Evaluation of the in vivo efficacy of intramuscularly administered ceftaroline fosamil, a novel cephalosporin, against a methicillin-resistant Staphylococcus aureus strain in a rabbit endocarditis model

New Antimicrobials and New Therapy Strategies for Endocarditis: Weapons That Should Be Defended

The overall low-quality evidence concerning the clinical benefits of different antibiotic regimens for the treatment of infective endocarditis (IE), which has made it difficult to strongly support or reject any regimen of antibiotic therapy, has led to a discrepancy between the available guidelines and clinical practice. In this complex scenario, very recently published guidelines have attempted to fill this gap. Indeed, in recent years several antimicrobials have entered the market, including ceftobiprole, ceftaroline, and the long-acting lipoglycopeptides dalbavancin and oritavancin. Despite being approved for different indications, real-world data on their use for the treatment of IE, alone or in combination, has accumulated over time. Furthermore, an old antibiotic, fosfomycin, has gained renewed interest for the treatment of complicated infections such as IE. In this narrative review, we focused on new antimicrobials and therapeutic strategies that we believe may provide important contributions to the advancement of Gram-positive IE treatment, providing a summary of the current in vitro, in vivo, and clinical evidence supporting their use in clinical practice.

Efficacy of Ceftaroline against Methicillin-Susceptible Staphylococcus aureus Exhibiting the Cefazolin High-Inoculum Effect in a Rat Model of Endocarditis

Certain Staphylococcus aureus strains exhibit an inoculum effect (InE) with cefazolin (CFZ) that has been associated with therapeutic failures in high-inoculum infections. We assessed the in vitro activities of ceftaroline (CPT), CFZ, and nafcillin (NAF) against 17 type A β-lactamase (βla)-producing, methicillin-susceptible S. aureus (MSSA) strains, including the previously reported TX0117, which exhibits the CFZ InE, and its βla-cured derivative, TX0117c. Additionally, we determined the pharmacokinetics of CPT in rats after single intramuscular doses of 20 and 40 mg/kg of body weight and evaluated the activities of CPT (40 mg/kg every 8 h [q8h]), CFZ, and NAF against TX0117 and TX0117c in a rat model of infective endocarditis. No InE was observed for CPT or NAF, whereas a marked InE was detected for CFZ (MIC, 8 to ≥128 μg/ml). CPT and NAF treatment against TX0117 resulted in mean bacterial counts of 2.3 and 2.1 log10 CFU/g in vegetations, respectively, compared to a mean of 5.9 log10 CFU/g in the CFZ-treated group (CPT and NAF versus CFZ, P = 0.001; CPT versus NAF, P = 0.9830). Both CFZ and CPT were efficacious against the βla-cured derivative, TX0117c, compared to time zero (t0) (P = <0.0001 and 0.0015, respectively). Our data reiterate the in vivo consequences of the CFZ InE and show that CPT is not affected by this phenomenon. CPT might be considered for high-inoculum infections caused by MSSA exhibiting the CFZ InE.

Ceftaroline fosamil: a brief clinical review

Ceftaroline is a novel cephalosporin with a favorable tolerability profile and broad in vitro activity against many resistant Gram-positive and common Gram-negative organisms. Ceftaroline fosamil is the first cephalosporin to be approved by the United States Food and Drug Administration (FDA) for the treatment of adults with acute bacterial skin and soft tissue infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). It is also approved by the FDA for the treatment of adults with community-acquired bacterial pneumonia, including cases caused by Streptococcus pneumoniae (with or without concurrent bacteremia), although there are no data at this time to support the use of ceftaroline fosamil for the treatment of pneumonia caused by MRSA. Ceftaroline fosamil is likewise approved by the European Commission for the treatment of adults with complicated skin and soft tissue infections or community-acquired pneumonia. This review summarizes the pharmacokinetic and microbiologic properties of ceftaroline, as well as the safety and efficacy data that led to its approval by the FDA in 2010 and the European Commission in 2012. Future directions to be addressed are also highlighted.

Ceftaroline fosamil: a new cephalosporin active against resistant Gram-positive organisms including MRSA

The growing prevalence of resistant Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus continues to pose a dilemma to clinicians. With strains developing reduced susceptibility to vancomycin, effective and well-tolerated antibiotics to combat these resistant pathogens are needed. Ceftaroline is a new parenteral cephalosporin that has been available in the USA for almost 2 years. Similar to other cephalosporins, it is well tolerated with mostly mild adverse events; however, compared with existing parenteral cephalosporins, ceftaroline has the unique attribute of being bactericidal against resistant Gram-positive aerobes including both hospital- and community-acquired methicillin-resistant S. aureus, S. aureus strains with reduced susceptibility or complete resistance to vancomycin, and resistant Streptococcus pneumoniae including multidrug-resistant strains. Current indications in the USA and Europe include treatment of adults with complicated skin, skin-structure infections and community-acquired pneumonia. This paper will review the properties of ceftaroline, its spectrum of activity, clinical use, safety profile and future role.

Animal models of organic heart valve disease

Heart valve disease is a frequently encountered pathology, related to high morbidity and mortality rates in industrialized and developing countries. Animal models are interesting to investigate the causality, but also underlying mechanisms and potential treatments of human valvular diseases. Recently, animal models of heart valve disease have been developed, which allow to investigate the pathophysiology, and to follow the progression and the potential regression of disease with therapeutics over time. The present review provides an overview of animal models of primary, organic heart valve disease: myxoid age-related, infectious, drug-induced, degenerative calcified, and mechanically induced valvular heart disease.

Ceftaroline fosamil: a cephalosporin with activity against methicillin-resistant Staphylococcus aureus

BACKGROUND

Ceftaroline is a cephalosporin with expanded gram-positive activity recently approved for clinical uses by the US Food and Drug Administration.

OBJECTIVE

This article provides an overview of the in vitro and in vivo activities, mechanism of action, pharmacologic and pharmacokinetic properties, clinical efficacy, and tolerability of ceftaroline.

METHODS

Relevant information was identified through a search of PubMed (1990-April 2011), EMBASE (1990-April 2011), International Pharmaceutical Abstracts (1970-April 2011), and Google Scholar using the key words ceftaroline, PPI-0903, PPI-0903M, T-91825, and TAK-599. A review of the reference lists of identified articles, a search of the US Food and Drug Administration Web site, and posters and abstracts from scientific meetings yielded additional publications.

RESULTS

In vitro, ceftaroline exhibits activity against most aerobic gram-positive isolates, common aerobic gram-negative respiratory pathogens, and some gram-positive anaerobes. The MIC range for most Staphylococcus aureus isolates, including vancomycin-resistant strains was between ≤0.008 and 4 μg/mL. In Phase III studies (CANVAS 1 and CANVAS 2), ceftaroline was found to be noninferior to vancomycin + aztreonam for the treatment of complicated skin and skin-structure infections, with a clinical cure rate of 91.6% among clinically evaluable patients (ceftaroline versus vancomycin + aztreonam: difference, -1.1; 95% CI, -4.2 to 2.0; P = NS). Ceftaroline's efficacy has also been assessed for the treatment of community-acquired pneumonia in 2 Phase III studies (FOCUS 1 and FOCUS 2) and was equivalent to ceftriaxone, with cure rates of 84.3% and 77.7%, respectively, among clinically evaluable patients in the combined analysis (ceftaroline versus ceftriaxone: difference, 6.7; 95% CI, 1.6 to 11.8). The recommended dosage for patients 18 years and older is 600 mg IV every 12 hours. Dosage adjustment is necessary in patients with renal impairment (creatinine clearance ≤50 mL/min). The pharmacokinetic properties of ceftaroline in patients with hepatic impairments are currently unavailable. Ceftaroline appeared to be well tolerated generally. The most frequently (>3%) reported adverse events were nausea, headaches, diarrhea, pruritus, rash, and insomnia; all were usually mild to moderate, self-limiting, and of little clinical significance.

CONCLUSIONS

Ceftaroline is a cephalosporin with broad gram-positive activity, including Methicillin-resistant S aureus and vancomycin-resistant S aureus. Its gram-negative activity includes common respiratory pathogens and members of the Enterobacteriaceae. Clinical trials have reported that ceftaroline was noninferior to ceftriaxone, and vancomycin + aztreonam for the treatment of community-acquired pneumonia and complicated skin and skin-structure infections, respectively.

Ceftaroline fosamil: a novel broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus

OBJECTIVE

To review the pharmacology, microbiology, chemistry, in vitro activity, pharmacokinetics, clinical efficacy, safety, dosage, and administration of ceftaroline fosamil (Teflaro, Forest Laboratories, Inc.), a novel parenteral broad-spectrum cephalosporin approved by the Food and Drug Administration (FDA) on October 29, 2010, for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP).

DATA SOURCES

A search of MEDLINE (1966-July 2011) using the search terms ceftaroline fosamil, ceftaroline, TAK-599, PPI-0903, PPI-0903M, and T-91825 was performed. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy, American Society of Microbiology, European Congress on Clinical Microbiology and Infectious Diseases, and the Infectious Diseases Society of America from 2005 to 2010, as well as information available from the manufacturer's Web site.

STUDY SELECTION AND DATA EXTRACTION

All English-language articles identified from the data sources were evaluated. In vitro, preclinical, and Phase 1, 2, and 3 clinical trials were included.

DATA SYNTHESIS

Clinical trials have been conducted evaluating use of ceftaroline for treatment of ABSSSI and CABP. Safety data from Phase 1, 2, and 3 clinical trials suggest that it is well tolerated and has a safety and tolerability profile common to the cephalosporin class. Ceftaroline has excellent in vitro activity against gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), which makes it an attractive monotherapy for the treatment of ABSSSI. However, it lacks activity against problem gram-negative bacteria (eg, Pseudomonas spp.), which will likely limit its use for serious health care-associated infections. While its role in treating CABP is supported by excellent in vitro activity against Streptococcus pneumoniae and clinical efficacy data, currently available comparators may offer some advantages over ceftaroline. Finally, data are lacking to assess its role in the treatment of serious infections due to MRSA (eg, pneumonia, bacteremia).

CONCLUSIONS

These considerations should be part of the formulary review process; however, when considering the significant role MRSA plays in ABSSSI in both the community and hospital settings, we believe that ceftaroline will provide clinicians with a welcome option in addition to currently available anti-MRSA therapies for the treatment of ABSSSI.

Management of serious meticillin-resistant Staphylococcus aureus infections: what are the limits?

Severe (life-threatening) meticillin-resistant Staphylococcus aureus (MRSA) infection continues to be treated with vancomycin despite accumulating evidence of poor outcome, increasing resistance and unachievable pharmacokinetic/pharmacodynamic (PK/PD) targets. The minimum inhibitory concentration (MIC) susceptibility breakpoint for vancomycin was recently reduced to 2 mg/L. Whilst the great majority of clinical isolates are thus still classified as susceptible, the available clinical evidence argues for a method-dependent breakpoint of 0.5 mg/L (broth dilution) or 1.0 mg/L (Etest), which would classify many strains as resistant, or at best intermediate. However, automated susceptibility testing systems are not currently capable of performing accurately at this low level, and such low breakpoints are unsatisfactory because the poor reproducibility of tests (plus or minus one doubling dilution) results in a critical non-reproducibility around the modal MIC of 1 mg/L described in most published data. Therefore, vancomycin should be used with caution in severe (life-threatening) staphylococcal disease and the MIC should always be reported by method. Daptomycin is generally preferred for bacteraemia/endocarditis and linezolid for pneumonia. Better outcome data for vancomycin, based on achievable PK/PD targets and using robust MIC tests, are urgently required.

Ceftaroline fosamil for treatment of community-acquired pneumonia: findings from FOCUS 1 and 2 and potential role in therapy

Cephalosporins have been widely used over the last few decades (often as first-line antibiotic therapy) for numerous infections, owing primarily to their broad spectrum of microbiologic activity and favorable safety profile. Current Infectious Diseases Society of America guidelines identify a third-generation cephalosporin in combination with a macrolide antibiotic as an option for treatment of hospitalized adult patients with community-acquired pneumonia (CAP) outside the intensive care unit setting. Although ceftriaxone is a frequently used agent for CAP, increasing incidence of multidrug-resistant Streptococcus pneumoniae and concerns regarding poor outcomes associated with ineffective therapy have prompted the search for a well-tolerated treatment alternative that is effective against bacteria that can cause CAP. Ceftaroline fosamil, the prodrug of ceftaroline, is a new extended-spectrum cephalosporin that exhibits time-dependant bactericidal activity against numerous Gram-negative and Gram-positive organisms, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. pneumoniae. Notable exceptions include Pseudomonas spp. and Gram-negative organisms that produce extended-spectrum β-lactamases or carbapenemases. Two large Phase III clinical trials (FOCUS 1 and 2) reported that ceftaroline fosamil was well tolerated, with a clinical cure rate of CAP that was noninferior to that with ceftriaxone in nonintensive care unit adult inpatients with moderately severe (Pneumonia Outcomes Research Team score of III or IV) community-acquired pneumonia.

Ceftaroline Fosamil

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Ceftaroline: a novel cephalosporin with activity against methicillin-resistant Staphylococcus aureus

Ceftaroline (PPI 0903, formerly TAK-599), the active metabolite of a N-phosphono prodrug, ceftaroline fosamil, has been approved by the US Food and Drug Administration for the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. This antimicrobial agent binds to penicillin binding proteins (PBP) inhibiting cell wall synthesis and has a high affinity for PBP2a, which is associated with methicillin resistance. Ceftaroline is consistently active against multidrug-resistant Streptococcus pneumoniae and Staphylococcus aureus, including methicillin-resistant, vancomycin-intermediate, linezolid-resistant, and daptomycin-nonsusceptible strains. It possesses variable activity against Enterobacteriaceae and good activity against oral anaerobes. The drug is usually administrated intravenously at 600 mg every 12 h. Ceftaroline has low protein binding and is excreted by the kidneys and thus requires dose adjustments in individuals with renal failure. Clinical trials have demonstrated noninferiority when compared with vancomycin in the treatment of acute bacterial skin and skin structure infections and noninferiority when compared with ceftriaxone in the treatment of community-acquired bacterial pneumonia. Ceftaroline demonstrated a safety profile similar to that of comparator drugs in clinical trials.