Pharmacokinetics, Safety, and Tolerability of a Single 500-mg or 1000-mg Intravenous Dose of Dalbavancin in Healthy Japanese Subjects

New Antibiotics for Staphylococcus aureus Infection: An Update from the World Association of Infectious Diseases and Immunological Disorders (WAidid) and the Italian Society of Anti-Infective Therapy (SITA)

Staphylococcus aureus is an extremely virulent pathogen that is capable of quickly evolving and developing antibiotic resistance. To overcome this problem, new antibiotics have been developed. Some of these have been licenced for use in clinical practice, mainly for the treatment of adults with acute skin and soft tissue infections, in addition to both community-acquired pneumonia (CAP) and nosocomial pneumonia (hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia). In this paper, the main characteristics and clinical use of new licenced anti-staphylococcal drugs have been discussed. In vitro studies have demonstrated that some new anti-staphylococcal antibiotics have better antimicrobial activity and, at least in certain cases, more favourable pharmacokinetic properties and higher safety and tolerability than the presently available anti-staphylococcal drugs. This suggests that they may have a potential use in reducing the risk of failure of S. aureus therapy. However, an in-depth analysis of microbiological and clinical studies carried out with these new drugs seems to indicate that further studies need to be conducted before the problem of resistance of S. aureus to the antibiotics available today can be completely solved. Considering the overall available research, the drugs that are active against S. aureus appear to present a great therapeutic opportunity for overcoming resistance to traditional therapy. There are advantages in the pharmacokinetic characteristics of some of these drugs and they have the potential to reduce hospital stays and economic costs associated with their use.

Dalbavancin in the treatment of acute bacterial skin and skin structure and other infections: a safety evaluation

INTRODUCTION

Dalbavancin is a second-generation lipoglycopeptide that was approved since 2014 to treat acute bacterial skin and skin-structure infections (ABSSSI). Dalbavancin is characterized by Gram-positive activity and novel pharmacokinetic properties that result in a prolonged terminal half-life, allowing once weekly dosing in adults. A good safety profile was reported by randomized clinical trials and meta-analyses.

AREAS COVERED

Dalbavancin safety and tolerability data from trials and post-marketing studies were reviewed. While most trials included predominantly ABSSSI, 2 clinical trials and recent observational studies have explored the use of dalbavancin for off-label indications, mainly including bloodstream and osteoarticular infections.

EXPERT OPINION

The occurrence of drug-related adverse effects (AE) was similar between dalbavancin and comparators in clinical trials enrolling patients with ABSSSI. Most common AE included gastrointestinal symptoms, infusion reaction, and hypersensitivity. Low rates of drug discontinuation and serious AE were reported across studies. In the past 5 years, several observational studies have reported safety data on the use of dalbavancin, confirming its favorable safety profile. Nevertheless, data from dalbavancin off-label use often derived from prolonged (> 2 weeks) treatments with variable dosing regimens, were mainly retrospective, and lacked comparators. Further research is required to allow a reliable analysis of short- and long-term dalbavancin-related AE in non-ABSSSI.

Clinical Pharmacokinetics and Pharmacodynamics of Dalbavancin

Dalbavancin is a synthetic lipoglycopeptide that exerts its antimicrobial activity through two distinct modes of action, inhibition of cell wall synthesis and an anchoring mechanism. Compared with previous glycopeptide antibiotics, dalbavancin demonstrates improved antibacterial potency against Gram-positive organisms and a long half-life of approximately 1 week, which is longer in tissues (e.g., skin, bone) than plasma. These factors facilitated the development of single-dose or once-weekly dosing regimens to treat acute bacterial skin and skin structure infections (ABSSSI). Dalbavancin exhibits dose-proportional pharmacokinetics and is highly protein bound (93%). Despite being highly protein bound, it has a steady-state volume of distribution >10 L and distributes widely into the skin, bone, peritoneal space, and epithelial lining fluid, but not cerebrospinal fluid. Dalbavancin elimination occurs via a combination of renal (approximately 45%) and non-renal clearance, with dose adjustments recommended only in patients with a creatinine clearance <30 mL/min not receiving any form of dialysis. The established pharmacokinetic/pharmacodynamic index associated with bacterial kill is free area under the concentration-time curve over the minimum inhibitory concentration (fAUC/MIC), with a goal 24-h fAUC/MIC of at least 27.1 for Staphylococcus aureus infections. Recent data suggest usefulness in the treatment of infections beyond ABSSSI, with convenient dosing and redosing strategies for complicated infections requiring extended treatment durations. Additional studies are needed to confirm these preliminary findings.

Long-Acting Lipoglycopeptides Can Interfere With Vancomycin Therapeutic Drug Monitoring

Oritavancin and dalbavancin are long-acting lipoglycopeptides with activity against susceptible gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Though similar in structure to traditional glycopeptide antibiotics like vancomycin, these antibiotics have terminal half-lives >10 days, and, as a result, there is potential for administration of vancomycin to a patient while oritavancin or dalbavancin are still appreciably present in serum. Given the structural similarities, this creates an opportunity for lab assay interference when performing therapeutic drug monitoring for vancomycin. Following higher-than-expected serum vancomycin concentrations in a patient who received both oritavancin and vancomycin within a short time frame, we evaluated the potential for lipoglycopeptide interference with clinical vancomycin assays. Five platforms covering 3 immunoassay technologies were used to quantify vancomycin concentrations in serum spiked with oritavancin or dalbavancin. Oritavancin generated spurious vancomycin concentrations (20%-84% increase) in both enzyme-multiplied immunoassay technique and a particle-enhanced turbidimetric inhibition immunoassay. However, the improper detection of oritavancin was not consistent across all particle-enhanced turbidimetric inhibition immunoassay platforms. Dalbavancin interference was not detected on any of the platforms tested. The interference from oritavancin may result in falsely elevated vancomycin concentrations and, subsequently, inappropriately adjusted vancomycin doses.

Therapeutic Drug Monitoring of Dalbavancin Treatment in Severe Necrotizing Fasciitis in 3 Critically Ill Patients: A Grand Round

BACKGROUND

Dalbavancin, albeit indicated for the treatment of skin structure infections, is used for a much wider range of infections. This drug is characterized by a long half-life (more than 200 hours), a favorable safety profile, and an activity against a wide array of gram-positive organisms, including several strains of Staphylococci and Enterococci.

METHODS

In this study, we presented 3 cases of critically ill patients treated with dalbavancin. All patients were therapeutically monitored for plasma dalbavancin concentrations; ultrafiltrate dalbavancin concentrations were assessed in a patient undergoing continuous renal-replacement therapy. Dalbavancin concentrations were measured using a validated liquid chromatographic method coupled with mass spectrometry.

RESULTS

All 3 severely ill patients experiencing necrotizing fasciitis were successfully treated during the acute phase with dalbavancin. Dalbavancin clearance in patient 3 (0.334 L/h) was considerably increased compared with values measured in the other 2 patients (0.054 and 0.075 L/h) and with data reported in the literature (0.04-0.06 L/h).

CONCLUSIONS

Our case reports presented preliminary evidence that dalbavancin can be considered a therapeutic option for necrotizing fasciitis in intensive care unit patients. The role of hypoalbuminemia during dalbavancin exposure merits further investigation.

Dalbavancin Efficacy and Impact on Hospital Length-of-Stay and Treatment Costs in Different Gram-Positive Bacterial Infections

Background and Objectives

The study aimed to evaluate the impact of dalbavancin therapy on both hospital length-of-stay (LOS) and treatment-related costs, as well as to describe the clinical outcome, in a retrospective cohort of patients with diverse Gram-positive bacterial infections, hospitalized in different specialty Units.

Methods

From July 2017 to July 2019, clinical and sociodemographic data were collected for all hospitalized patients switched to dalbavancin for the treatment of Gram-positive infections. LOS and treatment-related costs were assessed and compared to a hypothetical scenario where the initial standard antimicrobial therapy would have been administered in hospital for the same duration as dalbavancin.

Results

A total of 50 patients were enrolled. The observed infections were: acute bacterial skin and skin structure infections (ABSSSIs, 12 patients), complicated ABSSSIs (eight patients), osteoarticular infections (18 patients), vascular graft or cardiovascular implantable electronic devices (CIED) infections (12 patients). After a median of 14 [interquartile range (IQR) 7–28] days, the in-hospital antimicrobial therapy was switched to dalbavancin 1500 mg. When appropriate, considering the site and the clinical course of the infection, 1500 mg doses were repeated every 14 days until recovery. Overall, 49/50 (98%) patients reported clinical success at the end of therapy. No relapses were observed in 37 patients for whom a median follow-up of 150 (IQR 30–180) days was available. By switching to dalbavancin, a median of €8,259 (IQR 5644–17,270) and 14 hospital days (IQR 22–47) per patient were saved.

Conclusions

In this experience, the use of dalbavancin contributed to shorten LOS and treatment-related costs, especially in difficult Gram-positive infections requiring prolonged therapy.

Clinical Pharmacokinetics and Pharmacodynamics of Telavancin Compared with the Other Glycopeptides

Telavancin was discovered by modifying the chemical structure of vancomycin and belongs to the group of lipoglycopeptides. It employs its antimicrobial potential through two distinct mechanisms of action: inhibition of bacterial cell wall synthesis and induction of bacterial membrane depolarization and permeabilization. In this article we review the clinically relevant pharmacokinetic and pharmacodynamic data of telavancin. For comparison, the pharmacokinetic and pharmacodynamic data of the other glycopeptides are presented. Although, in contrast to the newer lipoglycopeptides, telavancin demonstrates a relatively short half-life and rapid total clearance, its apparent volume of distribution (V_d) is almost identical to that of dalbavancin. The accumulation of telavancin after repeated dosing is only marginal, whereas the pharmacokinetic values of the other glycopeptides show much greater differences after administration of multiple doses. Despite its high plasma-protein binding of 90% and relatively low V_d of approximately 11 L, telavancin shows near complete equilibration of the free fraction in plasma with soft tissue. The ratio of the area under the plasma concentration-time curve from time zero to 24 h (AUC₂₄) of unbound plasma concentrations to the minimal inhibitory concentration (MIC) required to inhibit growth of 90% of organisms (MIC₉₀) of Staphylococcus aureus and S. epidermidis of telavancin are sufficiently high to achieve pharmacokinetic/pharmacodynamic targets indicative for optimal bacterial killing. Considering both the AUC₂₄/MIC ratios of telavancin and the near complete equilibration of the free fraction in plasma with soft tissue, telavancin is an appropriate antimicrobial agent to treat soft tissue infections caused by Gram-positive pathogens. Although the penetration of telavancin into epithelial lining fluid (ELF) requires further investigations, the AUC₂₄/MIC ratio for S. aureus indicates that bactericidal activity in the ELF could be expected.

The role of dalbavancin in skin and soft tissue infections

PURPOSE OF REVIEW

The increase of skin and soft tissue infections (SSTIs) represents a major concern both in community and in the hospital setting. Staphylococcus aureus is the most frequently isolated pathogen, and the rise in infections due to methicillin-resistant Staphylococcus aureus (MRSA) has been associated with inadequate antibiotic treatment and increased morbidity.

RECENT FINDINGS

A number of new antimicrobials with activity against drug-resistant Gram-positive pathogens, including MRSA, have been recently approved for the treatment of SSTIs. New lipoglycopeptides, in particular dalbavancin, are long-acting antibiotics with potential for infrequent administration, offering the possibility for outpatient treatment and early hospital discharge.

SUMMARY

Dalbavancin is a new lipoglycopeptide showing high activity against Gram-positive bacteria, including drug-resistant strains. Dalbavancin presents a distinctive pharmacokinetic profile with a terminal prolonged half-life of approximately 14 days. This characteristic allows once-weekly dosing interval, avoiding the need for daily dosing and offering an advantage over other compounds for potential use in the outpatient setting or to promote early hospital discharge. Dalbavancin has a favorable adverse effect profile and appears to be a promising new alternative for treatment of SSTIs. We have reviewed the pharmacokinetic properties of dalbavancin and the clinical evidence for its use in complicated SSTIs and other potential applications.

Kinetic simulation method of C-reactive protein in beagle dogs during acute inflammation

The half-life ( t1/2) of C-reactive protein (CRP) and its ability to stimulate weak inflammatory responses were investigated in beagle dogs. Four beagle dogs were administered 20 mg/kg indomethacin and blood was collected from the cephalic vein pre-dosing and at 24, 48, 72, 96, 144, 192, 240, 312, and 360 h post-administration. The serum concentrations of CRP were measured by enzyme-linked immunosorbent assay. The serum t1/2 was calculated using the equation 0.693/elimination rate constant. The serum concentration of CRP beyond 192 h post-administration declined to levels in the normal range. The t1/2 was 148.3 h, which is considered to be the essential t1/2 of CRP. The simulation of CRP serum concentrations at arbitrary times using the elimination rate constant obtained in this study became possible.

Single-Dose Dalbavancin: A Review in Acute Bacterial Skin and Skin Structure Infections

Intravenous dalbavancin (Dalvance^®, Xydalba^®), first approved as a two-dose regimen for the treatment of acute bacterial skin and skin structure infections (ABSSSI), has now been additionally approved as a single-dose regimen. This narrative review discusses the pharmacological properties of intravenous dalbavancin and its clinical efficacy and tolerability as a single-dose regimen in the treatment of adult patients with ABSSSI. Single-dose dalbavancin is an effective and generally well tolerated treatment option for adults with ABSSSI, with noninferior efficacy to the two-dose dalbavancin regimen with regard to early clinical response (at 48-72 h) and low rates of adverse events. Clinical success rates at days 14 and 28 also did not significantly differ between the single- and two-dose dalbavancin regimens; neither did clinical success rates at day 14 when analysed by baseline pathogen. It has a broad spectrum of activity against common ABSSSI-related pathogens, and a favourable pharmacokinetic profile allowing for the convenience of single-dose administration. Thus, dalbavancin presents a promising alternative to conventional antibacterials for the treatment of ABSSSI in adult patients.

Diagnosis and management of skin and soft-tissue infections (SSTI). A literature review and consensus statement: an update

Skin and soft-tissue infections (SSTIs) are among the most common bacterial infections, posing considerable diagnostic and therapeutic challenges. Fourteen members of the Italian Society of Infectious Diseases, after a careful review of the most recent literature using Medline database and their own clinical experience, updated a previous paper published in 2011 by preparing a draught manuscript of the statements. The manuscript was successively reviewed by all members and ultimately re-formulated the present manuscript during a full day consensus meeting. The microbiological and clinical aspects together with diagnostic features were considered for necrotizing and not necrotizing SSTIs in the light of the most recent guidelines and evidences published in the last five years. The antimicrobial therapy was considered as well - both empirical and targeted to methicillin-resistant Staphylococcus aureus and/or other pathogens, also taking into account the epidemiological and bacterial resistance data and the availability of new antibacterial agents.