Nathalie Dartois

The Efficacy and Safety of Tigecycline for the Treatment of Complicated Intra-Abdominal Infections: Analysis of Pooled Clinical Trial Data

This pooled analysis includes 2 phase 3, double-blind trials designed to evaluate the safety and efficacy of tigecycline, versus that of imipenem-cilastatin, in 1642 adults with complicated intra-abdominal infections. Patients were randomized to receive either tigecycline (initial dose of 100 mg, followed by 50 mg intravenously every 12 h) or imipenem-cilastatin (500/500 mg intravenously every 6 h) for 5-14 days. The primary end point was the clinical response at the test-of-cure visit (12-42 days after therapy) in the co-primary end point microbiologically evaluable and microbiological modified intent-to-treat populations. For the microbiologically evaluable group, clinical cure rates were 86.1% (441/512) for tigecycline, versus 86.2% (442/513) for imipenem-cilastatin (95% confidence interval for the difference, -4.5% to 4.4%; P < .0001 for noninferiority). Clinical cure rates in the microbiological modified intent-to-treat population were 80.2% (506/631) for tigecycline, versus 81.5% (514/631) for imipenem-cilastatin (95% confidence interval for the difference, -5.8% to 3.2%; P < .0001 for noninferiority). Nausea (24.4% tigecycline, 19.0% imipenem-cilastatin [P = .01]), vomiting (19.2% tigecycline, 14.3% imipenem-cilastatin [P = .008]), and diarrhea (13.8% tigecycline, 13.2% imipenem-cilastatin [P = .719]) were the most frequently reported adverse events. This pooled analysis demonstrates that tigecycline was efficacious and well tolerated in the treatment of patients with complicated intra-abdominal infections.

Comparison of tigecycline with imipenem/cilastatin for the treatment of hospital-acquired pneumonia.

To compare efficacy and safety of a tigecycline regimen with an imipenem/cilastatin regimen in hospital-acquired pneumonia patients, a phase 3, multicenter, randomized, double-blind, study evaluated 945 patients. Coprimary end points were clinical response in clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) populations at test-of-cure. Cure rates were 67.9% for tigecycline and 78.2% for imipenem (CE patients) and 62.7% and 67.6% (c-mITT patients), respectively. A statistical interaction occurred between ventilator-associated pneumonia (VAP) and non-VAP subgroups, with significantly lower cure rates in tigecycline VAP patients compared to imipenem; in non-VAP patients, tigecycline was noninferior to imipenem. Overall mortality did not differ between the tigecycline (14.1%) and imipenem regimens (12.2%), although more deaths occurred in VAP patients treated with tigecycline than imipenem. Overall, the tigecycline regimen was noninferior to the imipenem/cilastatin regimen for the c-mITT but not the CE population; this difference appears to have been driven by results in VAP patients.

Safety and efficacy of tigecycline in treatment of skin and skin structure infections : Results of a double-blind phase 3 comparison study with vancomycin-aztreonam

ABSTRACT In a randomized, double-blind, controlled trial, 546 patients with complicated skin and skin structure infections received tigecycline 100 mg/day (a 100-mg initial dose and then 50 mg intravenously twice daily) or the combination of vancomycin 2 g/day (1 g intravenously twice daily) and aztreonam 4 g/day (2 g intravenously twice daily) for up to 14 days. The primary end point was the clinical response in the clinical modified intent-to-treat (c-mITT) and clinically evaluable (CE) populations at the test-of-cure visit 12 to 92 days after the last dose. The microbiologic response at the test-of-cure visit was also assessed. Safety was assessed by physical examination, laboratory results, and adverse event reporting. Five hundred twenty patients were included in the c-mITT population (tigecycline group, n = 261; combination group, n = 259), and 436 were clinically evaluable (tigecycline group, n = 223; combination group, n = 213). The clinical responses in the tigecycline and the combination vancomycin and aztreonam groups were similar in the c-mITT population (84.3% versus 86.9%; difference, −2.6% [95% confidence interval, −9.0, 3.8]; P = 0.4755) and the CE population (89.7% versus 94.4%; difference, −4.7% [95% confidence interval, −10.2, 0.8]; P = 0.1015). Microbiologic eradication (documented or presumed) occurred in 84.8% of the patients receiving tigecycline and 93.2% of the patients receiving vancomycin and aztreonam (difference, −8.5 [95% confidence interval, −16.0, −1.0]; P = 0.0243). The numbers of patients reporting adverse events were similar in the two groups, with increased nausea and vomiting rates in the tigecycline group and an increased incidence of rash and increases in alanine aminotransferase and aspartate aminotransferase levels in the combination vancomycin and aztreonam group. Tigecycline was shown to be safe and effective for the treatment of complicated skin and skin structure infections.

Randomized Phase 2 Trial To Evaluate the Clinical Efficacy of Two High-Dosage Tigecycline Regimens versus Imipenem-Cilastatin for Treatment of Hospital-Acquired Pneumonia

ABSTRACT In a previous phase 3 study, the cure rates that occurred in patients with hospital-acquired pneumonia treated with tigecycline at the approved dose were lower than those seen with patients treated with imipenem and cilastatin (imipenem/cilastatin). We hypothesized that a higher dose of tigecycline is necessary in patients with hospital-acquired pneumonia. This phase 2 study compared the safety and efficacy of two higher doses of tigecycline with imipenem/cilastatin in subjects with hospital-acquired pneumonia. Subjects with hospital-acquired pneumonia were randomized to receive one of two doses of tigecycline (150 mg followed by 75 mg every 12 h or 200 mg followed by 100 mg every 12 h) or 1 g of imipenem/cilastatin every 8 h. Empirical adjunctive therapy was administered for initial coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa infection, depending on the randomization regimen. Clinical response, defined as cure, failure of treatment, or indeterminate outcome, was assessed 10 to 21 days after the last day of therapy. In the clinically evaluable population, clinical cure with tigecycline 100 mg (17/20, 85.0%) was numerically higher than with tigecycline 75 mg (16/23, 69.6%) and imipenem/cilastatin (18/24, 75.0%). No new safety signals with the high-dose tigecycline were identified. A numerically higher clinical response was observed with the 100-mg dose of tigecycline. This supports our hypothesis that a higher area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) may be necessary to achieve clinical cure in patients with hospital-acquired pneumonia. Further studies are necessary. (The ClinicalTrials.gov identifier for this clinical trial is NCT00707239.)

Integrated results of 2 phase 3 studies comparing tigecycline and levofloxacin in community-acquired pneumonia

Tigecycline (TGC), a glycylcycline, has expanded activity against Gram-positive and Gram-negative, anaerobic, and atypical bacteria. Two phase 3 studies were conducted. Hospitalized patients with community-acquired pneumonia (CAP) were randomized to intravenous (IV) TGC (100 mg followed by 50 mg bid) or IV levofloxacin (LEV) (500 mg bid). In 1 study, patients could be switched to oral LEV after at least 3 days intravenously. The coprimary efficacy end points were as follows: clinical response in clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) populations at test-of-cure (TOC). The secondary end points were as follows: microbiologic efficacy and susceptibility to TGC for CAP bacteria. Safety evaluations were included. Eight hundred ninety-one were patients screened: 846 mITT (TGC 424, LEV 422), 574 CE (TGC 282, LEV 292). Most patients had Fine Pneumonia Severity Index II to IV (80.7% TGC, 74.4% LEV, mITT). At TOC (CE), TGC cured 253/282 patients (89.7%) and LEV cured 252/292 patients (86.3%); the absolute difference of TGC-LEV was 3.4% (95% confidence interval [CI], -2.2 to 9.1, noninferior [P < 0.001]). In c-mITT, TGC cured 319/394 patients (81.0%) and LEV cured 321/403 patients (79.7%); the absolute difference of TGC-LEV was 1.3% (95% CI -4.5 to 7.1, noninferior [P < 0.001]). The drug-related adverse events (AEs) of nausea (20.8% TGC versus 6.6% LEV) and vomiting (13.2% TGC versus 3.3% LEV) were significantly higher in TGC; elevated alanine aminotransferase (2.8% TGC versus 7.3% LEV) and aspartate aminotransferase (2.6% TGC versus 6.9% LEV) were significantly higher in LEV. Discontinuations for AEs were low (TGC, 26 patients [6.1%]; LEV, 34 patients [8.1%]). TGC appeared safe and achieved cure rates similar to LEV in hospitalized patients with CAP.

A Phase 3, open-label, non-comparative study of tigecycline in the treatment of patients with selected serious infections due to resistant Gram-negative organisms including Enterobacter species, Acinetobacter baumannii and Klebsiella pneumoniae

OBJECTIVES To evaluate the efficacy and safety of tigecycline in patients with selected serious infections caused by resistant Gram-negative bacteria, or failures who had received prior antimicrobial therapy or were unable to tolerate other appropriate antimicrobials. Secondary objectives included an evaluation of the microbiological efficacy of tigecycline and in vitro activity of tigecycline for resistant Gram-negative bacteria. METHODS This open-label, Phase 3, non-comparative, multicentre study assessed the efficacy and safety of intravenous tigecycline (100 mg initially, then 50 mg 12 hourly for 7-28 days) in hospitalized patients with serious infections including complicated intra-abdominal infection; complicated skin and skin structure infection (cSSSI); community-acquired pneumonia (CAP); hospital-acquired pneumonia, including ventilator-associated pneumonia; or bacteraemia, including catheter-related bacteraemia. All patients had infections due to resistant Gram-negative organisms, including extended-spectrum beta-lactamase-producing strains, or had failed on prior therapy or could not receive (allergy or intolerance) one or more agents from three classes of commonly used antibiotics. The primary efficacy endpoint was clinical response in the microbiologically evaluable (ME) population at test of cure (TOC). Safety data included vital signs, laboratory tests and adverse events (AEs). RESULTS In the ME population at TOC, the clinical cure rate was 72.2% [95% confidence interval (CI): 54.8-85.8], and the microbiological eradication rate was 66.7% (95% CI: 13.7-78.8). The most commonly isolated resistant Gram-negative pathogens were Acinetobacter baumannii (47%), Escherichia coli (25%), Klebsiella pneumoniae (16.7%) and Enterobacter spp. (11.0%); the most commonly diagnosed serious infection was cSSSI (67%). The most common treatment-emergent AEs were nausea (29.5%), diarrhoea (16%) and vomiting (16%), which were mild or moderate in severity. CONCLUSIONS In this non-comparative study, tigecycline appeared safe and efficacious in patients with difficult-to-treat serious infections caused by resistant Gram-negative organisms.

Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease

Pneumococcal disease (including community-acquired pneumonia and invasive pneumococcal disease) poses a burden to the community all year round, especially in those with chronic underlying conditions. Individuals with COPD, asthma or who smoke, and those with chronic heart disease or diabetes mellitus have been shown to be at increased risk of pneumococcal disease compared with those without these risk factors. These conditions, and smoking, can also adversely affect patient outcomes, including short-term and long-term mortality rates, following pneumonia. Community-acquired pneumonia, and in particular pneumococcal pneumonia, is associated with a significant economic burden, especially in those who are hospitalised, and also has an impact on a patients quality of life. Therefore, physicians should target individuals with COPD, asthma, heart disease or diabetes mellitus, and those who smoke, for pneumococcal vaccination at the earliest opportunity at any time of the year.

Pharmacological and Patient-Specific Response Determinants in Patients with Hospital-Acquired Pneumonia Treated with Tigecycline

ABSTRACT Pharmacokinetic and clinical data from tigecycline-treated patients with hospital-acquired pneumonia (HAP) who were enrolled in a phase 3 clinical trial were integrated in order to evaluate pharmacokinetic-pharmacodynamic (PK-PD) relationships for efficacy. Univariable and multivariable analyses were conducted to identify factors associated with clinical and microbiological responses, based on data from 61 evaluable HAP patients who received tigecycline intravenously as a 100-mg loading dose followed by 50 mg every 12 h for a minimum of 7 days and for whom there were adequate clinical, pharmacokinetic, and response data. The final multivariable logistic regression model for clinical response contained albumin and the ratio of the free-drug area under the concentration-time curve from 0 to 24 h (fAUC0–24) to the MIC (fAUC0–24:MIC ratio). The odds of clinical success were 13.0 times higher for every 1-g/dl increase in albumin (P < 0.001) and 8.42 times higher for patients with fAUC0–24:MIC ratios of ≥0.9 compared to patients with fAUC0–24:MIC ratios of <0.9 (P = 0.008). Average model-estimated probabilities of clinical success for the albumin/fAUC0–24:MIC ratio combinations of <2.6/<0.9, <2.6/≥0.9, ≥2.6/<0.9, and ≥2.6/≥0.9 were 0.21, 0.57, 0.64, and 0.93, respectively. For microbiological response, the final model contained albumin and ventilator-associated pneumonia (VAP) status. The odds of microbiological success were 21.0 times higher for every 1-g/dl increase in albumin (P < 0.001) and 8.59 times higher for patients without VAP compared to those with VAP (P = 0.003). Among the remaining variables evaluated, the MIC had the greatest statistical significance, an observation which was not surprising given the differences in MIC distributions between VAP and non-VAP patients (MIC50and MIC90 values of 0.5 and 0.25 mg/liter versus 16 and 1 mg/liter for VAP versus non-VAP patients, respectively; P = 0.006). These findings demonstrated the impact of pharmacological and patient-specific factors on the clinical and microbiological responses.

Efficacy and safety of tigecycline versus levofloxacin for community-acquired pneumonia

BackgroundTigecycline, an expanded broad-spectrum glycylcycline, exhibits in vitro activity against many common pathogens associated with community-acquired pneumonia (CAP), as well as penetration into lung tissues that suggests effectiveness in hospitalized CAP patients. The aim of the present study was to compare the efficacy and safety of intravenous (IV) tigecycline with IV levofloxacin in hospitalized adults with CAP.MethodsIn this prospective, double-blind, non-inferiority phase 3 trial, eligible patients with a clinical diagnosis of CAP supported by radiographic evidence were stratified by Fine Pneumonia Severity Index and randomized to tigecycline or levofloxacin for 7-14 days of therapy. Co-primary efficacy endpoints were clinical response in the clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) populations at test-of-cure (Day 10-21 post-therapy).ResultsOf the 428 patients who received at least one dose of study drug, 79% had CAP of mild-moderate severity according to their Fine score. Clinical cure rates for the CE population were 88.9% for tigecycline and 85.3% for levofloxacin. Corresponding c-mITT population rates were 83.7% and 81.5%, respectively. Eradication rates for Streptococcus pneumoniae were 92% for tigecycline and 89% for levofloxacin. Nausea, vomiting, and diarrhoea were the most frequently reported adverse events. Rates of premature discontinuation of study drug or study withdrawal because of any adverse event were similar for both study drugs.ConclusionThese findings suggest that IV tigecycline is non-inferior to IV levofloxacin and is generally well-tolerated in the treatment of hospitalized adults with CAP.Trial registrationNCT00081575

Pharmacokinetics and Safety Profile of Tigecycline in Children Aged 8 to 11 Years With Selected Serious Infections: A Multicenter, Open-Label, Ascending-Dose Study

BACKGROUND Tigecycline, a broad-spectrum antibiotic used for treating serious bacterial infections in adults, may be suitable for pediatric use once an appropriate dosage is determined. OBJECTIVE The aim of this study was to assess the pharmacokinetic (PK) properties, safety profile, and descriptive efficacy of tigecycline. METHODS In this Phase II, multicenter, open-label clinical trial, children aged 8 to 11 years with community-acquired pneumonia (CAP), complicated intra-abdominal infection (cIAI), or complicated skin and skin structure infections (cSSSI) were administered tigecycline 0.75, 1, or 1.25 mg/kg. RESULTS A total of 58 patients received ≥ 1 dose of tigecycline (31 boys; 44 white; mean age, 10 years; mean weight, 35 kg); 47 had data from samples available for PK analysis. The mean (SD) PK values were: C(max), 1899 (2954) ng/mL; T(max), 0.56 (0.18) hour; between-dose AUC, 2833 (1557) ng · h/mL; weight-normalized clearance, 0.503 (0.293) L/h/kg; and Vd(ss), 4.88 (4.84) L/kg. Overall clinical cure rates at test-of-cure were 94% (16/17), 76% (16/21), and 75% (15/20) in the 0.75-, 1-, and 1.25-mg/kg cohorts, respectively. The rates of protocol violations were higher in the 1- and 1.25-mg/kg groups, resulting in higher proportions of indeterminate clinical cure assessments relative to the 0.75-mg/kg cohort (19% and 15% vs 0%). The most frequent adverse event was nausea, which occurred in 50% of patients overall (29/58) and the prevalence of which was significantly higher in the 1.25-mg/kg group versus the 0.75-mg/kg group (65% vs 18%; P = 0.007). Pharmacodynamic simulations using MIC data from an ongoing microbiological surveillance trial predicted that a dosage of 1.2 mg/kg q12h would lead to therapeutic target attainment levels of up to 82% for the target AUC(0-24)/MIC ratios. CONCLUSION A tigecycline dosage of ∼1.2 mg/kg q12h may represent the most appropriate dosage for subsequent evaluation in Phase III clinical trials in children aged 8 to 11 years with selected serious bacterial infections. ClinicalTrials.gov identifier: NCT00488345.