Population Pharmacokinetic Analysis of Dalbavancin, a Novel Lipoglycopeptide

Dalbavancin for prosthetic joint infections: Empirical treatment

OBJECTIVES

Bone and joint infections are complex and require a long course of antibiotics. Dalbavancin is a long half-life lipoglycopeptide, only indicated for skin and soft tissue infections. Studies on bone and joint diffusion are promising. The objective of this study was to evaluate the efficacy and safety of dalbavancin in combination with piperacillin-tazobactam for intra-operative treatment of knee or hip prosthetic joint infections.

PATIENTS AND METHODS

This retrospective and bicentric study was conducted between 2018 and 2022 and included 56 patients. The criteria used to diagnose prosthetic joint infections were those established in 2011 by the MusculoSkeletal Infection Society (MSIS), modified in 2013 at the International Consensus Meeting on Periprosthetic Joint Infections. The efficacy endpoint was the absence of relapse during the two-year follow-up period.

RESULTS

Gram-positive cocci infections were the most common. All Gram-positive bacteria were susceptible to dalbavancin. The cure rate at two years was 91.5%. Only four patients experienced treatment failure. Few adverse events were reported, mainly digestive ones (diarrhea and pain).

CONCLUSION

This study provides data outside of the marketing authorization, while respecting the authorized dosage in a population of patients with clearly defined inclusion criteria and a two-year follow-up.

Multidose Dalbavancin Population Pharmacokinetic Analysis for Prolonged Target Attainment in Patients Requiring Long-Term Treatment

Introduction: Dalbavancin (DAL) is a long-acting lipoglycopeptide active against Gram-positive bacteria, including multidrug-resistant isolates. A growing body of evidence supports its efficacy in various difficult-to-treat infections. DAL shows time-dependent bactericidal activity in vitro at free drug concentrations equal to 4×MIC values. However, the optimal dosing scheme for achieving the PK/PD target in multidose treatment has not been fully established. Methods: Pharmacokinetic analysis was based on a nonlinear mixed effects modelling approach performed in NONMEM v7.5/Pirana, while R was used for data management and graphical summaries. Final model parameters were used to simulate the plasma disposition of DAL by Monte Carlo simulations to determine the multidose DAL regimen associated with a 90% target attainment of 100% fT > 4×MIC. Results: A two-compartmental model with first-order elimination and allometric-scaled bodyweight best described DAL disposition in patients with CLcr > 30 mL/min. Monte Carlo simulations showed that two 1500 mg DAL doses 7 days apart granted an optimal PTA > 90% of 100% fT > 4×MIC up to 5, 4, and 3 weeks in patients weighting from 40-80 kg, 80-120 kg and 120-200 kg, respectively. An additional third 1500 mg dose at the above time points by weight bands may extend the optimal PTA up to 9, 7, and 6 weeks of total treatment. Conclusions: Two 1500 mg DAL doses administered 7 days apart could be a valuable starting strategy for patients of all weight classes with CLcr > 30 mL/min. In patients requiring long-term DAL treatment, the optimal timing of additional administrations should be guided by routine TDM or empirically through patients' total body weight when TDM is unavailable.

Dalbavancin as sequential therapy in infective endocarditis: Real-life experience in elder and comorbid patients

OBJECTIVES

This study aimed to evaluate the effectiveness of dalbavancin as sequential therapy in patients with infective endocarditis (IE) due to gram positive bacteria (GPB) in a real-life heterogenous cohort with comorbid patients.

METHODS

A single center retrospective cohort study including all patients with definite IE treated with dalbavancin between January 2017 and February 2022 was developed. A 6-month follow-up was performed. The main outcomes were clinical cure rate, clinical and microbiological relapse, 6-month mortality, and adverse effects (AEs) rate.

RESULTS

The study included 61 IE episodes. The median age was 78.5 years (interquartile range [IQR] 63.2-85.2), 78.7% were male, with a median Charlson comorbidity index of 7 (IQR 4-9) points. Overall, 49.2% suffered native valve IE. The most common microorganism was Staphylococcus aureus (26.3%) followed by Enterococcus faecalis (21.3%). The median duration of initial antimicrobial therapy and dalbavancin therapy were 27 (IQR 20-34) and 14 days (IQR 14-28) respectively. The total reduction of hospitalization was 1090 days. The most frequent dosage was 1500mg of dalbavancin every 14 days (96.7%). An AE was detected in 8.2% of patients, only one (1.6%) was attributed to dalbavancin (infusion reaction). Clinical cure was achieved in 86.9% of patients. One patient (1.6%) with Enterococcus faecalis IE suffered relapse. The 6-month mortality was 11.5%, with only one IE-related death (1.6%).

CONCLUSION

This study shows a high efficacy of dalbavancin in a heterogeneous real-world cohort of IE patients, with an excellent safety profile. Dalbavancin allowed a substantial reduction of in-hospital length of stay.

Bridging the Gap: A Systematic Review with Expert Opinion on the Use of Dalbavancin for In-Label and Off-Label Indications in Pediatric Patients

OBJECTIVES

The aim of this work was to perform a systematic review assessing the pharmacokinetic/pharmacodynamic (PK/PD) properties of dalbavancin and the clinical use for in-label and off-label indications in pediatric patients.

METHODS

Two authors independently searched the PubMed-MEDLINE and Scopus databases and clinicaltrials.gov up to 20 November 2024, to retrieve randomized controlled trials (RCTs), observational studies, PK studies, and case series/reports assessing dalbavancin PK/PD properties or the clinical use for both in-label and off-label indications in pediatric patients. Data were independently extracted by the two authors, and the quality of the included studies was independently assessed by means of specific tools according to study design. Clinical success was selected as the primary outcome. Descriptive statistics were used for summarizing the retrieved data. Subgroup analysis according to PK/PD data, as well as in-label and off-label indications, was performed.

RESULTS

After screening 206 articles, nine studies were included in the systematic review (one RCT, three PK studies, and five case series/reports; n = 267). Dalbavancin exposure was 30% lower in pediatric patients compared to adults. In acute bacterial skin and skin structure infections (ABSSSIs), the overall clinical success of dalbavancin was 96.1-97.3% and 92.9% in RCT and case series, respectively. Bone and joint infections (60.7%) and central-line-associated bloodstream infections (14.3%) represented the most common dalbavancin off-label indications in pediatric patients. Overall, the clinical success for off-label indications was 92.9%. The rate of adverse events ranged from 7.1% to 10.7%.

CONCLUSIONS

Our systematic review summarized evidence concerning the PK/PD properties of dalbavancin and its use for in-label or off-label indications in pediatric patients. The available findings suggest that dalbavancin may be a valuable alternative for the management of ABSSSIs and/or off-label indications in pediatric patients according to efficacy and safety data, allowing for a potential minimized duration of hospital stay.

Using Dalbavancin for the Treatment of Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) in Obese Patients: A Real-Life, Single-Center Observational Study

Background/Objectives: Obesity is an established risk factor for several infective conditions, including Acute Bacterial Skin and Skin Structure Infections (ABSSSIs), with a rising trend in their incidence expected in this population. Although numerous antibiotics are available for the prevention and treatment of ABSSSIs, their characterization in obese patients is not a regulatory mandate, highlighting a knowledge gap in this field. Dalbavancin (DAL) is the first approved long-acting antibiotic for the treatment of ABSSSIs. The aim of the study was to describe the clinical effectiveness of DAL in the treatment of ABSSSI, with or without concomitant osteoarticular infections (OAIs), in obese patients compared with non-obese patients. Furthermore, we compared the effectiveness of DAL and intravenous standard of care (SOC) regimens in a subgroup of obese patients with ABSSSI. Results: Overall, 45 subjects treated with DAL (12 obese and 33 non-obese) and 8 obese subjects treated with SOC regimens (1:1 ratio) were included. Obese patients treated with DAL had a similar clinical resolution to non-obese patients. However, obese patients tended to have a better cure rate in ABSSSI than OAI. The subgroup of obese patients with ABSSSI had a high clinical resolution, which was comparable to that of SOC. DAL was overall highly tolerated in obese patients. Methods: Over a three-year period, hospitalized subjects with ABSSSI who were treated with DAL were included. Patients were further divided into two groups according to the presence/absence of obesity (BMI ≥ 30 kg/m2). Furthermore, obese patients treated with DAL were compared with obese patients treated with SOC (1:1 ratio). Conclusions: In our real-world study, DAL confirmed its high effectiveness in the treatment of ABSSSI, including in a difficult-to-treat population such as obese patients.

Model-Based Dose Identification of Dalbavancin for Long-Term Suppressive Outpatient Treatment of Ventricular Assist Device Infections

Increasing evidence suggests that dalbavancin is an effective long-term treatment for ventricular assist device (VAD) infections, with various prolonged dosing regimens currently in use. This retrospective study aimed to assess dalbavancin pharmacokinetics in VAD patients and identify optimal, feasible dosing regimens for long-term suppressive outpatient therapy. Data from Heidelberg University Hospital's VAD register were analyzed using non-linear mixed-effects modeling for pharmacokinetic analysis and dosing simulations (Lixoft®). The probability of target attainment (PTA) and cumulative fraction of response (CFR) were calculated for different protein-binding scenarios considering the minimum inhibitory concentration (MIC) distribution of Staphylococcus aureus. Using data from 13 patients with 38 blood samples, a two-compartment model best described the dalbavancin pharmacokinetics, with a typical value for clearance of 0.050 L/h, central volume of distribution of 6.5 L, and peripheral volume of 15.4 L. No covariates significantly improved the model fit. The observed protein binding varied between 96 and 98%. Dosing simulations demonstrated that 1500 mg every 3 weeks ensured the target attainment for stasis at MIC values of 0.125 mg/L (PTA ≥ 90%) up to a protein binding of 99%. Considering the CRF, longer dosing intervals up to 5 weeks might be possible. Depending on individual MICs and protein binding, a dalbavancin regimen of 1500 mg every 3 to 5 weeks therefore appears to be a valuable option for outpatient therapy of VAD infections. Therapeutic drug monitoring should be considered to manage inter-individual variability and to support clinicians in long-term treatments of subacute and chronic infections.

Safety and Efficacy of Dalbavancin in Real Life: Retrospective Analysis of a Large Monocentric Case Series of Patients Treated for Skin/Soft Tissue and Other Difficult-to-Treat Infections

Background: Dalbavancin is a long-acting lipoglycopeptide, approved for treatment of skin and skin structure infections. Its PK/PD profile and safety allow for short hospital stays even in the case of difficult-to-treat infections requiring long courses of therapy, e.g., osteomyelitis, cardiovascular, and prosthetic infections. Objectives: We aimed to evaluate the safety and efficacy of dalbavancin in real life settings for both in-label and off-label indications. Methods: retrospective evaluation of all consecutive patients treated with dalbavancin at our site between May 2017 and September 2021. Results: A total of 100 patients treated with dalbavancin and followed up for 6 months after treatment (58% male; median age 63.5 years, median Charlson Comorbidity Index CCI = 2.7, 28% inpatients) were included with the following indications: acute bacterial skin and skin structure infections (22%), bone and prosthetic infections (57%), and cardiovascular infections (19%). Infections were caused by MSSA (30%), MRSA (5%), MR-CoNS (20%), and Streptococcus spp. (8%). In 32 cases, no isolate was obtained. The average number of infusions was 5 (s.d. = 3). Neither ensuing alteration of renal function nor neutropenia or thrombocytopenia were observed during treatment and follow-up. Two self-limiting skin rashes occurred. The overall clinical success rate was 84%-91% for registered and 82% for unregistered indications. The prescription of higher loading doses was the only predictor independently associated with better outcomes in multivariate models (OR: 5.2, 95%CI: 1.5-17.9, p < 0.01). Conclusions: Dalbavancin proved to be effective for skin and skin structure infections, as well as for difficult-to-treat infections in highly comorbid patients. Regarding tolerability, our results support the use of dalbavancin for long-lasting treatments of deep-seated infections.

Population Pharmacokinetics and Pharmacodynamics of Dalbavancin and C-Reactive Protein in Patients with Staphylococcal Osteoarticular Infections

BACKGROUND AND OBJECTIVE

Dalbavancin is increasingly used for the long-term treatment of chronic osteoarticular infections. A population pharmacokinetic/pharmacodynamic (PK/PD) analysis for assessing the relationship between dalbavancin exposure and C-reactive protein (C-RP) over time was conducted.

METHODS

Non-linear mixed-effect modeling was fitted to dalbavancin and C-RP concentrations. Monte Carlo simulations assessed the weekly percentage of C-RP reduction associated with different dosing regimens, starting from baseline to < 1 mg/dL.

RESULTS

A total of 45 patients were retrospectively included in the analysis. The PK of dalbavancin was described by a two-compartment model, and the PD of C-RP was described by an indirect turnover maximum inhibition model. The total dalbavancin concentration model estimate producing 50% of maximum C-RP production inhibition (IC50) was 0.70 mg/L. Monte Carlo simulations showed that in patients with staphylococcal osteoarticular infections targeting total dalbavancin concentrations at > 14.5 mg/L at any time point may achieve C-RP production inhibition over time in > 95% of patients. Based on this, the findings showed that a cumulative dose of 3000 mg administered in the first 3 weeks may lead to a > 90% C-RP decrease versus baseline in approximately 5-6 weeks. In patients needing treatment prolongation, an additional 1500 mg dose after this period may maintain C-RP concentrations < 1 mg/dL for other 3 weeks.

CONCLUSIONS

A decrease in C-RP is related to dalbavancin exposure in osteoarticular infections. Targeting dalbavancin plasma concentrations above the efficacy threshold may be associated with effective treatment.

Dalbavancin plasma concentrations in 133 patients: a PK/PD observational study

OBJECTIVES

Limited pharmacokinetics data support dalbavancin long-term use in off-label indications and the optimal dosing regimen is debated. We aimed to describe dalbavancin concentrations in an observational retrospective multicentre study.

METHODS

Patients from 13 French hospitals, treated with 1500 mg doses of dalbavancin and for whom therapeutic drug monitoring was performed from June 2018 to March 2021 were included. Dalbavancin plasma concentrations were described at peak and 1, 2, 3, 4, 6 and 8 weeks after the last 1500 mg dose. Concentrations in patients weighing more or less than 75 kg and with a GFR greater or less than 60 mL/min were compared. Microbiological data were collected and dalbavancin MIC was measured when possible.

RESULTS

One hundred and thirty-three patients were included (69% treated for bone and joint infections, 16% for endocarditis). Thirty-five patients received a single dose of dalbavancin and 98 received several administrations. Two, 3 and 4 weeks after the last dose, median plasma concentrations were respectively 25.00, 14.80 and 9.24 mg/L for the first doses and 34.55, 22.60 and 19.20 mg/L for the second or subsequent doses. Weight and renal function had an impact on pharmacokinetics. Infection was documented in 105 patients (Staphylococcus spp. in 68% of cases). Staphylococcus aureus was isolated in 32.5% of cases (median MIC: 0.047 mg/L) and Staphylococcus epidermidis in 27% of cases (median MIC of 0.047 mg/L).

CONCLUSIONS

Plasma concentrations of dalbavancin were consistent with those described in clinical trials and those sought during the industrial development of the molecule.

Long-Term Suppressive Therapeutic-Drug-Monitoring-Guided Dalbavancin Therapy for Cardiovascular Prosthetic Infections

Dalbavancin represents a promising treatment for cardiovascular prosthetic infections due to its prolonged half-life, bactericidal activity, large spectrum of activity, and excellent biofilm penetration. However, the use of dalbavancin in this setting is limited, and only a few cases have performed therapeutic drug monitoring (TDM) analysis to optimize dosage in suppressive treatments longer than 4 weeks. Our retrospective case series reports the use of dalbavancin in a small cohort of patients with cardiovascular prosthetic infections (cardiac implantable electronic device infections (CEDIs), prosthetic valve endocarditis (PVE), prosthetic vascular graft infections (PVGIs)) treated with dalbavancin as sequential therapy. From May 2019 to May 2023, 14 patients were included: eight cases of PVE (57.1%), seven cases of PVGI (50%), three cases of CEDI (21.4%), and four cases with overlap of infection sites (28.6%). The main pathogen was Staphylococcus aureus (35.7%). Prosthesis replacement was obtained in four patients (28.6%). The median time between symptom onset and the end of treatment was 15 weeks (IQR 7-53), with a median duration of dalbavancin therapy of 8 weeks (IQR 1 to 45 weeks) and 3.5 doses per patient. Among patients managed with TDM-guided strategy, dalbavancin infusion intervals ranged from 4 to 9 weeks. The median length of follow-up was 65 weeks (IQR 23 to 144 weeks). Clinical success was achieved in 10 cases (76.9%); all clinical failures occurred in patients with the implant retained. Among patients monitored by TDM, clinical success was 87.5% vs. 60% in patients treated without TDM. Because of pharmacokinetic individual variability, dalbavancin TDM-guided administration could improve clinical outcomes by individualizing dosing and selecting dosing intervals. This case series seems to suggest a promising role of long-term suppressive dalbavancin treatment for difficult-to-treat cardiovascular prosthesis infection, also with limited surgical indications.

Systematic Review and Meta-Analysis of the Effect of Loop Diuretics on Antibiotic Pharmacokinetics

Loop diuretics and antibiotics are commonly co-prescribed across many clinical care settings. Loop diuretics may alter antibiotic pharmacokinetics (PK) via several potential drug interactions. A systematic review of the literature was performed to investigate the impact of loop diuretics on antibiotic PK. The primary outcome metric was the ratio of means (ROM) of antibiotic PK parameters such as area under the curve (AUC) and volume of distribution (V_d) on and off loop diuretics. Twelve crossover studies were amenable for metanalysis. Coadministration of diuretics was associated with a mean 17% increase in plasma antibiotic AUC (ROM 1.17, 95% CI 1.09-1.25, I² = 0%) and a mean decrease in antibiotic V_d by 11% (ROM 0.89, 95% CI 0.81-0.97, I² = 0%). However, the half-life was not significantly different (ROM 1.06, 95% CI 0.99-1.13, I² = 26%). The remaining 13 observational and population PK studies were heterogeneous in design and population, as well as prone to bias. No large trends were collectively observed in these studies. There is currently not enough evidence to support antibiotic dosing changes based on the presence or absence of loop diuretics alone. Further studies designed and powered to detect the effect of loop diuretics on antibiotic PK are warranted in applicable patient populations.

Dalbavancin as sequential therapy for infective endocarditis due to Gram-positive organisms: a review

Dalbavancin is a parenteral lipoglycopeptide antibiotic derived from teicoplanin, an analogue of vancomycin. It is mainly used for skin and soft tissue infections. The sustained half-life of approximately 14 days makes dalbavancin a novel option for potential use as sequential treatment in infections such as infective endocarditis, which require prolonged antibiotic courses. However, only a few studies have been reported in the literature, and the use of dalbavancin remains limited. This article is a review of the currently available literature using dalbavancin for the treatment of infective endocarditis due to Gram-positive organisms. Almost all patients received dalbavancin as sequential therapy following standard-of-care antibiotics. The overall clinical efficacy of dalbavancin was approximately 90%, and it appeared to be well tolerated.

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.

Population Pharmacokinetic and Pharmacodynamic Analysis of Dalbavancin for Long-Term Treatment of Subacute and/or Chronic Infectious Diseases: The Major Role of Therapeutic Drug Monitoring

A population pharmacokinetic analysis of dalbavancin was conducted in patients with different infection sites. Non-linear mixed effect modeling was used for pharmacokinetic analysis and covariate evaluation. Monte Carlo simulations assessed the probability of target attainment (PTA) of total dalbavancin concentration ≥ 8.04 mg/L over time (associated with ≥90% probability of optimal pharmacodynamic target attainment of fAUC24h/MIC > 111.1 against S. aureus) associated with a single or double dosage, one week apart, of 1000 or 1500 mg in patients with different classes of renal function. Sixty-nine patients with 289 concentrations were included. Most of them (53/69, 76.8%) had bone and joint infections. A two-compartment model adequately fitted dalbavancin concentration−time data. Creatinine clearance (CLCR) was the only covariate associated with dalbavancin clearance. Monte Carlo simulations showed that, in patients with severe renal dysfunction, the 1000 mg single or double one week apart dosage may ensure optimal PTAs of 2 and 5 weeks, respectively. In patients with preserved renal function, the 1500 mg single or double one-week apart dosage may ensure optimal PTAs of 2 and 4 to 6 weeks, respectively. Therapeutic drug monitoring should be considered mandatory for managing inter-individual variability and for supporting clinicians in long-term treatments of subacute and chronic infections.

Clinical failure of dalbavancin for MRSA bacteremia in patient with severe obesity and history of IVDU

Dalbavancin is a lipoglycopeptide antibiotic used off-label to treat serious gram-positive infections, including infections secondary to methicillin-resistant Staphylococcus aureus (MRSA). Dalbavancin has unique pharmacokinetic parameters and has a role in therapy for treating vulnerable patients, including intravenous drug users, who have challenges complying with typical care plans for serious infections. While there is data indicating successful clinical use of dalbavancin in patients with history of intravenous drug use as well as pharmacokinetic-pharmacodynamic data assessing dalbavancin in obesity, there is a lack of information regarding clinical effects of dalbavancin in patients with extreme obesity, especially in patients with concomitant drug use. This case report describes a 40-year-old morbidly obese female actively using intravenous drugs who developed prolonged MRSA bacteremia without a recognizable focus. Despite partial treatment with dalbavancin, the patient developed osteomyelitis and discitis of the spine with associated epidural phlegmon, likely complications of the MRSA bacteremia.

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.

Letter to the Editor on: "Population Pharmacokinetics of Dalbavancin and Dosing Considerations for Optimal Treatment of Adult Patients with Staphylococcal Osteoarticular Infections"

Dear Editor, Recently, Cojutti et al. [1] published a population pharmacokinetic (POP PK) model on dalbavancin administered to adult patients with Staphylococcal osteoarticular infections (OAI).….

Validation and Clinical Application of a New Liquid Chromatography Coupled to Mass Spectrometry (HPLC-MS) Method for Dalbavancin Quantification in Human Plasma

Dalbavancin (DBV) is an intravenous long-acting second-generation glycolipopeptide antibiotic with high efficacy and excellent tolerability, approved for use in the treatment of Gram-positive skin and skin structure infections (ABSSSI). Nevertheless, little is known about its pharmacokinetic/pharmacodynamic (PK/PD) properties in real life, which is also due to technical challenges in its quantification in human plasma, preventing an effective application of therapeutic drug monitoring (TDM). In fact, DBV has a high affinity to plasma proteins, possibly resulting in poor recovery after extraction procedure. The aim of this study was to validate a simple, cheap and reliable HPLC-MS method for use in TDM, in accordance with FDA and EMA guidelines. The optimized protein precipitation protocol required 50 μL of plasma, while chromatographic analysis could be performed in 12 min/sample. This method fulfilled the guidelines requirements and then, it was applied for routine DBV TDM in patients receiving off-label high doses (two 1500 + 1500 mg weekly infusions instead of 1000 + 500 mg), with normal renal function or undergoing hemodialysis: continuous hemodiafiltration caused a relevant reduction in DBV exposure, while intermittent dialysis showed comparable DBV concentrations with those of patients with normal renal function. This confirmed the eligibility of the presented method for use in TDM and its usefulness in clinical practice.

Regulatory utility of pharmacometrics in the development and evaluation of antimicrobial agents and its recent progress in China

Pharmacometrics is an emerging science that interprets drug, disease, and trial information in a mathematical fashion to inform and facilitate efficient drug development and/or regulatory decisions. Pharmacometrics study is increasingly adopted in the regulatory review of new antimicrobial agents. We summarized the 31 antimicrobial agents approved by the US Food and Drug Administration (FDA) and the 26 antimicrobial agents approved by European Medicines Agency (EMA) from January 2001 to May 2019. We also reviewed recent examples of utilizing pharmacometrics to support antimicrobial agent's registration in China, including modeling and simulation methods, effects of internal/external factors on pharmacokinetic (PK) parameters, safety and efficacy evaluation in terms of exposure-response analysis, refinement of the wording of product labeling and package leaflet, and possible postmarketing clinical trial. Ongoing communication among regulator, academia, and industry regarding pharmacometrics is encouraged to streamline and facilitate the development of new antimicrobial agents. The industry can maximize its benefit in drug development through continued pharmacometrics education/training.

Real-World Use of Dalbavancin in the Era of Empowerment of Outpatient Antimicrobial Treatment: A Careful Appraisal Beyond Approved Indications Focusing on Unmet Clinical Needs

Dalbavancin is a novel, long-acting lipoglycopeptide characterized by a long elimination half-life coupled with excellent in vitro activity against multidrug-resistant Gram-positives. Although it is currently approved only for the treatment of acute bacterial skin and skin structure infections, an ever-growing amount of evidence supports the efficacy of dalbavancin as a long-term therapy in osteomyelitis, prosthetic joint infections, endocarditis, and bloodstream infections. This article provides a critical reappraisal of real-world use of dalbavancin for off-label indications. A search strategy using specific keywords (dalbavancin, osteomyelitis, endocarditis, long-term suppressive therapy, bloodstream infection, pharmacokinetic/pharmacodynamic profile) until April 2021 was performed on the PubMed-MEDLINE database. As for other novel antibiotics, a conundrum between approved indications and potential innovative therapeutic uses has emerged for dalbavancin as well. The promising efficacy in challenging scenarios (i.e., osteomyelitis, endocarditis, prosthetic joint infections), coupled with the unique pharmacokinetic/pharmacodynamic properties, makes dalbavancin a valuable alternative to daily in-hospital intravenous or outpatient antimicrobial regimens in the treatment of long-term Gram-positive infections. This makes dalbavancin valuable in the current COVID-19 scenario, in which hospitalization and territorial medicine empowerment are unavoidable.

Population pharmacokinetics of dalbavancin and dosing consideration for optimal treatment of adult patients with staphylococcal osteoarticular infections

Background: Dalbavancin is gaining interest in the treatment of complex osteoarticular (OA) infections.Objective: To conduct a population pharmacokinetic analysis of dalbavancin in a prospective cohort of adult patients with Gram-positive OA infections and to identify optimal dosing regimens for long term-treatment.Methods: Non-linear mixed-effects modelling was performed with Monolix. Monte Carlo simulations were performed with six dalbavancin regimens (1500mg at day 1; 1000mg at day 1 plus 500mg at day 8; 1500mg at day1 and 8; 1500mg at day1 and 8 plus 500, 1000 or 1500mg at day 36) to assess the PTA of three pharmacodynamic target of fAUC_24h/MIC against S. aureus (>27.1, 53.3 and 111.1). Cumulative fraction of response (CFR) was calculated against MIC distribution of both MRSA and MSSA as well. Desirable PTAs and CFRs were ≥90%.Results: Fifteen patients provided 120 plasma concentrations. Most (73.3%) had prosthetic joint infections. Clinical cure rate was 87%. A two-compartment model with linear elimination well described the data. No covariate was retained in the final model. Pharmacokinetic dalbavancin estimates were 0.106L/h for CL and 36.4L for V_ss The tested dosing regimens granted desirable CFRs against S. aureus at the most effective PK/PD target for a period ranging 3-to-9 weeks. Conclusion: Giving a two 1500mg dosing regimen of dalbavancin one week apart may ensure efficacy against both MSSA and MRSA up to 5 weeks in patients with OA infections. Clinical assessment at that time may allow for considering whether or not an additional dose should be administered for prolonging effective treatment.

Review: A Safety Profile of Dalbavancin for On- and Off-Label Utilization

Introduction

Dalbavancin is a bactericidal lipoglycopeptide active against gram-positives. Its use has been approved for the treatment of acute bacterial skin and skin structure infections (ABSSSI).

Methods

We conducted a narrative review of the literature on the safety profile of dalbavancin. The bibliographic research was carried out on the PubMed database on 6 November 2020 by seeking combinations of the following keywords: dalbavancin, adverse effects, safety, drug interactions, and skin infections.

Results

Five double-blind Phase 3 randomized clinical trials, 2 open-label randomized trials, and 4 retrospective studies were identified. No statistically significant differences were found between dalbavancin and comparators in the incidence of adverse events. Retrospective studies confirm the low incidence of adverse events.

Conclusion

Dalbavancin is a therapeutic option that has demonstrated an excellent safety profile, also in relation to the other MRSA therapies available. Its use represents a cost-effective solution for the treatment of those patients with ABSSSI who would need hospitalization. One limitation of this study is that most of the available data are from Phase III clinical trials. Further real-life studies with a larger sample size are therefore needed to better assess the safety profile of the dalbavancin, especially to investigate the true incidence of rare adverse events.

Efficacy and safety of dalbavancin in the treatment of Gram-positive bacterial infections

OBJECTIVES

In this meta-analysis, we assessed the clinical efficacy and safety of dalbavancin compared with commonly used anti-Gram-positive agents.

METHODS

PubMed, Embase and Cochrane Library databases were searched from inception up to 25 February 2020. Randomised controlled trials (RCTs) comparing the efficacy and safety of dalbavancin with other antibiotics against Gram-positive infections were included. Reviews, conference abstracts, editorials, case reports, studies on healthy people, or those lacking a comparator group or focusing on different dosages were excluded.

RESULTS

Seven RCTs comprising 2665 patients were included. Five RCTs included 2109 patients with skin and skin-structure infections (SSSIs) and the other two included patients with catheter-related bloodstream infections (CRBSIs) and osteomyelitis, respectively. Clinical and microbiological responses to dalbavancin were similar to other antibiotics in treating infections caused by Gram-positive bacteria, including the SSSI subgroup. Clinical response to dalbavancin showed superiority in the CRBSI and osteomyelitis subgroups. No significant difference was observed between dalbavancin and other treatments in terms of adverse events (AEs), adverse drug reactions (ADRs) and serious AEs. However, the single-dose regimen had significantly more AEs compared with the comparator group, while the dual-dose regimen resulted in fewer AEs and ADRs and a lower incidence of diarrhoea compared with the comparator group. Moreover, the dalbavancin group showed a decreased mortality risk compared with other treatments.

CONCLUSION

Dalbavancin was comparable with other antibiotics in treating chronic Gram-positive infections in terms of efficacy and safety. The dual-dose regimen showed a better safety profile compared with the single-dose regimen in the treatment of SSSIs.

Simultaneous Quantification and Pharmacokinetic Study of Five Homologs of Dalbavancin in Rat Plasma Using UHPLC-MS/MS

Dalbavancin is a novel semisynthetic glycopeptide antibiotic that comprises multiple homologs and isomers of similar polarities. However, pharmacokinetic studies have only analyzed the primary components of dalbavancin, namely B₀ and B₁. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to simultaneously determinate and investigate the five homologous components of dalbavancin, namely, A₀, A₁, B₀, B₁, and B₂, in rat plasma. In this method, methanol was used to precipitate plasma, and a triple-bonded alkyl chromatographic column was used for molecule separation, using 0.1% formic acid-acetonitrile as the mobile phase for gradient elution. Targeted homologs were analyzed by a triple quadrupole mass spectrometer using positive electrospray ionization in multiple reaction monitoring mode. The linearity range was 50–2500 ng/mL with a high correlation coefficient (r² > 0.998). This method was successfully applied in the pharmacokinetic analysis of dalbavancin hydrochloride to investigate dalbavancin components in rats.

Dalbavancin and telavancin in the treatment of infective endocarditis: a literature review

Glycopeptides have an established role in the management of infective endocarditis, and feature in current treatment guidelines. Newer lipoglycopeptide agents (dalbavancin, telavancin and oritavancin), which are analogues of glycopeptides with structural modifications giving rise to added novel mechanisms of antimicrobial activity, are approved for the treatment of Gram-positive skin and skin structure infections, and also for nosocomial pneumonia (only telavancin has approval for the latter indication). Recent evidence has also emerged to support their use in the treatment of bone and joint infections. This article reviews the current literature on dalbavancin and telavancin in the treatment of infective endocarditis, a condition for which the role of these agents is yet to be established.

Dalbavancin for the Treatment of Complicated Gram-Positive Skin and Soft Tissue Infections

New antimicrobial agents have been developed to treat infections caused by methicillin-resistant Staphylococcus aureus and other multidrug-resistant pathogens. Dalbavancin is a novel semisynthetic lipoglycopeptide antibiotic, particularly active against methicillin-resistant Staphylococcus aureus. Due to its unique pharmacological characteristics and longer half-life, it can be administered once-weekly or every 15 days and in outpatient setting. Currently, it is indicated for complicated skin and soft tissue infections, but accumulating evidence points to its off-label efficacy in osteomyelitis and endocarditis. Further experience is still needed to increase our knowledge on the role of dalbavancin in a wider range of Gram-positive infections requiring prolonged antimicrobial treatment.

Intravenous and Intraperitoneal Pharmacokinetics of Dalbavancin in Peritoneal Dialysis Patients

Dalbavancin offers a possible treatment option for infectious peritonitis associated with peritoneal dialysis (PD) due to its coverage of Gram-positive bacteria and pharmacokinetic properties. We aimed to evaluate the clinical pharmacokinetics (PK) and pharmacodynamics of dalbavancin in a prospective, randomized, open-label, crossover PK study of adult patients with end-stage renal disease ESRD who were receiving PD. Sampling occurred prior to a single 30-min infusion of dalbavancin at 1,500 mg and at 1, 2, 3, 4, and 6 h and 7 and 14 days postadministration. Concentration-time data were analyzed via noncompartmental analysis. Pharmacodynamic parameters against common infectious peritonitis-causing pathogens were evaluated. Ten patients were enrolled. Patients were a median of 55 years old and had a median weight of 78.2 kg, 50% were female, and 70% were Caucasian. The terminal plasma half-life of dalbavancin was 181.4 ± 35.5 h. The day 0 to day 14 dalbavancin mean area under the curve (AUC) was 40,573.2 ± 9,800.3 mg·h/liter. The terminal-phase half-life of dalbavancin within the peritoneal fluid was 4.309 × 10⁸ ± 1.140 × 10⁹ h. The day 0 to day 14 dalbavancin mean peritoneal fluid AUC was 2,125.0 ± 1,794.3 mg·h/liter. The target plasma AUC/MIC was attained with the intravenous dose in all 10 patients for all Staphylococcus and Streptococcus species at the recommended MIC breakpoints. The intraperitoneal arm of the study was stopped early, because the first 3 patients experienced moderate to severe pain and bloating within 1 h following the administration of dalbavancin. Dalbavancin at 1,500 mg administered intravenously can be utilized without dose adjustment in peritoneal dialysis patients and will likely achieve the necessary peritoneal fluid concentrations to treat peritonitis caused by typical Gram-positive pathogens.

Novel Antibiotics for Multidrug-Resistant Gram-Positive Microorganisms

Increasing multidrug-resistance to Gram-positive pathogens, particularly to staphylococci, enterococci and streptococci, is a major problem, resulting in significant morbidity, mortality and healthcare costs. In recent years, only a small number of novel antibiotics effective against Gram-positive bacteria has been approved. This review will discuss the current evidence for novel branded antibiotics that are highly effective in the treatment of multidrug-resistant infections by Gram-positive pathogens, namely ceftobiprole, ceftaroline, telavancin, oritavancin, dalbavancin, tedizolid, besifloxacin, delafloxacin, ozenoxacin, and omadacycline. The mechanism of action, pharmacokinetics, microbiological spectrum, efficacy and safety profile will be concisely presented. As for any emerging antibiotic agent, resistance is likely to develop against these highly effective antibiotics. Only through appropriate dosing, utilization and careful resistance development monitoring will these novel antibiotics continue to treat Gram-positive pathogens in the future.

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.

Dalbavancin Population Pharmacokinetic Modeling and Target Attainment Analysis

Dalbavancin is indicated for the treatment of acute bacterial skin and skin structure infections caused by susceptible gram-positive microorganisms. This analysis represents the update of the population pharmacokinetics (popPK) modeling and target attainment simulations performed with data from the single-dose safety and efficacy study and an unrelated but substantial revision of the preclinical pharmacokinetic/pharmacodynamic target (fAUC/MIC, free area under concentration-time curve/minimum inhibitory concentration ratio). A 3-compartment distribution model with first-order elimination provided an appropriate fit, with typical dalbavancin clearance of 0.05 L/h and total volume of distribution of ∼15 L. Impact of intrinsic factors was modest, although statistically significant (P < .05) relationships with total clearance were found for the following covariates: creatinine clearance, weight, and albumin - dose adjustment was only indicated for severe renal impairment. Under the new nonclinical target, simulations of the popPK model projected that >99% of subjects would achieve the nonclinical target at MIC values up to and including 2 mg/L.

Emergence of a dalbavancin induced glycopeptide/lipoglycopeptide non-susceptible Staphylococcus aureus during treatment of a cardiac device-related endocarditis

In the present study, we demonstrated the emergence of dalbavancin non-susceptible and teicoplanin-resistant Staphylococcus aureus small colony variants which were selected in vivo through long-term treatment with dalbavancin. A 36-year-old man presented with a cardiac device-related S. aureus endocarditis and received long-term therapy with dalbavancin. Consecutively, two glycopeptide/lipoglycopeptide susceptible and two non-susceptible S. aureus isolates were obtained from blood cultures and the explanted pacemaker wire. The isolates were characterized by: standard typing methods, antimicrobial susceptibility testing, auxotrophic profiling, proliferation assays, scanning and transmission electron microscopy, as well as whole genome sequencing. The isolated SCVs demonstrated a vancomycin-susceptible but dalbavancin non-susceptible and teicoplanin-resistant phenotype whereof the respective MICs of the last isolate were 16- and 84-fold higher than the susceptible strains. All four strains were indistinguishable or at least closely related by standard typing methods (spa, MLST, and PFGE), and whole genome sequencing revealed only eight sequence variants. A consecutive increase in cell wall thickness (up to 2.1-fold), an impaired cell separation with incomplete or multiple cross walls and significantly reduced growth rates were observed in the present study. Therefore, the mutations in pbp2 and the DHH domain of GdpP were identified as the most probable candidates due to their implication in the biosynthesis and metabolism of the staphylococcal cell wall. For the first time, we demonstrated in vivo induced dalbavancin non-susceptible/teicoplanin resistant, but vancomycin and daptomycin susceptible S. aureus SCVs without lipopeptide or glycopeptide pretreatment, thus, indicating the emergence of a novel lipoglycopeptide resistance mechanism.

Dalbavancin for treatment of implant-related methicillin-resistant Staphylococcus aureus osteomyelitis in an experimental rat model

Dalbavancin is a new semisynthetic lipoglycopeptide with improved antimicrobial activity against various gram-positive pathogens. It demonstrates an extensive plasma half-life which permits outpatient parenteral antimicrobial therapy with weekly intervals and might therefore be an excellent treatment alternative for patients requiring prolonged antimicrobial therapy. The present study investigated dalbavancin monotherapy in an experimental implant-related methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis model. A clinical MRSA isolate and a Kirschner-wire were inserted into the proximal tibia of anaesthetized Sprague-Dawley rats. Four weeks after infection 34 animals were treated over 4 weeks with either dalbavancin (20 mg/kg loading-dose; 10 mg/kg daily), vancomycin (50 mg/kg twice daily) or left untreated. Twenty-four hours after the last treatment dose tibial bones and Kirschner-wires were harvested for microbiological examination. Based on quantitative bacterial cultures of osseous tissue, dalbavancin was as effective as vancomycin and both were superior to no treatment. No emergence of an induced glycopeptide-/lipoglycopeptide- resistance was observed after a treatment period of four weeks with either dalbavancin or vancomycin. In conclusion, monotherapy with dalbavancin was shown to be as effective as vancomycin for treatment of experimental implant-related MRSA osteomyelitis in rats, but both antimicrobials demonstrated only limited efficacy. Further studies are warranted to evaluate the clinical efficacy of dalbavancin for the treatment of periprosthetic S. aureus infections.

Dalbavancin Pharmacokinetics and Safety in Children 3 Months to 11 Years of Age

BACKGROUND

Dalbavancin is a novel lipoglycopeptide antibiotic that has potent in vitro activity against Gram-positive microorganisms.

METHODS

We performed a phase 1, open-label, multicenter study to investigate the pharmacokinetics (PK) and safety of a single dose of intravenous dalbavancin in hospitalized pediatric subjects 3 months to 11 years of age. We combined these data with previously collected adolescent PK data and performed a population PK analysis.

RESULTS

Model development was performed using 311 dalbavancin plasma concentrations from 43 subjects. The median age was 5.9 years (range: 0.3-16.9). A 3-compartment, linear PK model was developed. Based on simulations, the following age-dependent dosing regimen was found to achieve similar dalbavancin exposure to that in adults administered a 2-dose regimen: children 6 to <18 years of age, 12 mg/kg (1000 mg maximum) on day 1 and 6 mg/kg (500 mg maximum) on day 8 and children 3 months to <6 years of age, 15 mg/kg (1000 mg maximum) on day 1 and 7.5 mg/kg (500 mg maximum) on day 8. Similarly, the following age-dependent regimen was found to match adult exposure after a single-dose (1500 mg): 6 to <18 years of age, 18 mg/kg (1500 mg maximum) on day 1 and 3 months to <6 years of age, 22.5 mg/kg (1500 mg maximum) on day 1. Nineteen subjects experienced 36 treatment-emergent adverse events. Five of 36 adverse events were assessed as possibly or probably related to treatment.

CONCLUSIONS

Dalbavancin pediatric dosing that matched adult exposure was identified. Overall, dalbavancin was well tolerated in our study population.

Dalbavancin: A New Option for the Treatment of Gram-Positive Infections

Objective:

To review the pharmacology, microbiology, chemistry, in vitro susceptibility, pharmacokinetics, clinical efficacy, safety, tolerability, dosage, and administration of dalbavancin, a new semisynthetic lipoglycopeptide.

Data Sources:

A MEDLINE search, restricted to the English language, was conducted from 1966 through January 2006. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy, American Society of Microbiology, and the Infectious Diseases Society of America from 2000 to 2005 and information available from the manufacturer's Web site.

Study Selection and Data Extraction:

In vitro and preclinical studies, as well as Phase I, II, and III clinical trials, were evaluated to summarize the microbiology, pharmacology, clinical efficacy, and safety of dalbavancin. All published trials and abstracts citing dalbavancin were selected.

Data Synthesis:

Dalbavancin, a novel lipoglycopeptide, has a mechanism of action similar to that of other glycopeptides. It has in vitro activity against a variety of gram-positive organisms, but no activity against gram-negative or vancomycin-resistant enterococci that possess VanA gene. Due to its prolonged half-life (6–10 days), dalbavancin can be administered intravenously once weekly. In Phase II and III clinical trials, dalbavancin was effective and well tolerated for the treatment of skin and soft-tissue infections, catheter-related bloodstream infections, and skin and skin-structure infections. To date, adverse events are mild and limited; the most common include pyrexia, headache, nausea, oral candidiasis, diarrhea, and constipation.

Conclusions:

Dalbavancin appears to be a promising antimicrobial agent for the treatment of gram-positive infections. A new drug application was filed with the Food and Drug Administration (FDA) in December 2004. The FDA issued an approvable letter in 2005 for dalbavancin. If approved, dalbavancin is expected to be launched in the first quarter of 2006.

Dalbavancin for the treatment of paediatric infectious diseases

To review the topics of interest related to the use of dalbavancin in paediatric patients. PubMed was used to search for all of the studies published over the last 15 years using the key word "dalbavancin". A total of 36 manuscripts were selected, and due to the limited pediatric experience a further research was performed in order to identify clinical trials ongoing. Three studies that concerned children were found in clinicaltrials.gov. This review considers also the manuscripts published on the adult population in order to highlight the gaps requiring further research at pediatric age. Dalbavancin has emerged as a promising agent against resistant Gram-positive invasive infections. It is approved in the United States and Europe for the treatment of adult patients with acute bacterial skin and skin structure infections (SSTIs). Compared to other available antibiotics that are active against multi-resistant bacteria, the advantages of dalbavancin include a lower potential for drug interactions and the possibility of fewer required doses due to a longer half-life. Pharmacokinetic characteristics of dalbavacin are attractive for its clinical impact, especially for children who may avoid prolonged hospitalization and central venous access. However, further studies are needed to establish its appropriate paediatric dosage before it can be licensed for use in newborns and children. For younger patients, at a time when infections due to multidrug-resistant Gram-positive pathogens are increasing, dosage, efficacy and safety data for dalbavancin are needed to ensure the highest antimicrobial efficacy while also minimizing the risk of adverse events.

Dalbavancin and Oritavancin: An Innovative Approach to the Treatment of Gram-Positive Infections

Health care-associated infections, especially those caused by multidrug-resistant gram-positive organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), are a growing public health threat. In 2014, the U.S. Food and Drug Administration approved two new lipoglycopeptides, oritavancin and dalbavancin, for the treatment of acute bacterial skin and skin structure infections. The rationale for the development of these antimicrobials was partly to aid in the battle against vancomycin resistance in both Staphylococcus and Enterococcus. Considered a subclass of the glycopeptide antibiotics, the new lipoglycopeptides have similar mechanisms of action of binding to the carboxyl terminal d-alanyl-d-alanine residue of the growing peptide chains but differ from their parent glycopeptides by the addition of lipophilic tails. This addition allows for these agents to have prolonged half-lives, giving them unique dosing profiles. In addition, by concentrating at the site of action, they have increased potency against MRSA compared with vancomycin, the current mainstay of therapy. In this review, we focus on comparing and contrasting these two new agents with regard to their pharmacology, mechanisms of action, spectrum of activity, safety profiles, dosage and administration, and drug and laboratory interactions, and we review the clinical trials evaluating their use.

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

Background and Objectives

Dalbavancin is a novel, once-weekly glycopeptide antibiotic approved for treatment of acute bacterial skin infections. Given the importance of understanding any pharmacokinetic variability across different patient populations, a double-blind, placebo-controlled study was conducted to evaluate the pharmacokinetics, safety, and tolerability of a single 500-mg and a single 1000-mg intravenous dose of dalbavancin in healthy Japanese subjects.

Methods

Ten subjects received intravenous dalbavancin 1000 mg, five subjects received intravenous dalbavancin 500 mg, and three subjects received intravenous placebo.

Results

After a single infusion of dalbavancin, the maximal plasma concentration (C_max) and area under the plasma concentration–time curve (AUC) increased in a proportional manner from 500 mg to 1000 mg (C_max: 157 μg/ml and 299 μg/ml; AUC_last: 10,850 μg·h/ml and 22,679 μg·h/ml, on the 500-mg and 1000-mg regimens, respectively) with low inter-subject variability. The mean terminal phase half-life (t_1/2) was 204 and 193 h after the 500-mg and 1000-mg dose, respectively. Clearance and volume of distribution were similar for the two dose concentrations. Treatment-emergent adverse events reported were considered to be of mild intensity. There were no relevant changes in laboratory values or vital signs over time in subjects in either treatment group.

Conclusions

Overall, dalbavancin 500 mg and dalbavancin 1000 mg, administered as a single 30-min infusion, was well tolerated in this population and resulted in plasma exposures similar to those in non-Asians.

Clinical efficacy of dalbavancin for the treatment of acute bacterial skin and skin structure infections (ABSSSI)

Acute bacterial skin and skin structure infections (ABSSSI) are a common disease causing patients to seek treatment through the health care system. With the continued increase of drug-resistant bacterial pathogens, these infections are becoming more difficult to successfully cure. Lipoglycopeptides have unique properties that allow the drug to remain active toward both common and challenging pathogens at the infected site for lengthy periods of time. Dalbavancin, a new lipoglycopeptide, provides two unique dosing regimens for the treatment of ABSSSI. The original regimen of 1,000 mg intravenous infusion followed by a 500 mg intravenous infusion after a week has been shown as safe and effective in multiple, randomized noninferiority trials. These studies also demonstrated that dalbavancin was similar to standard regimens in terms of both safety and tolerability. Recently a single 1,500 mg dose was demonstrated to be equivalent to the dalbavancin two-dose regimen for treating ABSSSI. With the introduction of dalbavancin, clinicians have the option to provide an intravenous antimicrobial agent shown to be as effective as traditional therapies, without requiring admission into the hospitals or prescribing a medication which may not be utilized optimally. Further understanding of dalbavancin and its unusual properties can provide unique treatment situations with potential benefits for both the patient and the overall health care system, which should be further explored.

Dalbavancin (BI-387) for the treatment of complicated skin and skin structure infection

In the era of increasing antibiotic resistance, development of new agents that could provide therapeutic options for difficult to treat pathogens is vital. Dalbavancin is a new lipoglycopeptide recently approved by the US FDA for the treatment of acute bacterial skin and skin structure infections. A derivative of the older glycopeptide class, chemical structure alterations resulted in a molecule with a similar mechanism of action, however, with a comparatively increased activity as reflected by organism MICs. These modifications also resulted in an antibiotic with distinctive properties that allow for once-weekly dosing in the treatment of Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and drug resistant Streptococcus spp. As the first of these long acting compounds, understanding the pharmacokinetic and pharmacodynamic properties of agents like dalbavancin is essential for determining a place in therapy.

Efficacy of Extended-Interval Dosing of Micafungin Evaluated Using a Pharmacokinetic/Pharmacodynamic Study with Humanized Doses in Mice

The pharmacokinetic/pharmacodynamic (PK/PD) characteristics of the echinocandins favor infrequent administration of large doses. The in vivo investigation reported here tested the utility of a range of humanized dose levels of micafungin using a variety of prolonged dosing intervals for the prevention and therapy of established disseminated candidiasis. Humanized doses of 600 mg administered every 6 days prevented fungal growth in prophylaxis. Humanized doses of 300 to 1,000 mg administered every 6 days demonstrated efficacy for established infections.

Impact of Glycopeptide Resistance in Staphylococcus aureus on the Dalbavancin In Vivo Pharmacodynamic Target

Dalbavancin is a novel lipoglycopeptide with activity against Staphylococcus aureus, including glycopeptide-resistant isolates. The in vivo investigation reported here tested the effects of this antibiotic against seven S. aureus isolates with higher MICs, including several vancomycin-intermediate strains. Results of 1-log kill and 2-log kill were achieved against seven and six of the isolates, respectively. The mean free-drug area under the concentration-time curve (fAUC)/MIC values for net stasis, 1-log kill, and 2-log kill were 27.1, 53.3, and 111.1, respectively.