Tedizolid for 6 days versus linezolid for 10 days for acute bacterial skin and skin-structure infections (ESTABLISH-2): a randomised, double-blind, phase 3, non-inferiority trial

Once-Daily Treatments for Methicillin-Susceptible Staphylococcus aureus Bacteremia: Are They Good Enough?

PURPOSE OF THE REVIEW

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a common cause of morbidity and mortality. First-line treatment requires frequent daily doses of an anti-staphylococcal beta-lactam. However, some physicians prescribe simpler once-daily regimens to improve compliance and improve healthcare utilization. We reviewed the literature regarding advantages, pitfalls, and efficacy of once-daily treatment options for MSSA bacteremia.

RECENT FINDINGS

Several once-daily antibiotics are effective in vitro against MSSA (ceftriaxone, daptomycin, telavancin, dalbavancin, oritavancin, tedizolid, ertapenem, fluoroquinolones, and others), but there is insufficient evidence to support these agents for MSSA bacteremia. Ceftriaxone may be considered for therapy completion with MSSA bacteremia from osteomyelitis, and daptomycin may be considered in patients who cannot tolerate first-line therapy. However, they have not been compared to traditional second-line agents, and their role remains uncertain. Current evidence does not support the use of once-daily treatment options for MSSA bacteremia.

Risk factors for amendment in type, duration and setting of prescribed outpatient parenteral antimicrobial therapy (OPAT) for adult patients with cellulitis: a retrospective cohort study and CART analysis

PURPOSE OF THE STUDY

To measure the percentage rate and risk factors for amendment in the type, duration and setting of outpatient parenteral antimicrobial therapy (OPAT) for the treatment of cellulitis.

STUDY DESIGN

A retrospective cohort study of adult patients receiving OPAT for cellulitis was performed. Treatment amendment (TA) was defined as hospital admission or change in antibiotic therapy in order to achieve clinical response. Multivariable logistic regression (MVLR) and classification and regression tree (CART) analysis were performed.

RESULTS

There were 307 patients enrolled. TA occurred in 36 patients (11.7%). Significant risk factors for TA on MVLR were increased age, increased Numerical Pain Scale Score (NPSS) and immunocompromise. The median OPAT duration was 7 days. Increased age, heart rate and C reactive protein were associated with treatment prolongation. CART analysis selected age <64.5 years, female gender and NPSS <2.5 in the final model, generating a low-sensitivity (27.8%), high-specificity (97.1%) decision tree.

CONCLUSIONS

Increased age, NPSS and immunocompromise were associated with OPAT amendment. These identified risk factors can be used to support an evidence-based approach to patient selection for OPAT in cellulitis. The CART algorithm has good specificity but lacks sensitivity and is shown to be inferior in this study to logistic regression modelling.

Management of acute bacterial skin and skin structure infections with a focus on patients at high risk of treatment failure

Over the last 25 years, the terminology of skin and soft tissue infections, as well as their classification for optimal management of patients, has changed. The so-called and recently introduced term 'acute bacterial skin and skin structure infections' (ABSSSIs), a cluster of fairly common types of infection, including abscesses, cellulitis, and wound infections, require an immediate effective antibacterial treatment as part of a timely and cautious management. The extreme level of resistance globally to many antibiotic drugs in the prevalent causative pathogens, the presence of risk factors of treatment failure, and the high epidemic of comorbidities (e.g. diabetes and obesity) make the appropriate selection of the antibiotic for physicians highly challenging. The selection of antibiotics is primarily empirical for ABSSSI patients which subsequently can be adjusted based on culture results, although rarely available in outpatient management. There is substantial evidence suggesting that inappropriate antibiotic treatment is given to approximately 20-25% of patients, potentially prolonging their hospital stay and increasing the risk of morbidity and mortality. The current review paper discusses the concerns related to the management of ABSSSI and the patient types who are most vulnerable to poor outcomes. It also highlights the key management time-points that treating physicians and surgeons must be aware of in order to achieve clinical success and to discharge patients from the hospital as early as possible.

Pharmacokinetics, Safety, and Tolerability of Tedizolid Phosphate After Single-dose Administration in Healthy Korean Male Subjects

PURPOSE

Tedizolid phosphate is a next-generation oxazolidinone prodrug that is transformed into the active moiety tedizolid. Its indication is acute bacterial skin and skin structure infections caused by gram-positive species, including methicillin-resistant Staphylococcus aureus. Although tedizolid phosphate has been marketed in Korea, no data on the pharmacokinetic (PK) properties or tolerability of tedizolid phosphate in Korean subjects are available. This study was designed to evaluate the PK properties, oral bioavailability, and tolerability with a single-dose oral and intravenous administration of tedizolid phosphate in healthy Korean male subjects.

METHODS

A block-randomized, double-blind, placebo-controlled, single-dose study was conducted in 3 groups (200, 400, and 600 mg; 10 subjects in each group). In the second part of the study, subjects from the 200-mg group received administration orally and intravenously (1-hour infusion) via 2-way crossover for the evaluation of absolute bioavailability. There was a 7-day washout period between treatments in the absolute bioavailability part of the study. Serial blood samples for PK analysis were collected for up to 72 hours. Tolerability was assessed by analysis of adverse events.

FINDINGS

Thirty healthy Korean subjects completed the study and were included in the PK and tolerability analyses. Tedizolid phosphate was rapidly converted into tedizolid. After a single oral dose, the T_max of tedizolid was observed to be 1.5 to 2.5 hours, and the plasma concentration-time curve of tedizolid showed a 2-phase elimination pattern, with a half-life of ~11 hours. Dose-dependent increases were observed in the AUC_last value (29,441-78,062 μg · h/L) and in the C_{max value (}2679-6980 μg/L) with the administration of tedizolid phosphate 200 to 600 mg PO. The absolute bioavailability of tedizolid was 95.2% (90% CI, 92.7%-97.8%) in the 200-mg administration group. There were no serious adverse events or clinically significant changes in the tolerability assessment.

IMPLICATIONS

Tedizolid phosphate at doses of up to 600 mg was well-tolerated in these healthy Korean male subjects. Tedizolid shows dose linearity with oral administration, and no dose adjustment of tedizolid phosphate 200 mg would be needed when switching administration routes. ClinicalTrials.gov identifier: NCT02097043.

Susceptibility testing and reporting of new antibiotics with a focus on tedizolid: an international working group report

Inappropriate use and overuse of antibiotics are among the most important factors in resistance development, and effective antibiotic stewardship measures are needed to optimize outcomes. Selection of appropriate antimicrobials relies on accurate and timely antimicrobial susceptibility testing. However, the availability of clinical breakpoints and in vitro susceptibility testing often lags behind regulatory approval by several years for new antimicrobials. A Working Group of clinical/medical microbiologists from Brazil, Canada, Mexico, Saudi Arabia, Russia and the UK recently examined issues surrounding antimicrobial susceptibility testing for novel antibiotics. While commercially available tests are being developed, potential surrogate antibiotics may be used as marker of susceptibility. Using tedizolid as an example of a new antibiotic, this special report makes recommendations to optimize routine susceptibility reporting.

Future trends in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection: An in-depth review of newer antibiotics active against an enduring pathogen

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major public health problem. Vancomycin and teicoplanin have been in clinical use for several decades but their drawbacks are well described. In the last 10 years, several antibiotics have been made available for clinical use. Daptomycin and linezolid have been extensively used during this period. Other agents such as ceftaroline, ceftobiprole, dalbavancin, oritavancin, tedizolid and telavancin have been approved by regulatory agencies since 2009. Many others, such as the newer tetracyclines, fluoroquinolones, oxazolidinones and pleuromutilins, are in various stages of development. In addition, an ongoing multicentre trial is investigating the role of combination of vancomycin or daptomycin with β-lactam antibiotics. This review discusses the role of the newer antibiotics, reflecting the views of the 6th MRSA Consensus Conference meeting of the International Society of Chemotherapy MRSA Working Group that took place in 2016.

Tedizolid and Linezolid for Treatment of Acute Bacterial Skin and Skin Structure Infections of the Lower Extremity versus Non-Lower-Extremity InfectionsPooled Analysis of Two Phase 3 Trials

BACKGROUND

Tedizolid phosphate, the prodrug of the oxazolidinone tedizolid, has been approved in a number of countries, including the United States, those in the European Union, and Canada, for treatment of patients with acute bacterial skin and skin structure infections (ABSSSI). Two phase 3 trials demonstrated the noninferior efficacy of tedizolid (200 mg once daily for 6 days) to linezolid (600 mg twice daily for 10 days) in patients with ABSSSI. Because of the challenges of treating lower-extremity ABSSSI, the efficacy and safety of tedizolid and linezolid for treating lower-extremity versus non-lower-extremity infections were compared.

METHODS

This was a post hoc analysis of pooled data from patients with lower-extremity infections enrolled in two phase 3 studies, ESTABLISH-1 (NCT01170221) and ESTABLISH-2 (NCT01421511), comparing tedizolid to linezolid in patients with ABSSSI.

RESULTS

Lower-extremity ABSSSI were present in 40.7% of tedizolid-treated and 42.2% of linezolid-treated patients. Methicillin-resistant Staphylococcus aureus (MRSA) was present in 34.7% of all patients with a baseline causative pathogen. Early clinical responses at 48 to 72 hours and investigator-assessed responses at the post-therapy evaluation were similar between tedizolid and linezolid, regardless of ABSSSI type. With both treatments, the early clinical response was slightly higher in patients with non-lower-extremity infection than in those with lower-extremity ABSSSI (tedizolid, 84.8% versus 77.0%; linezolid, 81.4% versus 76.6%, respectively); however, by the post-therapy evaluation visit, response rates were similar (tedizolid, 87.1% versus 86.3%; linezolid, 86.6% versus 87.2%, respectively). Gastrointestinal adverse events and low platelet counts were observed more frequently with linezolid treatment.

CONCLUSIONS

Post-therapy evaluations showed that the clinical response of lower-extremity ABSSSI to tedizolid and linezolid was comparable to that of ABSSSI in other locations. A short 6-day course of once-daily tedizolid was as effective as a 10-day course of twice-daily linezolid in treating patients with lower-extremity ABSSSI.

Clinical Response of Tedizolid versus Linezolid in Acute Bacterial Skin and Skin Structure Infections by Severity Measure Using a Pooled Analysis from Two Phase 3 Double-Blind Trials

Tedizolid phosphate is approved for the treatment of acute bacterial skin and skin structure infections (ABSSSI). In a pooled analysis of 1,333 ABSSSI patients from the ESTABLISH clinical trials, treatment with tedizolid or linezolid demonstrated similar early and posttherapy clinical responses in nonsevere and severe disease, irrespective of the parameters used to measure ABSSSI severity. Shorter 6-day treatment of ABSSSI, including those that were severe, with tedizolid phosphate demonstrated efficacy comparable to that of 10-day treatment with linezolid. (The ESTABLISH studies discussed in this paper have been registered at ClinicalTrials.gov under identifiers NCT01170221 and NCT01421511.).

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

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

Effects of Tedizolid Phosphate on Survival Outcomes and Suppression of Production of Staphylococcal Toxins in a Rabbit Model of Methicillin-Resistant Staphylococcus aureus Necrotizing Pneumonia

The protective efficacy of tedizolid phosphate, a novel oxazolidinone that potently inhibits bacterial protein synthesis, was compared to those of linezolid, vancomycin, and saline in a rabbit model of Staphylococcus aureus necrotizing pneumonia. Tedizolid phosphate was administered to rabbits at 6 mg/kg of body weight intravenously twice daily, which yielded values of the 24-h area under the concentration-time curve approximating those found in humans. The overall survival rate was 83% for rabbits treated with 6 mg/kg tedizolid phosphate twice daily and 83% for those treated with 50 mg/kg linezolid thrice daily (P = 0.66 by the log-rank test versus the results obtained with tedizolid phosphate). These survival rates were significantly greater than the survival rates of 17% for rabbits treated with 30 mg/kg vancomycin twice daily (P = 0.003) and 17% for rabbits treated with saline (P = 0.002). The bacterial count in the lungs of rabbits treated with tedizolid phosphate was significantly decreased compared to that in the lungs of rabbits treated with saline, although it was not significantly different from that in the lungs of rabbits treated with vancomycin or linezolid. The in vivo bacterial production of alpha-toxin and Panton-Valentine leukocidin, two key S. aureus-secreted toxins that play critical roles in the pathogenesis of necrotizing pneumonia, in the lungs of rabbits treated with tedizolid phosphate and linezolid was significantly inhibited compared to that in the lungs of rabbits treated with vancomycin or saline. Taken together, these results indicate that tedizolid phosphate is superior to vancomycin for the treatment of S. aureus necrotizing pneumonia because it inhibits the bacterial production of lung-damaging toxins at the site of infection.

[New antibiotics - standstill or progress]

The development of resistance to antibiotics has been ignored for a long time. But nowadays, increasing resistance is an important topic. For a decade no new antibiotics had been developed and it is not possible to quickly close this gap of new resistance and no new drugs. This work presents six new antibiotics (ceftaroline, ceftobiprole, solithromycin, tedizolid, ceftolozane/tazobactam, ceftazidime/avibactam). In part, only expert opinions are given due to lack of study results.The two 5th generation cephalosporins ceftaroline and ceftobiprole have beside their equivalent efficacy to ceftriaxone (ceftaroline) and cefipim (ceftobiprole) high activity against MRSA. The fluoroketolide solithromycin should help against macrolide-resistant pathogens and has been shown to be noninferior to the fluorochinolones. The oxazolidinone tedizolid is effective against linezolid-resistant MRSA. The two cephalosporins ceftolozane/tazobactam and ceftazidime/avibactam are not only effective against gram-negative pathogens, but they have a very broad spectrum. Due to the efficacy against extended-spectrum β‑lactamases, they can relieve the selection pressure of the carbapenems. We benefit from all new antibiotics which can take the selection pressure from other often used antibiotics. The increasing number of resistant gram-negative pathogens worldwide is alarming. Thus, focusing on the development of new drugs is extremely important.

Characterization of Neurologic and Ophthalmologic Safety of Oral Administration of Tedizolid for Up to 21 Days in Healthy Volunteers

BACKGROUND

Antibacterials that inhibit protein synthesis may be associated with mitochondrial toxicity, manifested as serious optic or peripheral neuropathy or myelosuppression. Tedizolid is a novel oxazolidinone antibacterial that may have reduced the potential for mitochondrial toxicity.

STUDY QUESTION

Based on the results of 2 studies (NCT01623401 and NCT00671814) conducted early in the tedizolid development program, what is the potential for drug-induced optic and peripheral neuropathies with tedizolid treatment?

METHODS

Two phase-1 studies were conducted in healthy volunteers. The first was an open-label study in which subjects received 200 mg of oral tedizolid phosphate once daily for 10 days. The second was a double-blind, placebo- and active-controlled, dose-escalating (multiple-administration) study in which subjects received 200, 300, or 400 mg of oral tedizolid phosphate once daily or 600 mg of oral linezolid twice daily or oral placebo for 21 days. Overall safety and tolerability were assessed, and extensive ophthalmologic and neurologic assessments were performed in both studies.

RESULTS

In these 2 studies in healthy subjects, tedizolid administered for up to 21 days was not associated with drug-related ophthalmologic or neurologic adverse events. Incidences of adverse events involving the eye or the nervous system were generally low, and no clinically meaningful changes in ophthalmologic or neurologic test results were recorded during either study.

CONCLUSIONS

Using an extensive battery of ophthalmologic tests and detailed neurologic clinical examination, there was no evidence of clinical or subclinical neurologic or ophthalmologic changes suggestive of peripheral or optic neuropathy in healthy volunteers who received therapeutic and supratherapeutic doses of oral tedizolid for periods of up to 21 days.

Proposal for shorter antibiotic therapies

OBJECTIVES

Reducing antibiotic consumption has now become a major public health priority. Reducing treatment duration is one of the means to achieve this objective. Guidelines on the therapeutic management of the most frequent infections recommend ranges of treatment duration in the ratio of one to two. The Recommendation Group of the French Infectious Diseases Society (SPILF) was asked to collect literature data to then recommend the shortest treatment durations possible for various infections.

METHODS

Analysis of the literature focused on guidelines published in French and English, supported by a systematic search on PubMed. Articles dating from one year before the guidelines publication to August 31, 2015 were searched on the website.

RESULTS

The shortest treatment durations based on the relevant clinical data were suggested for upper and lower respiratory tract infections, central venous catheter-related and uncomplicated primary bacteremia, infective endocarditis, bacterial meningitis, intra-abdominal, urinary tract, upper reproductive tract, bone and joint, skin and soft tissue infections, and febrile neutropenia. Details of analyzed articles were shown in tables.

CONCLUSION

This work stresses the need for new well-conducted studies evaluating treatment durations for some common infections. Following the above-mentioned work focusing on existing literature data, the Recommendation Group of the SPILF suggests specific study proposals.

Pharmacokinetic drug evaluation of tedizolid for the treatment of skin infections

INTRODUCTION

Tedizolid is indicated for the treatment of acute bacterial skin and skin structure infections (ABSSSI). Although tedizolid shares many similar properties with linezolid, another oxazolidinone used to treat ABSSSI, the two antibiotics have several key differences. Areas covered: This review provides a detailed summary of the overall pharmacodynamics, pharmacokinetics, clinical efficacy, and safety of tedizolid for the treatment of ABSSSI. Expert opinion: Compared to other antibiotics used for ABSSSI, tedizolid has several advantages. Tedizolid has a long half-life, allowing for once daily dosing. Tedizolid also has broad spectrum of activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, Coagulase-negative Staphylococci, and Enterococci - including isolates demonstrating resistance to linezolid. It is available in both oral and intravenous formulations, and, has outstanding oral bioavailability, allowing for oral-step down therapy. There is also some evidence that, tedizolid has fewer significant interactions with serotonin reuptake inhibitors or monoamine oxidase inhibitors than linezolid. Finally, thrombocytopenia may occur less often with tedizolid than linezolid. However, these benefits must be weighed against the financial cost of tedizolid and the availability of alternative antibiotic choices.

Systematic review and network meta-analysis of tedizolid for the treatment of acute bacterial skin and skin structure infections caused by MRSA

BACKGROUND

Tedizolid, the active moiety of tedizolid phosphate, is approved in the United States, the European Union, Canada and a number of other countries for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by certain susceptible bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). This network meta-analysis (NMA) evaluates the comparative effectiveness of tedizolid and other antibacterials indicated for the treatment of ABSSSI caused by MRSA.

METHODS

Systematic review of 10 databases was undertaken to inform an NMA to estimate the relative effectiveness of tedizolid and established monotherapy comparators (ceftaroline, daptomycin, linezolid, teicoplanin, tigecycline, vancomycin) for treating MRSA-associated ABSSSI. Randomized controlled trials enrolling adults with ABSSSI or complicated skin and skin structure infections caused by suspected/documented MRSA were eligible for inclusion. Networks were developed based on similarity of study design, patient characteristics, outcome measures and available data. Outcomes of interest included clinical response at end of therapy (EOT), post-therapy evaluation (PTE) or test-of-cure assessment and treatment discontinuations resulting from adverse events (AEs). Bayesian NMA was conducted for each outcome using fixed-effects and random effects models.

RESULTS

Literature searches identified 3,618 records; 15 trials met the inclusion criteria and were considered suitable for NMA comparison. In fixed-effects models, tedizolid had higher odds of clinical response at EOT (odds ratio [OR], 1.7; credible interval, 1.0, 3.0) and PTE than vancomycin (OR, 1.6; credible interval, 1.1, 2.5). No differences in odds of clinical response at EOT or PTE were observed between tedizolid and other comparators. There was no evidence of a difference among treatments for discontinuation due to AEs. Results from random effects and fixed-effects models were generally consistent.

CONCLUSIONS

Tedizolid was superior to vancomycin for clinical response at EOT and PTE. There was no evidence of a difference between tedizolid and other comparators and no evidence of a difference between tedizolid and all comparators when evaluating discontinuation due to AEs. These findings suggest that tedizolid provides an alternative option for the management of serious skin infections caused by suspected or documented MRSA. This study is subject to the limitations inherent in all NMAs, and the results should be interpreted accordingly.

Treatment of Staphylococcus aureus Infections

Staphylococcus aureus, although generally identified as a commensal, is also a common cause of human bacterial infections, including of the skin and other soft tissues, bones, bloodstream, and respiratory tract. The history of S. aureus treatment is marked by the development of resistance to each new class of antistaphylococcal antimicrobial drugs, including the penicillins, sulfonamides, tetracyclines, glycopeptides, and others, complicating therapy. S. aureus isolates identified in the 1960s were sometimes resistant to methicillin, a ß-lactam antimicrobial active initially against a majority S. aureus strains. These MRSA isolates, resistant to nearly all ß-lactam antimicrobials, were first largely confined to the health care environment and the patients who attended it. However, in the mid-1990s, new strains, known as community-associated (CA-) MRSA strains, emerged. CA-MRSA organisms, compared with health care-associated (HA-) MRSA strain types, are more often susceptible to multiple classes of non ß-lactam antimicrobials. While infections caused by methicillin-susceptible S. aureus (MSSA) strains are usually treated with drugs in the ß-lactam class, such as cephalosporins, oxacillin or nafcillin, MRSA infections are treated with drugs in other antimicrobial classes. The glycopeptide drug vancomycin, and in some countries teicoplanin, is the most common drug used to treat severe MRSA infections. There are now other classes of antimicrobials available to treat staphylococcal infections, including several that have been approved after 2009. The antimicrobial management of invasive and noninvasive S. aureus infections in the ambulatory and in-patient settings is the topic of this review. Also discussed are common adverse effects of antistaphylococcal antimicrobial agents, advantages of one agent over another for specific clinical syndromes, and the use of adjunctive therapies such as surgery and intravenous immunoglobulin. We have detailed considerations in the therapy of noninvasive and invasive S. aureus infections. This is followed by sections on specific clinical infectious syndromes including skin and soft tissue infections, bacteremia, endocarditis and intravascular infections, pneumonia, osteomyelitis and vertebral discitis, epidural abscess, septic arthritis, pyomyositis, mastitis, necrotizing fasciitis, orbital infections, endophthalmitis, parotitis, staphylococcal toxinoses, urogenital infections, and central nervous system infections.

Critical role of tedizolid in the treatment of acute bacterial skin and skin structure infections

Tedizolid phosphate has high activity against the Gram-positive microorganisms mainly involved in acute bacterial skin and skin structure infections, such as strains of Staphylococcus aureus (including methicillin-resistant S. aureus strains and methicillin-sensitive S. aureus strains), Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and Enterococcus faecalis, including those with some mechanism of resistance limiting the use of linezolid. The area under the curve for time 0-24 hours/minimum inhibitory concentration (MIC) pharmacodynamic ratio has shown the best correlation with the efficacy of tedizolid, versus the time above MIC ratio and the maximum drug concentration/minimum inhibitory concentration ratio. Administration of this antibiotic for 6 days has shown its noninferiority versus administration of linezolid for 10 days in patients with skin and skin structure infections enrolled in two Phase III studies (ESTABLISH-1 and ESTABLISH-2). Tedizolid's more favorable safety profile and dosage regimen, which allow once-daily administration, versus linezolid, position it as a good therapeutic alternative. However, whether or not the greater economic cost associated with this antibiotic is offset by its shorter treatment duration and possibility of oral administration in routine clinical practice has yet to be clarified.

Early Clinical Response as a Predictor of Late Treatment Success in Patients With Acute Bacterial Skin and Skin Structure Infections: Retrospective Analysis of 2 Randomized Controlled Trials

In the treatment of acute bacterial skin and skin structure infections, pooled data from 2 clinical trials (N = 1333 patients) showed that programmatic and investigator-assessed early treatment success both had a high positive predictive value (94.3%-100.0%) for late clinical cure, including among hospitalized patients. The negative predictive value of programmatic early success was <20%. These exploratory findings require prospective real-world evaluation.

CLINICAL TRIALS REGISTRATION

 NCT01170221; NCT01421511.

Linezolid: a promising option in the treatment of Gram-positives

Linezolid, an oxazolidinone antimicrobial agent that acts by inhibiting protein synthesis in a unique fashion, is used in the treatment of community-acquired pneumonia, skin and soft-tissue infections and other infections caused by Gram-positive bacteria including VRE and methicillin-resistant staphylococci. Currently, linezolid resistance among these pathogens remains low, commonly <1.0%, although the prevalence of antibiotic resistance is increasing in many countries. Therefore, the development of resistance by clinical isolates should prompt increased attention of clinical laboratories to routinely perform linezolid susceptibility testing for this important agent and should be taken into account when considering its therapeutic use. Considering the importance of linezolid in the treatment of infections caused by Gram-positive bacteria, this review was undertaken to optimize the clinical use of this antibiotic.

New agents approved for treatment of acute staphylococcal skin infections

Vancomycin has been a predominant treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections for decades. However, growing reservations about its efficacy led to an urgent need for new antibiotics effective against MRSA and other drug-resistant Staphylococcus aureus strains. This review covers three new anti-MRSA antibiotics that have been recently approved by the FDA: dalbavancin, oritavancin, and tedizolid. The mechanism of action, indications, antibacterial activity profile, microbial resistance, pharmacokinetics, clinical efficacy, adverse effects, interactions as well as available formulations and administration of each of these new antibiotics are described. Dalbavancin is a once-a-week, two-dose, long-acting intravenous bactericidal lipoglycopeptide antibiotic. Oritavancin, a lipoglycopeptide with bactericidal activity, was developed as a single-dose intravenous treatment for acute bacterial skin and skin-structure infections (ABSSSI), which offers simplifying treatment of infections. Tedizolid is an oxazolidinone-class bacteriostatic once-daily agent, available for intravenous as well as oral use. Increased ability to overcome bacterial resistance is the main therapeutic advantage of the novel agents over existing antibiotics.

Resistance to Non-glycopeptide Agents in Serious Staphylococcus aureus Infections

The role of vancomycin in the treatment of serious Staphylococcus aureus infections, both methicillin-susceptible and methicillin-resistant, is becoming increasingly ineffective due to increasing MIC and failure. The development of reduced vancomycin susceptibility by S. aureus to glycopeptides highlights the need for clinicians to reexamine the roles of non-glycopeptide therapy. As the use of these alternative non-glycopeptides antimicrobials increases, it will become pertinent to monitor the rates of resistance. Large surveillance programs have provided data for resistance against S. aureus for the non-glycopeptides (daptomycin, ceftaroline, tigecycline, linezolid, and tedizolid). The current published literatures suggest that worldwide resistance rates to these non-glycopeptides for serious MRSA infections are still low. Implementation of antimicrobial stewardship programs will be crucial in prevention of resistance of these antimicrobials against S. aureus.

New therapeutic options for skin and soft tissue infections

PURPOSE OF REVIEW

The occurrence of methicillin-resistance in Staphylococcus aureus, that represents the most frequent cause of complicated skin and soft tissue infections (cSSTIs) worldwide, is a major concern and has been associated with increased length of stay, health care costs, and overall mortality. Although vancomycin is still considered the standard therapy in this setting, limitations of its use in clinical practice are represented by a progressive increase in methicillin-resistant S. aureus (MRSA) minimum inhibitory concentrations, drug-related toxicity, and the lack of an oral formulation. New therapeutic options for MRSA cSSTIs have recently become available, with promising implications for the management of cSSTIs in clinical practice.

RECENT FINDINGS

A number of new antimicrobials with activity against MRSA have been recently approved for the treatment of cSSTIs, and other agents are under investigation. We have reviewed the recent developments, with a specific focus on the possible advantages of new drugs for the management of cSSTIs into the everyday clinical practice.

SUMMARY

The new approved drugs for the treatment of cSSTIs are expected to offer many advantages for the management of patients with suspected or confirmed MRSA cSSTIs. The most promising features of the new compounds include the availability of oral formulations, once-weekly intravenous regimens, and broad spectra of activity.

In vitro activity of tedizolid against Staphylococcus aureus and Streptococcus pneumoniae collected in 2013 and 2014 from sites in Latin American countries, Australia, New Zealand, and China

Tedizolid is an oxazolidinone with an antimicrobial in vitro potency advantage against Gram-positive bacterial pathogens compared to other currently marketed drugs in this class, including linezolid. Tedizolid was compared to linezolid when tested against Staphylococcus aureus and Streptococcus pneumoniae isolates collected from countries in Latin America and the Asia-Pacific. Isolates were tested by broth microdilution susceptibility methods against tedizolid, linezolid, and non-class comparators in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines. The activity of tedizolid against S. aureus was potent and consistent in Latin America (MIC₉₀, 0.5 mg/L), Australia and New Zealand (MIC₉₀, 0.25 mg/L), and China (MIC₉₀, 0.5 mg/L). Based on MIC₉₀ results, tedizolid was four- to eight-fold more active than linezolid against S. aureus, including both methicillin-susceptible and -resistant isolates. Only two tedizolid non-susceptible strains were observed; both had intermediate minimum inhibitory concentration (MIC) values of 1 mg/L, for which the MICs of linezolid was higher (≥2 mg/L). Tedizolid (MIC₉₀, 0.25 mg/L) was four-fold more potent than linezolid (MIC₉₀, 1 mg/L) against S. pneumoniae in all countries that provided isolates. The findings from this study support the global clinical development of tedizolid for Gram-positive infections.

Clinician-reported lesion measurements in skin infection trials: Definitions, reliability, and association with patient-reported pain

OBJECTIVES

Outcome assessments as clinical trial endpoints should be well-defined, reliable, and reflect meaningful treatment benefits. For acute bacterial skin and skin structure infections (ABSSSI) trials, recent recommendations suggest a primary endpoint of reduction in skin lesion area. Objectives were: evaluate ABSSSI lesion area measurement reliability, evaluate impact of various lesion area definitions on treatment effect size, and explore relationships between lesion area and pain.

METHODS

Data from two randomized, double-blinded Phase 3 trials comparing tedizolid to linezolid in ABSSSI and one open-label, non-comparative Phase 2 study of tedizolid in cellulitis/erysipelas and skin abscess were analyzed. Repeated lesion area measurements were prospectively obtained in all studies. In the open-label study, lesion area was measured by two investigators, using four different definitions. Repeated pain assessments using two patient-reported outcome instruments (Visual Analog Scale [VAS] and Faces Rating Scale [FRS]) were elicited in the randomized trials.

RESULTS

At baseline, lesion size did not correlate with pain intensity: r=0.02 for VAS and r<0.01 for FRS pain scores. However, decreasing lesion size and decreasing pain were strongly associated over time, regardless of initial lesion size or pain intensity (r=0.20 for VAS and r=0.21 for FRS scores at Day 10-13). Each lesion area definition demonstrated high inter-observer reliability (intra-class correlation coefficient>0.95).

CONCLUSIONS

Decreasing lesion area (indirect clinician-reported measure of benefit) and pain (direct patient-reported measure of benefit) were strongly associated over time, and lesion area measurements were reliable, regardless of their definition. These findings support both measures as outcome assessments in ABSSSI clinical trials.

REGISTRATION

Clinicaltrials.govNCT01519778, NCT01170221, and NCT01421511.

Antimicrobial agents - optimising the ecological balance

BACKGROUND

There is no more challenging a group of pharmaceuticals than antimicrobials. With the antibiotic era came great optimism as countless deaths were prevented from what were previously fatal conditions. Although antimicrobial resistance was quickly identified, the abundance of antibiotics entering the market helped cement attitudes of arrogance as the "battle against pestilence appeared won". Opposite emotions soon followed as many heralded the return of the pre-antibiotic era, suggesting that the "antibiotic pipeline had dried up" and that our existing armament would soon be rendered worthless.

DISCUSSION

In reality, humans overrate their ecological importance. For millions of years there has been a balance between factors promoting bacterial survival and those disturbing it. The first half century of the "antibiotic era" was characterised by a cavalier attitude disturbing the natural balance; however, recent efforts have been made through several mechanisms to respond and re-strengthen the antimicrobial armament. Such mechanisms include a variety of incentives, educational efforts and negotiations. Today, there are many more "man-made" factors that will determine a new balance or state of ecological harmony.

CONCLUSION

Antibiotics are not a panacea nor will they ever be inutile. New resistance mechanisms will be identified and new antibiotics will be discovered, but most importantly, we must optimise our application of these extraordinary "biological tools"; therein lays our greatest challenge - creating a society that understands and respects the determinants of the effectiveness of antibiotics.

Pharmacokinetics and Safety of Tedizolid after Single and Multiple Intravenous/Oral Sequential Administrations in Healthy Chinese Subjects

PURPOSE

Tedizolid phosphate is a new antibacterial agent under investigation for the treatment of Gram-positive infections in China. This study was conducted to assess the pharmacokinetic (PK) properties, oral bioavailability, and safety of once daily tedizolid phosphate 200 mg in Chinese subjects to support its further clinical development in China.

METHODS

This Phase I single-center study, conducted in 16 healthy Chinese male subjects, consisted of a single-dose administration, 1:1 randomized, two-way, intravenous (IV)/oral (PO) crossover of tedizolid phosphate 200 mg (Part 1) and, after a 7-day washout, a nonrandomized, multiple-dose, 7-day tedizolid phosphate 200 mg once daily administration (IV for 3 days, PO for 4 days; Part 2). Blood samples were collected for up to 72 hours after single dosing and for up to 2 hours on Day 3 and 72 hours on Day 7 of multiple dosing to determine PK parameters. Adverse events (AEs) were recorded throughout the entire study.

FINDINGS

The Cmax and AUC of tedizolid (the active moiety of tedizolid phosphate) were 3.02 µg/mL and 30.50 µg • h/mL after single IV dosing of tedizolid phosphate, and 2.25 µg/mL and 26.10 µg • h/mL after single PO dosing, respectively, and the mean half-life was 10.1 hours for both administration routes. The oral bioavailability of tedizolid was 85.5%. PK parameters of tedizolid were similar after single and multiple dosing of tedizolid phosphate, indicating no time dependency. Only minor accumulation of tedizolid was observed after multiple dosing (expressed as accumulation ratios RAAUC: 1.18 for PO dosing, and RACmax: 1.16 and 1.05 for IV and PO dosing, respectively). Steady state of tedizolid was reached after about 3 days, and trough concentrations remained constant when switching from IV to PO dosing. Tedizolid phosphate was well tolerated with 6 subjects (37.5%) in Part 1 and 5 subjects (31.3%) in Part 2 experiencing an AE; all AEs but one were related to the study drug assessed by the investigator. All AEs were of mild intensity and had recovered or resolved by the end of the study. No serious AEs were observed, and no subjects prematurely discontinued the study due to an AE.

IMPLICATIONS

The results of this Phase I study conducted in Chinese male subjects indicate that no dosage adjustment of tedizolid phosphate 200 mg would be required when switching administration routes in this population. Tedizolid phosphate was well tolerated in healthy Chinese subjects. China Food and Drug Administration clinical trial permission numbers 2014L00360 and 2014L00361.

Early Response in Cellulitis: A Prospective Study of Dynamics and Predictors

In this prospective study of cellulitis, several nonpharmacological factors were associated with lack of early response. Such early nonresponse was rarely related to inappropriate therapy but strongly predictive of early treatment escalation, suggesting that broadening antibiotic treatment often may be premature.

Background. Skin and soft tissue infections are common reasons for medical care. Use of broad-spectrum therapy and costs have increased. Assessment of early treatment response has been given a central role both in clinical trials and everyday practice. However, there is a paucity of data on the dynamics of response, causes of early nonresponse, and how early nonresponse affects resource use and predicts outcome.

Methods. We prospectively enrolled 216 patients hospitalized with cellulitis. Clinical and biochemical response data during the first 3 days of treatment were analyzed in relation to baseline factors, antibiotic use, surgery, and outcome. Multivariable analysis included logistic lasso regression.

Results. Clinical or biochemical response was observed in the majority of patients the day after treatment initiation. Concordance between clinical and biochemical response was strongest at days 2 and 3. Female sex, cardiovascular disease, higher body mass index, shorter duration of symptoms, and cellulitis other than typical erysipelas were predictors of nonresponse at day 3. In contrast, baseline factors were not predictive of clinical failure assessed posttreatment. Among cases with antibiotic treatment escalation by day 2, 90% (37/41) had nonresponse at day 1, but only 5% (2/40) had inappropriate initial therapy. Nonresponse at day 3 was a predictor of treatment duration >14 days, but not of clinical failure.

Conclusions. Nonpharmacological factors had a major impact on early response dynamics. Delayed response was rarely related to inappropriate therapy but strongly predictive of early treatment escalation, suggesting that broadening antibiotic treatment may often be premature.

Significant publications on infectious diseases pharmacotherapy in 2014

PURPOSE

The most important articles on infectious diseases (ID) pharmacotherapy published in the peer-reviewed literature in 2014, as nominated and selected by panels of pharmacists and others with ID expertise, are summarized.

SUMMARY

Members of the Houston Infectious Diseases Network were asked to nominate articles published in 2014 from prominent peer-reviewed journals that were felt to have a major impact in the field of ID pharmacotherapy. A list of 19 nominated articles on general ID-related topics and 9 articles specifically related to human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) was compiled. In a national online survey, members of the Society of Infectious Diseases Pharmacists (SIDP) were asked to select from the list 10 general ID articles believed to have made a significant contribution to the field of ID pharmacotherapy and 1 article contributing to HIV/AIDS pharmacotherapy. Of the 291 SIDP members surveyed, 134 (46%) and 56 (19%) participated in the selection of general ID-related articles and HIV/AIDS-related articles, respectively. The 11 highest-ranked papers (10 general ID-related articles, 1 HIV/AIDS-related article) are summarized here.

CONCLUSION

With the vast number of articles published each year, it is difficult to remain up-to-date on current, significant ID pharmacotherapy publications. This review of significant publications in 2014 may be helpful by lessening this burden.

Pharmacokinetics, Safety and Tolerability of Single Oral or Intravenous Administration of 200 mg Tedizolid Phosphate in Adolescents

BACKGROUND

Tedizolid is a novel oxazolidinone antibacterial US FDA approved for treatment of acute bacterial skin and skin structure infections in adults. This study assessed the pharmacokinetics, safety and tolerability of tedizolid phosphate in adolescents (12-17 years old) after administration of a single intravenous (IV) or oral dose.

METHODS

In this multicenter, open-label study, a single IV infusion (N = 10) or oral dose (N = 10) of 200 mg tedizolid phosphate was administered to adolescents already receiving antibacterial treatment for presumed or documented infection. Blood and urine samples were collected predose and over 24 hours.

RESULTS

Tedizolid pharmacokinetics was generally similar after IV or oral administration of 200 mg tedizolid phosphate. Mean (standard deviation) half-life values were similar for oral and IV routes, 8.3 (2.0) and 6.6 (0.7) hours, respectively. Absolute oral bioavailability of tedizolid (90% confidence interval) was 88.8% (70.4%-112.1%). Geometric mean ratio (90% confidence interval) of area under the concentration-time curve values for adolescents relative to values previously reported for adults after 200 mg of single-dose IV or oral administration were 0.847 (0.736-0.975). Tedizolid was well tolerated.

CONCLUSIONS

Overall pharmacokinetics of tedizolid was similar after administration of a single oral or IV 200 mg dose, and bioavailability was high. Exposure profiles were similar to those in adults. With clinical outcomes based on area under the concentration-time curve/minimum inhibitory concentration and current susceptibility of Gram-positive pathogens, results suggest that the 200 mg daily regimen of tedizolid phosphate can be extended to adolescents for clinical trials, and that dose adjustment may not be required when switching routes.

Failure of antibiotics in cellulitis trials: a systematic review and meta-analysis

OBJECTIVES

The objectives of the study are to quantify trial-to-trial variability in antibiotic failure rates, in randomized clinical trials of cellulitis treatment and to provide a point estimate for the treatment failure rate across trials.

METHODS

We conducted a structured search for clinical trials evaluating antibiotic treatment of cellulitis, indexed in PubMed by August 2015. We included studies published in English and excluded studies conducted wholly outside of developed countries because the pathophysiology of cellulitis is likely to be different in such settings. Two authors reviewed all abstracts identified for possible inclusion. Of studies identified initially, 5% met the selection criteria. Two reviewers extracted data independently, and data were pooled using the Freeman-Tukey transformation under a random-effects model. Our primary outcome was the summary estimate of treatment failure across intent-to-treat and clinically evaluable participants.

RESULTS

We included 19 articles reporting data from 20 studies, for a total of 3935 patients. Treatment failure was reported in 6% to 37% of participants in the 9 trials reporting intent-to-treat results, with a summary point estimate of 18% failing treatment (95% confidence interval, 15%-21%). In the 15 articles evaluating clinically evaluable participants, treatment failure rates ranged from 3% to 42%, and overall, 12% (95% confidence interval, 10%-14%) were designated treatment failures.

CONCLUSIONS

Treatment failure rates vary widely across cellulitis trials, from 6% to 37%. This may be due to confusion of cellulitis with its mimics and perhaps problems with construct validity of the diagnosis of cellulitis. Such factors bias trials toward equivalence and, in routine clinical care, impair quality and antibiotic stewardship. Objective diagnostic tools are needed.

Antimicrobial and immunomodulatory effects of tedizolid against methicillin-resistant Staphylococcus aureus in a murine model of hematogenous pulmonary infection

Tedizolid (TZD) is a second-generation oxazolidinone and demonstrates potent in-vitro activity against multidrug-resistant Gram-positive bacteria. Phase III studies in patients with acute bacterial skin and skin structure infections (ABSSSI) have demonstrated the non-inferiority of TZD to linezolid (LZD). However, there are only a few studies that show the effect of TZD in pulmonary infections. In this study, we investigated the effect of TZD in a murine model of hematogenous pulmonary infection caused by methicillin-resistant Staphylococcus aureus (MRSA). The mice were treated either twice daily with saline (control), 25mg/kg of vancomycin (low-VAN), 110mg/kg of vancomycin (high-VAN), 120mg/kg of LZD or once daily with 20mg/kg of TZD. As compared to the control, the low- and high-VAN treatment groups, LZD and TZD significantly improved the survival rate, reduced the bacterial count in the lungs. Furthermore, TZD decreased the area of central bacterial colony zone (CBCZ) at 36h post-inoculation, compared with the control. In addition, we investigated the immunomodulatory effect of TZD by evaluating the plasma concentrations of the inflammatory cytokines. Although there were no significant differences in the bacterial count in the lungs amongst the drugs at 26h post-inoculation, TZD and LZD significantly improved the plasma concentrations of TNF-alpha, IL-6 and MIP-2, in comparison with the control. In this study, both TZD and LZD demonstrated antimicrobial and immunomodulatory efficacy in a murine model of hematogenous pulmonary infection caused by MRSA.

Advances in antibiotic therapy in the critically ill

Infections occur frequently in critically ill patients and their management can be challenging for various reasons, including delayed diagnosis, difficulties identifying causative microorganisms, and the high prevalence of antibiotic-resistant strains. In this review, we briefly discuss the importance of early infection diagnosis, before considering in more detail some of the key issues related to antibiotic management in these patients, including controversies surrounding use of combination or monotherapy, duration of therapy, and de-escalation. Antibiotic pharmacodynamics and pharmacokinetics, notably volumes of distribution and clearance, can be altered by critical illness and can influence dosing regimens. Dosing decisions in different subgroups of patients, e.g., the obese, are also covered. We also briefly consider ventilator-associated pneumonia and the role of inhaled antibiotics. Finally, we mention antibiotics that are currently being developed and show promise for the future.

Hot topics in the diagnosis and management of skin and soft-tissue infections

Eighteen hot topics regarding the diagnosis and management of skin and soft-tissue infections (SSTIs) were selected and reviewed by members of the SSTI Working Group of the International Society of Chemotherapy (ISC). Despite the large amount of literature available on the issue selected, there are still many unknowns with regard to many of them and further studies are required to answer these challenging issues that face clinicians on a daily basis.

New Is Old, and Old Is New: Recent Advances in Antibiotic-Based, Antibiotic-Free and Ethnomedical Treatments against Methicillin-Resistant Staphylococcus aureus Wound Infections

Staphylococcus aureus is the most common pathogen of wound infections. Thus far, methicillin-resistant S. aureus (MRSA) has become the major causative agent in wound infections, especially for nosocomial infections. MRSA infections are seldom eradicated by routine antimicrobial therapies. More concerning, some strains have become resistant to the newest antibiotics of last resort. Furthermore, horizontal transfer of a polymyxin resistance gene, mcr-1, has been identified in Enterobacteriaceae, by which resistance to the last group of antibiotics will likely spread rapidly. The worst-case scenario, "a return to the pre-antibiotic era", is likely in sight. A perpetual goal for antibiotic research is the discovery of an antibiotic that lacks resistance potential, such as the recent discovery of teixobactin. However, when considering the issue from an ecological and evolutionary standpoint, it is evident that it is insufficient to solve the antibiotic dilemma through the use of antibiotics themselves. In this review, we summarized recent advances in antibiotic-based, antibiotic-free and ethnomedical treatments against MRSA wound infections to identify new clues to solve the antibiotic dilemma. One potential solution is to use ethnomedical drugs topically. Some ethnomedical drugs have been demonstrated to be effective antimicrobials against MRSA. A decline in antibiotic resistance can therefore be expected, as has been demonstrated when antibiotic-free treatments were used to limit the use of antibiotics. It is also anticipated that these drugs will have low resistance potential, although there is only minimal evidence to support this claim to date. More clinical trials and animal tests should be conducted on this topic.

Empirical therapy in Methicillin-resistant Staphylococcus Aureus infections: An Up-To-Date approach

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be an important pathogen worldwide, with high prevalence of infection in both community and hospital settings. Timely and appropriate choice of empirical therapy in the setting of MRSA infection is imperative due to the high rate of associated morbidity and mortality with MRSA infections. Initial choices should be made based on the site and severity of the infection, most notably moderate skin and soft tissue infections which may be treated with oral antibiotics (trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, linezolid) in the outpatient setting, versus choice of parenteral therapy in the inpatient setting of more invasive or severe disease. Though the current recommendations continue to strongly rely on vancomycin as a standard empiric choice in the setting of severe/invasive infections, alternative therapies exist with studies supporting their non-inferiority. This includes the use of linezolid in pneumonia and severe skin and skin structure infections (SSSI) and daptomycin for MRSA bacteremia, endocarditis, SSSIs and bone/joint infections. Additionally, concerns continue to arise in regards to vancomycin, such as increasing isolate MICs, and relatively high rates of clinical failures with vancomycin. Thus, the growing interest in vanomycin alternatives, such as ceftaroline, ceftobribole, dalbavancin, oritavancin, and tedizolid, and their potential role in treating MRSA infections.

Investigational drugs in phase I and phase II clincial trials for the treatment of hospital-acquired pneumonia

INTRODUCTION

Hospital acquired pneumonia (HAP) is one of the main infections acquired by patients during a stay in hospital. The main issue when dealing with patients with HAP and ventilator associated pneumonia (VAP) is the increasing role of multi-drug resistant organisms (MDROs).

AREAS COVERED

In this review the authors summarize the actual situation of MDROs as a cause of HAP and VAP. They also review the current treatment options stated in the most important international guidelines. Finally, they focus on the investigational drugs that have reached the phase III stage of development and the novel compounds that are being studied in phase I and II clinical trials.

EXPERT OPINION

Thanks to their excellent activity against MDROs, drugs in development for the treatment of HAP and VAP can significantly improve the therapeutic options available. In selected patients, the possibility to administer directed therapy with monoclonal antibodies to specific pathogens is an exciting strategy in the fight against widespread resistance.

New Gram-Positive Agents: the Next Generation of Oxazolidinones and Lipoglycopeptides

The growing problem of antimicrobial resistance among bacterial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), has reached a critical state. Tedizolid phosphate, dalbavancin, and oritavancin have recently been approved by the U.S. Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and represent the next generation of oxazolidinones and lipoglycopeptides. All three agents exhibit in vitro activity and clinical efficacy against MRSA. Tedizolid phosphate and oritavancin demonstrate in vitro activity against VRE. These new Gram-positive agents are reviewed here.