Ceftobiprole Compared With Vancomycin Plus Aztreonam in the Treatment of Acute Bacterial Skin and Skin Structure Infections: Results of a Phase 3, Randomized, Double-blind Trial (TARGET)

Evaluation of in vitro activity of ceftaroline, ceftobiprole and their combination with trimethoprim/sulfamethoxazole against MRSA isolates: a two center study

There is an increasing need for new synergistic antimicrobial combinations against multidrug-resistant bacteria. Our objective was to evaluate the activity of ceftaroline, ceftobiprole and their combination with trimethoprim/sulfamethoxazole against methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered at two centers in Turkey. Activities of ceftaroline and ceftobiprole were tested against 100 MRSA isolates using gradient diffusion method. Activities of ceftaroline and ceftobiprole in combination with trimethoprim/sulfamethoxazole against 20 selected isolates (including all isolates that were non-susceptible to ceftaroline or ceftobiprole, and randomly selected isolates) were investigated using MIC:MIC ratio method. Antimicrobial interactions were interpreted using the fractional inhibitory concentration (FIC) index. The MIC50/MIC90 values for ceftaroline and ceftobiprole were 0.75/1 and 1/1.5 mg/L, respectively. Ceftaroline and ceftobiprole susceptibility rates among 100 MRSA isolates were 94% and 96%, respectively. Ceftaroline, ceftobiprole and trimethoprim/sulfamethoxazole MICs of isolates were not increased when ceftaroline or ceftobiprole was combined with trimethoprim/sulfamethoxazole. Ceftobiprole- trimethoprim/sulfamethoxazole combination demonstrated additivity against 35%, whereas ceftaroline- trimethoprim/sulfamethoxazole combination demonstrated additivity against 10% of 20 MRSA isolates. The remaining interactions for MRSA isolates were indifference. Three (75%) of four ceftobiprole-resistant isolates became susceptible to ceftobiprole after adding trimethoprim/sulfamethoxazole. None of the ceftaroline non-susceptible isolates became susceptible to ceftaroline after adding trimethoprim/sulfamethoxazole. Ceftobiprole- trimethoprim/sulfamethoxazole combination may be a better treatment option than ceftaroline- trimethoprim/sulfamethoxazole combination for MRSA infections. Clinical studies are needed to confirm the results of our in vitro study.

Synthesis and evaluation of in vitro antioxidant, anticancer, and antibacterial properties of new benzylideneiminophenylthiazole analogues

A series of new benzylideneiminophenylthiazole analogues were designed and synthesized. Common spectroscopic methods, such as FT-IR, 1H-, 13C-NMR, and MASS spectra, and elemental analysis, were used to confirm the molecular structures. Then, the antioxidant, cytotoxicity, and anti-bacterial effects of synthesized analogues were assessed against 2,2-diphenyl-1-picrylhydrazyl (DPPH), three cancer cell lines, and two bacterial strains, respectively. Among the analogues, 7f was detected as the most potent compound for antioxidant activity. Moreover, the compounds 7b, 7f, and 7 g exhibited the maximum cytotoxicity activity against MCF-7, HepG-2, and A549 cell lines, respectively. Finally, 7e showed the highest anti-bacterial activity against both S. aureus and E. coli strains. It was concluded from the antioxidant, cytotoxicity, and anti-bacterial effects that the benzylideneiminophenylthiazoles might serve as candidate molecules for the development of small molecules with medicinal potential.

How is ceftobiprole used in Canada: the CLEAR study final results

BACKGROUND

We report the final results of the clinical usage of ceftobiprole in patients in Canada from data in the national CLEAR (Canadian Le adership on Antimicrobial Real-Life Usage) registry.

RESEARCH DESIGN AND METHODS

The authors review the final data using the national ethics approved CLEAR study. Thereafter, the literature is surveyed regarding the usage of ceftobiprole to treat patients with infectious diseases via PubMed (up to March 2024).

RESULTS

In Canada, ceftobiprole is primarily used as directed therapy to treat a variety of severe infections caused by MRSA. It is primarily used in patients failing previous antimicrobials, is frequently added to daptomycin and/or vancomycin with high microbiological and clinical cure rates, along with an excellent safety profile. Several reports attest to the microbiological/clinical efficacy and safety of ceftobiprole. Ceftobiprole is also reported to be used empirically in select patients with community-acquired bacterial pneumonia (CABP), as well as hospital-acquired bacterial pneumonia (HABP).

CONCLUSIONS

In Canada, ceftobiprole is used mostly as directed therapy to treat a variety of severe infections caused by MRSA, in patients failing previous antimicrobials. It is frequently added to, and thus used in combination with daptomycin and/or vancomycin with high microbiological/clinical cure rates, and an excellent safety profile.

Pharmacotherapies for multidrug-resistant gram-positive infections: current options and beyond

INTRODUCTION

Infections due to multidrug-resistant organisms (MDRO) are a serious concern for public health with high morbidity and mortality. Though many antibiotics have been introduced to manage these infections, there are remaining concerns regarding the optimal management of Gram-positive MDROs.

AREAS COVERED

A literature search on the PubMed/Medline database was conducted. We applied no language and time limits for the search strategy. In this narrative review, we discuss the current options for managing Gram-positive MDROs as well as non-traditional antibacterial agents in development.

EXPERT OPINION

Despite their introduction more than 70 years ago, glycopeptides are still the cornerstone in treating Gram-positive infections: all registrative studies of new antibiotics have glycopeptides as control; these studies are designed as not inferior studies, therefore it is almost impossible to give recommendations other than the use of glycopeptides in the treatment of Gram-positive infections. The best evidence on treatments different from glycopeptides comes from post-hoc analysis and meta-analysis. Non-traditional antibacterial agents are being studied to aid in short and effective antibiotic therapies. The use of non-traditional antibacterial agents is not restricted to replacing traditional antibacterial agents with alternative therapies; instead, they should be used in combination with antibiotic therapies.

Antistaphylococcal discovery pipeline; where are we now?

The serious spread of antibiotic-resistant Staphylococcal aureus strains is alarming. This is reflected by the measures governments and health-related bodies are offering to ease antibiotic drug development. Finding new active agents, preferably with novel mechanism of action, or even finding new targets for drug development are essential. In this review, we summarize the current status of novel antistaphylococcal agents undergoing clinical trials. We mainly discuss antistaphylococcal small molecules and peptides in the text with a special focus on their chemistry, while antistaphylococcal immunotherapy (antibodies) are mentioned in a summative table. This review shall serve as a summary that influences future synthetic efforts in the antistaphyloccocals development field.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.

AREAS COVERED

The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.

EXPERT OPINION

The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

Treatment of MRSA Infection: Where are We?

Staphylococcus aureus is a leading cause of septicemia, endocarditis, pneumonia, skin and soft tissue infections, bone and joint infections, and hospital-acquired infections. In particular, methicillin-resistant Staphylococcus aureus (MRSA) is associated with high morbidity and mortality, and continues to be a major public health problem. The emergence of multidrug-resistant MRSA strains along with the wide consumption of antibiotics has made anti-MRSA treatment a huge challenge. Novel treatment strategies (e.g., novel antimicrobials and new administrations) against MRSA are urgently needed. In the past decade, pharmaceutical companies have invested more in the research and development (R&D) of new antimicrobials and strategies, spurred by favorable policies. All research articles were collected from authentic online databases, including Google Scholar, PubMed, Scopus, and Web of Science, by using different combinations of keywords, including 'anti-MRSA', 'antibiotic', 'antimicrobial', 'clinical trial', 'clinical phase', clinical studies', and 'pipeline'. The information extracted from articles was compared to information provided on the drug manufacturer's website and Clinical Trials.gov (https://clinicaltrials.gov/) to confirm the latest development phase of anti-MRSA agents. The present review focuses on the current development status of new anti-MRSA strategies concerning chemistry, pharmacological target(s), indications, route of administration, efficacy and safety, pharmacokinetics, and pharmacodynamics, and aims to discuss the challenges and opportunities in developing drugs for anti-MRSA infections.

Ceft-to-Ceft Study: Real-Life Experience with Ceftaroline and Ceftobiprole in Treatment of the Principal Infectious Syndromes in a Spanish Multicenter Hospital Cohort

BACKGROUND

To compare the real-life effectiveness and safety of ceftaroline fosamil (ceftaroline-F) and ceftobiprole medocaril (ceftobiprole-M) for infections in hospitalized patients.

METHODS

This comparative, observational, retrospective, and multicenter Spanish study included patients receiving outpatient parenteral antimicrobial therapy (OPAT) and hospitalized patients treated for at least 48 h with ceftaroline-F or ceftobiprole-M between their first incorporation in the clinical protocol of each hospital and 31 July 2022.

RESULTS

Ceftaroline-F was administered to 227 patients and ceftobiprole-M to 212. In comparison to the latter, ceftaroline-F-treated participants were younger (63.02 vs. 66.40 years, OR 1.1; 95%CI: 1.001-1.05) and had higher rates of septic shock (OR 0.27; 95%CI: 0.09-0.81) and higher frequencies of targeted (57.7 vs. 29.7%; OR: 0.35; 95%CI: 0.18-0.69) and combined (89.0 vs. 45.8%, OR: 0.13; 95%CI: 0.06-0.28) therapies that were second line or more (82.4% vs. 64.6%%; OR 0.35; 95%CI: 0.18-0.69), and higher rates of infections due to Gram-positive cocci (92.7 vs. 64.7%, p = 0.001), bacteremia (51.9 vs. 21.7%, p = 0.001), infective endocarditis (24.2 vs. 2.4%, p = 0.0001), and mechanical ventilation-associated pneumonia (8.8 vs. 2.4%, p = 0.0001). Ceftobiprole-M was more frequently administered against polymicrobial infections (38.1 vs. 14.0%, p = 0.001), those produced by Gram-negative bacilli (19.7 vs. 6.0%, p = 0.0001), nosocomial pneumonia (33 vs. 10.6%, p = 0.0001), and skin and soft-tissue infections (25.4 vs. 10.1%, p = 0.0001). Patients treated with ceftaroline-F had a longer hospital stay (36 (IQR: 19-60) vs. 19.50 (IQR: 12-30.75, p = 0.0001) days), with no difference in infection-related mortality at 14 (13.2 vs. 8.0%, p = 0.078) or 28 (4.8 vs. 3.3%, p = 0.415) days or in dropout rate for adverse effects (2.2 vs. 0.9%; p = 1).

CONCLUSIONS

The fifth-generation cephalosporins, ceftaroline-F and ceftobiprole-M, are safe and effective in real life, with no difference between them in health outcomes.

Ceftobiprole for Treatment of Complicated Staphylococcus aureus Bacteremia

BACKGROUND

Ceftobiprole is a cephalosporin that may be effective for treating complicated Staphylococcus aureus bacteremia, including methicillin-resistant S. aureus.

METHODS

In this phase 3, double-blind, double-dummy, noninferiority trial, adults with complicated S. aureus bacteremia were randomly assigned in a 1:1 ratio to receive ceftobiprole at a dose of 500 mg intravenously every 6 hours for 8 days and every 8 hours thereafter, or daptomycin at a dose of 6 to 10 mg per kilogram of body weight intravenously every 24 hours plus optional aztreonam (at the discretion of the trial-site investigators). The primary outcome, overall treatment success 70 days after randomization (defined as survival, bacteremia clearance, symptom improvement, no new S. aureus bacteremia-related complications, and no receipt of other potentially effective antibiotics), with a noninferiority margin of 15%, was adjudicated by a data review committee whose members were unaware of the trial-group assignments. Safety was also assessed.

RESULTS

Of 390 patients who underwent randomization, 387 (189 in the ceftobiprole group and 198 in the daptomycin group) had confirmed S. aureus bacteremia and received ceftobiprole or daptomycin (modified intention-to-treat population). A total of 132 of 189 patients (69.8%) in the ceftobiprole group and 136 of 198 patients (68.7%) in the daptomycin group had overall treatment success (adjusted difference, 2.0 percentage points; 95% confidence interval [CI], -7.1 to 11.1). Findings appeared to be consistent between the ceftobiprole and daptomycin groups in key subgroups and with respect to secondary outcomes, including mortality (9.0% and 9.1%, respectively; 95% CI, -6.2 to 5.2) and the percentage of patients with microbiologic eradication (82.0% and 77.3%; 95% CI, -2.9 to 13.0). Adverse events were reported in 121 of 191 patients (63.4%) who received ceftobiprole and 117 of 198 patients (59.1%) who received daptomycin; serious adverse events were reported in 36 patients (18.8%) and 45 patients (22.7%), respectively. Gastrointestinal adverse events (primarily mild nausea) were more frequent with ceftobiprole.

CONCLUSIONS

Ceftobiprole was noninferior to daptomycin with respect to overall treatment success in patients with complicated S. aureus bacteremia. (Funded by Basilea Pharmaceutica International and the U.S. Department of Health and Human Services; ERADICATE ClinicalTrials.gov number, NCT03138733.).

New Antimicrobials for Gram-Positive Sustained Infections: A Comprehensive Guide for Clinicians

Antibiotic resistance is a public health problem with increasingly alarming data being reported. Gram-positive bacteria are among the protagonists of severe nosocomial and community infections. The objective of this review is to conduct an extensive examination of emerging treatments for Gram-positive infections including ceftobiprole, ceftaroline, dalbavancin, oritavancin, omadacycline, tedizolid, and delafloxacin. From a methodological standpoint, a comprehensive analysis on clinical trials, molecular structure, mechanism of action, microbiological targeting, clinical use, pharmacokinetic/pharmacodynamic features, and potential for therapeutic drug monitoring will be addressed. Each antibiotic paragraph is divided into specialized microbiological, clinical, and pharmacological sections, including detailed and appropriate tables. A better understanding of the latest promising advances in the field of therapeutic options could lead to the development of a better approach in managing antimicrobial therapy for multidrug-resistant Gram-positive pathogens, which increasingly needs to be better stratified and targeted.

Ceftobiprole Medocaril Is an Effective Post-Exposure Treatment in the Fischer 344 Rat Model of Pneumonic Tularemia

Francisella tularensis subspecies tularensis is a category-A biothreat agent that can cause lethal tularemia. Ceftobiprole medocaril is being explored as a medical countermeasure for the treatment of pneumonic tularemia. The efficacy of ceftobiprole medocaril against inhalational tularemia was evaluated in the Fischer 344 rat model of infection. The dose was expected to be effective against F. tularensis isolates with ceftobiprole minimum inhibitory concentrations ≤0.5 µg/mL. Animals treated with ceftobiprole medocaril exhibited a 92% survival rate 31 days post-challenge, identical to the survival of levofloxacin-treated rats. By comparison, rats receiving placebo experienced 100% mortality. Terminally collected blood, liver, lung, and spleen samples confirmed disseminated F. tularensis infections in most animals that died prior to completing treatments (placebo animals and a rat treated with ceftobiprole medocaril), although levels of bacteria detected in the placebo samples were significantly elevated compared to the ceftobiprole-medocaril-treated group geometric mean. Furthermore, no evidence of infection was detected in any rat that completed ceftobiprole medocaril or levofloxacin treatment and survived to the end of the post-treatment observation period. Overall, survival rates, body weights, and bacterial burdens consistently demonstrated that treatment with ceftobiprole medocaril is efficacious against otherwise fatal cases of pneumonic tularemia in the rat model.

In Vitro Activities of Ceftobiprole, Dalbavancin, Tedizolid and Comparators against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus Associated with Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) are associated with significant morbidity and healthcare costs, especially when caused by methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin is a preferred antimicrobial therapy for the management of complicated SSTIs (cSSTIs) caused by MRSA, with linezolid and daptomycin regarded as alternative therapeutic options. Due to the increased rates of antimicrobial resistance in MRSA, several new antibiotics with activity against MRSA have been recently introduced in clinical practice, including ceftobiprole, dalbavancin, and tedizolid. We evaluated the in vitro activities of the aforementioned antibiotics against 124 clinical isolates of MRSA obtained from consecutive patients with SSTIs during the study period (2020-2022). Minimum inhibitory concentrations (MICs) for vancomycin, daptomycin, ceftobiprole, dalbavancin, linezolid and tedizolid were evaluated by the MIC Test Strip using Liofilchem strips. We found that when compared to the in vitro activity of vancomycin (MIC₉₀ = 2 μg/mL), dalbavancin possessed the lowest MIC₉₀ (MIC₉₀ = 0.094 μg/mL), followed by tedizolid (MIC₉₀ = 0.38 μg/mL), linezolid, ceftobiprole, and daptomycin (MIC₉₀ = 1 μg/mL). Dalbavancin demonstrated significantly lower MIC₅₀ and MIC₉₀ values compared to vancomycin (0.064 vs. 1 and 0.094 vs. 2, respectively). Tedizolid exhibited an almost threefold greater level of in vitro activity than linezolid, and also had superior in vitro activity compared to ceftobiprole, daptomycin and vancomycin. Multidrug-resistant (MDR) phenotypes were detected among 71.8% of the isolates. In conclusion, ceftobiprole, dalbavancin and tedizolid exhibited potent activity against MRSA and are promising antimicrobials in the management of SSTIs caused by MRSA.

Clinical evidence supporting ceftaroline fosamil and ceftobiprole for complicated skin and soft tissue infections

PURPOSE OF REVIEW

Ceftaroline and ceftobiprole are advanced generation cephalosporins with activity against methicillin-resistant Staphylococcus aureus (MRSA). This review summarizes their clinical efficacy for complicated skin and soft tissue infections (cSSTIs).

RECENT FINDINGS

Both these agents retain excellent in vitro activity against both MRSA and Gram-negative isolates from patients with CSSTIs. Both these agents are registered for the management of cSSTIs based on the results of large scale phase III noninferiority trials. Ceftaroline and ceftobiprole are noninferior to the combination of vancomycin and aztreonam as this was assessed by their clinical cure rate at the test-of-cure visits. Furthermore, ceftobiprole is noninferior to comparators for the achievement of early clinical success at 72 h. Ceftaroline achieves 81% clinical cure against diabetic foot infections.

SUMMARY

Ceftaroline and ceftobiprole can be used as monotherapy for the treatment of cSSTIs.

Current and emerging drug treatment strategies to tackle invasive community-associated methicillin-resistant Staphylococcus aureus (MRSA) infection: what are the challenges?

INTRODUCTION

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections represent a leading cause of purulent skin and soft tissue infections in some geographical regions. Traditionally, 'old antibiotics' such as trimethoprim-sulfamethoxazole, tetracyclines, clindamycin, chloramphenicol,vancomycin, and teicoplanin have been used to treat these infections, but these were often associated with low efficacy and excessive side effects and toxicity, especially nephrotoxicity. Along with the development of new compounds, the last decade has seen substantial improvements in the management of CA-MRSA infections.

AREAS COVERED

In this review, the authors discuss the current and emerging drug treatment strategies to tackle invasive CA-MRSA infections. Articles reported in this review were selected from through literature searches using the PubMed database.

EXPERT OPINION

The availability of new drugs showing a potent in vitro activity against CA-MRSA represents a unique opportunity to face the threat of resistance while potentially reducing toxicity. All these compounds represent promising options to enhance our antibiotic armamentarium. However, data regarding the use of these new drugs in real-life studies are limited and their best placement in therapy and in terms of optimization of medical resources and balance of cost-effectiveness requires further investigation.

Escalation of antimicrobial resistance among MRSA part 2: focus on infections and treatment

INTRODUCTION

MRSA is associated with causing a variety of infections including skin and skin structure infections, catheter and device-related (e.g. central venous catheter, prosthetic heart valve) infections, infectious endocarditis, blood stream infections, bone, and joint infections (e.g. osteomyelitis, prosthetic joint, surgical site), central nervous system infections (e.g. meningitis, brain/spinal cord abscess, ventriculitis, hydrocephalus), respiratory tract infections (e.g. hospital-acquired pneumonia, ventilator-associated pneumonia), urinary tract infections, and gastrointestinal infections. The emergence and spread of multidrug resistant (MDR) MRSA clones has limited therapeutic options. Older agents such as vancomycin, linezolid and daptomycin and a variety of newer MRSA antimicrobials and combination therapy are available to treat serious MRSA infections.

AREAS COVERED

The authors discuss infections caused by MRSA as well as common older and newer antimicrobials and combination therapy for MRSA infections. A literature search of MRSA was performed via PubMed (up to September 2022), using the keywords: antimicrobial resistance; β-lactams; multidrug resistance, Staphylococcus aureus, vancomycin; glycolipopeptides.

EXPERT OPINION

Innovation, discovery, and development of new and novel classes of antimicrobial agents are critical to expand effective therapeutic options. The authors encourage the judicious use of antimicrobials in accordance with antimicrobial stewardship programs along with infection-control measures to minimize the spread of MRSA.

Study of Degradation Kinetics and Structural Analysis of Related Substances of Ceftobiprole by HPLC with UV and MS/MS Detection

Ceftobiprole is a novel β-lactam antibiotic, active against methicillin-resistant Staphylococcus aureus, vancomycin-resistant S. aureus and penicillin-resistant Streptococcus pneumoniae. To artificially generate potential degradation products (DPs) of ceftobiprole that may be formed under relevant storage conditions, acidic, alkaline, oxidative, photolytic and thermolytic stress tests were performed in both solution and solid state. A novel selective HPLC method was developed for the separation of ceftobiprole from its DPs and synthesis by-products (SBPs) using Kinetex Biphenyl column, ammonium acetate buffer pH 5.8 and acetonitrile. The kinetic studies demonstrated the low stability of ceftobiprole in alkaline solution, in the presence of an oxidising agent and under irradiation with near UV. In the solid state, ceftobiprole underwent oxidation when the powder was irradiated with visible light and UV. Based on mass spectroscopic analysis, 13 new structural formulas of SBPs and DPs were proposed, along with molecular formulas for three other DPs obtained in solution and four oxidative DPs characteristic of solid-state degradation.

Efficacy and safety of optional parenteral antimicrobial therapy for complicated skin and soft tissue infections: A systematic review and Bayesian network meta-analysis

BACKGROUND

Skin and soft tissue infections (SSTIs) carry significant economic burden, as well as morbidity and mortality, especially when caused by methicillin-resistant Staphylococcus aureus. This study aims to investigate the efficacy and safety of optional antimicrobial therapy for the treatment of complicated SSTIs (cSSTIs).

METHODS

We searched PubMed, Medline (Via Ovid SP), Embase (Via Ovid SP), and the Cochrane Central Register of Controlled Trials from their inception to March 22, 2021 for randomized controlled trials (RCTs) that studied the use of optional antimicrobial therapy for cSSTIs. Citations' screening, study selection, data extraction, and risk of bias assessment were independently performed by 2 authors. The primary outcomes were clinical and microbiological treatment success, and adverse events (AEs) were also assessed.

RESULTS

A total of 48 trials covering 24,381 patients assessing 20 types of antimicrobial treatment modalities were included. Overall, omadacycline was associated with the highest beneficial effect on clinical and microbiological treatment success and with the largest rank probability based on surface under the cumulative ranking curve values, avarofloxacin was closely followed. Both had, however, omadacycline was related to moderately safety profiles. Lefamulin ranked as the best option was associated with the lowest risk of severe AEs. Subgroup analysis showed similar results. The quality of primary outcomes was moderate to low.

CONCLUSIONS

The use of omadacycline was associated with higher rates of clinical and microbiological treatment success for the treatment of cSSTIs, with a relative low risk of AEs. Due to the limitations of the included RCTs, high-quality and well-designed RCTs are needed to further confirm the results.

Diagnosis and management of infections caused by multidrug-resistant bacteria: guideline endorsed by the Italian Society of Infection and Tropical Diseases (SIMIT), the Italian Society of Anti-Infective Therapy (SITA), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Association of Clinical Microbiologists (AMCLI) and the Italian Society of Microbiology (SIM)

Management of patients with infections caused by multidrug-resistant organisms is challenging and requires a multidisciplinary approach to achieve successful clinical outcomes. The aim of this paper is to provide recommendations for the diagnosis and optimal management of these infections, with a focus on targeted antibiotic therapy. The document was produced by a panel of experts nominated by the five endorsing Italian societies, namely the Italian Association of Clinical Microbiologists (AMCLI), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Society of Microbiology (SIM), the Italian Society of Infectious and Tropical Diseases (SIMIT) and the Italian Society of Anti-Infective Therapy (SITA). Population, Intervention, Comparison and Outcomes (PICO) questions about microbiological diagnosis, pharmacological strategies and targeted antibiotic therapy were addressed for the following pathogens: carbapenem-resistant Enterobacterales; carbapenem-resistant Pseudomonas aeruginosa; carbapenem-resistant Acinetobacter baumannii; and methicillin-resistant Staphylococcus aureus. A systematic review of the literature published from January 2011 to November 2020 was guided by the PICO strategy. As data from randomised controlled trials (RCTs) were expected to be limited, observational studies were also reviewed. The certainty of evidence was classified using the GRADE approach. Recommendations were classified as strong or conditional. Detailed recommendations were formulated for each pathogen. The majority of available RCTs have serious risk of bias, and many observational studies have several limitations, including small sample size, retrospective design and presence of confounders. Thus, some recommendations are based on low or very-low certainty of evidence. Importantly, these recommendations should be continually updated to reflect emerging evidence from clinical studies and real-world experience.

New drugs for methicillin-resistant Staphylococcus aureus skin and soft tissue infections

PURPOSE OF REVIEW

Staphylococcus aureus is a pathogen incriminated in skin and soft tissue infections (SSTIs), with methicillin-resistant S. aureus (MRSA) becoming the predominant cause and representing a significant burden to the healthcare system. The last updated Infectious Diseases Society of America (IDSA) guidelines concerning MRSA infections and SSTIs management were published in 2011 and 2014, respectively. The UK updated guidelines for MRSA infection treatment were published in 2021. Older treatment options may be associated with toxicity and require frequent dosing. There is a paucity of recent reviews on the armamentarium of new agents for MRSA SSTIs treatment.

RECENT FINDINGS

Since 2005, several new antibiotics received a fast-track approval by the Food and Drug Administration (FDA) for SSTI treatment. These drugs include delafloxacin, omadacycline, tedizolid, ceftaroline, dalbavancin, oritavancin and telavancin. In this manuscript, we will review the data that led to these new drugs approval and discuss their advantages and disadvantages in MRSA SSTIs management.

SUMMARY

MRSA is a major cause of SSTIs. Several novel therapies covering MRSA were FDA-approved for SSTIs. However, the current IDSA guidelines for MRSA infection and SSTIs as well as the recently published UK guidelines on MRSA treatment only consider these drugs as alternative choices or do not mention them at all.

Novel investigational treatments for ventilator-associated pneumonia and critically ill patients in the intensive care unit

INTRODUCTION

Ventilator-associated pneumonia (VAP) is common; its prevalence has been highlighted by the Covid-19 pandemic. Even young patients can suffer severe nosocomial infection and prolonged mechanical ventilation. Multidrug-resistant bacteria can spread alarmingly fast around the globe and new antimicrobials are struggling to keep pace; hence physicians must stay abreast of new developments in the treatment of nosocomial pneumonia and VAP.

AREAS COVERED

This narrative review examines novel antimicrobial investigational drugs and their implementation in the ICU setting for VAP. The paper highlights novel approaches such as monoclonal antibody treatments for P. aeruginosa and S. aureus, and phage antibiotic synthesis. The paper also examines mechanisms of resistance in gram-negative bacteria, virulence factors and inhaled antibiotics and questions what may be on the horizon in terms of emerging treatment strategies.

EXPERT OPINION

The post-antibiotic era is rapidly approaching and the need for personalised medicine, point-of-care microbial sensitivity testing and development of biomarkers for severe infections is clear. Results from emerging and new antibiotics are encouraging, but infection control measures and de-escalation protocols must be employed to prolong their usefulness in critical illness.

OUP accepted manuscript

Objectives

To evaluate the susceptibility to ceftobiprole of clinical bacterial isolates obtained from hospitalized patients in Europe.

Methods

A total of 20 000 non-duplicate bacterial isolates were collected in 2016–19 from patients with documented infections at medical centres located in 17 countries in Europe. Bacterial identification was confirmed and susceptibility to ceftobiprole and comparator agents was tested using the EUCAST broth microdilution methodology and interpretive criteria by a central microbiology laboratory.

Results

Of the 20 000 isolates, 10 007 (50.0%) were Gram-positive and 9993 (50.0%) were Gram-negative. The most common species was Staphylococcus aureus (35.0%), followed by Streptococcus pneumoniae (15.0%), Klebsiella pneumoniae (11.1%), Pseudomonas aeruginosa (11.0%), Escherichia coli (9.7%) and Haemophilus influenzae (3.0%). Overall, 99.7% (6981/7000) of S. aureus, including 99.5% (3483/3502) of MRSA, 97.8% (2941/3007) of S. pneumoniae, 100% (605/605) of H. influenzae and 76.3% (5492/7197) of Enterobacterales isolates were susceptible to ceftobiprole. Susceptibility to ceftobiprole was higher for isolates from northern and western Europe as compared with eastern and southern Europe.

Conclusions

Ceftobiprole continues to exhibit potent and broad-spectrum activity against Gram-positive and Gram-negative clinical isolates from Europe, and as expected, with a slight north-to-south and west-to-east susceptibility gradient.

Translation of Pharmacodynamic Biomarkers of Antibiotic Efficacy in Specific Populations to Optimize Doses

Antibiotic efficacy determination in clinical trials often relies on non-inferiority designs because they afford smaller study sample sizes. These efficacy studies tend to exclude patients within specific populations or include too few patients to discern potential differences in their clinical outcomes. As a result, dosing guidance in patients with abnormal liver and kidney function, age across the lifespan, and other specific populations relies on drug exposure-matching. The underlying assumption for exposure-matching is that the disease course and the response to the antibiotic are similar in patients with and without the specific condition. While this may not be the case, clinical efficacy studies are underpowered to ensure this is true. The current paper provides an integrative review of the current approach to dose selection in specific populations. We review existing clinical trial endpoints that could be measured on a more continuous rather than a discrete scale to better inform exposure-response relationships. The inclusion of newer systemic biomarkers of efficacy can help overcome the current limitations. We use a modeling and simulation exercise to illustrate how an efficacy biomarker can inform dose selection better. Studies that inform response-matching rather than exposure-matching only are needed to improve dose selection in specific populations.

Efficacy and appropriateness of novel antibiotics in response to antimicrobial-resistant Gram-negative bacteria in patients with sepsis in the ICU

INTRODUCTION

There is an ever-increasing range of antibiotic-resistant pathogens that have led to higher community-acquired infections, and substantial mortality rates in critically ill patients.

AREAS COVERED

We have critically appraised available evidence through a structured literature review, investigating effective empiric antibiotic administration and appropriateness on outcomes of critically ill patients with an increased risk of developing resistant pathogens. The use of new antibiotics should be determined based on relevant knowledge of their spectrum and properties to provide effective mode of action for critically ill patients.

EXPERT OPINION

Restricting severely ill patients access to new broad-spectrum empirical drugs is not the answer. Rather there should be a focus on identifying host response to infection to differentiate between colonization or contamination and true infection, and the sensitivity to antibiotics used in the intensive care unit (ICU).

Management relies on adequate antibiotic administration, the ability to monitor response, and facilitate the cessation of antibiotic treatment. The major determinant of patient success in a patient with a severe infection is the 'right' antibiotic or complementary course of treatment. As an overarching criterion, the following 3 appropriate "Ds" should be considered: Dosing, Duration and De-escalation to empirically assess the right antibiotic optimal antimicrobial selection.

Pharmacokinetics and Safety of Ceftobiprole in Pediatric Patients

BACKGROUND

Ceftobiprole, the active moiety of the prodrug ceftobiprole medocaril, is an advanced-generation, broad-spectrum, intravenous cephalosporin, which is currently approved for the treatment of adults with hospital-acquired or community-acquired pneumonia.

METHODS

Noncompartmental pharmacokinetics and safety were analyzed from 2 recently completed pediatric studies, a single-dose, phase 1 study in neonates and infants up to 3 months of age (7.5 mg/kg) and a phase 3 study in patients 3 months to 17 years of age with pneumonia (10-20 mg/kg with a maximum of 500 mg per dose every 8 hours for up to 14 days).

RESULTS

Total ceftobiprole plasma concentrations peaked at the end of infusion. Half life (median ranging from 1.9 to 2.9 hours) and overall exposure (median AUC ranging from 66.6 to 173 μg•h/mL) were similar to those in adults (mean ± SD, 3.3 ± 0.3 hours and 102 ± 11.9 μg•h/mL, respectively). Calculated free-ceftobiprole concentrations in the single-dose study remained above a minimum inhibitory concentration (MIC) of 4 mg/L (fT > MIC of 4 mg/L) for a mean of 5.29 hours after dosing. In the pneumonia study, mean fT > MIC of 4 mg/L was ≥5.28 hours in all dose groups. Ceftobiprole was well tolerated in both studies.

CONCLUSIONS

Pharmacokinetic parameters of ceftobiprole characterized in the pediatric population were within the range of those observed in adults. In the pneumonia study, the lowest percentage of the dosing interval with fT > MIC of 4 mg/L was 50.8%, which suggests that pharmacokinetic-pharmacodynamic target attainment can be sufficient in pediatric patients. Ceftobiprole was well tolerated.

Anti-MRSA Cephalosporin versus Vancomycin-Based Treatment for Acute Bacterial Skin and Skin Structure Infection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) compared the clinical efficacy and safety of anti-MRSA cephalosporin and vancomycin-based treatment in treating acute bacterial skin and skin structure infections (ABSSSIs). PubMed, Embase, Cochrane Central Register of Controlled Trials, Turning Research into Practice, and ClinicalTrials.gov databases were searched for relevant articles from inception to 15 June 2020. RCTs comparing the clinical efficacy and safety of anti-MRSA cephalosporin with those of vancomycin-based regimens in treating adult patients with ABSSSIs were included. The primary and secondary outcomes were clinical response at the test-of-cure assessments and risk of adverse events (AEs), respectively. Eight RCTs were enrolled. The clinical response rate was not significantly different between anti-MRSA cephalosporin and vancomycin-based treatments (odds ratio [OR], 1.05; 95% CI, 0.90–1.23; I² = 0%). Except for major cutaneous abscesses in which anti-MRSA cephalosporin-based treatment was associated with a lower clinical response rate than vancomycin-based treatment (OR, 0.62; 95% CI, 0.40–0.97; I² = 0%), other subgroup analyses according to the type of cephalosporin (ceftaroline or ceftobiprole), type of infection, and different pathogens did not show significant differences in clinical response. Anti-MRSA cephalosporin-based treatment was only associated with a higher risk of nausea than vancomycin-based treatment (OR, 1.41; 95% CI, 1.07–1.85; I² = 0%). In treating ABSSSIs, the clinical efficacy of anti-MRSA cephalosporin is comparable to that of vancomycin-based treatment, except in major cutaneous abscesses. In addition to nausea, anti-MRSA cephalosporin was as tolerable as vancomycin-based treatment.

Potential role of new-generation antibiotics in acute bacterial skin and skin structure infections

PURPOSE OF REVIEW

To summarize the available results of primary analyses from high-quality randomized studies of either recently approved or possible future agents for the treatment of acute bacterial skin and skin structure infections (ABSSSI).

RECENT FINDINGS

In the last 2 decades, several novel agents have been approved for the treatment of ABSSSI, that are also active against methicillin-resistant Staphylococcus aureus (MRSA). In addition to already available agents, further molecules are in clinical development that could become available for treating ABSSSI in the forthcoming future.

SUMMARY

The current and future availability of several new-generation antibiotics will allow to modulate therapeutic choices not only on efficacy but also on other relevant factors such as the combination of the drug safety profile and the comorbidities of any given patient, the expected adherence to outpatient therapy, and the possibilities of early discharge or avoiding hospitalization by means of oral formulations, early switch from intravenous to oral therapy, or single-dose administration of long-acting intravenous agents. With the advent of new-generation antibiotics, all these factors are becoming increasingly essential for tailoring treatment to individual patients in line with the principles of personalized medicine, and for optimizing the use of healthcare resources.

Optimizing Ceftobiprole Dosage in Pediatric Patients: A Model-Based Approach

Ceftobiprole is an advanced-generation cephalosporin for intravenous administration with activity against Gram-positive and Gram-negative organisms. A population pharmacokinetic (PK) model characterizing the disposition of ceftobiprole in plasma using data from patients in three pediatric studies was developed. Model-based simulations were subsequently performed to assist in dose optimization for the treatment of pediatric patients with hospital-acquired or community-acquired pneumonia. The population PK data set comprised 518 ceftobiprole plasma concentrations from 107 patients from 0 (birth) to 17 years of age. Ceftobiprole PK was well described by a three-compartment model with linear elimination. Ceftobiprole clearance was modeled as a function of glomerular filtration rate; other PK parameters were scaled to body weight. The final population PK model provided a robust and reliable description of the PK of ceftobiprole in the pediatric study population. Model-based simulations using the final model suggested that a ceftobiprole dose of 15 mg/kg of body weight infused over 2 h and administered every 12 h in neonates and infants <3 months of age or every 8 h in older pediatric patients would result in a ceftobiprole exposure consistent with that in adults and good pharmacokinetic-pharmacodynamic target attainment. The dose should be reduced to 10 mg/kg every 12 h in neonates and infants <3 months of age who weigh <4 kg to avoid high exposures. Extended intervals and reduced doses may be required for pediatric patients older than 3 months of age with renal impairment.

A post hoc analysis of two Phase III trials showing the efficacy and tolerability of ceftobiprole in East Asian patients

Aim: To evaluate the efficacy and safety of ceftobiprole in patients from East Asia. Materials & methods: A post hoc analysis was conducted of two randomized, double-blind, Phase III studies in patients with community- or hospital-acquired pneumonia. Results: Findings for East Asian patients were consistent with the overall study populations. A trend toward higher microbiological eradication rates and numerically lower rates of all-cause mortality were reported for ceftobiprole versus comparators (all-cause mortality [intent-to-treat]: community-acquired pneumonia, 1.5 vs 2.8%; hospital-acquired pneumonia excluding ventilator-associated pneumonia, 5.9 vs 11.4%). The incidence of adverse events was similar between treatment groups. Conclusion: This post hoc analysis supports the efficacy and tolerability of ceftobiprole in East Asian patients. ClinicalTrials.gov trial identifiers: NCT00326287, NCT00210964, NCT00229008.

Clinical efficacy and safety of ceftobiprole in the treatment of acute bacterial skin and skin structure infection: a systematic review and meta-analysis of randomized controlled trials

Objectives: To investigate the clinical efficacy and safety of ceftobiprole for acute bacterial skin and skin structure infections (ABSSSIs).Methods: PubMed, Web of Science, EBSO, Ovid Medline, ClinicalTrial.gov and Cochrane Library were searched until 25 December 2020. Only randomized controlled trials that compared the treatment efficacy of ceftobiprole with that of other antibiotics for adult patients with ABSSSIs were included in this meta-analysis.Results: The 3 RCTs involving 2291 adult patients with ABSSSIs were included. No significant difference in clinical success, as measured by the TOC, was observed between ceftobiprole and comparators among the intention-to-treat population (OR, 1.06; 95% CI, 0.85-1.33; I² = 0%) and clinical evaluable population (OR, 1.17; 95% CI, 0.76-1.79; I² = 17%). Ceftobiprole was associated with a similar risk of adverse events (AEs) to that of comparators.Conclusions: Ceftobiprole can achieve similar clinical and microbiological responses as alternative antibiotics in patients with ABSSSIs. In addition, ceftobiprole shares a similar safety profile to comparators.

A Phase 3, Randomized, Investigator-blinded Trial Comparing Ceftobiprole With a Standard-of-care Cephalosporin, With or Without Vancomycin, for the Treatment of Pneumonia in Pediatric Patients

BACKGROUND

The advanced-generation, broad-spectrum, intravenous (IV) cephalosporin, ceftobiprole, is an effective and well-tolerated treatment for adults with hospital-acquired pneumonia (HAP) or community-acquired pneumonia (CAP), but its effects in pediatric patients have not been established.

METHODS

In this multicenter, investigator-blinded, active-controlled, phase 3 study, patients 3 months to <18 years old with HAP or CAP requiring hospitalization were randomized (2:1) to ceftobiprole versus standard-of-care (SoC) IV cephalosporin treatments (ceftazidime or ceftriaxone), with or without vancomycin. After at least 3 days' IV treatment, patients demonstrating clinical improvement could be switched to an oral antibiotic, to complete a minimum of 7 days' treatment.

RESULTS

Overall, 138 patients were randomized to ceftobiprole (n = 94) or a SoC cephalosporin (n = 44). Median time to oral switch was 6.0 days in the ceftobiprole group and 8.0 days in the SoC cephalosporin group. While on IV therapy, adverse events and treatment-related adverse events were reported by 20.2% and 8.5% of ceftobiprole-treated patients and 18.2% and 0% of SoC cephalosporin-treated patients. Early clinical response rates at day 4 in the intention-to-treat population were 95.7% and 93.2% (between-group difference, 2.6%; 95% confidence interval, -5.5% to 14.7%) in the ceftobiprole and comparator groups, and clinical cure rates at the test-of-cure visit were 90.4% and 97.7% (between-group difference, -7.3%; 95% confidence interval, -15.7% to 3.6%), respectively.

CONCLUSIONS

Ceftobiprole was well tolerated and, in this small phase 3 study, demonstrated similar efficacy to SoC cephalosporins in pediatric patients with HAP or CAP requiring hospitalization.

Efficacy and safety of ceftobiprole in patients aged 65 years or older: a post hoc analysis of three Phase III studies

Aim: To evaluate the efficacy and safety of ceftobiprole in patients aged ≥65 years. Materials & methods: We conducted a post hoc analysis of three randomized, double-blind, Phase III studies in patients with acute bacterial skin and skin structure infections, community-acquired pneumonia and hospital-acquired pneumonia. Results: Findings for patients aged ≥65 years (n = 633) were consistent with those for the overall study populations, although a trend toward improved outcomes was reported in some subgroups, for example, patients aged ≥75 years with community-acquired pneumonia were more likely to achieve an early clinical response with ceftobiprole than comparator (treatment difference 16.3% [95% CI:1.8-30.8]). The safety profile was similar between treatment groups in all studies. Conclusion: This analysis further supports the efficacy and safety of ceftobiprole in older patients with acute bacterial skin and skin structure infections or pneumonia. Clinicaltrials.gov trial identifiers: NCT03137173, NCT00326287, NCT00210964, NCT00229008.

Ceftobiprole Perspective: Current and Potential Future Indications

Ceftobiprole combines an excellent spectrum for community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) pathogens, with a low/medium MDR risk, and the β-lactams' safety in frail patients admitted to the hospital in internal medicine wards which may be at high risk of adverse events by anti-MRSA coverage as oxazolidinones or glycopeptides. We aimed to report the available evidence regarding ceftobiprole use in pneumonia and invasive bacterial infections, shedding light on ceftobiprole stewardship. The clinical application and real-life experiences of using ceftobiprole for bloodstream infections, including infective endocarditis, are limited but nevertheless promising. In addition, extended-spectrum ceftobiprole activity, including Enterococcus faecalis, Enterobacteriaceae, and Pseudomonas aeruginosa, has theoretical advantages for use as empirical therapy in bacteremia potentially caused by a broad spectrum of microorganisms, such as catheter-related bacteremia. In the future, the desirable approach to sepsis and severe infections will be administered to patients according to their clinical situation, the intrinsic host characteristics, the susceptibility profile, and local epidemiology, while the "universal antibiotic strategy" will no longer be adequate.

No Evidence for Ceftobiprole-Induced Immune Hemolytic Anemia in Three Phase 3 Clinical Trials

Purpose

Drug-induced immune hemolytic anemia (DIIHA) is a rare but serious adverse event associated with a number of drugs, including second- and third-generation cephalosporins. A positive direct antiglobulin test (DAT) is a reliable finding in DIIHA, but positive results without evidence of hemolysis can occur, particularly in hospitalized patients. There have been no reports of hemolytic anemia in four previous Phase 3 trials or from post-marketing surveillance of the advanced-generation, broad-spectrum cephalosporin, ceftobiprole. The aim of this analysis was to review the incidence of positive DAT results and any evidence of hemolytic anemia from three recent Phase 3 trials of ceftobiprole.

Patients and Methods

Patients were enrolled in three Phase 3 randomized controlled trials: 94 pediatric patients with pneumonia received ceftobiprole in the BPR-PIP-002 trial; 335 adults with acute bacterial skin and skin structure infections received ceftobiprole in the TARGET trial; and 201 adults with Staphylococcus aureus bacteremia have been randomized 1:1 to ceftobiprole or daptomycin ± aztreonam in the ongoing ERADICATE trial. In all three trials, DAT results were obtained at baseline, and follow-up tests were performed either at the test of cure (TOC) visit (BPR-PIP-002), end-of-treatment (EOT) visit (TARGET), or both EOT and post-treatment Day 70 visits (ERADICATE).

Results

In the BPR-PIP-002 trial, five patients (all ceftobiprole treated) had a documented negative DAT result at baseline followed by a positive result at the TOC visit. One patient in the ongoing, blinded ERADICATE trial had a positive DAT result at both baseline and EOT. Results from other laboratory investigations showed no evidence of hemolytic anemia in these patients. No positive DAT results were reported in the TARGET trial.

Conclusion

No evidence of hemolytic anemia associated with ceftobiprole was observed in either adults or children across several indications in this analysis of three large Phase 3 trials.