Evaluating the Rapid Emergence of Daptomycin Resistance in Corynebacterium: a Multicenter Study

Members of the genus Corynebacterium are increasingly recognized as pathobionts and can be very resistant to antimicrobial agents. Previous studies have demonstrated that Corynebacterium striatum can rapidly develop high-level daptomycin resistance (HLDR) (MIC, ≥256 μg/ml). Here, we conducted a multicenter study to assay for this in vitro phenotype in diverse Corynebacterium species. Corynebacterium clinical isolates (n = 157) from four medical centers were evaluated. MIC values to daptomycin, vancomycin, and telavancin were determined before and after overnight exposure to daptomycin to identify isolates able to rapidly develop daptomycin nonsusceptibility. To investigate assay reproducibility, 18 isolates were evaluated at three study sites. In addition, the stability of daptomycin nonsusceptibility was tested using repeated subculture without selective pressure. The impact of different medium brands was also investigated. Daptomycin nonsusceptibility emerged in 12 of 23 species evaluated in this study (C. afermentans, C. amycolatum, C. aurimucosum, C. bovis, C. jeikeium, C. macginleyi, C. pseudodiphtheriticum, C. resistens, C. simulans, C. striatum, C. tuberculostearicum, and C. ulcerans) and was detected in 50 of 157 (31.8%) isolates tested. All isolates displayed low (susceptible) MIC values to vancomycin and telavancin before and after daptomycin exposure. Repeated subculture demonstrated that 2 of 9 isolates (22.2%) exhibiting HLDR reverted to a susceptible phenotype. Of 30 isolates tested on three medium brands, 13 (43.3%) had differences in daptomycin MIC values between brands. Multiple Corynebacterium species can rapidly develop daptomycin nonsusceptibility, including HLDR, after a short daptomycin exposure period.

Efficacy of Telavancin in Comparison to Linezolid in a Porcine Model of Severe Methicillin-Resistant Staphylococcus aureus Pneumonia

Current guidelines recommend vancomycin and linezolid as first-line agents against methicillin-resistant Staphylococcus aureus (MRSA) nosocomial pneumonia. Telavancin is a potential new therapeutic alternative, specifically in monomicrobial MRSA pneumonia. This study compared the efficacies of telavancin versus linezolid in a porcine model of severe MRSA pneumonia. In 18 mechanically ventilated pigs (32.11 ± 1.18 kg), 75 ml of 10⁶ CFU/ml of MRSA was administered into each pulmonary lobe. After the onset of pneumonia, pigs were randomized into three groups: a control group, a group receiving 22.5 mg/kg of body weight every 24 h (q24h) of telavancin, and a group receiving 10 mg/kg q12h of linezolid intravenously. Tracheal aspirate and bronchoalveolar lavage (BAL) fluids were cultured every 24 h. After 48 h of treatment, tissue samples were collected from the ventral and dorsal sections of each lobe. Microbiological and histopathological analyses were performed. Lung tissue concentrations differed among the groups (P = 0.019), with the lowest MRSA lung burden in the telavancin group (P < 0.05 versus the control). MRSA was detected in 46.7%, 40.0%, and 21.7% of the lung tissue samples from the control, linezolid, and telavancin groups, respectively (P < 0.001). MRSA concentrations differed among the groups in tracheal aspirate fluid (P = 0.011) but not in BAL fluid. Furthermore, there was no increased risk of kidney injury during telavancin use. Thus, telavancin has higher bactericidal efficacy than linezolid during the first 48 h of treatment in a porcine model of severe MRSA pneumonia. However, studies are needed to confirm the benefits of telavancin in treating MRSA nosocomial pneumonia.

Glycopeptide Hypersensitivity and Adverse Reactions

Glycopeptides, such as vancomycin and teicoplanin, are primarily used in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections, such as cellulitis, endocarditis, meningitis, pneumonia, and septicemia, and are some of the most commonly prescribed parenteral antimicrobials. Parenteral glycopeptides are first-line therapy for severe MRSA infections; however, oral vancomycin is used as a first-line treatment of Clostridioides difficile infections. Also, we currently have the longer-acting lipoglycopeptides, such as dalbavancin, oritavancin, and telavancin to our armamentarium for the treatment of MRSA infections. Lastly, vancomycin is often used as an alternative treatment for patients with β-lactam hypersensitivity. Common adverse effects associated with glycopeptide use include nephrotoxicity, ototoxicity, and Redman Syndrome (RMS). The RMS is often mistaken for a true allergy; however, it is a histamine-related infusion reaction rather than a true immunoglobulin E (IgE)-mediated allergic reaction. Although hypersensitivity to glycopeptides is rare, both immune-mediated and delayed reactions have been reported in the literature. We describe the various types of glycopeptide hypersensitivity reactions associated with glycopeptides and lipoglycopeptides, including IgE-mediated reactions, RMS, and linear immunoglobulin A bullous dermatosis, as well as describe cross-reactivity with other glycopeptides.

Pharmacokinetics of Telavancin in Adult Patients with Cystic Fibrosis during Acute Pulmonary Exacerbation

Adults with cystic fibrosis (CF) frequently harbor Staphylococcus aureus, which is increasingly antibiotic resistant. Telavancin is a once-daily rapidly bactericidal antibiotic active against methicillin-, linezolid-, and ceftaroline-resistant S. aureus Because CF patients experience alterations in pharmacokinetics, the optimal dose of telavancin in this population is unknown. Adult CF patients (n = 18) admitted for exacerbations received 3 doses of telavancin 7.5 mg/kg of body weight (first 6 patients) or 10 mg/kg (final 12 patients) every 24 h (q24h). Population pharmacokinetic models with and without covariates were fitted using the nonparametric adaptive grid algorithm in Pmetrics. The final model was used to perform 5,000-patient Monte Carlo simulations for multiple telavancin doses. The best fit was a 2-compartment model describing the volume of distribution of the central compartment (V_c ) as a multiple of total body weight (TBW) and the volume of distribution of the central compartment scaled to total body weight (V _θ) normalized by the median observed value (V_c  = V _θ × TBW/52.1) and total body clearance (CL) as a linear function of creatinine clearance (CRCL) (CL = CL_NR + CL_θ × CRCL), where CL_NR represents nonrenal clearance and CL_θ represents the slope term on CRCL to estimate renal clearance. The mean population parameters were as follows: V _θ, 4.92  ± 0.76 liters · kg^-1; CL_NR, 0.59  ± 0.30 liters · h^-1; CL_θ, 5.97 × 10^-3 ± 1.24 × 10^-3; V_p (volume of the peripheral compartment), 3.77  ± 1.41 liters; Q (intercompartmental clearance), 4.08  ± 2.17 liters · h^-1 The free area under the concentration-time curve (fAUC) values for 7.5 and 10 mg/kg were 30  ± 4.6 and 52  ± 12 mg · h/liter, respectively. Doses of 7.5 mg/kg and 10 mg/kg achieved 76.5% and 100% probability of target attainment (PTA) at a fAUC/MIC threshold of >215, respectively, for MIC of ≤0.12 mg/liter. The probabilities of reaching the acute kidney injury (AKI) threshold AUC (763 mg · h · liter^-1) for these doses were 0% and 0.96%, respectively. No serious adverse events occurred. Telavancin 10 mg/kg yielded optimal PTA and minimal risk of AKI, suggesting that this FDA-approved dose is appropriate to treat acute pulmonary exacerbations in CF adults. (The clinical trial discussed in this study has been registered at ClinicalTrials.gov under identifier NCT03172793.).

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.

Activity of Telavancin against Staphylococcus aureus Isolates, Including Those with Decreased Susceptibility to Ceftaroline, from Cystic Fibrosis Patients

Methicillin-resistant Staphylococcus aureus (MRSA) acquisition in cystic fibrosis (CF) patients confers a clinical outcome worse than that in non-CF patients with an increased rate of declined lung function. Telavancin, an approved lipoglycopeptide used to treat infections due to S. aureus, has a dual mode of action causing inhibition of peptidoglycan synthesis and membrane depolarization. MRSA infections in CF patients remain an important problem with no foreseeable decline in prevalence rates. Although telavancin is currently in clinical use for the treatment of complicated skin infections and hospital-acquired pneumonia, the activity against S. aureus infections in CF patients has not been investigated. In this work, we studied the activity of telavancin against CF patient-derived S. aureus strains collected from geographically diverse CF centers in the United States. We found that the telavancin MIC90 was 0.06 μg/ml, 8-fold lower than the ceftaroline or daptomycin MIC90 and 25-fold lower than the linezolid and vancomycin MIC90 We demonstrate that telavancin at serum free concentrations has rapid bactericidal activity, with a decrease of more than 3 log10 CFU/ml being achieved during the first 4 to 6 h of treatment, performing better in this assay than vancomycin and ceftaroline, including against S. aureus strains resistant to ceftaroline. Telavancin resistance was infrequent (0.3%), although we found that it can occur in vitro in both CF- and non-CF patient-derived S. aureus strains by progressive passages with subinhibitory concentrations. Genetic analysis of telavancin-resistant in vitro mutants showed gene polymorphisms in cell wall and virulence genes and increased survival in a Galleria mellonella infection model. Thus, we conclude that telavancin represents a promising therapeutic option for infections in CF patients with potent in vitro activity and a low resistance development potential.

Time Course and Extent of Renal Function Changes in Patients Receiving Treatment for Staphylococcal Pneumonias: An Analysis Comparing Telavancin and Vancomycin from the ATTAIN Trials

STUDY OBJECTIVE

Telavancin and vancomycin are both approved for treatment of hospital-acquired and ventilator-associated bacterial pneumonias caused by Staphylococcus aureus, and both agents can cause renal dysfunction. The objective of this study was to assess renal function changes by performing renal shift table analyses of telavancin- and vancomycin-treated patients in phase III trials.

DESIGN

Retrospective, descriptive analysis of data from the safety population from the Assessment of Telavancin for Treatment of Hospital-Acquired Pneumonia (ATTAIN) trials.

PATIENTS

A total of 1503 adults with hospital-acquired or ventilator-associated bacterial pneumonia primarily caused by gram-positive pathogens and who received telavancin (n = 751) or vancomycin (n = 752).

MEASUREMENTS AND MAIN RESULTS

Decline or improvement in creatinine clearance (CrCl) across seven defined categories (≤30, >30-40, >40-50, >50-60, >60-70, >70-80, and >80 ml/min) was classified as negative or positive shifts, respectively. The number of categories crossed (either positive or negative) determined the grade of shift (of a potential grades 1-6, with crossing from one category to the next adjacent category defined as a grade 1 shift) at specific time points compared with baseline: day 4, day 7, and end of therapy (EOT). Approximately 77%-91.6% of patients had either no change or improvement of CrCl across all time points for both treatments. Negative shifts were consistent for telavancin (day 4, 19.3%; day 7, 19.0%; EOT, 23.0%) but increased over time for vancomycin (day 4, 8.4%; day 7, 12.3%; EOT, 19.3%). A significantly lower proportion of patients receiving vancomycin showed renal function decline on day 4 and day 7. At EOT, negative shift rates were similar between treatments (treatment difference 3.6% [95% CI -0.7 to 7.9]). At day 7 and EOT, a higher percentage of vancomycin-treated patients experienced high-grade negative shifts relative to telavancin (day 7, vancomycin 2.8% vs telavancin 1.9%; EOT, vancomycin 4.7% vs telavancin 4.1%), though differences were not statistically significant.

CONCLUSION

Use of shift tables revealed differences in timing of renal function changes in patients receiving telavancin and vancomycin. Telavancin-related declines in renal function were similar at day 4 and day 7, with a slight increase by EOT. This differed from vancomycin, which caused a steady increase in the percentage of patients with renal function decline over time. A significant difference in negative renal shifts between treatments occurred at day 4 and day 7 and favored vancomycin; however, the difference was minimal and not significant at EOT.

Evaluation of Telavancin Alone and Combined with Ceftaroline or Rifampin against Methicillin-Resistant Staphylococcus aureus in an In Vitro Biofilm Model

Infections caused by biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) bacteria are challenging due to increasing antibiotic resistance. Synergistic activities of lipopeptides and lipoglycopeptides with β-lactams have been demonstrated for MRSA, but little is known about biofilm-embedded organisms. Our objective was to evaluate two telavancin (TLV) dosage regimens (7.5 mg/kg of body weight and 10 mg/kg every 24 h [q24h]) alone and in combination with ceftaroline (CPT) (600 mg every 8 h [q8h]) or rifampin (RIF) (450 mg every 12 h [q12h]) against two biofilm-producing MRSA strains (494 and N315). Pharmacokinetic/pharmacodynamic CDC biofilm reactor models with polyurethane coupons were used to evaluate the efficacies of the antibiotic combinations over 72 h. Overall, there were no significant differences observed between the two TLV dosing regimens either alone or in combination with RIF or CPT against these strains. Both TLV dosing regimens and CPT alone demonstrated killing but did not reach bactericidal reduction at 72 h. However, both TLV regimens in combination with RIF demonstrated enhanced activity against both strains, with a rapid decrease in CFU/ml at 4 h that was bactericidal and maintained over the 72-h experiment (-Δ3.75 log10 CFU/ml from baseline; P < 0.0001). Of interest, no enhanced activity was observed for TLV combined with CPT. No development of resistance was observed in any of the combination models. However, resistance to RIF developed as early as 24 h, with MIC values exceeding 32 mg/liter. Our results show that TLV plus RIF displayed therapeutic improvement against biofilm-producing MRSA. These results suggest that TLV at 7.5 and 10 mg/kg q24h are equally effective in eradicating biofilm-associated MRSA strains in vitro.

Treatment strategies for persistent methicillin-resistant Staphylococcus aureus bacteraemia

WHAT IS KNOWN AND OBJECTIVE

Treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is a long-standing challenge to health care, often complicated by metastatic infections, treatment failure and mortality. When MRSA bacteraemia persists despite adequate initial treatment, current Infectious Diseases Society of America guidelines recommend evaluation and removal of possible sources of infection. In addition, a change in therapy may be considered. The objective of this review was to explore the therapeutic options for the treatment of persistent MRSA bacteraemia.

METHODS

A literature search of PubMed, MEDLINE and Google Scholar was performed using the following search terms: [methicillin-resistant Staphylococcus aureus OR MRSA] AND [bacteraemia OR bloodstream infection] AND [persistent OR persistence OR refractory OR treatment failure OR salvage] AND treatment. We evaluated relevant, adult, English-language, peer-reviewed studies published between 1985 and May 2018. In vitro and animal studies were considered as supportive of in vivo data.

RESULTS AND DISCUSSION

Randomized, controlled trials are lacking. However, case series and case reports support multiple treatment options including high-dose daptomycin in combination with an antistaphylococcal β-lactam, ceftaroline, trimethoprim-sulfamethoxazole (TMP-SMX) or fosfomycin; ceftaroline alone or in combination with vancomycin or TMP-SMX; linezolid alone or in combination with a carbapenem, or telavancin.

WHAT IS NEW AND CONCLUSION

Given the heterogeneity of the data, a preferred regimen has not emerged. Prescribers must take into consideration recent exposure, source control, and available synergy and clinical data. Further comparative trials are needed to establish a preferred regimen and the creation of a universal treatment algorithm.

Morbidity, mortality, and management of methicillin-resistant S. aureus bacteremia in the USA: update on antibacterial choices and understanding

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with significant healthcare costs, morbidity, and mortality in the United States. Complications of MRSA bacteremia include infective endocarditis, osteomyelitis, and sepsis, all of which are difficult to treat. Time to effective therapy and antibacterial choice greatly affect patient outcomes. Vancomycin and daptomycin remain first-line therapies; however, reports of vancomycin-associated treatment failure and reduced daptomycin susceptibility highlight the need to define alternative strategies for MRSA bacteremia treatment. In addition, several patient- and pathogen-specific factors influence the outcomes of MRSA bacteremia. It is, therefore, critical to explore the interaction between host- and pathogen-specific factors and its effect on MRSA bacteremia pathogenesis and mortality. This review discusses the factors that drive the development of MRSA bacteremia and examines alternative treatment strategies.

Pharmacokinetics of Telavancin at Fixed Doses in Normal-Body-Weight and Obese (Classes I, II, and III) Adult Subjects

A recommended total-body-weight (TBW) dosing strategy for telavancin may not be optimal in obese patients. The primary objective of this study was to characterize and compare the pharmacokinetics (PK) of telavancin across four body size groups: normal to overweight and obese classes I, II, and III. Healthy adult subjects (n = 32) received a single, weight-stratified, fixed dose of 500 mg (n = 4), 750 mg (n = 8), or 1,000 mg (n = 20) of telavancin. Noncompartmental PK analyses revealed that subjects with a body mass index (BMI) of ≥40 kg/m² had a higher volume of distribution (16.24 ± 2.7 liters) than subjects with a BMI of <30 kg/m² (11.71 ± 2.6 liters). The observed area under the concentration-time curve from time zero to infinity (AUC_0-∞) ranged from 338.1 to 867.3 mg · h/liter, with the lowest exposures being in subjects who received 500 mg. AUC_0-∞ values were similar among obese subjects who received 1,000 mg. A two-compartment population PK model best described the plasma concentration-time profile of telavancin when adjusted body weight (ABW) was included as a predictive covariate. Fixed doses of 750 mg and 1,000 mg had similar target attainment probabilities for efficacy as doses of 10 mg/kg of body weight based on ABW and TBW, respectively. However, the probability of achieving a target area under the concentration-time curve from time zero to 24 h of ≥763 mg · h/liter in association with acute kidney injury was highest (19.7%) with TBW-simulated dosing and lowest (0.4%) at the 750-mg dose. These results suggest that a fixed dose of 750 mg is a safe and effective alternative to telavancin doses based on TBW or ABW for the treatment of obese patients with normal renal function and Staphylococcus aureus infections. (This study has been registered at ClinicalTrials.gov under identifier NCT02753855.).

Optimizing skin and skin structure infection outcomes: considerations of cost of care

INTRODUCTION

Skin and skin structure infections (SSSIs) refer to a collection of clinical infectious syndromes involving layers of skin and associated soft tissues. Although associated with less morbidity and mortality than other common skin infections, SSSIs represent a significant increasing source of healthcare expense, with a prevalence of 500 episodes per 10,000 patient-years in the United States resulting in burdening health care systems, of approximately $6 billion annually.

AREAS COVERED

Opportunities to reduce costs of care associated with SSSI are highlighted, including transitions of care and avoiding unnecessary hospital admissions. Moreover, we reviewed new antibiotics (e.g. single dose glycopeptides), and the impact of consulting specialists in the emergency department on SSSI treatment outcomes.

EXPERT COMMENTARY

New healthcare models and payment strategies combined with new therapeutics are challenging norms of care. Newer drugs to treat skin infections can move a substantive percent of patients previously admitted to hospital care to the outpatient setting. Additionally, patients can be managed with oral or one time intravenous regimens, improving the likelihood of patient adherence and satisfaction. These variables need to be weighed against added acquisition costs and the development of thoughtful algorithms is needed to direct care and optimize treatment, cost, and patient satisfaction.

Effective Antimicrobial Stewardship Strategies for Cost-effective Utilization of Telavancin for the Treatment of Patients With Hospital-acquired Bacterial Pneumonia Caused by Staphylococcus aureus

PURPOSE

Clinicians and stewardship programs are challenged with positioning of novel, higher priced antibiotic agents for the treatment of clinical infections. We developed a decision-analytic model to describe costs, including drug, total treatment costs, and health care outcomes, associated with telavancin (TLV) compared with vancomycin (VAN) for patients with Staphylococcus aureus (SA) hospital-acquired bacterial pneumonia (HABP).

METHODS

This decision-analytic model assessed the treatment of SA-HABP with TLV versus VAN. Data were obtained from the ATTAIN (Assessment of Telavancin for Treatment of Hospital-Acquired Pneumonia) clinical trials on the following: the probability of clinical cure; probability of nephrotoxicity; and prevalence of polymicrobial infection (30%), methicillin-resistant Staphylococcus aureus (MRSA) (68%), and SA with VAN MIC ≥1 µg/mL (85%). Data on length of stay for cure (10 days), failure (10 additional days), and nephrotoxicity (3.5 days) were based on literature. Cost per treated patient and incremental cost-effectiveness ratio (ICER) per additional cure were calculated for SA-HABP and for monomicrobial SA-HABP. One-way sensitivity analyses were performed.

FINDINGS

Patients with SA-HABP were sub-grouped by methicillin susceptibility (n = 140, 32%) or resistance (n = 293, 68%), and occurrence of polymicrobial (n = 128, 30%) vs monomicrobial (n = 305, 70%) infections. Under the base case, hospital cost for patients with HABP treated with TLV was $42,564 and with VAN, it was $42,296. Telavancin was associated with higher drug ($2082) and nephrotoxicity ($467) costs and lower intensive care unit (-$1738) and ventilator (-$114) costs. ICER was $4156 per additional cure. ICER was sensitive to probabilities of cure, length of treatment in cures, intensive care unit cost, TLV cost, and additional length of stay due to failure. For monomicrobial SA-HABP, TLV was associated with a net cost savings of $907 per patient and yielded economic dominance.

IMPLICATIONS

Our decision-analytic model suggests that TLV for monomicrobial SA-HABP is associated with higher drug acquisition costs but a favorable ICER relative to VAN, provided that effective antimicrobial stewardship limits therapy to 7 days. Sensitivity analyses suggest a potential economic benefit of TLV treatment with appropriate patient selection. Antimicrobial stewardship programs may be able to reduce total costs through judicious use of novel antimicrobial agents. ClinicalTrials.gov identifiers: NCT00107952 and NCT00124020.

When Good Bugs Go Bad: Epidemiology and Antimicrobial Resistance Profiles of Corynebacterium striatum, an Emerging Multidrug-Resistant, Opportunistic Pathogen

Infections with Corynebacterium striatum have been described in the literature over the last 2 decades, with the majority being bacteremia, central line infections, and occasionally, endocarditis. In recent years, the frequency of C. striatum infections appears to be increasing; a factor likely contributing to this is the increased ease and accuracy of the identification of Corynebacterium spp., including C. striatum, from clinical cultures. The objective of this study was to retrospectively characterize C. striatum isolates recovered from specimens submitted as part of routine patient care at a 1,250-bed, tertiary-care academic medical center. Multiple strain types were recovered, as demonstrated by repetitive-sequence-based PCR. Most of the strains of C. striatum characterized were resistant to antimicrobials commonly used to treat Gram-positive organisms, such as penicillin, ceftriaxone, meropenem, clindamycin, and tetracycline. The MIC₅₀ for ceftaroline was >32 μg/ml. Although there are no interpretive criteria for susceptibility with telavancin, it appeared to have potent in vitro efficacy against this species, with MIC₅₀ and MIC₉₀ values of 0.064 and 0.125 μg/ml, respectively. Finally, as previously reported in case studies, we demonstrated rapid in vitro development of daptomycin resistance in 100% of the isolates tested (n = 50), indicating that caution should be exhibited when using daptomycin for the treatment of C. striatum infections. C. striatum is an emerging, multidrug-resistant pathogen that can be associated with a variety of infection types.

In Vitro Activity of Telavancin Against Clinically Important Gram-Positive Pathogens from 69 U.S. Medical Centers (2015): Potency Analysis by U.S. Census Divisions

A total of 8,072 gram-positive isolates collected from 69 medical centers among all 9 U.S. Census Divisions during the 2015 SENTRY Antimicrobial Surveillance Program were included. Telavancin had minimal inhibitory concentration (MIC)₅₀ and MIC₉₀ values of 0.03/0.06 μg/mL, respectively, against methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). Similar activity was also observed among coagulase-negative staphylococci (MIC_50/90, 0.03/0.06 μg/ml; 100.0% inhibited by ≤0.12 μg/ml). Telavancin was active against vancomycin-susceptible Enterococcus faecalis (MIC_50/90, 0.12/0.12 μg/ml) and Enterococcus faecium (MIC_50/90, 0.03/0.06 μg/ml), but was less active against vancomycin-resistant E. faecium (MIC₉₀, >2 μg/ml) and E. faecalis (MIC₉₀, >2 μg/ml). Streptococci showed modal MIC results of 0.008 μg/ml (Streptococcus pneumoniae) to 0.015 μg/ml (β-hemolytic streptococci and viridans group streptococci). Potency variations for telavancin within Census Divisions were not observed. Telavancin remains potent in vitro against indicated pathogens recovered from U.S. medical centers (2015).

Comparative Pharmacodynamics of Telavancin and Vancomycin in the Neutropenic Murine Thigh and Lung Infection Models against Staphylococcus aureus

The pharmacodynamics of telavancin and vancomycin were compared using neutropenic murine thigh and lung infection models. Four Staphylococcus aureus strains were included. The telavancin MIC ranged from 0.06 to 0.25 mg/liter, and the vancomycin MIC ranged from 1 to 4 mg/liter. The plasma pharmacokinetics of escalating doses (1.25, 5, 20, and 80 mg/kg of body weight) of telavancin and vancomycin were linear over the dose range. Epithelial lining fluid (ELF) pharmacokinetics for each drug revealed that penetration into the ELF mirrored the percentage of the free fraction (the fraction not protein bound) in plasma for each drug. Telavancin (0.3125 to 80 mg/kg/6 h) and vancomycin (0.3125 to 1,280 mg/kg/6 h) were administered by the subcutaneous route in treatment studies. Dose-dependent bactericidal activity against all four strains was observed in both models. A sigmoid maximum-effect model was used to determine the area under the concentration-time curve (AUC)/MIC exposure associated with net stasis and 1-log₁₀ kill relative to the burden at the start of therapy. The 24-h plasma free drug AUC (fAUC)/MIC values associated with stasis and 1-log kill were remarkably congruent. Net stasis for telavancin was noted at fAUC/MIC values of 83 and 40.4 in the thigh and lung, respectively, and 1-log kill was noted at fAUC/MIC values of 215 and 76.4, respectively. For vancomycin, the fAUC/MIC values for stasis were 77.9 and 45.3, respectively, and those for 1-log kill were 282 and 113, respectively. The 24-h ELF total drug AUC/MIC targets in the lung model were very similar to the 24-h plasma free drug AUC/MIC targets for each drug. Integration of human pharmacokinetic data for telavancin, the results of the MIC distribution studies, and the pharmacodynamic targets identified in this study suggests that the current dosing regimen of telavancin is optimized to obtain drug exposures sufficient to treat S. aureus infections.

Efficacy of Telavancin Alone and in Combination with Ampicillin in a Rat Model of Enterococcus faecalis Endocarditis

We first assessed telavancin (TLV) pharmacokinetics in rats after a single subcutaneous dose of 35 mg/kg of body weight. The pharmacokinetic data were used to predict a TLV dose that simulates human exposure, and the efficacy of TLV was then evaluated using a TLV dose of 21 mg/kg every 12 h against Enterococcus faecalis OG1RF (TLV MIC of 0.06 μg/ml) in a rat endocarditis model with an indwelling catheter. Therapy was given for 3 days with TLV, daptomycin (DAP), or ampicillin (AMP) monotherapy and with combinations of TLV plus AMP, AMP plus gentamicin (GEN), and AMP plus ceftriaxone (CRO); rats were sacrificed 24 h after the last dose. Antibiotics were given to simulate clinically relevant concentrations or as used in other studies. TLV treatment resulted in a significant decrease in bacterial burden (CFU per gram) in vegetations from 6.0 log₁₀ at time 0 to 3.1 log₁₀ after 3 days of therapy. Bacterial burdens in vegetations were also significantly lower in the TLV-treated rats than in the AMP (P = 0.0009)- and AMP-plus-GEN (P = 0.035)-treated rats but were not significantly different from that of the AMP-plus-CRO-treated rats. Bacterial burdens from vegetations in TLV monotherapy and TLV-plus-AMP-and-DAP groups were similar to each other (P ≥ 0.05). Our data suggest that further study of TLV as a therapeutic alternative for deep-seated infections caused by vancomycin-susceptible E. faecalis is warranted.

Successful salvage treatment of native valve Enterococcus faecalis infective endocarditis with telavancin: two case reports

Infective endocarditis (IE) one-year mortality rates approach 40%. Here, we report two native valve Enterococcus faecalis IE cases in patients successfully treated with telavancin. An 88-year-old with mitral valve endocarditis and a penicillin allergy, initially treated with intravenous vancomycin, was switched to telavancin. A 69-year-old, who previously received amoxicillin and intravenous vancomycin for presumed enterococcal bacteraemia, was diagnosed with dual valve endocarditis for which he received telavancin. Both received six weeks of telavancin. Neither had telavancin-related adverse events, evidence of infection at six months, nor required telavancin dosing adjustments. Documented use of novel treatments for serious enterococcal infections is needed.

Telavancin Is Active against Experimental Aortic Valve Endocarditis Caused by Daptomycin- and Methicillin-Resistant Staphylococcus aureus Strains

We compared the efficacy of telavancin (TLV) and daptomycin (DAP) in an experimental rabbit endocarditis model caused by two clinically derived daptomycin-resistant (DAP^r) methicillin-resistant Staphylococcus aureus (MRSA) strains. TLV treatment significantly reduced MRSA densities in all target tissues and increased the percentage of these organs rendered culture negative compared to those with the untreated control or DAP-treated animals. These results demonstrate that TLV has potent in vivo efficacy against DAP^r MRSA isolates in this invasive endovascular infection model.

Systematic Review and Meta-Analysis of the Efficacy and Safety of Telavancin for Treatment of Infectious Disease: Are We Clearer?

Objective: Telavancin is approved to treat complicated skin and skin structure infections, hospital-acquired, and ventilator-associated bacterial pneumonia caused by Staphylococcus aureus. A previous meta-analysis of randomized controlled trials suggested that it might be an alternative to vancomycin in cases of difficult-to-treat meticillin-resistant S. aureus infections. We did a meta-analysis including one new trial to access the efficacy and safety of telavancin. Methods: We searched PubMed, Cochrane Central Register of Controlled Trials, EMBASE and ClinicalTrials.gov up to December 30, 2015 to identify randomized controlled trials that assessed the clinical efficacy, eradication efficiency, adverse events and laboratory abnormalities of telavancin vs. other antibiotic agents for bacterial infection. Meta-analysis was performed using Review Manager 5.3.0. Results: Five studies (3790 participants) were included in the meta-analysis. There was no significant difference in treatment success with telavancin than with control antibiotic agents. The pooled pathogen eradication for the telavancin group was numerically higher than that for the control groups, but there was no significant difference. While all-cause mortalities and serious adverse events were comparable between telavancin and control antibiotic agents, adverse event-related withdrawals (OR 1.47, 95% CI 1.13-1.91) were higher in telavancin group. The total number adverse events were more in the telavancin group than in the control groups, especially in the digestive system (OR 1.57, 95% CI 1.37-1.79), nervous system (OR 2.14, 95% CI 1.86-2.47) and urogenital system (OR 2.54, 95% CI 1.99-3.25). Serum creatinine increase (OR 2.25, 95% Cl 1.78-2.85) and hypokalemia (OR 1.74, 95% CI 1.19-2.53) occurred more frequently in telavancin group compared to control groups. Conclusion: Telavancin may be as effective as but no better than the comparison therapy for S. aureus infection. However, because of the high risk of adverse event-related withdrawals and potential nephrotoxicity, prudence with the clinical use of telavancin in infections is required.

Telavancin in the treatment of Staphylococcus aureus hospital-acquired and ventilator-associated pneumonia: clinical evidence and experience

Telavancin (TLV) is a lipoglycopeptide derivative of vancomycin (VAN), which has activity against Gram-positive aerobic bacteria, and is especially effective against methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive bacteria resistant to VAN. Comparative clinical studies of TLV have demonstrated noninferiority compared with VAN in the treatment of hospital-acquired Gram-positive pneumonia, with high cure rates for TLV-treated patients with monomicrobial S. aureus infection, including isolates with reduced VAN susceptibility. The results based on the patients' clinical response were supported by supplemental post-hoc analyses of 28-day mortality. In Europe and the USA, TLV is approved as a useful alternative for patients with difficult-to-treat, hospital-acquired MRSA pneumonia when there are very few alternatives. The present article reviews TLV's pharmacological characteristics and clinical efficacy resulting from clinical trials giving a detailed picture of its properties and position in the management of hospital-acquired pneumonia.

Telavancin hospital-acquired pneumonia trials: impact of Gram-negative infections and inadequate Gram-negative coverage on clinical efficacy and all-cause mortality

BACKGROUND

When hospital-acquired or ventilator-associated bacterial pneumonia (HABP/VABP) is caused by gram-positive and gram-negative pathogens or both (mixed infections), the adequacy of gram-negative coverage (GNC) can confound the assessment of a gram-positive agent under study. This analysis examines the influence of gram-negative infections and the adequacy of GNC on clinical efficacy and all-cause mortality in the telavancin HABP/VABP phase 3 ATTAIN trials (Assessment of Telavancin for Treatment of Hospital-Acquired Pneumonia).

METHODS

This post hoc analysis evaluated 3 patient groups from ATTAIN: (1) gram-positive-only infections, (2) gram-positive-only and mixed infections-adequate GNC, and (3) gram-negative-only infections and mixed infections with inadequate GNC. For each, clinical efficacy at test of cure and all-cause mortality at day 28 were compared for telavancin and vancomycin.

RESULTS/CONCLUSIONS

In the ATTAIN safety population there were 16 more deaths in the telavancin arms than in the vancomycin arms. Of these, 13 were in patients with gram-negative-only infections (n = 9) or with mixed infections and inadequate GNC (n = 4) and all had estimated baseline creatinine clearances of <30ml/min. Based on this analysis, clinical response and all-cause mortality could be confounded because there were more patients with gram-negative pathogens at baseline and more patients received inadequate treatment of these gram-negative infections in the telavancin groups.

Skin and soft-tissue infections: a critical review and the role of telavancin in their treatment

Skin and soft-tissue infections (SSTIs) are an important cause of morbidity and mortality among hospitalized patients and a major therapeutic challenge for clinicians. Although uncomplicated SSTIs are managed successfully on an outpatient basis, more serious infections extending to the subcutaneous tissue, fascia, or muscle require complex management. Early diagnosis, selection of appropriate antimicrobials, and timely surgical intervention are key to successful treatment. Surgical-site infections, an important category of SSTI, occur in approximately half a million patients in North America annually. SSTIs are also a potential source for life-threatening bacteremia and metastatic abscesses. Gram-positive organisms, such as Staphylococcus aureus and Streptococcus pyogenes, are the dominant organisms isolated early in the infectious process, whereas gram-negative organisms are found in chronic wounds. Methicillin-resistant S. aureus (MRSA) is a potential bloodstream invader that requires aggressive antimicrobial treatment and surgery. Recent concerns regarding vancomycin activity include heteroresistance in MRSA and increase in the minimum inhibitory concentrations (>1 or 2 µg/mL); however, alternative agents, such as telavancin, daptomycin, linezolid, ceftaroline, dalbavancin, oritavancin, and tedizolid, are now available for the treatment of severe MRSA infections. Here, we present a review of the epidemiology, etiology, and available treatment options for the management of SSTIs.

Telavancin: mechanisms of action, in vitro activity, and mechanisms of resistance

Telavancin is a semisynthetic lipoglycopeptide derivative of vancomycin. Telavancin has a dual mechanism of antibacterial action, disrupting peptidoglycan synthesis and cell membrane function. In 2014, the Clinical and Laboratory Standards Institute (CLSI) revised the antimicrobial susceptibility testing method for telavancin, resulting in minimum inhibitory concentration (MIC) determinations that are more accurate and reproducible and demonstrate greater in vitro potency than shown with the previous testing method. The CLSI testing method changes coincided with revised telavancin MIC interpretive break point criteria for susceptibility approved by the US Food and Drug Administration for Staphylococcus aureus (≤0.12 µg/mL), Streptococcus pyogenes (≤0.12 µg/mL), Streptococcus agalactiae (≤0.12 µg/mL), Streptococcus anginosus group (≤0.06 µg/mL), and Enterococcus faecalis (vancomycin susceptible, ≤0.25 µg/mL). Telavancin is equally potent against methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). It demonstrates activity against isolates of heterogeneous vancomycin-intermediate S. aureus and vancomycin-intermediate S. aureus but is poorly active against vancomycin-resistant S. aureus. It also demonstrates potent activity against Staphylococcus epidermidis and Streptococcus spp. (MIC90 ≤0.03 µg/mL). Thus far, it has not been possible to select for high-level telavancin resistance in the laboratory using serially passaged clinical isolates of MRSA and MSSA.

Post-reconstitution Stability of Telavancin with Commonly Used Diluents and Intravenous Infusion Solutions

Objective

The post-reconstitution chemical stability and microbial challenge hold time of nonpreserved telavancin for injection was determined using common reconstitution diluents and intravenous (IV) infusion solutions stored at room temperature with light (ambient) or at 2°C to 8°C without light (refrigeration).

Methods

Telavancin was reconstituted with 5% dextrose, 0.9% normal saline, or sterile water (15 mg/mL). Infusion solutions at 0.6 and 8.0 mg/mL were prepared in ViaFlex (polyvinyl chloride) IV bags (Baxter International Inc, Deerfield, Illinois) using 5% dextrose, 0.9% normal saline, or lactated Ringer’s solution. Chemical stability was evaluated for up to 14 days under refrigeration and for up to 3 days under ambient conditions. Telavancin concentration and degradant levels were determined using a stability-indicating HPLC method. Solutions were subjected to microbial-challenge testing for up to 48 hours (ambient) or for up to 6 days (refrigeration).

Results

All reconstituted or infused telavancin solutions met the prespecified stability acceptance criteria after 2 days under ambient and minimum 7 days under refrigeration. Following inoculation with gram-positive and gram-negative microorganisms, telavancin infusion solutions stored under ambient conditions reduced or inhibited populations of all organisms up to 48 hours, except for Serratia marcescens, which exhibited growth of >0.5 log₁₀ after 12 hours. All refrigerated samples inhibited or reduced bacterial populations up to 6 days.

Conclusions

These results are supportive of a total hold time for reconstituted telavancin in vials plus the time in IV infusion solutions in polyvinyl chloride bags to not exceed 12 hours under ambient conditions and 7 days under refrigeration.

Chemical Stability of Telavancin in Elastomeric Pumps

Background

VIBATIV is a once-daily, injectable lipoglycopeptide antibiotic approved in the U.S. for the treatment of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by susceptible isolates of Staphylococcus aureus when alternative treatments are not suitable. In addition, VIBATIV is approved in the U.S. for the treatment of adult patients with complicated skin & skin structure infections (cSSSI) caused by susceptible isolates of Gram-positive bacteria, including Staphylococcus aureus, both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains.

Objective

To evaluate the chemical stability of telavancin (Vibativ; Theravance Biopharma US, Inc, Northbrook, Illinois), a lipoglycopeptide antibiotic with activity against methicillin-resistant Staphylococcus aureus, in 2 types of elastomeric pumps, the Intermate Infusion System (Baxter International Inc) and the Homepump Eclipse (I-Flow Corporation).

Methods

Different sizes of the Baxter (Ontario, Canada) (105 mL and 275 mL) and I-Flow (Stoughton, Massachusetts) (100 mL and 250 mL) pumps were compared with glass controls. The telavancin drug product was reconstituted and diluted to concentrations of 0.6 mg/mL and 8.0 mg/mL using either 0.9% saline, 5% dextrose in water, or sterilized water for injection (0.6 mg/mL telavancin) or saline (8.0 mg/mL telavancin) followed by Ringer’s Lactate solution. Pumps were filled and stored at 2°C to 8°C, protected from light. Aliquots from both pump types and for all telavancin reconstitution/dilution schemes and concentrations were taken over a period of 8 days and analyzed for appearance, pH, telavancin concentration and purity, and degradation products.

Results

The pH of all pump solutions remained consistent throughout the 8-day analysis period, within a range of 4.6 to 5.7 for the 0.6 mg/mL and 4.4 to 4.9 for the 8.0 mg/mL telavancin solutions. There was no significant change in the chromatographic purity for any of the pump solutions examined. All decreases in telavancin concentration were ≤2.7%. Comparison of each test sample solution to the corresponding glass control indicated no loss of active drug due to absorption by the elastomeric material of the pumps. The greatest increase in the amount of total degradants observed over the 8-day period was ~0.7 w/w%.

Conclusions

The results of this study indicate that telavancin remains chemically stable when diluted in the Intermate Infusion System and the Homepump Eclipse elastomeric pumps and stored at 2°C to 8°C for up to 8 days protected from light at the concentration range and dilution schemes evaluated.

Glycopeptide antibiotics: evolving resistance, pharmacology and adverse event profile

The first glycopeptide antibiotic was vancomycin, isolated from the soil in the 1950s; since then, the class has expanded to include teicoplanin and the new semisynthetic glycopeptides dalbavancin, oritavancin and telavancin. They are bactericidal, active against most Gram-positive organisms, and in a concentration-dependent manner, inhibit cell wall synthesis. Resistance to vancomycin has emerged, especially among enterococci and Staphylococcus aureus through a variety of mechanisms. This emerging resistance to vancomycin makes proper dosing and monitoring of the area under the curve/MIC critically important. The chief adverse effect of vancomycin is nephrotoxicity, which is also intricately related to its dose. The efficacy of the semisynthetic glycopeptides has been demonstrated in skin and soft-tissue infections, but remains to be seen in serious methicillin-resistant Staphylococcus aureus infections.

Telavancin (VIBATIV) for the treatment of complicated skin and skin structure infections

Methicillin-resistant Staphylococcus aureus has emerged as a major causative pathogen in complicated skin and skin structure infections (cSSSIs). Unfortunately, treatment failure with vancomycin has been increasingly reported. Over the past decade, several alternative antimicrobial agents have been studied and approved for the treatment of cSSSIs. One such agent is the lipoglycopeptide telavancin, which was approved by the US FDA 2009. Given its dual mechanism of action, telavancin is characterized by a highly bactericidal activity and low potential for resistance selection. In addition, in clinical trials, it was efficacious and safe in the treatment of cSSSI. The purpose of this review is to give a background overview of telavancin, highlighting its microbiological, pharmacokinetic and pharmacodynamics characteristics, to summarize the available evidence for its use in the treatment of cSSSIs, and to provide an updated evaluation of its safety profile.

Update on the emerging role of telavancin in hospital-acquired infections

Telavancin is a lipoglycopeptide that has activity against Gram-positive aerobic and anaerobic bacteria. It has activity against methicillin-resistant Staphylococcus aureus, vancomycin-intermediate S. aureus and non-Van-A strains of vancomycin-resistant enterococci. It has been approved by the US Food and Drug Administration (FDA) for complicated skin and skin structure infections and hospital-acquired pneumonia. There is a need for more clinical studies to determine the role of telavancin in treating bacteremia and prosthetic device infections. In this review, we discuss the published data on the use of telavancin in treating hospital-acquired infections and provide an update on new research.

Potential role for telavancin in bacteremic infections due to gram-positive pathogens: focus on Staphylococcus aureus

Staphylococcus aureus bacteremia (SAB) is one of the most common serious bacterial infections and the most frequent invasive infection due to methicillin-resistant S. aureus (MRSA). Treatment is challenging, particularly for MRSA, because of limited treatment options. Telavancin is a bactericidal lipoglycopeptide antibiotic that is active against a range of clinically relevant gram-positive pathogens including MRSA. In experimental animal models of sepsis telavancin was shown to be more effective than vancomycin. In clinically evaluable patients enrolled in a pilot study of uncomplicated SAB, cure rates were 88% for telavancin and 89% for standard therapy. Among patients with infection due to only gram-positive pathogens enrolled in the 2 phase 3 studies of telavancin for treatment of hospital-acquired pneumonia, cure rates for those with bacteremic S. aureus pneumonia were 41% (9/22, telavancin) and 40% (10/25, vancomycin) with identical mortality rates. These data support further evaluation of telavancin in larger, prospective studies of SAB.

Analysis of Phase 3 telavancin nosocomial pneumonia data excluding patients with severe renal impairment and acute renal failure

Objectives

Telavancin is approved in Europe for the treatment of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus when other alternatives are not suitable. The approved European prescribing information contraindicates the use of telavancin in patients with severe renal impairment (creatinine clearance <30 mL/min, including patients on haemodialysis) and pre-existing acute renal failure owing to the higher observed mortality in these patients. Data from the ATTAIN studies were reanalysed, excluding patients with these contraindicating conditions at baseline. (At the time of submission of this article, the European marketing authorization of telavancin for the treatment of nosocomial pneumonia was suspended pending evidence of a new European Medicines Agency-approved supplier. Clinigen Healthcare Ltd, Theravance's commercialization partner for telavancin in Europe, is in the process of seeking approval of a new manufacturing source.)

Methods

A post hoc analysis of data from two Phase 3 ATTAIN trials of telavancin for the treatment of Gram-positive nosocomial pneumonia assessing clinical outcomes and safety.

Results

The all-treated population for this analysis represented 84.2% (1266/1503) of the ATTAIN all-treated population. The cure rates in the clinically evaluable population were similar in the telavancin (82.5%, 231/280) and vancomycin (81.3%, 243/299) groups [treatment difference (95% CI): 1.3% (−5.0% to 7.6%)], and were consistent with the overall ATTAIN study results. The cure rate was higher in the telavancin than the vancomycin treatment group in microbiologically evaluable patients with only Gram-positive pathogens isolated at baseline [85.0% (130/153) versus 75.2% (109/145), respectively; treatment difference (95% CI): 9.7% (0.6%–18.8%)]. The incidences of adverse events were similar between treatment groups and consistent with the overall findings of the ATTAIN study.

Conclusions

This analysis demonstrated that in the subset of patients without severe renal impairment or pre-existing acute renal failure, clinical and safety outcomes were similar in the telavancin and vancomycin treatment groups.

In Vitro Synergy of Telavancin and Rifampin Against Enterococcus faecium Resistant to Both Linezolid and Vancomycin

BACKGROUND

An emerging pathogen is Enterococcus faecium resistant to both linezolid and vancomycin (LRVRE). Antimicrobial combinations may be required for therapy and need to be evaluated. The combination of daptomycin and rifampin has demonstrated good in vitro activity against gram-positive bacteria, including E faecium. Telavancin, a newer lipoglycopeptide, has shown in vitro activity against E faecium. We evaluated the combination of telavancin and rifampin and compared the results to the combination of daptomycin and rifampin used previously on the same isolates.

METHODS

Twenty-four genetically unique (by pulsed-field gel electrophoresis), clinical LRVRE isolates were collected in the United States from 2001-2004. Etest minimal inhibitory concentrations (MICs) (μg/mL) were 0.064-8 for telavancin, 1-4 for daptomycin, and 0.012 to >32 for rifampin. In vitro synergy testing was performed in triplicate by an Etest MIC:MIC ratio method, and summation fractional inhibitory concentration (ΣFIC) was calculated: synergy ≤0.5; indifference >0.5-4; and antagonism >4.

RESULTS

The Etest method showed synergy (ΣFICs of 0.1-0.5) with telavancin + rifampin in 20/24 (83%) isolates and indifference (ΣFICs of 0.6-0.8) in 4/24 (17%) isolates. Similarly, the daptomycin + rifampin combination showed synergy (ΣFICs of 0.1-0.5) in 21/24 (88%) isolates and indifference (ΣFICs of 0.6-1.0) in 3/24 (12%) isolates by the Etest method. No antagonism was found.

CONCLUSIONS

In vitro synergy with both combinations (rifampin + telavancin or daptomycin) was 83% and 88%, respectively, by Etest against these LRVRE isolates. Although both daptomycin and telavancin in combination with rifampin showed a high incidence of synergistic activity, further in vitro synergy testing with this combination should be performed against additional E faecium isolates. In vitro synergy may or may not translate into in vivo effectiveness.

Telavancin for the treatment of nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA)

Telavancin is a bactericidal lipoglycopeptide antibiotic that is structurally related to vancomycin. It demonstrates in vitro activity against a variety of Gram-positive pathogens including, but not limited to, methicillin-resistant Staphylococcus aureus (MRSA). Telavancin is currently FDA-approved for the treatment of complicated skin and skin-structure infections. Recently, two randomized clinical trials demonstrated the efficacy and safety of telavancin compared to vancomycin for the treatment of nosocomial pneumonia. Overall, telavancin has a favorable safety profile. However, mild gastrointestinal disturbances and reversible increases in serum creatinine were observed in clinical studies. Additional clinical studies are needed to evaluate telavancin's efficacy and safety in comparison to other antistaphylococcal agents for the treatment of infections such as bacteremia and endocarditis.

A review of telavancin in the treatment of complicated skin and skin structure infections (cSSSI)

Telavancin is a novel antibiotic being investigated for the treatment of serious infections caused by Gram-positive bacteria, including complicated skin and skin structure infections (cSSSI) and pneumonia. This once-daily intravenous lipoglycopeptide exerts rapid bactericidal activity via a dual mechanism of action. It is intended for use to combat infections caused by Staphylococcus aureus and other Gram-positive bacteria, including methicillin-resistant and vancomycin-intermediate strains of S. aureus (MRSA and VISA, respectively). Vancomycin is the current gold standard in treating serious infections caused by Gram-positive bacteria, especially MRSA. In recent clinical trials, telavancin has shown excellent efficacy in phase II and III multinational, randomized, double-blinded studies of cSSSI. In the phase II FAST 2 study, which compared telavancin 10 mg/kg intravenously q 24 h vs standard therapy (an antistaphylococcal penicillin at 2 g IV q 6 h or vancomycin 1 gm IV q 12 h), the clinical success rate in the telavancin-treated group was 96% vs 94% in the standard therapy group. In two identical phase III trials comparing telavancin versus vancomycin at the doses of the FAST 2 study for cSSSI, the clinical cure rates were 88.3% and 87.1%, respectively. Two additional phase III clinical trials investigating telavancin for use in hospital-acquired pneumonia, caused by Gram-positive bacteria are currently ongoing. Telavancin is currently under regulatory review in both the United States and Europe for the indication of treatment of cSSSI.

Telavancin, a new lipoglycopeptide antimicrobial, in complicated skin and soft tissue infections

Telavancin, a novel lipoglycopeptide with rapid concentration-dependent bactericidal effects, is a semisynthetic derivative of the glycopeptide, vancomycin. Telavancin has a dual mechanism of action, ie, inhibition of peptidoglycan polymerization and disruption of the bacterial membrane. It has linear pharmacokinetics, rapid bactericidal killing, and broad spectrum activity against Gram positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus. Phase II and III clinical trials for complicated skin and skin structure infections have shown telavancin to have similar efficacy and tolerability to that of vancomycin and standard anti-staphylococcal β-lactams plus vancomycin. In Phase II trials, there was a significant difference in eradication of MRSA between groups, ie, telavancin therapy 92% and standard therapy (vancomycin, nafcillin, oxacillin, or cloxacillin) 68% (P < 0.05). In Phase III trials, among clinically evaluable patients who had MRSA isolated at baseline, the overall therapeutic response was higher in patients treated with telavancin than in patients treated with vancomycin (89.9% versus 84.7%; 95% CI −0.3, 10.5). Also, the efficacy of telavancin was not inferior to that of vancomycin for the treatment of complicated skin and skin structure infections in the clinical trials.

Role of telavancin in treatment of skin and skin structure infections

Skin and skin structure infections (SSSIs) are a common diagnosis encountered by ambulatory and inpatient practitioners across the country. As the SSSIs become more complicated, they require increased health care resources and often involve hospitalization and intravenous antimicrobials. Complicated SSSIs are caused by a variety of pathogens, including Gram-positive, Gram-negative, and anerobic bacteria. Empiric broad-spectrum antibiotic coverage is warranted, taking into account area disease-state epidemiology and antimicrobial susceptibility data. Telavancin is an antimicrobial agent with a broad Gram-positive spectrum of activity which was recently approved for the treatment of SSSIs. It may especially benefit patients with resistant organisms, such as methicillin-resistant Staphylococcus aureus. This article reviews telavancin and its pharmacology, efficacy, and safety data to enhance the practitioner’s knowledge base on the appropriateness of telavancin for the treatment of SSSIs.