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

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.

Current state of the art in rapid diagnostics for antimicrobial resistance

Antimicrobial resistance (AMR) is a fundamental global concern analogous to climate change threatening both public health and global development progress. Infections caused by antimicrobial-resistant pathogens pose serious threats to healthcare and human capital. If the increasing rate of AMR is left uncontrolled, it is estimated that it will lead to 10 million deaths annually by 2050. This global epidemic of AMR necessitates radical interdisciplinary solutions to better detect antimicrobial susceptibility and manage infections. Rapid diagnostics that can identify antimicrobial-resistant pathogens to assist clinicians and health workers in initiating appropriate treatment are critical for antimicrobial stewardship. In this review, we summarize different technologies applied for the development of rapid diagnostics for AMR and antimicrobial susceptibility testing (AST). We briefly describe the single-cell technologies that were developed to hasten the AST of infectious pathogens. Then, the different types of genotypic and phenotypic techniques and the commercially available rapid diagnostics for AMR are discussed in detail. We conclude by addressing the potential of current rapid diagnostic systems being developed as point-of-care (POC) diagnostic tools and the challenges to adapt them at the POC level. Overall, this review provides an insight into the current status of rapid and POC diagnostic systems for AMR.

Baseline Characteristics and Outcomes Among Patients with Complicated Skin and Soft Tissue Infections Admitted to the Intensive Care Unit: Analysis of the Phase 3 COVERS Randomized Trial of Ceftaroline Fosamil Versus Vancomycin Plus Aztreonam

Aim

Exploratory analyses evaluated patient characteristics and outcomes among patients with complicated skin and soft tissue infection (cSSTI) in the phase 3 COVERS study who were admitted to an intensive care unit (ICU).

Methods

Adults with cSSTI (surface area ≥ 75 cm²) and evidence of systemic inflammation and/or underlying comorbidities were randomized 2:1 to intravenous ceftaroline fosamil (600 mg every 8 h [q8h]) or vancomycin (15 mg/kg every 12 h) plus aztreonam (1 g q8h) for 5–14 days. Clinical response and ICU length of stay (LOS) within first hospitalization were evaluated in the modified intent-to-treat (MITT) and clinically evaluable (CE) populations; a Cox proportional hazards model identified factors associated with increased hospital LOS.

Results

Overall, 42 of 761 randomized patients were admitted to the ICU (ceftaroline fosamil, n = 32; vancomycin plus aztreonam, n = 10) prior to, or at start of, study treatment. Baseline differences between the ICU and non-ICU populations were indicative of more severe disease in ICU patients; within this subset, there were also some notable imbalances between treatment groups. Clinical cure rates at test-of-cure (ceftaroline fosamil vs. vancomycin plus aztreonam) were generally similar in the non-ICU and ICU subsets (MITT population 79% vs. 79% and 69% vs. 90.0%, respectively; CE population 87% vs. 85% and 80% vs. 89%, respectively). Median ICU LOS was 8 vs. 13 days, respectively. ICU admission was a risk factor predicting increased hospital LOS (P < 0.001).

Conclusions

Clinical outcomes for patients admitted to the ICU were generally similar to non-ICU patients, despite more severe baseline disease, with shorter median treatment duration in the ceftaroline fosamil group. ICU admission was associated with longer hospital LOS. Given the small sample size and unbalanced patient and disease characteristics within the ICU subgroup, differences between treatment groups should be interpreted with caution.

Trial registration

ClinicalTrials.gov identifier, NCT01499277.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00297-3) contains supplementary material, which is available to authorized users.

New antibiotics for the treatment of infections by multidrug-resistant microorganisms

One of the current priorities of the World Health Organization is multidrug-resistant bacteria, because they are a global problem due to their rapid spread and the difficulty of their treatment. In addition, they are associated with high morbidity, mortality and high economic costs. There are multidrug-resistant bacteria, both Gram-positive and Gram-negative, including Pseudomonas aeruginosa and Acinetobacter baumannii resistant to carbapenems, enterobacteria producing carbapenemases, Staphylococcus aureus resistant to methicillin and/or with intermediate sensitivity to vancomycin, and Enterococcus faecium (and less frequently Enterococcus faecalis) resistant to vancomycin. This review will comment on the new antibiotics that have been incorporated into the therapeutic arsenal in recent years, as well as other promising antibiotics that are in their final stages of development.

Dalbavancin is a novel antimicrobial against Gram-positive pathogens: clinical experience beyond labelled indications

Very limited labelled indications have been approved for the newer antimicrobials. Data on the clinical uses, efficacy and safety of dalbavancin are scarce, thus here we sought to describe our clinical experience. 16-month observational prospective study was performed. 19 (86%) were used under off-label indications. 10 (46%) for osteoarticular infections, 5 (23%) bloodstream infections and 3 (14%) endocarditis. To highlight, one patient received dalbavancin as long-term suppressive therapy. Most frequent use reasons were promptly hospital discharge, 11 (65%), and the presence of resistant organisms involving limited treatment options, 5 (23%). Successful outcome was observed in >95% of the patients and only 1 (4.5%) adverse event was reported. Further evidence beyond labelled indications is urgently needed. Despite the limitations, dalbavancin appears to be a safe and efficient option for adult patients who have tried and/or failed other therapies due to multidrug-resistant Gram-positive organisms.

Antibiotic Classification and Indication Review for the Infusion Nurse

Outpatient parenteral antimicrobial therapy (OPAT) has become an increasingly common practice for the treatment of infections. The infusion nurse plays a vital role in administering, monitoring, and educating patients about parenteral antibiotics, while bridging communication between the patient and OPAT team. It is important for the infusion nurse to know common indications, adverse effects, monitoring parameters, and the mechanism of action for antibiotics used in OPAT to provide optimal patient care. This review includes those antibiotics, which are frequently administered or recently approved with a high likelihood of being used in OPAT.

Empiric Antibiotic Therapy of Nosocomial Bacterial Infections

Broad-spectrum antibiotics are commonly used by physicians to treat various infections. The source of infection and causative organisms are not always apparent during the initial evaluation of the patient, and antibiotics are often given empirically to patients with suspected sepsis. Fear of attempting cephalosporins and carbapenems in penicillin-allergic septic patients may result in significant decrease in the spectrum of antimicrobial coverage. Empiric antibiotic therapy should sufficiently cover all the suspected pathogens, guided by the bacteriologic susceptibilities of the medical center. It is important to understand the major pharmacokinetic properties of antibacterial agents for proper use and to minimize the development of resistance. In several septic patients, negative cultures do not exclude active infection and positive cultures may not represent the actual infection. This article will review the important differences in the spectrum of commonly used antibiotics for nosocomial bacterial infections with a particular emphasis on culture-negative sepsis and colonization.

Ceftobiprole- and ceftaroline-resistant methicillin-resistant Staphylococcus aureus

The role of mecA mutations in conferring resistance to ceftobiprole and ceftaroline, cephalosporins with anti-methicillin-resistant Staphylococcus aureus (MRSA) activity, was determined with MRSA strains COL and SF8300. The SF8300 ceftaroline-passaged mutant carried a single mecA mutation, E447K (E-to-K change at position 447), and expressed low-level resistance. This mutation in COL conferred high-level resistance to ceftobiprole but only low-level resistance to ceftaroline. The COL ceftaroline-passaged mutant, which expressed high-level resistance to ceftobiprole and ceftaroline, had mutations in pbp2, pbp4, and gdpP but not mecA.

Novel antibiotic treatment for skin and soft tissue infection

PURPOSE OF REVIEW

Acute bacterial skin and skin structure infection (ABSSSI) is a common and significant indication for antibiotic treatment. The microbial aetiology is becoming more resistant to available antibiotics and the treatment of patients is additionally challenged by extremes of age, obesity, diabetes and other co-morbidities. This review examines recent antimicrobial developments.

RECENT FINDINGS

In many parts of the world, multidrug-resistant (MDR) staphylococci are the predominant cause of ABSSSI in both the community and in hospital. Increasing resistance in Gram-negative organisms presents problems in the management of surgical-site infections. Most new antibiotics have been developed to treat MDR Gram-positive bacteria and there are few agents to treat infections caused by MDR Gram-negative pathogens.

SUMMARY

A number of novel agents are available clinically, with other agents of related chemical structure under development. There are no entirely new classes of antibiotics. Maintaining the efficacy of antimicrobial treatment require effective antibiotic stewardship, good infection prevention and the development of further new antibiotics.

Bacterial meningitis: new therapeutic approaches

Bacterial meningitis remains a disease with high mortality and long-term morbidity. Outcome critically depends on the rapid initiation of effective antibiotic therapy. Since a further increase of the incidence of pathogens resistant to antibacterials can be expected both in community-acquired and nosocomial bacterial meningitis, the choice of an optimum initial empirical antibiotic regimen will gain significance. In this context, the use of antibiotics which are bactericidal but do not lyse bacteria, may emerge as a therapeutic option. Conversely, the role of corticosteroids, which decrease the entry of hydrophilic antibacterials into the cerebrospinal fluid, as adjunctive therapy will probably decline as a consequence of the increasing antibiotic resistance of bacteria causing meningitis. Consequent vaccination of all children at present is the most efficient manner to reduce disease burden.

Antibiotics in the clinical pipeline in 2013

The continued emergence of multi-drug-resistant bacteria is a major public health concern. The identification and development of new antibiotics, especially those with new modes of action, is imperative to help treat these infections. This review lists the 22 new antibiotics launched since 2000 and details the two first-in-class antibiotics, fidaxomicin (1) and bedaquiline (2), launched in 2011 and 2012, respectively. The development status, mode of action, spectra of activity, historical discovery and origin of the drug pharmacophore (natural product, natural product derived, synthetic or protein/mammalian peptide) of the 49 compounds and 6 β-lactamase/β-lactam combinations in active clinical development are discussed, as well as compounds that have been discontinued from clinical development since 2011. New antibacterial pharmacophore templates are also reviewed and analyzed.

Ceftaroline fosamil: a review of its use in the treatment of complicated skin and soft tissue infections and community-acquired pneumonia

Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil (Zinforo, Teflaro), is an advanced-generation, parenteral cephalosporin with broad-spectrum antibacterial activity in vitro against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant Streptococcus pneumoniae and Gram-negative bacteria, including Haemophilus influenzae and Moraxella catarrhalis, but not Pseudomonas aeruginosa. Ceftaroline has demonstrated a low potential for the selection of resistance in vitro for drug-resistant Gram-positive organisms, including MRSA, as well as for Gram-negative respiratory pathogens. In pivotal phase III studies, intravenous ceftaroline fosamil demonstrated noninferiority to intravenous vancomycin plus aztreonam in patients hospitalized with complicated skin and soft tissue infections (cSSTIs) and intravenous ceftriaxone in patients hospitalized with community-acquired pneumonia (CAP) [Pneumonia Outcomes Research Team (PORT) risk class III or IV]; however, patients with CAP admitted to the intensive care unit were not evaluated. Ceftaroline fosamil was generally well tolerated in these trials, with an adverse event profile similar to that of other cephalosporins. Diarrhoea was the most commonly reported adverse event; however, the risk of Clostridium difficile-associated diarrhoea with ceftaroline fosamil appeared to be low. Potential limitations of the drug include the lack of an oral formulation and the requirement for twice-daily administration. Nonetheless, ceftaroline fosamil represents an attractive option (either alone or in combination with other agents) for the initial empirical treatment of patients hospitalized with cSSTIs (including those with suspected MRSA infection) or CAP (PORT risk class III or IV) who require intravenous antimicrobial therapy. As with all antibacterial agents, ceftaroline fosamil should be used in accordance with good antimicrobial stewardship.