, chemistry, in vitro susceptibility, pharmacokinetics, clinical efficacy, safety, tolerability, dosage, and administration of dalbavancin, a new semisynthetic lipoglycopeptide. DATA SOURCES: A MEDLINE search, restricted to the English language, was conducted from 1966 through January 2006. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy, American Society of Microbiology, and the Infectious Diseases Society of America from 2000 to 2005 and information available from the manufacturer's Web site. STUDY SELECTION AND DATA EXTRACTION: In vitro and preclinical studies, as well as Phase I, II, and III clinical trials, were evaluated to summarize the microbiology, pharmacology, clinical efficacy, and safety of dalbavancin. All published trials and abstracts citing dalbavancin were selected. DATA SYNTHESIS: Dalbavancin, a novel lipoglycopeptide, has a mechanism of action similar to that of other glycopeptides. It has in vitro activity against a variety of gram-positive organisms, but no activity against gram-negative or vancomycin-resistant enterococci that possess VanA gene. Due to its prolonged half-life (6-10 days), dalbavancin can be administered intravenously once weekly. In Phase II and III clinical trials, dalbavancin was effective and well tolerated for the treatment of skin and soft-tissue infections, catheter-related bloodstream infections, and skin and skin-structure infections. To date, adverse events are mild and limited; the most common include pyrexia, headache, nausea, oral candidiasis, diarrhea, and constipation. CONCLUSIONS: Dalbavancin appears to be a promising antimicrobial agent for the treatment of gram-positive infections. A new drug application was filed with the Food and Drug Administration (FDA) in December 2004. The FDA issued an approvable letter in 2005 for dalbavancin. If approved, dalbavancin is expected to be launched in the first quarter of 2006.     

Proteolytic enzymes: a new treatment strategy for prosthetic infections?

Among the different mechanisms of bacterial resistance to antimicrobial agents that have been studied, biofilm formation is one of the most widespread. This mechanism is frequently the cause of failure in the treatment of prosthetic device infections, and several attempts have been made to develop molecules and protocols that are able to inhibit biofilm-embedded bacteria. We present data suggesting the possibility that proteolytic enzymes could significantly enhance the activities of antibiotics against biofilms. Antibiotic susceptibility tests on both planktonic and sessile cultures, studies on the dynamics of colonization of 10 biofilm-forming isolates, and then bioluminescence and scanning electron microscopy under seven different experimental conditions showed that serratiopeptidase greatly enhances the activity of ofloxacin on sessile cultures and can inhibit biofilm formation.     

Caspofungin: an echinocandin antifungal agent

BACKGROUND: The mainstays of treatment for nosocomial fungal infections have been amphotericin B and azole derivatives. Caspofungin acetate is a new echinocandin antifungal agent with a mechanism of action that targets a structural component of the fungal cell wall. OBJECTIVE: This article describes the pharmacologic properties and potential clinical usefulness of caspofungin. METHODS: Relevant information was identified through searches of MEDLINE (1966-September 2001). Iowa Drug Information Service (1966-September 2001), and International Pharmaceutical Abstracts (1970-September 2001), as well as meeting abstracts of the Infectious Diseases Society of America and the Interscience Conference on Antimicrobial Agents and Chemotherapy (1996-2001), using the terms caspofungin, MK-0991, pneumocandin, echinocandin, candin, and beta-(1,3)-glucan inhibitor. RESULTS: In vitro, caspofungin exhibits antifungal activity against an array of clinically important yeasts and molds, including Candida and Aspergillus spp. The proposed susceptibility breakpoint for caspofungin against Candida spp, the most common cause of nosocomial fungal infections, is a minimum inhibitory concentration of < or =1 microg/mL. In humans, caspofungin has a volume of distribution of 9.67 L, is extensively bound to albumin (97%), has a plasma elimination half-life of 9 to 11 hours, and is metabolized to inactive metabolites in the liver. Dose adjustment based on age, sex, race, or renal function does not appear to be necessary, although patients with moderate hepatic insufficiency (Child-Pugh score 7-9) should receive a lower maintenance dose. The results of clinical trials, although somewhat preliminary, suggest that caspofungin is effective in the treatment of esophageal and oropharyngeal candidiasis and invasive aspergillosis. When combined with other antifungal agents, caspofungin produces a synergistic or additive effect against a variety of clinically important fungi. The most commonly reported adverse events with caspofungin have included fever, infusion-related reactions, headache, nausea, elevations in liver transaminase levels, and histamine-type reactions. The recommended dosage in adults is 70 mg IV on day 1 followed by 50 mg/d, with the duration of treatment depending on the severity of the patient's underlying condition and the clinical response. CONCLUSION: Although additional studies are needed, caspofungin appears to be a promising agent for the treatment of patients with difficult-to-treat or life-threatening fungal infections.     

Effect of an arginine-glycine-aspartic acid-containing peptide on hematogenous candidal infections in rabbits.

The adherence of Candida albicans yeast cells to the subendothelial extracellular matrix, fibronectin, laminin, and type I and IV collagen was tested. Fibronectin (10(-7) M) and a peptide, PepTite-2000 (Telios Pharmaceuticals Inc., San Diego, Calif.), containing the sequence arginine-glycine-aspartic acid (RGD) inhibited Candida adherence to these targets by greater than 90%. When C. albicans was perfused over ex vivo rabbit aortic endothelium, there was no significant difference in the amount of adherence in the presence or absence of the RGD-containing peptide. However, the RGD-containing peptide reduced the number of Candida organisms present in liver, brain, heart, and kidneys (P less than 0.05) of rabbits 4 h after intravenous inoculation of 5 x 10(7) C. albicans yeast cells. The peptide also reduced the number of macroscopic Candida abscesses in the kidneys of rabbits 72 h after intravenous inoculation of 10(7) C. albicans yeast cells (P less than 0.05). Inhibition of Candida adherence in vitro and in vivo may occur because the peptide blocks a fungal receptor that is necessary for adherence.     

Limited-Sampling Strategies for Anidulafungin in Critically Ill Patients

Efficacy of anidulafungin is driven by the area under the concentration-time curve (AUC)/MIC ratio. Determination of the anidulafungin AUC along with MIC values can therefore be useful. Since obtaining a full concentration-time curve to determine an AUC is not always feasible or appropriate, limited-sampling strategies may be useful in adequately estimating exposure. The objective of this study was to develop a model to predict the individual anidulafungin exposure in critically ill patients using limited-sampling strategies. Pharmacokinetic data were derived from 20 critically ill patients with invasive candidiasis treated with anidulafungin. These data were used to develop a two-compartment model in MW\Pharm using an iterative 2-stage Bayesian procedure. Limited-sampling strategies were subsequently investigated using two methods, a Bayesian analysis and a linear regression analysis. The best possible strategies for these two methods were evaluated by a Bland-Altman analysis for correlation of the predicted and observed AUC from 0 to 24 h (AUC_0–24) values. Anidulafungin exposure can be adequately estimated with the concentration from a single sample drawn 12 h after the start of the infusion either by linear regression (R² = 0.99; bias, 0.05%; root mean square error [RMSE], 3%) or using a population pharmacokinetic model (R² = 0.89; bias, −0.1%; RMSE, 9%) in critically ill patients and also in less severely ill patients, as reflected by healthy volunteers. Limited sampling can be advantageous for future studies evaluating the pharmacokinetics and pharmacodynamics of anidulafungin and for therapeutic drug monitoring in selected patients. (This study has been registered at ClinicalTrials.gov under registration no. {"type":"clinical-trial","attrs":{"text":"NCT01047267","term_id":"NCT01047267"}}NCT01047267.)     

Anidulafungin for neonatal hematogenous Candida meningoencephalitis: identification of candidate regimens for humans using a translational pharmacological approach

Hematogenous Candida meningoencephalitis (HCME) is a serious infection in premature neonates. Anidulafungin is an echinocandin antifungal agent with potent activity against Candida spp., but its efficacy and optimal regimens for human neonates with HCME are not known. A well-validated rabbit model of HCME was used to define pharmacokinetic-pharmacodynamic (PK-PD) relationships of anidulafungin. A mathematical model was fitted to the entire data set. The experimental data were bridged to humans. A population PK model was fitted to the data from human neonates receiving anidulafungin receiving a loading dose of 3 mg/kg, followed by 1.5 mg/kg/day. Monte Carlo simulations were performed to identify candidate anidulafungin regimens for humans. All untreated rabbits succumbed by ≤96 h postinoculation. The PK of anidulafungin was linear with dose-dependent penetration into the cerebrum. Anidulafungin exerted a rapid antifungal effect that was apparent in the first dosing interval. Near-maximal antifungal activity was observed with dosages of 10 to 20 mg/kg/day. The bridging studies suggested that the current regimen of first 3 mg/kg, followed by 1.5 mg/kg/day, is suboptimal. Higher dosages were associated with progressively greater antifungal effect. Anidulafungin is effective for the treatment of experimental HCME. Higher dosages than those currently used for clinical care are required for maximal antifungal effect.     

Nosocomial infections: new therapeutic alternatives

This symposium on nosocomial infections, antimicrobial resistance and the benefits of doripenem in this setting was held in Madrid, Spain, on 7 October 2009, and was supported by Janssen-Cilag. The topic was presented under an interdisciplinary approach by different international experts in the field.     

Ceftobiprole: a new cephalosporin for the treatment of skin and skin structure infections

Ceftobiprole is among the first of a new generation of cephalosporins with activity against aerobic Gram-negative bacilli, which extends to cefepime-sensitive Pseudomonas aeruginosa, and activity against Gram-positive organisms, which includes methicillin-resistant Staphylococcus aureus. Ceftobiprole is currently undergoing evaluation by the US FDA for the treatment of complicated skin and skin structure infections, with a decision pending further evaluation of study site monitoring. It is also being evaluated for the treatment of community-acquired and healthcare-associated pneumonia. Two Phase III multicenter trials have demonstrated noninferiority in complicated skin and skin structure infections when tested against vancomycin in primarily Gram-positive bacterial infections, and when tested against vancomycin plus ceftazidime in Gram-positive and Gram-negative bacterial infections. It is well tolerated, with the most common side effects being nausea and dysgeusia. Ceftobiprole is likely to prove useful as an empiric as well as directed monotherapy in patients with complicated skin and skin structure infections, in which both Gram-positive pathogens including methicillin-resistant S. aureus and Gram-negative pathogens including cefepime-sensitive P. aeruginosa may be involved.