Population pharmacokinetic rationale for intravenous contezolid acefosamil followed by oral contezolid dosage regimens.

Contezolid is a novel oxazolidinone antibiotic with a promising safety profile. Oral contezolid and its intravenous (IV) prodrug contezolid acefosamil (CZA) are in development for treatment of diabetic foot and acute bacterial skin and skin structure infections (ABSSSI). The prodrug CZA is converted to active contezolid via intermediate MRX-1352. This study aimed to provide the pharmacokinetic rationale for safe, effective, and flexible dosage regimens with initial IV CZA followed by oral contezolid. We simultaneously modeled plasma concentrations from 110 healthy volunteers and 74 phase 2 patients with ABSSSI via population pharmacokinetics (using the importance sampling estimation algorithm), and optimized dosage regimens by Monte Carlo simulations. This included data on MRX-1352, contezolid, and its metabolite MRX-1320 from 66 healthy volunteers receiving intravenous CZA (150-2400 mg) for up to 28 days, and 74 patients receiving oral contezolid [800 mg every 12 h (q12h)] for 10 days. The apparent total clearance for 800 mg oral contezolid with food was 16.0 L/h (23.4% coefficient of variation) in healthy volunteers and 17.7 L/h (53.8%) in patients. CZA was rapidly converted to MRX-1352, which subsequently transformed to contezolid. The proposed dosage regimen used an IV CZA 2000 mg loading dose with 1000 mg IV CZA q12h as maintenance dose(s), followed by 800 mg oral contezolid q12h (with food). During each 24-h period, Monte Carlo simulations predicted this regimen to achieve consistent areas under the curve of 91.9 mg·h/L (range: 76.3-106 mg·h/L) under all scenarios. Thus, this regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.IMPORTANCEThis study provides the population pharmacokinetic rationale for the dosage regimen of the intravenous (IV) prodrug contezolid acefosamil (CZA) followed by oral contezolid. We developed the first integrated population model for the pharmacokinetics of the MRX-1352 intermediate prodrug, active contezolid, and its main metabolite MRX-1320 based on data from three clinical studies in healthy volunteers and phase 2 patients. The proposed regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.

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.).

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.

Effects of therapeutic and supratherapeutic doses of oral tedizolid phosphate on cardiac repolarisation in healthy volunteers: a randomised controlled study.

Drug-induced prolongation of the QT interval on the electrocardiogram (ECG) infrequently results in Torsades de pointes, a potentially fatal arrhythmia. Therefore, thorough QT analysis of new drugs is a regulatory requirement. The objective of this phase 1 study was to assess the effects of oral tedizolid phosphate on the QT interval corrected with Fridericia's formula (QTcF) in healthy adult subjects. A single therapeutic dose (200 mg) and a supratherapeutic dose (1200 mg) of tedizolid phosphate were administered to characterise QTc changes following typical systemic exposure and with markedly higher exposures, respectively. This was a four-way crossover study with 48 subjects randomly assigned to receive therapeutic and supratherapeutic doses of tedizolid phosphate, moxifloxacin (positive control for QT interval prolongation) and placebo (negative control). A continuous 12-lead ECG was recorded from 1 h before drug administration to 23 h after administration. Adverse events, which were generally mild, occurred most frequently with moxifloxacin or with a supratherapeutic dose of tedizolid phosphate; however, all treatments were well tolerated. This study demonstrated that therapeutic or supratherapeutic doses of the antibacterial tedizolid had no clinically significant effect on QT interval in healthy adults [ClinicalTrials.gov registration no.: NCT01461460].

Efficacy, safety, tolerability and population pharmacokinetics of tedizolid, a novel antibiotic, in Latino patients with acute bacterial skin and skin structure infections

Abstract Acute bacterial skin and skin structure infections are caused mainly by Gram-positive bacteria which are often treated with intravenous vancomycin, daptomycin, or linezolid, with potential step down to oral linezolid for outpatients. Tedizolid phosphate 200 mg once daily treatment for six days demonstrated non-inferior efficacy, with a favourable safety profile, compared with linezolid 600 mg twice daily treatment for 10 days in the Phase 3 ESTABLISH-1 and -2 trials. The objective of the current post-hoc analysis of the integrated dataset of ESTABLISH-1 and -2 was to evaluate the efficacy and safety of tedizolid (N = 182) vs linezolid (N = 171) in patients of Latino origin enrolled into these trials. The baseline demographic characteristics of Latino patients were similar between the two treatment groups. Tedizolid demonstrated comparable efficacy to linezolid at 48–72 h in the intent-to-treat population (tedizolid: 80.2% vs linezolid: 81.9%). Sustained clinical success rates were comparable between tedizolid- and linezolid-treated Latino patients at end-of-therapy (tedizolid: 86.8% vs linezolid: 88.9%). Tedizolid phosphate treatment was well tolerated by Latino patients in the safety population with lower abnormal platelet counts at end-of-therapy (tedizolid: 3.4% vs linezolid: 11.3%, p = 0.0120) and lower incidence of gastrointestinal adverse events (tedizolid: 16.5% vs linezolid: 23.5%). Population pharmacokinetic analysis suggested that estimated tedizolid exposure measures in Latino patients vs non-Latino patients were similar. These findings demonstrate that tedizolid phosphate 200 mg, once daily treatment for six days was efficacious and well tolerated by patients of Latino origin, without warranting dose adjustment.

Efficacy, safety, tolerability and population pharmacokinetics of tedizolid, a novel antibiotic, in Latino patients with acute bacterial skin and skin structure infections.

Acute bacterial skin and skin structure infections are caused mainly by Gram-positive bacteria which are often treated with intravenous vancomycin, daptomycin, or linezolid, with potential step down to oral linezolid for outpatients. Tedizolid phosphate 200mg once daily treatment for six days demonstrated non-inferior efficacy, with a favourable safety profile, compared with linezolid 600mg twice daily treatment for 10 days in the Phase 3 ESTABLISH-1 and -2 trials. The objective of the current post-hoc analysis of the integrated dataset of ESTABLISH-1 and -2 was to evaluate the efficacy and safety of tedizolid (N=182) vs linezolid (N=171) in patients of Latino origin enrolled into these trials. The baseline demographic characteristics of Latino patients were similar between the two treatment groups. Tedizolid demonstrated comparable efficacy to linezolid at 48-72h in the intent-to-treat population (tedizolid: 80.2% vs linezolid: 81.9%). Sustained clinical success rates were comparable between tedizolid- and linezolid-treated Latino patients at end-of-therapy (tedizolid: 86.8% vs linezolid: 88.9%). Tedizolid phosphate treatment was well tolerated by Latino patients in the safety population with lower abnormal platelet counts at end-of-therapy (tedizolid: 3.4% vs linezolid: 11.3%, p=0.0120) and lower incidence of gastrointestinal adverse events (tedizolid: 16.5% vs linezolid: 23.5%). Population pharmacokinetic analysis suggested that estimated tedizolid exposure measures in Latino patients vs non-Latino patients were similar. These findings demonstrate that tedizolid phosphate 200mg, once daily treatment for six days was efficacious and well tolerated by patients of Latino origin, without warranting dose adjustment.

Analysis of the phase 3 ESTABLISH trials of tedizolid versus linezolid in acute bacterial skin and skin structure infections.

Tedizolid, a novel oxazolidinone with activity against a wide range of Gram-positive pathogens, was evaluated in two noninferiority phase 3 acute bacterial skin and skin structure infection trials. The data from individual trials showed its noninferior efficacy compared to that of linezolid and a favorable tolerability profile. To evaluate potential differences, the pooled data were analyzed. The patients received 200 mg of tedizolid once daily for 6 days or 600 mg of linezolid twice daily for 10 days. Efficacy was evaluated at 48 to 72 h (primary endpoint), on days 11 to 13 (end of therapy [EOT]), and 7 to 14 days after the EOT (posttherapy evaluation). Treatment-emergent adverse events and hematologic and clinical laboratory parameters were collected. The baseline characteristics were comparable between the treatment groups: 852/1,333 (64%) patients were from North America, and the majority of infections were caused by Staphylococcus aureus. Tedizolid was noninferior to linezolid (early clinical responses, 81.6% versus 79.4%, respectively). The early responses remained relatively consistent across various host/disease factors and severity measures. Nausea was the most frequently reported adverse event (tedizolid, 8.2%; linezolid, 12.2%; P=0.02), with onset occurring primarily during the first 6 days. Fewer tedizolid than linezolid patients had platelet counts of <150,000 cells/mm3 at the EOT (tedizolid, 4.9%; linezolid, 10.8%; P=0.0003) and during the postbaseline period through the last day of active drug visit (tedizolid, 6.4%; linezolid, 12.6%; P=0.0016). Efficacy was achieved with a 6-day once-daily course of therapy with the option of an intravenous/oral regimen, and fewer low platelet counts and gastrointestinal side effects were reported with tedizolid than with linezolid, all of which aligns well with antimicrobial stewardship principles. (These studies have been registered at ClinicalTrials.gov under registration no. NCT01170221 and NCT01421511.).

Platelet profile in patients with acute bacterial skin and skin structure infections receiving tedizolid or linezolid: findings from the Phase 3 ESTABLISH clinical trials.

Tedizolid, the active moiety of tedizolid phosphate, is a recently approved oxazolidinone antibacterial with activity against a wide range of Gram-positive pathogens, including resistant strains such as methicillin-resistant Staphylococcus aureus. To date, 6 days of 200 mg tedizolid once daily has been shown to be noninferior to 10 days of 600 mg linezolid twice daily in two randomized, double-blind phase 3 trials (ESTABLISH-1 and ESTABLISH-2) for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSIs). The intent of this study was to characterize the platelet profiles of patients receiving tedizolid relative to linezolid over the course of treatment using pooled data from these two trials. The occurrences of clinically defined and statistical analysis plan-specified reduced platelet counts were assessed at the study days 7 to 9 visit, the study days 11 to 13 visit, and the posttherapy evaluation (PTE) visit. At the study days 7 to 9 visit, incidences of reduced platelet counts were low and largely similar between the groups. The only notable difference was a lower incidence of thrombocytopenia (platelet counts, <150,000 cells/mm(3)) among patients who received tedizolid (3.2%) relative to those who received linezolid (5.6%). At the study days 11 to 13 visit, patients who received tedizolid had lower incidences of platelet counts of <150,000 cells/mm(3) (-5.9%), <112,500 cells/mm(3) (-2.4%), and <100,000 cells/mm(3) (-1.9%) than patients in the linezolid group. Similar differences were noted at the PTE visit. Findings across the two phase 3 ABSSSI trials suggest that 6 days of 200 mg tedizolid daily confers a low potential for reduced platelet counts among patients with ABSSSIs. (The ESTABLISH-1 and ESTABLISH-2 trials have been registered at ClinicalTrials.gov under registration numbers NCT01170221 and NCT01421511, respectively.).

Single- and multiple-dose pharmacokinetics and absolute bioavailability of tedizolid.

OBJECTIVES: Tedizolid phosphate is a novel antibacterial under investigation for the treatment of gram-positive infections. This study was conducted to assess the pharmacokinetics, safety, and tolerability of intravenous tedizolid phosphate as well as the oral bioavailability of tedizolid phosphate. DESIGN: Double-blind, single-ascending dose, multiple-dose pharmacokinetics study, as well as tolerability and open-label crossover studies. SETTING: Single center in the United States (Covance Clinical Research Unit, Madison, WI) between September 2009 and January 2010. PARTICIPANTS: Ninety healthy volunteers. INTERVENTION: Single intravenous (IV) doses of tedizolid phosphate 50 mg (lead-in) and 100-400 mg. Single oral and IV dose of tedizolid phosphate 200 mg in crossover fashion. Multiple IV doses of tedizolid phosphate 200 and 300 mg for up to 7 days. MEASUREMENTS AND MAIN RESULTS: A dose-dependent increase was observed in the maximum plasma concentration (1.2-5.1 µg/ml) and the area under the concentration-time curve (17.4-58.7 µg × hr/ml) of tedizolid (the microbiologically active moiety of tedizolid phosphate) after single IV doses of tedizolid phosphate 100-400 mg. Administration of IV tedizolid phosphate 200 mg once/day for 7 days resulted in minimal (28%) tedizolid accumulation. The absolute oral bioavailability of tedizolid after a single 200-mg dose of tedizolid phosphate was 91%; pharmacokinetic parameters of tedizolid were similar with oral and IV administration. Treatment-related adverse events occurred in 41% of subjects. Most adverse events were related to infusion site and became more frequent with multiple dosing. In an additional 3-day tolerability study, IV tedizolid phosphate 200 mg and placebo were similarly tolerated, based on visual infusion phlebitis scores. CONCLUSION: These results from a population of healthy volunteers support once/day dosing of tedizolid phosphate 200 mg with both the oral and IV formulations, without the need for dose adjustment when switching administration routes.

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.

BACKGROUND: New antibiotics are needed to treat infections caused by drug-resistant bacteria. Tedizolid is a novel oxazolidinone antibacterial drug designed to provide enhanced activity against Gram-positive pathogens. We aimed to assess the efficacy and safety of intravenous to oral tedizolid for treatment of patients with acute bacterial skin and skin-structure infections. METHODS: ESTABLISH-2 was a randomised, double-blind, phase 3, non-inferiority trial done between Sept 28, 2011, and Jan 10, 2013, at 58 centres in nine countries. Patients (aged ≥12 years) with acute bacterial skin and skin-structure infections (cellulitis or erysipelas, major cutaneous abscess, or wound infection) that had a minimum lesion area of 75 cm(2) and were suspected or documented to be associated with a Gram-positive pathogen, were randomly assigned (1:1), via an interactive voice-response system with block randomisation, to receive intravenous once-daily tedizolid (200 mg for 6 days) or twice-daily linezolid (600 mg for 10 days), with optional oral step-down. Randomisation was stratified by geographic region and type of acute bacterial skin and skin-structure infection. The primary endpoint was early clinical response (≥20% reduction in lesion area at 48-72 h compared with baseline), with a non-inferiority margin of -10%. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01421511. FINDINGS: 666 patients were randomly assigned to receive tedizolid (n=332) or linezolid (n=334). 283 (85%) patients in the tedizolid group and 276 (83%) in the linezolid group achieved early clinical response (difference 2·6%, 95% CI -3·0 to 8·2), meeting the prespecified non-inferiority margin. Gastrointestinal adverse events were less frequent with tedizolid than linezolid, taking place in 52 (16%) of 331 patients and 67 (20%) of 327 patients in the safety population. Treatment-emergent adverse events leading to discontinuation of study drug were reported by one (<1%) patient in the tedizolid group and four (1%) patients in the linezolid group. INTERPRETATION: Intravenous to oral once-daily tedizolid 200 mg for 6 days was non-inferior to twice-daily linezolid 600 mg for 10 days for treatment of patients with acute bacterial skin and skin-structure infections. Tedizolid could become a useful option for the treatment of acute bacterial skin and skin-structure infections in the hospital and outpatient settings. FUNDING: Cubist Pharmaceuticals.

Absorption, distribution, metabolism, and excretion of the novel antibacterial prodrug tedizolid phosphate.

Tedizolid phosphate is a novel antibacterial prodrug with potent activity against Gram-positive pathogens. In vitro and in vivo studies demonstrated that the prodrug is rapidly converted by nonspecific phosphatases to the biologically active moiety tedizolid. Single oral dose radiolabeled (14)C-tedizolid phosphate kinetic studies in human subjects (100 µCi in 204 mg tedizolid phosphate free acid) confirmed a rapid time to maximum tedizolid concentration (Tmax, 1.28 hours), a long terminal half-life (10.6 hours), and a Cmax of 1.99 µg/ml. Metabolite analysis of plasma, fecal, and urine samples from rats, dogs, and humans confirmed that tedizolid is the only measurable metabolite in plasma after intravenous (in animals only) or oral administration and that tedizolid sulfate is the major metabolite excreted from the body. Excellent mass balance recovery was achieved and demonstrated that fecal excretion is the predominant (80-90%) route of elimination across species, primarily as tedizolid sulfate. Urine excretion accounted for the balance of drug elimination but contained a broader range of minor metabolites. Glucuronidation products were not detected. Similar results were observed in rats and dogs after both intravenous and oral administration. The tedizolid metabolites showed less potent antibacterial activity than tedizolid. The observations from these studies support once daily dosing of tedizolid phosphate and highlight important metabolism and excretion features that differentiate tedizolid phosphate from linezolid.

Tedizolid phosphate for the management of acute bacterial skin and skin structure infections: efficacy summary.

The novel oxazolidinone tedizolid phosphate is in late-stage development for acute bacterial skin and skin structure infections (ABSSSIs). Preclinical and phase 1 trials have shown that 200-mg once-daily tedizolid phosphate dosing achieves the appropriate pharmacokinetic goals for optimal antimicrobial effect, and a randomized phase 2 dose-ranging trial confirmed that tedizolid phosphate may be an option for the treatment of ABSSSIs at the 200-mg dose, the lowest effective dose, over a mean of 6.4 days of therapy. In the first of two phase 3 trials, 6 days of 200-mg once-daily oral tedizolid phosphate (plus 4 days of placebo) was noninferior to 10 days of 600-mg twice-daily oral linezolid when evaluated at both the early (48- to 72-hour assessment) and test-of-cure (7-14 days after the last dose of active or placebo agent was given) time points. Initial results from the second phase 3 trial (intravenous to oral therapy design) confirm the study met all primary and secondary endpoints and continues to add insight into the clinical utility of tedizolid phosphate.

Tedizolid phosphate for the management of acute bacterial skin and skin structure infections: safety summary.

The novel oxazolidinone tedizolid phosphate is in late-stage clinical development. In an effort to improve efficacy and safety, the adverse event profile and safety aspects of tedizolid phosphate have been evaluated in several preclinical animal models and through ongoing clinical trials. Early dose-ranging studies demonstrated a favorable overall adverse event profile and low thrombocytopenia rates, which have been consistently confirmed in phase 2 and 3 clinical trials. Pharmacokinetic modeling suggests a lower potential for monoamine oxidase interaction, and animal and human subject testing has confirmed these predictions. Studies in special patient populations showed a consistent and predictable pharmacokinetic profile across age groups and comorbid conditions, without evidence of increased incidence of adverse effects over matched controls. The favorable safety profile makes tedizolid phosphate an important new option for the management of serious Gram-positive infections, including those caused by methicillin-resistant Staphylococcus aureus.

Parainflammation associated with advanced glycation endproduct stimulation of RPE in vitro: implications for age-related degenerative diseases of the eye.

Age related macular degeneration (AMD) is one of the leading causes of blindness in Western society. A hallmark of early stage AMD are drusen, extracellular deposits that accumulate in the outer retina. Advanced glycation endproducts (AGE) accumulate with aging and are linked to several age-related diseases such as Alzheimer's disease, osteoarthritis, atherosclerosis and AMD. AGE deposits are found in drusen and in Bruch's membrane of the eye and several studies have suggested its role in promoting oxidative stress, apoptosis and lipofuscin accumulation. Recently, complement activation and chronic inflammation have been implicated in the pathogenesis of AMD. While AGEs have been shown to promote inflammation in other diseases, whether it plays a similar role in AMD is not known. This study investigates the effects of AGE stimulation on pro- and anti-inflammatory pathways in primary culture of human retinal pigment epithelial cells (RPE). Differential gene expression studies revealed a total of 41 up- and 18 down-regulated RPE genes in response to AGE stimulation. These genes fell into three categories as assessed by gene set enrichment analysis (GSEA). The main categories were inflammation (interferon-induced, immune response) and proteasome degradation, followed by caspase signaling. Using suspension array technology, protein levels of secreted cytokines and growth factors were also examined. Anti-inflammatory cytokines including IL10, IL1ra and IL9 were all overexpressed. Pro-inflammatory cytokines including IL4, IL15 and IFN-γ were overexpressed, while other pro-inflammatory cytokines including IL8, MCP1, IP10 were underexpressed after AGE stimulation, suggesting a para-inflammation state of the RPE under these conditions. Levels of mRNA of chemokine, CXCL11, and viperin, RSAD2, were up-regulated and may play a role in driving the inflammatory response via the NF-kB and JAK-STAT pathways. CXCL11 was strongly immunoreactive and associated with drusen in the AMD eye. The pathways and novel genes identified here highlight inflammation as a key response to AGE stimulation in primary culture of human RPE, and identify chemokine CXCL11 as putative novel agent associated with the pathogenesis of AMD.

Inflammatory mediators induced by amyloid-beta in the retina and RPE in vivo: implications for inflammasome activation in age-related macular degeneration.

PURPOSE: Drusen are hallmarks of age-related macular degeneration (AMD). Amyloid-beta 1-40 (Aß 1-40), a constituent of drusen, is known to stimulate inflammatory pathways in RPE; however, its effect in vivo is not known. The purpose of this study was to examine the effect of Aß 1-40 on cytokine expression and inflammasome activation relevant to AMD in an animal model. METHODS: Wild-type rats received intravitreal injections of Aß 1-40, and eyes were taken at days 1, 4, 14, and 49 postinjection. The RPE, neuroretina, and vitreous were analyzed for cytokine expression, inflammasome activation, and microglial response via RT-PCR, immunohistochemistry, and suspension array assay. Retinal cell loss was assessed via apoptotic markers and retinal thickness. RESULTS: Aß 1-40 stimulated upregulation of IL-6, TNF-α, IL-1ß, IL-18, caspase-1, NLRP3, and XAF1 genes in the RPE/choroid and the neuroretina. Increased IL-1ß and IL-6 immunoreactivity was found in retinal sections, and elevated levels of IL-1ß and IL-18 were found in the vitreous of Aß-injected eyes. Aß 1-40 induced a moderate increase in CD11b/c-reactive cells on day 1 postinjection only. No evidence of the proapoptotic XAF1 protein, p53, TUNEL immunoreactivity, or retinal thinning was observed. CONCLUSIONS: These results confirm earlier in vitro work and support the proinflammatory role of drusen component Aß 1-40 in the RPE and retina. Inflammasome activation may be responsible for this effect in vivo. This model is useful for understanding cellular triggers of inflammasome activation and proposed early inflammatory events in the outer retina associated with the etiology of AMD.

Tedizolid phosphate vs linezolid for treatment of acute bacterial skin and skin structure infections: the ESTABLISH-1 randomized trial.

IMPORTANCE: Acute bacterial skin and skin structure infections (ABSSSIs), including cellulitis or erysipelas, major cutaneous abscesses, and wound infections, can be life-threatening and may require surgery and hospitalization. Increasingly, ABSSSIs are associated with drug-resistant pathogens, and many antimicrobial agents have adverse effects restricting their use. Tedizolid phosphate is a novel oxazolidinone in development for the treatment of ABSSSIs. OBJECTIVES: To establish the noninferiority of tedizolid phosphate vs linezolid in treating ABSSSIs and compare the safety of the 2 agents. DESIGN, SETTING, AND PATIENTS: The Efficacy and Safety of 6-day Oral Tedizolid in Acute Bacterial Skin and Skin Structure Infections vs 10-day Oral Linezolid Therapy (ESTABLISH-1) was a phase 3, randomized, double-blind, noninferiority trial that was conducted from August 2010 through September 2011 at 81 study centers in North America, Latin America, and Europe. The intent-to-treat analysis set consisted of data from 667 adults aged 18 years or older with ABSSSIs treated with tedizolid phosphate (n = 332) or linezolid (n = 335). INTERVENTIONS: A 200 mg once daily dose of oral tedizolid phosphate for 6 days or 600 mg of oral linezolid every 12 hours for 10 days. MAIN OUTCOME MEASURES: The primary efficacy outcome was early clinical response at the 48- to 72-hour assessment (no increase in lesion surface area from baseline and oral temperature of ≤37.6°C, confirmed by a second temperature measurement within 24 hours). A 10% noninferiority margin was predefined. RESULTS: In the intent-to-treat analysis set, the early clinical treatment response rates were 79.5% (95% CI, 74.8% to 83.7%) of 332 patients in the tedizolid phosphate group and 79.4% (95% CI, 74.7% to 83.6%) of 335 patients in the linezolid group (a treatment difference of 0.1% [95% CI, -6.1% to 6.2%]). The sustained clinical treatment response rates at the end of treatment (day 11) were 69.3% (95% CI, 64.0% to 74.2%) in the tedizolid phosphate group and 71.9% (95% CI, 66.8% to 76.7%) in the linezolid group (a treatment difference of -2.6% [95% CI, -9.6% to 4.2%]). Results of investigator-assessed clinical treatment success rates at a posttherapy evaluation visit (1-2 weeks after the end-of-treatment visit) were 85.5% (95% CI, 81.3% to 89.1%) in the tedizolid phosphate group and 86.0% (95% CI, 81.8% to 89.5%) in the linezolid group (a treatment difference of -0.5% [95% CI, -5.8% to 4.9%), and were similar for 178 patients with methicillin-resistant Staphylococcus aureus isolated from the primary lesion. CONCLUSIONS AND RELEVANCE: Tedizolid phosphate was a statistically noninferior treatment to linezolid in early clinical response at 48 to 72 hours after initiating therapy for an ABSSSI. Tedizolid phosphate may be a reasonable alternative to linezolid for treating ABSSSI. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01170221.

Use and perceived benefits of handheld computer-based clinical references.

OBJECTIVE: Clinicians are increasingly using handheld computers (HC) during patient care. We sought to assess the role of HC-based clinical reference software in medical practice by conducting a survey and assessing actual usage behavior. DESIGN: During a 2-week period in February 2005, 3600 users of a HC-based clinical reference application were asked by e-mail to complete a survey and permit analysis of their usage patterns. The software includes a pharmacopeia, an infectious disease reference, a medical diagnostic and therapeutic reference and transmits medical alerts and other notifications during HC synchronizations. Software usage data were captured during HC synchronization for the 4 weeks prior to survey completion. MEASUREMENTS: Survey responses and software usage data. RESULTS: The survey response rate was 42% (n = 1501). Physicians reported using the clinical reference software for a mean of 4 years and 39% reported using the software during more than half of patient encounters. Physicians who synchronized their HC during the data collection period (n = 1249; 83%) used the pharmacopeia for unique drug lookups a mean of 6.3 times per day (SD 12.4). The majority of users (61%) believed that in the prior 4 weeks, use of the clinical reference prevented adverse drug events or medication errors 3 or more times. Physicians also believed that alerts and other notifications improved patient care if they were public health warnings (e.g. about influenza), new immunization guidelines or drug alert warnings (e.g. rofecoxib withdrawal). CONCLUSION: Current adopters of HC-based medical references use these tools frequently, and found them to improve patient care and be valuable in learning of recent alerts and warnings.