Antianaerobe activity of ceftobiprole, a new broad-spectrum cephalosporin

Ceftobiprole: drug evaluation and place in therapy

Introduction: Ceftobiprole is a fifth-generation cephalosporin with a broad spectrum of antimicrobial activity, including also methicillin-resistant Staphylococcus aureus (MRSA). Ceftobiprole is approved for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP), excluding ventilator-associated pneumonia, in several European and non-European countries. Areas covered: In this narrative review, we discuss the current place in therapy of ceftobiprole, both within and outside approved indications. An inductive MEDLINE/PubMed search of the available literature was conducted. Expert opinion: There are three main reasons which render ceftobiprole an attractive option for the empirical and targeted treatment of CAP and HAP: (i) its broad spectrum of activity; (ii) its activity against MRSA; (iii) its good safety profile. For these indications, ceftobiprole should be employed thoughtfully, in those scenarios in which its intrinsic advantages could be maximized. The use of ceftobiprole outside approved indications could be justified in specific scenarios, such as when other approved alternatives are ineffective, when the risk of toxicity due to other agents is unacceptable, and for salvage therapy. In the near future, ongoing phase 3 studies and further observational experiences could both enlarge the current panel of approved indications and enrich our knowledge on the use of ceftobiprole for off-label indications.

Ceftobiprole medocaril for the treatment of community-acquired pneumonia

INTRODUCTION

Ceftobiprole is a novel broad-spectrum cephalosporin with excellent activity against a broad range of pathogens that are important in community-acquired pneumonia (CAP), including drug-resistant pneumococci, methicillin-resistant Staphylococcus aureus, and Pseudomonas aeruginosa. Areas covered: This article reviews the spectrum of activity, the main pharmacological and pharmacodynamic characteristics of ceftobiprole as well its clinical efficacy and safety in the treatment of CAP in adult patients. Expert opinion: Taking into account that the current treatment guidelines for CAP recommend the use of an adequate empirical therapy to improve its prognosis, ceftobiprole shows a profile of antimicrobial activity that would cover most etiological agents in patients with risk factors for infection caused by multidrug resistant organisms. The results of the pivotal clinical trial of patients hospitalized with CAP treated with ceftobiprole showed a high rate of clinical cure. The clinical tolerance of ceftobiprole in clinical trials was generally very good. These findings make ceftobiprole a good parenteral therapeutic alternative for the empirical treatment of CAP that requires hospitalization, especially in patients with risk factors for CAP caused by resistant microorganisms.

In Vitro Activity of Tedizolid, Dalbavancin, and Ceftobiprole Against Clostridium difficile

Background:Clostridium difficile (C. difficile) is a major nosocomial pathogen that colonizes in the human gut. Recently, the U.S. FDA approved three new antimicrobial agents against gram-positive bacteria: Tedizolid, Dalbavancin, and Ceftobiprole. The efficacy of these antibiotics for treatment of C. difficile infection has not been thoroughly examined. The current study aimed to examine the in vitro activity of these antibiotics against C. difficile. In addition, to compare between Dalbavancin and Ceftobiprole to antibiotics from the same class: Vancomycin and Ceftriaxone, respectively. Methods: Eighty-four C. difficile isolates were tested for susceptibility to Tedizolid, Dalbavancin, Ceftobiprole, Vancomycin, and Ceftriaxone by Etest technique in order to determine the minimum inhibitory concentration (MIC). Results: Upon comparison of the novel antibiotic agents, Dalbavancin demonstrated the lowest MIC values and ceftobiprole the highest at MIC₅₀ (0.016, 0.38, and 1.5 μg/mL, for Dalbavancin, Tedizolid, and Ceftobiprole, respectively) and MIC₉₀ (0.03, 0.78, and 3.17 μg/mL, respectively). Dalbavancin demonstrated significantly lower MIC₅₀ and MIC₉₀ values compared to Vancomycin (0.016 vs. 0.38 and 0.03 vs. 3.5, respectively) (p < 0.001) and ceftobiprole had significantly lower MIC values compare to ceftriaxone (1.5 vs. 32 and 3.17 vs. 28.8, respectively) (p < 0.001). Conclusion: Dalbavancin and Tedizolid may play a role as potential therapeutic agents for treatment of C. difficile infection. Examination of antibiotic effect on the intestinal microbiome and clinical trials are needed for more accurate results.

Role of cephalosporins in the era of Clostridium difficile infection

The incidence of Clostridium difficile infection (CDI) in Europe has increased markedly since 2000. Previous meta-analyses have suggested a strong association between cephalosporin use and CDI, and many national programmes on CDI control have focused on reducing cephalosporin usage. Despite reductions in cephalosporin use, however, rates of CDI have continued to rise. This review examines the potential association of CDI with cephalosporins, and considers other factors that influence CDI risk. EUCLID (the EUropean, multicentre, prospective biannual point prevalence study of CLostridium difficile Infection in hospitalized patients with Diarrhoea) reported an increase in the annual incidence of CDI from 6.6 to 7.3 cases per 10 000 patient bed-days from 2011-12 to 2012-13, respectively. While CDI incidence and cephalosporin usage varied widely across countries studied, there was no clear association between overall cephalosporin prescribing (or the use of any particular cephalosporin) and CDI incidence. Moreover, variations in the pharmacokinetic and pharmacodynamic properties of cephalosporins of the same generation make categorization by generation insufficient for predicting impact on gut microbiota. A multitude of additional factors can affect the risk of CDI. Antibiotic choice is an important consideration; however, CDI risk is associated with a range of antibiotic classes. Prescription of multiple antibiotics and a long duration of treatment are key risk factors for CDI, and risk also differs across patient populations. We propose that all of these are factors that should be taken into account when selecting an antibiotic, rather than focusing on the exclusion of individual drug classes.

Ceftobiprole for the treatment of pneumonia: a European perspective

Ceftobiprole, a new broad spectrum, parenteral cephalosporin, exhibits potent in vitro activity against a number of Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and penicillin-resistant Streptococcus pneumoniae, and Gram-negative pathogens associated with hospital-acquired pneumonia (HAP) and community-acquired pneumonia (CAP). Ceftobiprole has demonstrated noninferiority in two large-scale pivotal studies comparing it to ceftriaxone with or without linezolid in CAP, with clinical cure rates 86.6% versus 87.4%, or ceftazidime in HAP, with clinical cure rates of 77% versus 76%, respectively. However, ceftobiprole was inferior in the subgroup of patients undergoing mechanical ventilation. Ceftobiprole has so far demonstrated a good safety profile in preliminary studies, with similar tolerability to comparators. The most commonly observed adverse events of ceftobiprole included headache and gastrointestinal upset. It is the first cephalosporin monotherapy approved in the EU for the treatment of both CAP and HAP (excluding ventilator-associated pneumonia).

Frequency of resistance in obligate anaerobic bacteria isolated from dogs, cats, and horses to antimicrobial agents

Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ≥ 16/8 μg/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ≥ 2 μg/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ≥ 32 μg/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ≥ 8 μg/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ≥ 32 μg/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ≥ 2 μg/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro.

Pharmacokinetic and pharmacodynamics evaluation of ceftobiprole medocaril for the treatment of hospital-acquired pneumonia

INTRODUCTION

Ceftobiprole is a cephalosporin with activity against methicillin-resistant Staphylococcus aureus, Enterobacteriaceae, and Pseudomonas aeruginosa with a promising role in the treatment of hospital-acquired pneumonia (HAP). Cure rates, however, with ceftobiprole at the doses studied may be inferior to conventional treatment in the ventilator-acquired subset of HAP.

AREAS COVERED

Literature was sought using PubMed and through abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy (2006 - 2012) and the European Congress of Clinical Microbiology and Infectious Diseases (2007 - 2012). The authors used the search terms "ceftobiprole," "BAL9141," "RO63-9141," "BAL5788," and 'RO5788." The article discusses the activity, mechanism of action, pharmacokinetics (PK), pharmacodynamics (PD), and clinical trials of ceftobiprole in HAP. The article also provides discussion of how PK/PD parameters play a role in the outcome of HAP treatment and how dosing in ventilator-associated pneumonia (VAP) should be reconsidered in light of altered PK/PD.

EXPERT OPINION

In patients with normal PK and non-VAP, ceftobiprole is effective for the treatment of HAP in the recommended doses, ceftobiprole is unlikely to achieve the desired PD targets when PK parameters are altered in VAP (e.g., increased volume of distribution and clearance). In these settings, off-label use at higher doses may overcome these limitations; but in the presence of alternative therapies, it cannot be currently recommended.

New insights into Prevotella diversity and medical microbiology

In light of recent studies based on cultivation-independent methods, it appears that the diversity of Prevotella in human microbiota is greater than was previously assumed from cultivation-based studies, and that the implication of these bacteria in several human diseases was unrecognized. While some Prevotella taxa were found during opportunistic infections, changes in Prevotella abundance and diversity were discovered during dysbiosis-associated diseases. As member of the microbiota, Prevotella may also be considered as a reservoir for resistance genes. Greater knowledge on Prevotella diversity, as well as new insights into its pathogenic potential and implication in dysbiosis are expected from the use of human microbe identification microarrays, from whole-genome sequence analyse, and from the NIH Human Microbiome Project data. New approaches, including molecular-based methods, could contribute to improve the diagnosis of Prevotella infections.

Effect of ceftobiprole treatment on growth of and toxin production by Clostridium difficile in cecal contents of mice

Ceftobiprole and ceftobiprole medocaril did not promote growth of or toxin production by Clostridium difficile in mouse cecal contents, whereas ceftazidime, cefoxitin, ceftriaxone, cefotaxime, and ertapenem did. The relatively low propensity of ceftobiprole to promote C. difficile was attributable to inhibitory activity against C. difficile and sparing of anaerobic microflora.

Emerging agents to combat complicated and resistant infections: focus on ceftobiprole

Antimicrobial resistance is a global concern. Over the past few years, considerable efforts and resources have been expended to detect, monitor, and understand at the basic level the many different facets of emerging and increasing resistance. Development of new antimicrobial agents has been matched by the development of new mechanisms of resistance by bacteria. Current antibiotics act at a variety of sites within the target bacteria, including the cross-linking enzymes in the cell wall, various ribosomal enzymes, nucleic acid polymerases, and folate synthesis. Ceftobiprole is a novel parenteral cephalosporin with high affinity for most penicillin-binding proteins, including the mecA product penicillin-binding protein 2a, rendering it active against methicillin-resistant staphylococci. Its in vitro activity against staphylococci and multiresistant pneumococci, combined with its Gram-negative spectrum comparable to that of other extended-spectrum cephalosporins, its stability against a wide range of beta-lactamases, and its pharmacokinetic and safety profiles make ceftobiprole an attractive and well tolerated new antimicrobial agent. The US Food and Drug Administration granted ceftobiprole medocaril fast-track status in 2003 for the treatment of complicated skin infections and skin structure infections due to methicillin-resistant staphylococci, and subsequently extended this to treatment of hospital-acquired pneumonia, including ventilator-associated pneumonia due to suspected or proven methicillin-resistant Staphylococcus aureus.

Ceftobiprole: a new beta-lactam antibiotic

The increasing threat of antimicrobial resistance in general, and that of methicillin-resistant Staphylococcus aureus (MRSA) in particular, is raising significant medical, economical and public health challenges worldwide, both within hospitals and throughout the community. These considerations, along with the extensive time and costs associated with the development and approval of new therapeutic agents, represent some of the major reasons why understanding the advantages and limitations of new antibiotics, ensuring their judicious use and maximising their active shelf life should become global priorities. On March 18, 2008, the Food and Drug Administration issued an approvable letter for ceftobiprole, a broad-spectrum beta-lactam antibiotic active against MRSA and other clinically relevant Gram-positive and Gram-negative pathogens. Ceftobiprole is currently available only for parenteral administration, and besides its remarkable antimicrobial spectrum, this antibiotic possesses additional desirable characteristics, such as low propensity to select for resistance, efficacy in animal models of disease and good safety profile. Furthermore, in recently completed clinical trials, ceftobiprole demonstrated non-inferiority to comparator compounds such as vancomycin, and emerged as a promising clinical option of monotherapy for the treatment of complicated skin and skin structure infections and community-acquired pneumonia. Here, we discuss some of the most important clinically relevant findings on ceftobiprole obtained from in vitro studies, animal models of disease and recently completed phase III clinical trials.

Ceftobiprole: a review of a broad-spectrum and anti-MRSA cephalosporin

Ceftobiprole, an investigational cephalosporin, is currently in phase III clinical development. Ceftobiprole is a broad-spectrum cephalosporin with demonstrated in vitro activity against Gram-positive cocci, including meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-resistant S. epidermidis, penicillin-resistant S. pneumoniae, Enterococcus faecalis, Gram-negative bacilli including AmpC-producing Escherichia coli and Pseudomonas aeruginosa, but excluding extended-spectrum beta-lactamase-producing strains. Like cefotaxime, ceftriaxone, ceftazidime, and cefepime, ceftobiprole demonstrates limited activity against anaerobes such as Bacteroides fragilis and non-fragilis Bacteroides spp. In single-step and serial passage in vitro resistance development studies, ceftobiprole demonstrated a low propensity to select for resistant subpopulations. Ceftobiprole, like cefepime, is a weak inducer and a poor substrate for AmpC beta-lactamases.Ceftobiprole medocaril, the prodrug of ceftobiprole, is converted by plasma esterases to ceftobiprole in <30 minutes. Peak serum concentrations of ceftobiprole observed at the end of a single 30-minute infusion were 35.5 mug/mL for a 500-mg dose and 59.6 mug/mL for a 750-mg dose. The volume of distribution of ceftobiprole is 0.26 L/kg ( approximately 18 L), protein binding is 16%, and its serum half-life is approximately 3.5 hours. Ceftobiprole is renally excreted ( approximately 70% in the active form) and systemic clearance correlates with creatinine clearance, meaning that dosage adjustment is required in patients with renal dysfunction. Ceftobiprole has a modest post-antibiotic effect (PAE) of approximately 0.5 hours for MRSA and a longer PAE of approximately 2 hours for penicillin-resistant pneumococci. Ceftobiprole, when administered intravenously at 500 mg once every 8 hours (2-hour infusion), has a >90% probability of achieving f T(>MIC) (free drug concentration exceeds the minimum inhibitory concentration [MIC]) for 40% and 60%, respectively, of the dosing interval for isolates with ceftobiprole MIC < or =4 and < or =2 mg/L, respectively.Currently, only limited clinical trial data are published for ceftobiprole. In a phase III trial, 784 patients with Gram-positive skin infections were randomized to treatment with either ceftobiprole 500 mg or vancomycin 1 g, each administered twice daily for 7-14 days; 93.3% of patients were clinically cured with ceftobiprole compared with 93.5% receiving vancomycin, and the eradication rate for MRSA infections was 91.8% for ceftobiprole compared with 90% for vancomycin. A phase III, randomized, double-blind, multicenter trial compared ceftobiprole 500 mg every 8 hours with vancomycin 1 g every 12 hours plus ceftazidime 1 g every 8 hours in patients with complicated skin and skin structure infections. Of the 828 patients enrolled, 31% had diabetic foot infections, 30% had abscesses, and 22% had wounds. No difference in clinical cure was reported in the clinically evaluable, intent-to-treat and microbiologically evaluable populations with cure rates of 90.5%, 81.9%, and 90.8%, respectively, in the ceftobiprole-treated patients and 90.2%, 80.8%, and 90.5%, respectively, in the vancomycin plus ceftazidime-treated group. Microbiologic eradication of Gram-positive cocci meticillin-susceptible S. aureus (MSSA) [ceftobiprole 91% vs vancomycin plus ceftazidime 92%] and MRSA (ceftobiprole 87% vs vancomycin plus ceftazidime 80%), as well as Gram-negative bacilli, E. coli (ceftobiprole 89% vs vancomycin plus ceftazidime 92%), and P. aeruginosa (ceftobiprole 87% vs vancomycin plus ceftazidime 100%), was not significantly different between groups. Similar cures rates in the microbiologically evaluable population occurred in both groups for Panton-Valentine leukocidin (PVL)-positive MSSA and PVL-positive MRSA.Currently, ceftobiprole has completed phase III trials for complicated skin and skin structure infections due to MRSA and nosocomial pneumonia due to suspected or proven MRSA; phase III trials are also ongoing in community-acquired pneumonia. Ceftobiprole has so far demonstrated a good safety profile in preliminary studies with similar tolerability to comparators. The broad-spectrum activity of ceftobiprole may allow it to be used as monotherapy in situations where a combination of antibacterials might be required. Further clinical studies are needed to determine the efficacy and safety of ceftobiprole and to define its role in patient care.

Ceftobiprole: an extended-spectrum anti-methicillin-resistant Staphylococcus aureus cephalosporin

OBJECTIVE

To summarize and evaluate the literature concerning ceftobiprole.

DATA SOURCES

Literature identification was conducted through MEDLINE (1966-February 2008) and International Pharmaceutical Abstracts (1970-February 2008) using the terms ceftobiprole, medocaril, BAL 5788, RO-5788, BAL 9141, RO 63-9141, pyrrolidinone cephalosporin, MRSA, complicated skin and skin-structure infections (cSSSIs), community-acquired pneumonia, and nosocomial pneumonia. Additional publications were identified through a review of articles and abstracts from infectious disease meetings.

STUDY SELECTION AND DATA EXTRACTION

All articles in English were evaluated and all pertinent information was included.

DATA SYNTHESIS

Ceftobiprole medocaril is an extended-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus spp., vancomycin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant Enterococcus faecalis, Enterobacteriaceae, and Pseudomonas aeruginosa. Inactivity includes extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and Enterococcus faecium. Preliminary data suggest that ceftobiprole may be effective with a 1-hour infusion of 500 mg every 12 hours for gram-positive infections and 500 mg every 8 hours with a 2-hour infusion for polymicrobial infections. Two clinical trials support these dosing regimens for cSSSIs. Ceftobiprole was noninferior to vancomycin in suspected gram-positive cSSSIs, with cure rates of 93.3% and 93.5%, respectively. Furthermore, ceftobiprole was noninferior to vancomycin and ceftazidime in polymicrobial cSSSIs (cure rates 90.5% vs 90.2%, respectively). Although the total number of adverse effects was similar to those of the comparator, more patients in the ceftobiprole group experienced nausea, vomiting, and dysgeusia.

CONCLUSIONS

The activity of ceftobiprole and limited clinical data suggest that it may be useful as empiric monotherapy for cSSSI and in combination with other antimicrobials in lower respiratory tract infections for which Phase 3 clinical trials are currently exploring. Although not shown in vitro, ceftobiprole may induce resistance due to its broad spectrum of activity. Approval is expected for the treatment of cSSSI.