scholarly journals Pharmacokinetic and Pharmacodynamic Analyses To Determine the Optimal Fixed Dosing Regimen of Iclaprim for Treatment of Patients with Serious Infections Caused by Gram-Positive Pathogens

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Thomas P. Lodise ◽  
John Bosso ◽  
Colleen Kelly ◽  
Paul J. Williams ◽  
James R. Lane ◽  
...  

ABSTRACT Iclaprim is a bacterial dihydrofolate reductase inhibitor that is currently being evaluated in two phase 3 trials for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI). Prior animal infection model studies suggest that the pharmacokinetic/pharmacodynamic (PK/PD) drivers for efficacy are area under the concentration-time curve from 0 to 24 h at steady state (AUC0–24ss), AUC/MIC, and time above the MIC during the dosing interval (T > MIC), while QTc prolongation was associated with the maximal concentration at steady state (C maxss) in a thorough QTc phase 1 study. Using PK data collected from 470 patients from the previously conducted phase 3 complicated skin and skin structure infection (cSSSI) trials, population PK modeling and Monte Carlo simulation (MCS) were used to identify a fixed iclaprim dosage regimen for the ongoing phase 3 ABSSSI studies that maximizes AUC0–24ss, AUC/MIC, and T > MIC while minimizing the probability of a C maxss of ≥800 ng/ml relative to the values for the previously employed cSSSI regimen of 0.8 mg/kg of body weight infused intravenously over 0.5 h every 12 h. The MCS analyses indicated that administration of 80 mg as a 2-h infusion every 12 h provides 28%, 28%, and 32% increases in AUC0–24ss, AUC/MIC, and T > MIC, respectively, compared to values for the 0.8-mg/kg cSSSI regimen, while decreasing the probability of a C maxss of ≥800 ng/ml, by 9%. Based on PK/PD analyses, 80 mg iclaprim administered over 2 h every 12 h was selected as the dosing scheme for subsequent phase 3 clinical trials.

2006 ◽  
Vol 50 (11) ◽  
pp. 3701-3707 ◽  
Author(s):  
S. A. Van Wart ◽  
J. S. Owen ◽  
E. A. Ludwig ◽  
A. K. Meagher ◽  
J. M. Korth-Bradley ◽  
...  

ABSTRACT Tigecycline, a first-in-class expanded glycylcycline antimicrobial agent, has demonstrated efficacy in the treatment of complicated skin and skin structure infections (cSSSI) and complicated intra-abdominal (cIAI) infections. A population pharmacokinetic (PK) model for tigecycline was developed for patients with cSSSI or cIAI enrolled in two phase 2 clinical trials, and the influence of selected demographic factors and clinical laboratory measures was investigated. Tigecycline was administered as an intravenous loading dose followed by a 0.5- or 1-h infusion every 12 h for up to 14 days. Blood samples were collected the day before or the day of hospital discharge for the determination of serum tigecycline concentrations. Patient covariates were evaluated using stepwise forward (α = 0.05) and backward (α = 0.001) procedures. The predictive performance of the model was assessed separately using pooled data from either two phase 3 studies for patients with cSSSI or two phase 3 studies for patients with cIAI. A two-compartment model with zero-order input and first-order elimination adequately described the steady-state tigecycline concentration-time data. Tigecycline clearance was shown to increase with increasing weight, increasing creatinine clearance, and male gender (P < 0.001). The final model provided a relatively unbiased fit to each data set. Individual predicted values of the area under the concentration-time curve from 0 to 12 h (AUC0-12) were generally unbiased (median prediction error, −1.60% to −3.78%) and were similarly precise (median absolute prediction error, <4%) when compared across data sets. The population PK model provided the basis to obtain individual estimates of steady-state AUC0-12 in later exposure-response analyses of tigecycline safety and efficacy in patients with cSSSI or cIAI.


2015 ◽  
Vol 59 (10) ◽  
pp. 6170-6174 ◽  
Author(s):  
Richard Pushkin ◽  
Steven L. Barriere ◽  
Whedy Wang ◽  
G. Ralph Corey ◽  
Martin E. Stryjewski

ABSTRACTTwo phase 3 ATLAS trials demonstrated noninferiority of telavancin compared with vancomycin for complicated skin and skin structure infections. Data from these trials were retrospectively evaluated according to 2013 U.S. Food and Drug Administration (FDA) guidance on acute bacterial skin and skin structure infections. Thispost hocanalysis included patients with lesion sizes of ≥75 cm2and excluded patients with ulcers or burns (updated all-treated population;n= 1,127). Updated day 3 (early) clinical response was defined as a ≥20% reduction in lesion size from baseline and no rescue antibiotic. Updated test-of-cure (TOC) clinical response was defined as a ≥90% reduction in lesion size, no increase in lesion size since day 3, and no requirement for additional antibiotics or significant surgical procedures. Day 3 (early) clinical responses were achieved in 62.6% and 61.0% of patients receiving telavancin and vancomycin, respectively (difference, 1.7%, with a 95% confidence interval [CI] of −4.0% to 7.4%). Updated TOC visit cure rates were similar for telavancin (68.0%) and vancomycin (63.3%), with a difference of 4.8% (95% CI, −0.7% to 10.3%). Adopting current FDA guidance, this analysis corroborates previous noninferiority findings of the ATLAS trials of telavancin compared with vancomycin.


2012 ◽  
Vol 56 (5) ◽  
pp. 2231-2236 ◽  
Author(s):  
H. David Friedland ◽  
Tanya O'Neal ◽  
Donald Biek ◽  
Paul B. Eckburg ◽  
Douglas R. Rank ◽  
...  

ABSTRACTScientific and regulatory interest in assessing clinical endpoints after 48 to 72 h of treatment for acute bacterial skin and skin structure infections (ABSSSI) has increased. Historical, pre-antibiotic-era data suggest that a treatment effect relative to untreated controls can be discerned in this time interval. Ceftaroline fosamil, a broad-spectrum bactericidal cephalosporin with activity against Gram-positive organisms, including methicillin-resistantStaphylococcus aureus(MRSA), and Gram-negative organisms was efficacious in two phase 3 trials of complicated skin infections (CANVAS 1 and 2) using clinical cure rates at the test-of-cure visit. To assess an early clinical response in the CANVAS trials, a retrospective analysis using a day 3 clinical endpoint was conducted. Adults with ABSSSI received intravenous ceftaroline fosamil at 600 mg every 12 h (q12h) or vancomycin at 1 g plus aztreonam at 1 g (V/A) q12h for 5 to 14 days. Clinical response at day 3, defined as cessation of infection spread and absence of fever, was analyzed in patients with a lesion size of ≥75 cm2and either deep and/or extensive cellulitis, major abscess, or an infected wound. Day 3 integrated CANVAS clinical response rates were 74.0% (296/400) for ceftaroline and 66.2% (263/397) for V/A (difference, 7.8%; 95% confidence interval [CI], 1.3% to 14.0%). In the individual studies, absolute treatment differences of 9.4% (CANVAS 1) and 5.9% (CANVAS 2) favoring ceftaroline were observed. For ABSSSI due to MRSA, response rates were 81.7% and 77.4% in the ceftaroline and V/A groups, respectively. In this retrospective analysis, ceftaroline fosamil monotherapy had a numerically higher clinical response than V/A at day 3 in the treatment of ABSSSI.


2008 ◽  
Vol 52 (9) ◽  
pp. 3418-3423 ◽  
Author(s):  
Karen M. Amsler ◽  
Todd A. Davies ◽  
Wenchi Shang ◽  
Michael R. Jacobs ◽  
Karen Bush

ABSTRACT In phase 3 clinical trials for ceftobiprole treatment of complicated skin and skin structure infections, 1,219 gram-positive and 276 gram-negative aerobic baseline pathogens were identified. Ceftobiprole inhibited all staphylococcal isolates, including methicillin-resistant strains, at MICs of ≤4 μg/ml. Against Enterobacteriaceae and Pseudomonas aeruginosa isolates, the potency of ceftobiprole was similar to that of cefepime.


2012 ◽  
Vol 56 (4) ◽  
pp. 2067-2073 ◽  
Author(s):  
Emil Samara ◽  
Jeng-Pyng Shaw ◽  
Steven L. Barriere ◽  
Shekman L. Wong ◽  
Philip Worboys

ABSTRACTA population pharmacokinetic model of telavancin, a lipoglycopeptide antibiotic, was developed and used to identify sources of interindividual variability. Data were obtained from healthy subjects (seven phase 1 studies), patients with complicated skin and skin structure infections (cSSSI; two phase 2 and two phase 3 studies), and patients with hospital-acquired pneumonia (HAP; two phase 3 studies). A two-compartment open model with zero-order input best fit the telavancin data from healthy individuals and patients with cSSSI or HAP. Telavancin clearance was highly correlated with renal function and, to a lesser extent, with body weight. Other covariates were related to at least one parameter in cSSSI (gender, bacterial eradication, and surgery) or HAP (age of ≥75 years) but did not markedly affect exposure. These analyses support current dosing recommendations for telavancin based on patient weight and renal function.


2011 ◽  
Vol 55 (5) ◽  
pp. 2290-2296 ◽  
Author(s):  
Thomas N. Kakuda ◽  
Samantha Abel ◽  
John Davis ◽  
Julia Hamlin ◽  
Monika Schöller-Gyüre ◽  
...  

ABSTRACTThe effects of darunavir-ritonavir at 600 and 100 mg twice daily (b.i.d.) alone, 200 mg of etravirine b.i.d. alone, or 600 and 100 mg of darunavir-ritonavir b.i.d. with 200 mg etravirine b.i.d. at steady state on the steady-state pharmacokinetics of maraviroc, and vice versa, in healthy volunteers were investigated in two phase I, randomized, two-period crossover studies. Safety and tolerability were also assessed. Coadministration of 150 mg maraviroc b.i.d. with darunavir-ritonavir increased the area under the plasma concentration-time curve from 0 to 12 h (AUC12) for maraviroc 4.05-fold relative to 150 mg of maraviroc b.i.d. alone. Coadministration of 300 mg maraviroc b.i.d. with etravirine decreased the maraviroc AUC12by 53% relative to 300 mg maraviroc b.i.d. alone. Coadministration of 150 mg maraviroc b.i.d. with etravirine-darunavir-ritonavir increased the maraviroc AUC123.10-fold relative to 150 mg maraviroc b.i.d. alone. Maraviroc did not significantly affect the pharmacokinetics of etravirine, darunavir, or ritonavir. Short-term coadministration of maraviroc with darunavir-ritonavir, etravirine, or both was generally well tolerated, with no safety issues reported in either trial. Maraviroc can be coadministered with darunavir-ritonavir, etravirine, or etravirine-darunavir-ritonavir. Maraviroc should be dosed at 600 mg b.i.d. with etravirine in the absence of a potent inhibitor of cytochrome P450 3A (CYP3A) (i.e., a boosted protease inhibitor) or at 150 mg b.i.d. when coadministered with darunavir-ritonavir with or without etravirine.


2020 ◽  
Vol 69 (4) ◽  
pp. 625-630
Author(s):  
Stephanie Noviello ◽  
G. Ralph Corey ◽  
Thomas L. Holland ◽  
Thomas Lodise ◽  
William O’Riordan ◽  
...  

Introduction. Iclaprim is a diaminopyrimidine antibiotic for the treatment of acute bacterial skin and skin structure infections (ABSSSI) due to Gram-positive pathogens. Aim. This analysis evaluates patients with wound infections from two Phase 3 trials of ABSSSI. Methodology. Six-hundred-two patients with wound infections from two Phase 3, double-blinded, randomized, multicenter, active controlled trials (REVIVE-1/–2) were evaluated in a post hoc analysis of iclaprim 80 mg compared with vancomycin 15 mg kg–1 administered intravenously every 12 h for 5–14 days. The primary endpoint was to determine whether iclaprim was non-inferior (10 % margin) to vancomycin in achieving a ≥20 % reduction from baseline in lesion size 48–72 h after starting study drug (early clinical response [ECR]). Safety was assessed. Results. In REVIVE-1, ECR was 83.5 % with iclaprim versus 79.7 % with vancomycin (treatment difference 3.77%, 95 % CI −4.50%, 12.04%). In REVIVE-2, ECR was 82.7 % with iclaprim versus 76.3 % with vancomycin (treatment difference 6.38%, 95 % CI −3.35%, 16.12%). In the pooled dataset, iclaprim had similar ECR rates compared with vancomycin among wound infection patients (83.2 % vs 78.2 %) with a treatment difference of 5.01 % (95 % CI −1.29%, 11.32%). The safety profile was similar in iclaprim- and vancomycin-treated patients, except for a higher incidence of diarrhea with vancomycin (n=17) compared with iclaprim (n=6) and fatigue with iclaprim (n=17) compared with vancomycin (n=8). Conclusion. Based on early clinical response, iclaprim achieved non-inferiority to vancomycin with a similar safety profile in patients with wound infections suspected or confirmed as caused by Gram-positive pathogens. Iclaprim may be a valuable treatment option for wound infections.


2007 ◽  
Vol 51 (6) ◽  
pp. 1939-1945 ◽  
Author(s):  
A. K. Meagher ◽  
J. A. Passarell ◽  
B. B. Cirincione ◽  
S. A. Van Wart ◽  
K. Liolios ◽  
...  

ABSTRACT Exposure-response analyses were performed for the microbiological and clinical efficacy of tigecycline in the treatment of complicated skin and skin-structure infections, where Staphylococcus aureus and streptococci are the predominant pathogens. A prospective method was developed to create homogeneous patient populations for PK-PD analyses. Evaluable patients from three clinical trials were pooled for analysis. Patients received a tigecycline 100-mg loading dose/50 mg every 12 h or a 50-mg loading dose/25 mg every 12 h. At the test-of-cure visit, microbiologic and clinical responses were evaluated. Patients were prospectively evaluated and classified into cohorts based on baseline pathogens: S. aureus only (cohort 1), monomicrobial S. aureus or streptococci (cohort 2), two gram-positive pathogens (cohort 3), polymicrobial (cohort 4), or other monomicrobial infections (cohort 5). A prospective procedure for combining cohorts was used to increase the sample size. Logistic regression evaluated steady-state 24-h area under the concentration-time curve (AUC24)/MIC ratio as a predictor of response, and classification and regression tree (CART) analyses were utilized to determine AUC/MIC breakpoints. Analysis began with pooled cohorts 2 and 3, the focus of these analyses, and included 35 patients with 40 S. aureus and/or streptococcal pathogens. CART analyses identified a significant AUC/MIC breakpoint of 17.9 (P = 0.0001 for microbiological response and P = 0.0376 for clinical response). The continuous AUC/MIC ratio was predictive of microbiological response based on sample size (P = 0.0563). Analysis of all pathogens combined decreased the ability to detect exposure-response relationships. The prospective approach of creating homogeneous populations based on S. aureus and streptococci pathogens was critical for identifying exposure-response relationships.


2012 ◽  
Vol 57 (1) ◽  
pp. 647-650 ◽  
Author(s):  
George H. Talbot ◽  
Tanya O'Neal ◽  
Anita F. Das ◽  
Dirk Thye

ABSTRACTWilson et al. (Am. J. Surg.185:369–375, 2003) developed a disease severity classification system for use in complicated skin and skin structure infections (cSSSI). Two phase 3 trials of ceftaroline fosamil in cSSSI provided the opportunity to evaluate the association between Wilson Severity Risk Class and clinical cure rates. Our analyses did not confirm that an association exists between Wilson Severity Risk Class and clinical cure rate and, thus, did not validate its predictive utility.


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