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Brensocatib is an investigational, first-in-class, selective, and reversible dipeptidyl peptidase 1 inhibitor that blocks activation of neutrophil serine proteases (NSPs). The NSPs neutrophil elastase, cathepsin G, and proteinase 3 are believed to be central to the pathogenesis of several chronic inflammatory diseases, including bronchiectasis. In a phase II study, oral brensocatib 10 mg and 25 mg reduced sputum neutrophil elastase activity and prolonged the time to pulmonary exacerbation in patients with non-cystic fibrosis bronchiectasis (NCFBE). A population pharmacokinetic (PPK) model was developed to characterize brensocatib exposure, determine potential relationships between brensocatib exposure and efficacy and safety measures, and inform dose selection in clinical studies.Pharmacokinetic (PK) data pooled from a phase I study of once-daily brensocatib (10, 25, and 40 mg) in healthy adults and a phase II study of once-daily brensocatib (10 mg and 25 mg) in adults with NCFBE were used to develop a PPK model and to evaluate potential covariate effects on brensocatib pharmacokinetics. PK-efficacy relationships for sputum neutrophil elastase below the level of quantification (BLQ) and reduction in pulmonary exacerbation and PK-safety relationships for adverse events of special interest (AESIs; periodontal disease, hyperkeratosis, and infections other than pulmonary infections) were evaluated based on model-predicted brensocatib exposure. A total of 1284 steady-state brensocatib concentrations from 225 individuals were included in the PPK data set; 241 patients with NCFBE from the phase II study were included in the pharmacodynamic (PD) population for the PK/PD analyses.The PPK model that best described the observed data consisted of two distributional compartments and linear clearance. Two significant covariates were found: age on volume of distribution and renal function on apparent oral clearance. PK-efficacy analysis revealed a threshold brensocatib exposure (area under the concentration-time curve) effect for attaining sputum neutrophil elastase BLQ and a strong relationship between sputum neutrophil elastase BLQ and reduction in pulmonary exacerbations. A PK-safety evaluation showed no noticeable trends between brensocatib exposure and the incidence of AESIs. Based on the predicted likelihood of clinical outcomes for sputum neutrophil elastase BLQ and pulmonary exacerbations, brensocatib doses of 10 mg and 25 mg once daily were selected for a phase III clinical trial in patients with NCFBE (ClinicalTrials.gov identifier: NCT04594369).PPK results revealed that age and renal function have a moderate effect on brensocatib exposure. However, this finding does not warrant dose adjustments based on age or in those with mild or moderate renal impairment. The PK/PD evaluation demonstrated the clinically meaningful relationship between suppression of neutrophil elastase activity and reduction in exacerbations in brensocatib-treated patients with NCFBE, supporting further development of brensocatib for bronchiectasis.

Supplemental Digital Content is available in the text., Background: Ceftobiprole, the active moiety of the prodrug ceftobiprole medocaril, is an advanced-generation, broad-spectrum, intravenous cephalosporin, which is currently approved for the treatment of adults with hospital-acquired or community-acquired pneumonia. Methods: Noncompartmental pharmacokinetics and safety were analyzed from 2 recently completed pediatric studies, a single-dose, phase 1 study in neonates and infants up to 3 months of age (7.5 mg/kg) and a phase 3 study in patients 3 months to 17 years of age with pneumonia (10–20 mg/kg with a maximum of 500 mg per dose every 8 hours for up to 14 days). Results: Total ceftobiprole plasma concentrations peaked at the end of infusion. Half life (median ranging from 1.9 to 2.9 hours) and overall exposure (median AUC ranging from 66.6 to 173 μg•h/mL) were similar to those in adults (mean ± SD, 3.3 ± 0.3 hours and 102 ± 11.9 μg•h/mL, respectively). Calculated free-ceftobiprole concentrations in the single-dose study remained above a minimum inhibitory concentration (MIC) of 4 mg/L (fT > MIC of 4 mg/L) for a mean of 5.29 hours after dosing. In the pneumonia study, mean fT > MIC of 4 mg/L was ≥5.28 hours in all dose groups. Ceftobiprole was well tolerated in both studies. Conclusions: Pharmacokinetic parameters of ceftobiprole characterized in the pediatric population were within the range of those observed in adults. In the pneumonia study, the lowest percentage of the dosing interval with fT > MIC of 4 mg/L was 50.8%, which suggests that pharmacokinetic-pharmacodynamic target attainment can be sufficient in pediatric patients. Ceftobiprole was well tolerated.

Meropenem-vaborbactam is a fixed-dose beta-lactam/beta-lactamase inhibitor with potent in vitro and in vivo activity against Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales . Pharmacokinetic-pharmacodynamic (PK-PD) target attainment analyses were undertaken using population pharmacokinetic models, nonclinical PK-PD targets for efficacy, in vitro surveillance data, and simulation to provide support for 2 g meropenem-2 g vaborbactam every 8 h (q8h) administered as a 3-h intravenous (i.v.) infusion, and dosing regimens adjusted for patients with renal impairment.

Cefazolin is an antibiotic frequently used for perioperative prophylaxis. Data from healthy adults and pediatric surgery patients were pooled to refine a previously developed population pharmacokinetic (PK) model and to determine the optimal body weight cutoff for selecting fixed doses of either 1 or 2 g cefazolin to produce exposures in pediatric surgery patients similar to a single 2‐g dose in adults. Regardless of dose used, cefazolin was well tolerated in pediatric patients. A total of 1102 plasma samples from 62 patients from 3 studies were available to assess the previous model. The pooled data set allowed for simplification of the model such that allometrically scaled clearance and volume parameters were found to provide a robust fit while removing unnecessary covariate relationships. Monte Carlo simulations using the final cefazolin population PK model suggested an optimal weight cutoff of 50 kg, in contrast to the previously suggested 60 kg for a single 2‐g dose. Patients at or above this 50‐kg cutoff would receive a 2‐g dose of cefazolin, and those below 50 kg but ≥25 kg would receive a 1‐g dose of cefazolin.

IMPORTANCE: Phase 3 trials have not compared semaglutide and liraglutide, glucagon-like peptide-1 analogues available for weight management. OBJECTIVE: To compare the efficacy and adverse event profiles of once-weekly subcutaneous semaglutide, 2.4 mg, vs once-daily subcutaneous liraglutide, 3.0 mg (both with diet and physical activity), in people with overweight or obesity. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label, 68-week, phase 3b trial conducted at 19 US sites from September 2019 (enrollment: September 11-November 26) to May 2021 (end of follow-up: May 11) in adults with body mass index of 30 or greater or 27 or greater with 1 or more weight-related comorbidities, without diabetes (N = 338). INTERVENTIONS: Participants were randomized (3:1:3:1) to receive once-weekly subcutaneous semaglutide, 2.4 mg (16-week escalation; n = 126), or matching placebo, or once-daily subcutaneous liraglutide, 3.0 mg (4-week escalation; n = 127), or matching placebo, plus diet and physical activity. Participants unable to tolerate 2.4 mg of semaglutide could receive 1.7 mg; participants unable to tolerate 3.0 mg of liraglutide discontinued treatment and could restart the 4-week titration. Placebo groups were pooled (n = 85). MAIN OUTCOMES AND MEASURES: The primary end point was percentage change in body weight, and confirmatory secondary end points were achievement of 10% or more, 15% or more, and 20% or more weight loss, assessed for semaglutide vs liraglutide at week 68. Semaglutide vs liraglutide comparisons were open-label, with active treatment groups double-blinded against matched placebo groups. Comparisons of active treatments vs pooled placebo were supportive secondary end points. RESULTS: Of 338 randomized participants (mean [SD] age, 49 [13] years; 265 women [78.4%]; mean [SD] body weight, 104.5 [23.8] kg; mean [SD] body mass index, 37.5 [6.8]), 319 (94.4%) completed the trial, and 271 (80.2%) completed treatment. The mean weight change from baseline was –15.8% with semaglutide vs –6.4% with liraglutide (difference, –9.4 percentage points [95% CI, –12.0 to –6.8]; P

Ceftobiprole is an advanced-generation cephalosporin for intravenous administration with activity against Gram-positive and Gram-negative organisms. A population pharmacokinetic (PK) model characterizing the disposition of ceftobiprole in plasma using data from patients in three pediatric studies was developed. Model-based simulations were subsequently performed to assist in dose optimization for the treatment of pediatric patients with hospital-acquired or community-acquired pneumonia. The population PK data set comprised 518 ceftobiprole plasma concentrations from 107 patients from 0 (birth) to 17 years of age. Ceftobiprole PK was well described by a three-compartment model with linear elimination. Ceftobiprole clearance was modeled as a function of glomerular filtration rate; other PK parameters were scaled to body weight. The final population PK model provided a robust and reliable description of the PK of ceftobiprole in the pediatric study population. Model-based simulations using the final model suggested that a ceftobiprole dose of 15 mg/kg of body weight infused over 2 h and administered every 12 h in neonates and infants

Rezafungin is a novel antifungal agent of the echinocandin class with potent activity against species of Candida and Aspergillus, including subsets of resistant strains, and Pneumocystis jirovecii. The objective of this analysis was to develop a population pharmacokinetic (PK) model to characterize the disposition of rezafungin in plasma following intravenous (IV) administration in healthy volunteers and in patients with candidemia and/or invasive candidiasis. The population PK model was based on a previous model from phase 1 data; formal covariate analyses were conducted to identify any relationships between subject characteristics and rezafungin PK variability. A four-compartment model with linear elimination and zero-order drug input provided a robust fit to the pooled data. Several statistically significant relationships between subject descriptors (sex, infection status, serum albumin, and body surface area [BSA]) and rezafungin PK parameters were identified, but none were deemed clinically relevant. Previous dose justification analyses conducted using data from phase 1 subjects alone are expected to remain appropriate. The final model provided a precise and unbiased fit to the observed concentrations and can be used to reliably predict rezafungin PK in infected patients.

Meropenem-vaborbactam is a broad-spectrum carbapenem-beta-lactamase inhibitor combination approved in the USA and Europe to treat patients with complicated urinary tract infections and in Europe, other serious bacterial infections, including hospital- acquired and ventilator-associated pneumonia. Population pharmacokinetic (PK) models were developed to characterize the time-course of meropenem and vaborbactam using pooled data from two Phase 1 and two Phase 3 studies. Multi-compartment disposition model structures with linear elimination processes were fit to the data using NONMEM 7.2. Since both drugs are cleared primarily by the kidneys, estimated glomerular filtration rate (eGFR) was evaluated as part of the base structural models. For both agents, a two-compartment model with zero-order input and first-order elimination best described the pharmacokinetic PK data and a sigmoidal Hill-type equation best described the relationship between renal clearance and eGFR. For meropenem, the following significant covariate relationships were identified: clearance (CL) decreased with increasing age, CL was systematically different in subjects with end stage renal disease, and all PK parameters increased with increasing weight. For vaborbactam, the following significant covariate relationships were identified: CL increased with increasing height, volume of the central compartment (Vc) increased with increasing body surface area, and CL, Vc, and volume of the peripheral compartment were systematically different in Phase 1 non-infected subjects relative to Phase 3 infected patients, respectively. Visual predictive checks demonstrated minimal bias, supporting the robustness of the final models. These models were useful for generating individual PK exposures for pharmacokinetic-pharmacodynamic (PK-PD) analyses for efficacy and Monte Carlo simulations to evaluate PK-PD target attainment.

Temozolomide (TEM) is an active treatment in metastatic neuroendocrine tumors (NETs). Patients affected by glioblastoma multiforme or advanced melanoma treated with TEM who have deficiency of OWe conducted a systematic review of the literature and meta-analysis, based on PRISMA methodology, searching in the main databases (PubMed, Embase, Scopus, Web of Science, Cochrane Library and clinical trial.gov) and the proceedings of the main international congresses, until April 26, 2021.Twelve out of 616 articles were selected for our analysis, regarding a total of 858 NET patients treated with TEM-based chemotherapy. The status of MGMT had been tested in 513 (60%) patients, using various methods. The pooled overall response rate (ORR) was higher in MGMT-deficient compared with MGMT-proficient NETs, with a risk difference of 0.31 (95% confidence interval, CI: 0.13-0.50; p 0.001; IOur meta-analysis suggested that MGMT status may be predictive of TEM efficacy. However, due to the high heterogeneity of the evaluated studies the risk of biases should be considered. On this hypothesis future homogeneous prospective studies are warranted.

Purpose To assess the safety and efficacy of less dense panretinal photocoagulation after intravitreal bevacizumab in aggressive posterior retinopathy of prematurity infants. Methods Retrospective consecutive case series of premature infants diagnosed with aggressive posterior retinopathy of prematurity between August 2012 and November 2015 who received intravitreal bevacizumab with subsequent modified indirect diode laser panretinal photocoagulation for reactivation or incomplete vascularization. Main outcome measures included postprocedural reactivation, retinal detachments, or anterior segment ischemia. Results Sixty-one eyes of 31 premature infants were identified. The average gestational age was 24 ± 2.2 weeks (range 22-27), and the average birth weight was 661.5 ± 167.1 g (range 340.0-930.5 g). The average follow-up was 3.9 ± 1.3 years (range 1.3-5.4 years). At the last follow-up, no patient had experienced postlaser reactivation, retinal detachments, anterior segment ischemia, or other laser complications. Conclusion This study suggests that nonconfluent panretinal photocoagulation for aggressive posterior retinopathy of prematurity infants who have received intravitreal bevacizumab may be safe and effective. This study's strengths include a sizeable sample size, long-term follow-up of nearly 4 years, and consistency in treatment among patients by a single, experienced retinopathy of prematurity specialist.

Omadacycline, a novel aminomethylcycline antibiotic with activity against Gram-positive and -negative organisms, including tetracycline-resistant pathogens, received FDA approval in October 2018 for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). A previously developed population pharmacokinetic (PK) model based on phase 1 intravenous and oral PK data was refined using data from infected patients. Data from 10 phase 1 studies used to develop the previous model were pooled with data from three additional phase 1 studies, a phase 1b uncomplicated urinary tract infection study, one phase 3 CABP study, and two phase 3 ABSSSI studies., Omadacycline, a novel aminomethylcycline antibiotic with activity against Gram-positive and -negative organisms, including tetracycline-resistant pathogens, received FDA approval in October 2018 for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). A previously developed population pharmacokinetic (PK) model based on phase 1 intravenous and oral PK data was refined using data from infected patients. Data from 10 phase 1 studies used to develop the previous model were pooled with data from three additional phase 1 studies, a phase 1b uncomplicated urinary tract infection study, one phase 3 CABP study, and two phase 3 ABSSSI studies. The final population PK model was a three-compartment model with first-order absorption using transit compartments to account for absorption delay following oral dosing and first-order elimination. Epithelial lining fluid (ELF) concentrations were modeled as a subcompartment of the first peripheral compartment. A food effect on oral bioavailability was included in the model. Sex was the only significant covariate identified, with 15.6% lower clearance for females than males. Goodness-of-fit diagnostics indicated a precise and unbiased fit to the data. The final model, which was robust in its ability to predict plasma and ELF exposures following omadacycline administration, was also able to predict the central tendency and variability in concentration-time profiles using an external phase 3 ABSSSI data set. A population PK model, which described omadacycline PK in healthy subjects and infected patients, was developed and subsequently used to support pharmacokinetic-pharmacodynamic (PK-PD) and PK-PD target attainment assessments.

To investigate the rate of return to the operating room after vitrectomy surgery for vitreous opacities.Retrospective registry cohort.Individuals receiving care in ophthalmology practices participating in the Intelligent Research in Sight (IRIS®) Registry.Data from the IRIS Registry were analyzed for patients who underwent vitrectomy for vitreous opacities. Cases were identified by the combination of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), and International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), codes (379.21, 379.22, 379.24, and 379.25), and a Current Procedural Terminology (CPT) code for vitrectomy surgery.The number and percentage of eyes that underwent additional eye surgery within 1 year after vitrectomy for vitreous opacities were identified, as was the nature of the additional procedures per CPT code.Fifty thousand eight hundred thirty-six eyes that underwent vitrectomy surgery linked to one of the ICD-9-CM or ICD-10-CM codes for vitreous opacities were identified. In 17 615 eyes, the surgery was linked to the vitreous opacities code exclusively, and not to epiretinal membrane or macular hole codes. Of these, 2187 eyes (12.4%) returned to the operating room for cataract surgery, and 643 eyes (3.7%) returned to the operating room for a noncataract procedure. Four hundred fifty-seven eyes (2.6%) returned to the operating room for retinal detachment repair.In the IRIS Registry, eyes undergoing vitrectomy for vitreous opacities returned to the operating room for an ophthalmic surgery other than cataract extraction 3.7% of the time, and retinal detachment repair was performed 2.6% of the time.

Background Hydromethylthionine is a potent inhibitor of pathological aggregation of tau and TDP-43 proteins. Objective To compare hydromethylthionine treatment effects at two doses and to determine how drug exposure is related to treatment response in bvFTD. Methods We undertook a 52-week Phase III study in 220 bvFTD patients randomized to compare hydromethylthionine at 200 mg/day and 8 mg/day (intended as a control). The principal outcomes were change on the Addenbrookes Cognitive Examination - Revised (ACE-R), the Functional Activities Questionnaire (FAQ), and whole brain volume. Secondary outcomes included Modified Clinical Global Impression of Change (Modified-CGIC). A population pharmacokinetic exposure-response analysis was undertaken in 175 of the patients with available blood samples and outcome data using a discriminatory plasma assay for the parent drug. Results There were no significant differences between the two doses as randomized. There were steep concentration-response relationships for plasma levels in the range 0.3-0.6 ng/ml at the 8 mg/day dose on clinical and MRI outcomes. There were significant exposure-dependent differences at 8 mg/day for FAQ, Modified-CGIC, and whole brain atrophy comparing patients with plasma levels greater than 0.346 ng/ml with having minimal drug exposure. The exposure-response is biphasic with worse outcomes at the high concentrations produced by 200 mg/day. Conclusions Hydromethylthionine has a similar concentration-response profile for effects on clinical decline and brain atrophy at the 8 mg/day dose in bvFTD as recently reported in AD. Treatment responses in bvFTD are predicted to be maximal at doses in the range 20-60 mg/day. A confirmatory placebo-controlled trial is now planned.

ME1100 (arbekacin inhalation solution) is an inhaled aminoglycoside that is being developed to treat patients with hospital-acquired and ventilator-associated bacterial pneumonia (HABP and VABP, respectively). Pharmacokinetic-pharmacodynamic (PK-PD) target attainment analyses were undertaken to evaluate ME1100 regimens for the treatment of patients with HABP/VABP. The data used included a population pharmacokinetic (PPK) 4-compartment model with 1st-order elimination, nonclinical PK-PD targets from one-compartment in vitro and/or in vivo infection models, and in vitro surveillance data. Using the PPK model, total-drug epithelial lining fluid (ELF) concentration-time profiles were generated for simulated patients with varying creatinine clearance (CLcr) (ml/min/1.73 m(2)) values. Percent probabilities of PK-PD target attainment by MIC were determined based on the ratio of total-drug ELF area under the concentration-time curve (AUC) to MIC (AUC/MIC ratio) targets associated with 1- and 2-log(10) CFU reductions from baseline for Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Percent probabilities of PK­PD target attainment based on PK-PD targets for a 1-log(10) CFU reduction from baseline at MIC values above the MIC(90) value for K. pneumoniae (8 μg/ml), P. aeruginosa (4 μg/ml), and S. aureus (0.5 μg/ml) were ≥99.8% for ME1100 600 mg twice daily (BID) in simulated patients with CLcr values >80 to ≤120 ml/min/1.73 m(2). ME1100 600 mg BID, 450 mg BID, and 600 mg once daily in simulated patients with CLcr values >50 to ≤80, >30 to ≤50, and 0 to ≤30 ml/min/1.73 m(2), respectively, provided arbekacin exposures that best matched those for 600 mg BID in simulated patients with normal renal function. These data provide support for ME1100 as a treatment for patients with HABP/VABP.

Current dosing recommendations for rivaroxaban advocate dosage reduction in patients with moderate to severe renal impairment and avoidance of concomitant strong inhibitors of CYP3A or P-glycoprotein. However, rivaroxaban dosing in patients with mild renal impairment taking concomitant moderate inhibitors of CYP3A and P-glycoprotein is not addressed. To quantify the impacts of concomitant verapamil administration and renal impairment on rivaroxaban pharmacokinetics, a minimal physiologically based pharmacokinetic model system was developed and used to evaluate potential increases in rivaroxaban exposure and the consequent increase in risk of major bleeding. Data from a phase 1, drug-drug interaction study were used to qualify the minimal physiologically based pharmacokinetic model system. Model-based simulations indicate that coadministration of rivaroxaban with verapamil substantially increases rivaroxaban exposure across all renal function categories, resulting in an exponential increase in bleeding risk. Reduction of the daily rivaroxaban dose to 10 to 15 mg reduces the major bleeding risk below the designated 4.5% threshold in the majority of patients with normal or mildly impaired renal function. A reduction to 10 mg daily in patients with moderate to severe renal impairment provides additional risk reduction so that 90% of those patients fall below the 4.5% threshold. A risk threshold of 4.5% was selected because it is the median predicted risk in patients treated concomitantly with ketoconazole, which is contraindicated for use with rivaroxaban. Patients taking both rivaroxaban and verapamil should take a reduced daily dose of rivaroxaban to minimize bleeding risk.

Use of parenteral amikacin to treat refractory nontuberculous mycobacterial (NTM) lung disease is limited by systemic toxicity. A population pharmacokinetic model was developed using data pooled from two randomized trials to evaluate the pharmacokinetic properties of once-daily amikacin liposome inhalation suspension (ALIS) in patients with treatment-refractory NTM lung disease.In phase 2 (TR02-112) and phase 3 (CONVERT) studies, patients with sputum cultures positive for Mycobacterium avium complex (both studies) or M. abscessus (TR02-112) despite ≥ 6 months of guideline-based therapy were treated with once-daily ALIS 590 mg.Fifty-three patients (28 Japanese; 25 White) were assessed. At baseline and ≈ 6 months after daily dosing, median maximum concentration (CSystemic exposure to amikacin in serum and urine following once-daily ALIS administration in patients with treatment-refractory NTM lung disease was notably lower than that previously reported for parenteral amikacin.ClinicalTrials.gov NCT01315236 (registered March 15, 2011) and NCT02344004 (registered January 22, 2015).

Pharmacokinetics and antithrombotic effects of the Factor Xa inhibitor rivaroxaban were studied in subjects with mild renal insufficiency concurrently taking the P-glycoprotein and moderate CYP3A inhibitor verapamil, a drug commonly administered to patients with hypertension, ischemic heart disease, or atrial fibrillation. Age-matched controls with normal renal function were studied concurrently. Subjects' overall mean age was 59 years. Mean creatinine clearance values in the 2 groups were 105 and 71 mL/min. After single 20-mg oral doses, rivaroxaban area under the curve (AUC) was increased by a factor of 1.11 (ratio of geometric means [RGM]) in mild renal insufficiency compared to controls. Verapamil coadministration independently increased AUC to the same extent in both the mild renal insufficiency and control groups (RGM, 1.39 and 1.43). Concurrent mild renal insufficiency and verapamil produced additive inhibition compared to controls without verapamil (RGM, 1.58). Prothrombin time (PT) prolongation and Factor Xa inhibition tracked plasma rivaroxaban, and were enhanced by verapamil. Concentration-response relationships for PT (linear) and Factor Xa inhibition (hyperbolic) were unaffected by renal function or verapamil. The absolute and relative increases in rivaroxaban AUC caused by verapamil in mild renal insufficiency subjects are potentially associated with an increased bleeding risk. Modification of recommended dosage may be required in this combination of circumstances to reduce risk to patients.

A WW (formerly Weight Watchers) program adapted for persons with type 2 diabetes mellitus (T2DM) previously was found to be more effective than standard care (SC) intervention for weight loss, improved glycemic control, and weight- and diabetes-related quality of life measures. With data from the same national trial, this study examined whether WW adapted for persons with T2DM also increased engagement in weight control behaviors and decreased hedonic hunger, each of which could contribute to improved diabetes management.Individuals with T2DM (n = 563) and overweight or obesity participated in a 12-month, 16-site, randomized trial of WW with diabetes counseling or SC. Hierarchical linear modeling (HLM) evaluated whether 12-month changes in weight control behaviors (Eating Behavior Inventory; EBI) and hedonic hunger (Power of Food Scale; PFS) differed by treatment condition. If a significant treatment effect was found, 12-month changes in EBI/PFS were regressed on 12-month changes in HbAEBI scores increased significantly over the 12-months (p 0.001), with greater improvements in WW than SC (p 0.001). PFS decreased significantly in the 12-months (p 0.001), with no differences between treatment groups (p = 0.15). HLM analyses that followed up on the significant treatment effect for 12-month change in EBI revealed no significant differences by treatment condition for the relationship between change in EBI scores and change in HbAWW with diabetes counseling produced greater engagement in weight control behaviors in those with T2DM than did SC. Across both groups, improved weight control behaviors and hedonic hunger were related to improved glycemic control and weight loss.

Objectives Lefamulin is a semi-synthetic intravenous and oral pleuromutilin antibiotic with activity against pathogens commonly associated with community-acquired bacterial pneumonia. Using data from two Phase 1 studies, a population pharmacokinetics (PPK) model for lefamulin in plasma and epithelial lining fluid (ELF) was constructed. Methods Plasma pharmacokinetic (PK) data from a crossover, bioavailability, food-effect study and plasma and ELF PK data from a tissue penetration study in normal healthy volunteers were used to construct a PPK model for lefamulin. Model development involved refinement of a previous PPK model for intravenous and oral administration, followed by application of the model to plasma and ELF data from the tissue penetration study. The ELF penetration ratio of lefamulin was determined using model-based simulations. Results The PPK analysis data set contained 1103 plasma and 12 ELF lefamulin concentrations from 32 subjects. A three-compartment model with non-linear protein binding and two parallel absorption processes provided precise and unbiased estimated plasma concentration–time profiles. The absorption rate was slower and bioavailability was decreased after a high-fat/high-calorie meal. ELF data were well described using first-order rate constants into and out of the ELF compartment. The median predicted lefamulin total-drug ELF AUC0–24/free-drug plasma AUC0–24 ratio was ∼5:1 after intravenous or oral administration. Conclusions The final PPK model allowed precise characterization of plasma and ELF exposures after intravenous and oral administration. The high ELF penetration ratio suggests that the penetration of lefamulin into the effect site is rapid and extensive, irrespective of route of administration.

Objectives Lefamulin is a semi-synthetic intravenous (iv) and oral pleuromutilin antibiotic active against community-acquired bacterial pneumonia (CABP) pathogens. Pharmacokinetic/pharmacodynamic (PK/PD) target attainment analyses were carried out to evaluate lefamulin 150 mg iv q12h and 600 mg orally q12h under fed and fasted conditions for the treatment of patients with CABP. Methods The analyses undertaken used a population PK model based on Phase 1 PK data, non-clinical PK/PD targets for efficacy and in vitro surveillance data for Streptococcus pneumoniae (SP) and Staphylococcus aureus (SA), and Monte Carlo simulation. Percentage probabilities of PK/PD target attainment by MIC on day 1 were determined using median total-drug epithelial lining fluid (ELF) and free-drug plasma AUC:MIC ratio targets associated with 1 and 2 log10 cfu reductions from baseline. Results Percentage probabilities of attaining the total-drug ELF AUC:MIC ratio target for a 1 log10 cfu reduction from baseline for SP were ≥99.2% at the MIC90 of 0.12 mg/L and 96.7%, 82.1% and 96.3% for iv and oral dosing regimens under fed and fasted conditions, respectively, at the MIC99 of 0.25 mg/L. Percentage probabilities of attaining the free-drug plasma AUC:MIC target for the same endpoint at the SP MIC99 were 100% for each regimen. For the SA MIC90 of 0.12 mg/L and AUC:MIC ratio targets for the same endpoint, percentage probabilities were 92.7%–100% for iv and oral dosing regimens. Conclusions These data provide support for lefamulin 150 mg iv q12h and 600 mg orally q12h for the treatment of patients with CABP and suggest that doses may not need to be taken under fasted conditions.

Rezafungin (CD101) is a novel echinocandin antifungal agent currently in clinical development for the treatment of candidemia and invasive candidiasis. Rezafungin has potent in vitro activity against Candida albicans and Candida glabrata, including azole- and echinocandin-resistant isolates. The objective of this analysis was to develop a population pharmacokinetic (PK) model to characterize the disposition of rezafungin in plasma following intravenous (i.v.) administration. Data from two phase 1 studies, a single-ascending-dose study and a multiple-ascending-dose study, were available. Candidate population PK models were fit to the pooled data using the Monte Carlo parametric expectation maximization algorithm in S-ADAPT. The data were best described using a linear four-compartment model with zero-order drug input via i.v. infusion and first-order elimination. In order to account for the relationships between the structural PK parameters and subject body weight, all parameters in the model were scaled to subject body weight using standard allometric coefficients (a power of 0.75 for the clearance terms and 1.0 for the volume terms). The final model fit the observed data with very little bias and excellent precision. The prediction-corrected visual predictive check demonstrated that the final model could accurately simulate both the central tendency and the variability of observed rezafungin plasma concentrations. Given this, the final rezafungin population PK model is expected to provide reliable simulated concentration-time profiles and can provide dose selection decision support for future clinical studies.

ME1100, an inhalation solution of arbekacin, an aminoglycoside, is being developed for the treatment of hospital-acquired and ventilator-associated bacterial pneumonia. The objective of these analyses was to develop a population pharmacokinetic model to describe the arbekacin concentration-time profile in plasma and epithelial lining fluid (ELF) following ME1100 administration. Data were obtained from a postmarketing study for an intravenous (i.v.) formulation of arbekacin, a phase 1 study of ME1100 in healthy volunteers, and a phase 1b study of ME1100 in mechanically ventilated subjects with bacterial pneumonia. Data from the postmarketing study were utilized to develop a population pharmacokinetic model following i.v. administration, and this model was subsequently utilized as the foundation for development of the model characterizing arbekacin disposition following inhalation of ME1100. The final model utilized two compartments for both plasma and ELF disposition, with movement of arbekacin between the ELF and plasma parameterized using linear first-order rate constants. A bioavailability term was included for the inhalational route of administration, which was estimated to be 19.5% for a typical subject. The model included normalized creatinine clearance (CLcrn) and weight as covariates on arbekacin clearance: CL = (weight/52.2)0.855·[(CLcrn–77)·0.0289 + 2.32]. The model simultaneously described arbekacin concentrations following both i.v. and inhaled administration and provided acceptable fits to the plasma and ELF data (r2 of 0.922 and 0.557 for observed versus fitted concentrations, respectively). The developed model will be useful for conducting future analyses to support ME1100 dose selection.

Background Although hydromethylthionine is a potent tau aggregation inhibitor, no difference was found in either of two Phase III trials in mild to moderate Alzheimer's disease (AD) comparing doses in the range 150-250 mg/day with 8 mg/day intended as a control. Objective To determine how drug exposure is related to treatment response. Methods A sensitive plasma assay for the drug was used in a population pharmacokinetic analysis of samples from 1,162 of the 1,686 patients who participated in either of the Phase III trials with available samples and efficacy outcome data. Results There are steep concentration-response relationships for steady state plasma levels in the range 0.3-0.8 ng/ml at the 8 mg/day dose. Using a threshold based on the lower limit of quantitation of the assay on Day 1, there are highly significant differences in cognitive decline and brain atrophy in patients with above threshold plasma levels, both for monotherapy and add-on therapy, but with effect sizes reduced by half as add-on. Plasma concentrations in the range 4-21 ng/ml produced by the high doses are not associated with any additional benefit. Conclusions Hydromethylthionine has pharmacological activity on brain structure and function at the 8 mg/day dose as monotherapy or as add-on to symptomatic treatments. This combined with a plateau at higher doses is consistent with the lack of dose-response seen in the Phase III trials. Treatment benefit is predicted to be maximal at 16 mg/day as monotherapy. A placebo-controlled trial in mild/moderate AD is now ongoing to confirm efficacy at this dose.

We describe a technique for treating Eaton stage IV osteoarthritis of the first ray, which is a development of our previously published technique for treating trapeziometacarpal arthritis. This simple technique is based on a limited resection arthroplasty of the first trapeziometacarpal and the scaphotrapezial joints, with the aim of inducing the formation of a narrow pseudoarthrosis at both sites. A total of 26 consecutive patients were treated for Eaton stage IV arthritis at a mean follow-up of 4.7 years (range 3.2–6.6). There were statistically significant improvements in all clinical parameters: mean appositional and oppositional pinch strength, mean DASH score (65 points pre-operatively to 8.7 points at final follow-up), and in mean visual analogue scale score (8.6 to 0.2 points). Although a larger cohort and a longer follow-up will be necessary to evaluate this new technique fully, these results encourage us to believe that the limited excision arthroplasty of the trapeziometacarpal and scaphotrapezial joints is a viable alternative to the existing surgical treatments for stage IV thumb arthritis.Level of evidence: 4

eB4CAST, evidence-Based forecast C-capture, A-assemble, S-sustain, T-timelessness (eB4CAST), framework was developed from existing dissemination and implementation (D &amp, I) constructs as a dissemination tool to promote community-based program usability and future application in targeted populations. eB4CAST captures and transforms research findings into a dissemination report that shows program need and impact to endorse program continuation and expansion. This is achieved through direct and indirect data collection of community factors and program impact that can showcase the need for program sustainability and potential for future dissemination sites. Testimonials, individual feedback, and program process and outcomes contribute to the direct data while data collected from census, county, and state databases and reports allow for indirect information to be captured and analyzed. Capturing data in the two levels allow eB4CAST to forecast program need and highlight program impact through a footprint. eB4CAST framework for dissemination tool creation is organized into four sections: Capture, Assemble, Sustainability, and Timelessness. Capture encompasses the collection of indirect and direct data related to intervention goals. Assemble is the compilation of the data into a visually appealing and easily understood media. Sustainability encourages the use of dissemination tools to provide forecast of program need and footprint of program impact back to community participants, program leaders, and key stakeholders to endorse program sustainability. Lastly, timelessness encourages cyclic movement through these constructs to continue program monitoring and data sharing to ensure timeless program evaluation and conformation to change in needs. The eB4CAST framework provides a systematic method to capture justification of program need and impact of community-based research that can be modified to fit diverse public health interventions providing a necessary D &amp, I tool.

Rezafungin (CD101) is a novel echinocandin antifungal agent with activity against Aspergillus and Candida species, including azole- and echinocandin-resistant isolates. The objective of these analyses was to conduct pharmacokinetic (PK)-pharmacodynamic (PD) target attainment analyses to evaluate single and once-weekly rezafungin dosing to provide dose selection support for future clinical studies. Using a previously developed rezafungin population PK model, Monte Carlo simulations were conducted utilizing the following three intravenous rezafungin regimens: (i) a single 400 mg dose, (ii) 400 mg for week 1 followed by 200 mg weekly for 5 weeks, and (iii) 400 mg weekly for 6 weeks. Percent probabilities of achieving the nonclinical PK-PD targets associated with net fungal stasis and 1-log 10 CFU reductions from baseline for Candida albicans and Candida glabrata were calculated for each rezafungin regimen. At the MIC 90 for C. albicans and C. glabrata , a single 400 mg dose of rezafungin achieved probabilities of PK-PD target attainment of ≥90% through week 3 of therapy for all PK-PD targets evaluated. When evaluating the multiple-dose (i.e., weekly) regimens under these conditions, percent probabilities of PK-PD target attainment of 100% were achieved through week 6. Moreover, high (>90%) probabilities of PK-PD target attainment were achieved through week 6 following administration of the weekly regimens at or above the MIC 100 values for C. albicans and C. glabrata based on contemporary in vitro surveillance data. These analyses support the use of single and once-weekly rezafungin regimens for the treatment of patients with candidemia and/or candidiasis due to C. albicans or C. glabrata .

Ventilator-associated bacterial pneumonia (VABP) is a difficult therapeutic problem. Considerable controversy exists regarding the optimal chemotherapy for this entity. The recent guidelines of the Infectious Diseases Society of America and the American Thoracic Society recommend a 7-day therapeutic course for VABP based on the balance of no negative impact on all-cause mortality, less resistance emergence, and fewer antibiotic treatment days, counterbalanced with a higher relapse rate for patients whose pathogen is a nonfermenter. The bacterial burden causing an infection has a substantial impact on treatment outcome and resistance selection. We describe the baseline bronchoalveolar lavage (BAL) fluid burden of organisms in suspected VABP patients screened for inclusion in a clinical trial. We measured the urea concentrations in plasma and BAL fluid to provide an index of the dilution of the bacterial and drug concentrations in the lung epithelial lining fluid introduced by the BAL procedure. We were then able to calculate the true bacterial burden as the diluted colony count times the dilution factor. The median dilution factor was 28.7, with the interquartile range (IQR) being 11.9 to 53.2. Median dilution factor-corrected colony counts were 6.18 log

Meropenem-vaborbactam is a fixed combination of the novel β-lactamase inhibitor vaborbactam and the carbapenem antibiotic meropenem, developed for the treatment of serious infections caused by drug-resistant Gram-negative bacteria. The safety, tolerability, and pharmacokinetics (PK) of vaborbactam and meropenem following single and multiple ascending doses of each study drug administered alone or combined were evaluated in 76 healthy adult subjects in a randomized, placebo-controlled, double-blind study. Subjects were enrolled in 1 of 5 dose cohorts (receiving 250 to 2,000 mg vaborbactam and/or 1,000 to 2,000 mg meropenem) alone or in combination. No subjects discontinued the study due to adverse events (AEs), and no serious AEs were observed. The pharmacokinetics of meropenem and vaborbactam were similar when given alone or in combination; all evaluated plasma PK exposure measures (peak plasma concentration, area under the plasma concentration-time curve [AUC] from time zero to the last measurable concentration area under the plasma concentration-time curve, and AUC from time zero to infinity) were similar for the study drugs alone versus those in combination, indicating no pharmacokinetic interaction between meropenem and vaborbactam. Across all treatments, 47 to 64% of an administered meropenem dose and 75 to 95% of vaborbactam was excreted unchanged in the urine over 48 h postdose. Meropenem and vaborbactam, when given alone or in combination, have similar pharmacokinetic properties, with no plasma or urine PK drug-drug interactions, and are well tolerated. These findings supported further clinical investigation of the combination product. (This study is registered at ClinicalTrials.gov under registration no. NCT01897779.)

Objectives: To assess the single-dose and steady-state pharmacokinetics of a single-entity hydrocodone extended-release (ER) formulation in patients enrolled in two separate phase 2 clinical studies . Setting: Both studies were multicenter clinical studies . Subjects and interventions: In study 1, 115 subjects with postsurgical pain (bunionectomy) received single doses of 10, 20, 30, or 40 mg hydrocodone-ER, 10 mg hydrocodone/325 mg acetaminophen immediate-release (IR), or placebo. In study 2, 37 subjects with osteoarthritic pain received doses of 10, 20, 30, or 40 mg of hydrocodone-ER twice-daily for 7 days. Venous blood samples were taken periodically up to 24 hours postdosing after the single dose (study 1) or after 7 days of dosing (study 2) and were assayed for concentrations of hydrocodone and its major metabolites . Main outcome measures: Standard pharmacokinetic parameters were estimated by noncompartmental analysis methods . Results: Following a single dose of hydrocodone-ER, T max was prolonged to approximately 6 hours at all dose levels of hydrocodone-ER compared with 2.9 hours for the IR formulation. All doses of hydrocodone-ER formulations provided prolonged and sustained release of hydrocodone throughout the 12-hour dosing interval with reduced peak-to-trough fluctuation at steady state compared with hydrocodone/acetaminophen-IR comparator. Both single-dose and steady-state mean C max and AUC last values showed reasonable dose-proportionality. Norhydrocodone and hydromorphone plasma concentrations were 32-38 percent and

Despite over 40 years of worldwide usage, relatively few data have been published on the pharmacokinetics of cefazolin in pediatric surgical patients. The primary objectives of this study were to examine the pharmacokinetics and safety of cefazolin in children 10 to 12 years of age (inclusive) receiving 1 or 2 g of cefazolin, based on body weight. This multiple-center, open-label study enrolled pediatric patients electively scheduled for surgical procedures who required cefazolin as part of their routine clinical management. Patients weighing ≥25 to

Dalbavancin is a lipoglycopeptide antibiotic with Gram-positive activity and novel pharmacokinetic (PK) properties that result in a prolonged terminal half-life of 15.5 days in adults. Once weekly dosing in adults in phase 3 studies of complicated skin and skin structure infections documented dalbavancin exposures associated with clinical and microbiologic efficacy. PK properties have not been examined in children. The primary objective of this open-label, multicenter single-dose phase 1 study was to characterize the PK of dalbavancin in hospitalized pediatric subjects 12-17 years of age.A single dose of 1000 mg of dalbavancin (the standard adult dose) was administered as a 30-minute intravenous infusion to subjects weighing 60 kg or greater and 15 mg/kg for subjects weighing60 kg. A noncompartmental PK analysis was performed.The apparent terminal t1/2 was approximately 9 days and was similar for dalbavancin dosages of 1000 mg and 15 mg/kg. Median dalbavancin plasma exposures (Cmax and AUCinf) when administered as 1000 mg to subjects weighing 60 kg or greater were similar to those when dalbavancin was administered at 15 mg/kg to subjects weighing60 kg and slightly lower than exposures in adults given 1000 mg in prior PK and treatment studies. Single dose dalbavancin was well tolerated.Given dalbavancin exposures documented in children 12-17 years of age, and recognized dose proportionality, appropriate dosing can be modeled for pediatric phase 3 trials in acute bacterial skin and skin structure infections, to achieve the same exposure that is reported to be safe and effective in adults.

Ceftaroline is a cephalosporin with broad-spectrum in vitro activity against pathogens commonly associated with acute bacterial skin and skin structure infections (ABSSSI), including methicillin-resistant Staphylococcus aureus . Ceftaroline fosamil, the prodrug of ceftaroline, is approved for the treatment of patients with ABSSSI. Using data from the microbiologically evaluable population from two phase 2 and two phase 3 randomized, multicenter, double-blind studies of patients with ABSSSI, an analysis examining the relationship between drug exposure, as measured by the percentage of time during the dosing interval that free-drug steady-state concentrations remain above the MIC ( f % T >MIC), and clinical and microbiological responses was undertaken. The analysis population included 526 patients, of whom 423 had infections associated with S. aureus . Clinical and microbiological success percentages were 94.7 and 94.5%, respectively, among all of the patients and 95.3 and 95.7%, respectively, among those with S. aureus infections. Univariable analysis based on data from all of the patients and those with S. aureus infections demonstrated significant relationships between f % T >MIC and microbiological response ( P < 0.001 and P = 0.026, respectively). Multivariable logistic regression analyses demonstrated other patient factors in addition to f % T >MIC to be significant predictors of microbiological response, including age and infection type for all of the patients evaluated and age, infection type, and the presence of diabetes mellitus for patients with S. aureus infections. Results of these analyses confirm that a ceftaroline fosamil dosing regimen of 600 mg every 12 h provides exposures associated with the upper plateau of the pharmacokinetic-pharmacodynamic relationship for efficacy.

CD101 is a novel echinocandin with concentration-dependent fungicidal activity in vitro and a long half-life (∼133 h in humans, ∼70 to 80 h in mice). Given these characteristics, it is likely that the shape of the CD101 exposure (i.e., the time course of CD101 concentrations) influences efficacy. To test this hypothesis, doses which produce the same total area under the concentration-time curve (AUC) were administered to groups of neutropenic ICR mice infected with Candida albicans R303 using three different schedules. A total CD101 dose of 2 mg/kg was administered as a single intravenous (i.v.) dose or in equal divided doses of either 1 mg/kg twice weekly or 0.29 mg/kg/day over 7 days. The studies were performed using a murine disseminated candidiasis model. Animals were euthanized at 168 h following the start of treatment. Fungi grew well in the no-treatment control group and showed variable changes in fungal density in the treatment groups. When the CD101 AUC from 0 to 168 h (AUC 0–168 ) was administered as a single dose, a >2 log 10 CFU reduction from the baseline at 168 h was observed. When twice-weekly and daily regimens with similar AUC values were administered, net fungal stasis and a >1 log 10 CFU increase from the baseline were observed, respectively. These data support the hypothesis that the shape of the CD101 AUC influences efficacy. Thus, CD101 administered once per week demonstrated a greater degree of fungal killing than the same dose divided into twice-weekly or daily regimens.

Vaborbactam is a member of a new class of β-lactamase inhibitors with inhibitory activity against serine carbapenemases (e.g., Klebsiella pneumoniae carbapenemase) that has been developed in combination with meropenem. The pharmacokinetics of the combination was evaluated in 41 subjects with chronic renal impairment in a phase 1, open-label, single-dose study. Subjects were assigned to one of five groups based on renal function: normal (creatinine clearance of ≥90 ml/min), mild (estimated glomerular filtration rate [eGFR] of 60 to 89 ml/min/1.73 m 2 ), moderate (eGFR of 30 to P < 0.001) and vaborbactam (mean of 5.11-fold increase, P = 0.0235) relative to drug administration off dialysis, consistent with dose recovery rates of 38.3% and 52.9% for meropenem and vaborbactam, respectively, in dialysate. Plasma clearance of meropenem and vaborbactam is reduced with renal impairment, requiring dose adjustment. Hemodialysis removes both drugs. (This study has been registered at ClinicalTrials.gov under identifier NCT02020434.)

Pharmacokinetic studies and analyses can be expensive, time consuming, and labor intensive. However, it is crucial to understand that much of what happens in antimicrobial drug development, such as dose-selection and clinical study design, can be optimized with a strong understanding of the underlying pharmacokinetics of an agent. In this way, pharmacokinetics forms the bedrock of a pharmacometric approach to antimicrobial development. Thus, pharmacokinetic analyses must be considered an integral part of a drug's development strategy and studies must be planned and designed accordingly. This paper provides a brief overview of pharmacokinetic analysis methods, including best practices and their use in the context of a drug development program. In addition we will conclude with an overview of proper design and conduct of pharmacokinetic studies to optimize their use in evaluating clinical study data.

Introduction Pirfenidone film-coated tablets were developed to offer an alternative to the marketed capsule formulation. This study assessed the bioequivalence of the tablet and capsule formulations under fed and fasted states. Methods A Phase I, open-label, randomized, four-treatment-period, four-sequence, crossover pharmacokinetics study (NCT02525484) was conducted. Each subject received an 801-mg single dose of pirfenidone as three 267-mg capsules or one 801-mg tablet under fasted and fed conditions. Pirfenidone plasma C max, AUC0–t and AUC0–∞ were used to assess bioequivalence. Results Forty-four subjects were randomized to treatment. The 801-mg tablet in the fasted state met bioequivalence criteria [90% confidence intervals (CI) 80.00–125.00%] for the GLSM ratios of natural log-transformed C max, AUC0–t and AUC0–∞. Under fed conditions, the 801-mg tablet met the bioequivalence criteria for AUC0–t and AUC0–∞, but slightly exceeded the bioequivalence criteria for the C max (90% CI of 108.26–125.60%). The tablet C max was approximately 17% higher than that of the capsules. In the fed state, the tablet C max, and both AUC0–t and AUC0–∞ were reduced by 39% and 17%, respectively, relative to the fasted state. The tablet and capsules had acceptable tolerability profiles. Conclusions The pirfenidone 801-mg tablet met bioequivalence criteria when compared with three 267-mg capsules in the fasted state. The tablet C max was slightly higher relative to capsules in the fed state, but this is not expected to have a clinically meaningful impact on the benefit–risk profile of pirfenidone. Funding This work was supported by F. Hoffmann-La Roche Ltd. Electronic supplementary material The online version of this article (doi:10.1007/s12325-017-0594-8) contains supplementary material, which is available to authorized users.

Previous studies have shown that some lipoglycopeptide and lipopeptide antimicrobial agents may cause falsely elevated values for some phospholipid-dependent coagulation tests. The effect of oritavancin, a lipoglycopeptide antibiotic, on coagulation test results was explored using pooled human plasma samples spiked with drug and in a clinical study after an infusion of a single 1,200-mg intravenous dose of oritavancin in normal healthy volunteers. Pooled plasma with oritavancin added ex vivo showed concentration-dependent prolongation of prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), and dilute Russell viper venom time (DRVVT) test results. In contrast, oritavancin had no effect on the activated protein C resistance assay, chromogenic anti-factor Xa assay (anti-FXa), thrombin time, and an immunoassay for the laboratory diagnosis of heparin-induced thrombocytopenia. In participants that received a single dose of oritavancin, elevations in PT/INR result, aPTT, DRVVT, activated clotting time, and silica clotting time occurred, with the maximum times to resolution of test interference determined to be 12, 120, 72, 24, and 18 h, respectively. The anti-FXa assay was unaffected, whereas transient elevations in D dimer levels were observed in 30% of participants, with a maximum time to resolution of 72 h. Although oritavancin has no impact on the coagulation system in vivo , a single dose of oritavancin can produce falsely elevated values of some coagulation tests used to monitor hemostasis. The interference of oritavancin on affected tests is transient, and the test results revert to normal ranges within specified times after dosing.

To provide support for in vitro susceptibility test interpretive criteria decisions for ceftaroline against Staphylococcus aureus and Streptococcus pneumoniae , as well as dose adjustment recommendations for renal impairment, pharmacokinetic-pharmacodynamic (PK-PD) target attainment was evaluated for simulated patients administered intravenous (i.v.) ceftaroline fosamil at 600 mg twice daily (q12h) and simulated patients with renal impairment administered various dosing regimens. Using a previously developed population PK model, Monte Carlo simulation was used to generate ceftaroline plasma concentration profiles for simulated patients with normal renal function or mild, moderate, or severe renal impairment. Using these profiles, the percentage of time during the dosing interval that free-drug concentrations remained above the MIC ( f % T >MIC) for ceftaroline at steady state was calculated. Percentages of simulated patients achieving f % T >MIC targets for S. aureus and S. pneumoniae based on murine infection models were calculated by MIC. At MICs of 2 mg/liter for S. aureus and 1 mg/liter for S. pneumoniae , the percentages of simulated patients with normal renal function and mild renal impairment following administration of ceftaroline fosamil at 600 mg q12h, moderate renal impairment following administration of ceftaroline fosamil at 400 mg q12h, and severe renal impairment following administration of ceftaroline fosamil at 300 mg q12h achieving f % T >MIC targets (≥26 for S. aureus and ≥44 for S. pneumoniae ) exceeded 90%. The results of these analyses, which suggested that in vitro susceptibility test interpretive criteria defining susceptible could be as high as MICs of ≤2 and ≤1 mg/liter for ceftaroline against S. aureus and S. pneumoniae , respectively, provide support for current FDA and CLSI criteria, which define susceptible as MICs of 1 and 0.5 mg/liter, respectively. Recommendations for dose adjustments for patients with renal impairment were also supported by the results of these analyses.

Hydrocodone is a semi-synthetic narcotic analgesic and antitussive. Although hydrocodone products have been on the market for over 50 years, relatively little is known about its pharmacokinetics. Additionally, there are no published reports of population pharmacokinetic analyses for hydrocodone. Furthermore, current labeling of hydrocodone-containing products provides little guidance in terms of the impact of patient descriptors on the pharmacokinetics of hydrocodone. The objectives of this analysis were to develop a population pharmacokinetic model that characterizes the pharmacokinetics of hydrocodone following single and multiple oral doses of hydrocodone extended-release capsules (hydrocodone bitartrate ER capsules) in healthy subjects and patients, to examine the impact of patient descriptors on pharmacokinetic parameters and to assess the dose-proportionality of hydrocodone pharmacokinetic.A total of 4,714 plasma hydrocodone concentrations from 220 subjects were available for this analysis. The data were extracted from seven studies (five phase 1 and two phase 2 studies). A two-compartment open mamillary model with linear elimination and a complex absorption model was used to fit the data, using NONMEM(®) version 7.1.2 software. The absorption model involved two sequential first-order absorption processes with the delay in the first process accomplished by means of multiple transit compartments. Covariate analysis was performed using standard forward selection followed by backward elimination processes. Model evaluation was performed using a prediction-corrected visual predictive check (pcVPC).The population estimates of apparent oral central volume of distribution and apparent oral linear clearance were 714 L and 64.4 L/h, respectively. The first absorption process was rapid. Creatinine clearance and body surface area (BSA) were statistically significant predictors of the apparent oral clearance and apparent oral volume of distribution. The pcVPC indicated that the model provided a robust and unbiased fit to the data.A linear model for hydrocodone elimination provided an adequate fit to the observed data over the entire dose range, which supports that hydrocodone bitartrate ER capsules exhibit dose-proportional pharmacokinetics. The formulation of hydrocodone bitartrate ER capsules results in absorption profiles that are variable across and within subjects. Despite the variability in absorption profiles, a relatively simple model provided an adequate fit to the data. Creatinine clearance and BSA were statistically significant predictors of the apparent oral clearance and apparent oral volume of distribution. Absorption characteristics of hydrocodone bitartrate ER capsules should still allow effective plasma concentrations of hydrocodone to be reached quickly and for effective concentrations to be maintained for a long period.

The objective of this study is to investigate bone metabolism, density, and quality in patients with diabetes type 2 using DEXA and spinal deformity index (SDI), a surrogate index of bone quality. Fifty-six patients with type 2 diabetes were studied; exclusion criteria were diseases and medications that affect bone and mineral metabolism. Mean age was 65 ± 7 years. Mean diabetes duration was 10 ± 7 years and mean HbA1C was 6.6 ± 0.5 %. BMI was 30 ± 4. Fifty-six sex, age, and BMI matched served as controls. All subjects underwent a clinical and biochemical examination. Spinal and femoral neck BMD were measured by DEXA, and a spine radiography was performed to assess vertebral fractures and to calculate SDI. Mean serum 25-OH vitamin D levels were 19.6 ± 3.7 ng/ml in patients and 30 ± 14 ng/ml in controls (p < 0.01). PTH serum levels were 47.9 ± 40 pg/ml in patients versus 37 ± 5.3 pg/ml in controls (p < 0.01). At lumbar spine there was a significant difference between patients and controls only for T-score (p =

Antimicrobial stewardship programs face many challenges, one of which is a lack of guidance regarding antimicrobial dose, interval, and duration. There is no tool that considers patient demographic, pathogen susceptibility, and pharmacokinetic-pharmacodynamic (PK-PD) targets for efficacy in order to evaluate appropriate antimicrobial dosing regimens. The PK-PD Compass, an educational mobile application, was developed to address this unmet need. The application consists of a Monte Carlo simulation algorithm which integrates pharmacokinetic (PK) and PK-PD data, patient-specific characteristics, and pathogen susceptibility data. Through the integration of these data, the application allows practitioners to assess the percent probability of PK-PD target attainment for 35 intravenous antimicrobial agents across 29 infection categories. Population PK models for each drug were identified, evaluated, and refined as needed. Susceptibility breakpoints were based upon FDA and CLSI criteria. By incorporating these data into one interface, clinicians can select the infection, pathogen, and antimicrobial agents of interest and obtain the percent probability of PK-PD target attainment for each regimen based upon patient-specific characteristics. The antimicrobial dosing regimens provided include those recommended by standard guidelines and reference texts. However, unlike these references, potential choices are prioritized based on percent probabilities of PK-PD target attainment. Such data will educate clinicians on selecting optimized antibiotic regimens through the lens of PK-PD.

Modest weight loss from clinical interventions improves glycemic control in type 2 diabetes (T2DM). Data are sparse on the effects of weight loss via commercial weight loss programs. This study examined the effects on glycemic control and weight loss of the standard Weight Watchers program, combined with telephone and email consultations with a certified diabetes educator (WW), compared with standard diabetes nutrition counseling and education (standard care, SC).In a 12-month randomized controlled trial at 16 U.S. research centers, 563 adults with T2DM (HbAFollow-up rate was 86%. Twelve-month HbAWidely available commercial weight loss programs with community and online components, combined with scalable complementary diabetes education, may represent accessible and effective components of management plans for adults with overweight/obesity and T2DM.

Pharmacokinetic and pharmacodynamic models estimate the potency of antiviral agents but do not capture viral and immunologic factors that drive the natural dynamics of infection. We designed a mathematical model that synthesizes pharmacokinetics, pharmacodynamics, and viral pathogenesis concepts to simulate the activity of pritelivir, a DNA helicase-primase inhibitor that targets herpes simplex virus. Our simulations recapitulate detailed viral kinetic shedding features in five dosage arms of a phase 2 clinical trial. We identify that in vitro estimates of median effective concentration (EC50) are lower than in vivo values for the drug. Nevertheless, pritelivir potently decreases shedding at appropriate doses based on its mode of action and long half-life. Although pritelivir directly inhibits replication in epithelial cells, our model indicates that pritelivir also indirectly limits downstream viral spread from neurons to genital keratinocytes, within genital ulcers, and from ulcer to new mucosal sites of infection. We validate our model based on its ability to predict outcomes in a subsequent trial with a higher dose. The model can therefore be used to optimize dose selection in clinical practice.

Antimicrobial drug development has greatly diminished due to regulatory uncertainty about the magnitude of the antibiotic treatment effect. Herein we evaluate the utility of pharmacometric-based analyses for determining the magnitude of the treatment effect. Frequentist and Bayesian pharmacometric-based logistic regression analyses were conducted by using data from a phase 3 clinical trial of tigecycline-treated patients with hospital-acquired pneumonia (HAP) to evaluate relationships between the probability of microbiological or clinical success and the free-drug area under the concentration-time curve from time zero to 24 h (AUC 0-24 )/MIC ratio. By using both the frequentist and Bayesian approaches, the magnitude of the treatment effect was determined using three different methods based on the probability of success at free-drug AUC 0-24 /MIC ratios of 0.01 and 25. Differences in point estimates of the treatment effect for microbiological response (method 1) were larger using the frequentist approach than using the Bayesian approach (Bayesian estimate, 0.395; frequentist estimate, 0.637). However, the Bayesian credible intervals were tighter than the frequentist confidence intervals, demonstrating increased certainty with the former approach. The treatment effect determined by taking the difference in the probabilities of success between the upper limit of a 95% interval for the minimal exposure and the lower limit of a 95% interval at the maximal exposure (method 2) was greater for the Bayesian analysis (Bayesian estimate, 0.074; frequentist estimate, 0.004). After utilizing bootstrapping to determine the lower 95% bounds for the treatment effect (method 3), treatment effect estimates were still higher for the Bayesian analysis (Bayesian estimate, 0.301; frequentist estimate, 0.166). These results demonstrate the utility of frequentist and Bayesian pharmacometric-based analyses for the determination of the treatment effect using contemporary trial endpoints. Additionally, as demonstrated by using pharmacokinetic-pharmacodynamic data, the magnitude of the treatment effect for patients with HAP is large.

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 ( f AUC 0–24 ) to the MIC ( f AUC 0–24 :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 f AUC 0–24 :MIC ratios of ≥0.9 compared to patients with f AUC 0–24 :MIC ratios of P = 0.008). Average model-estimated probabilities of clinical success for the albumin/ f AUC 0–24 :MIC ratio combinations of 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 (MIC 50 and MIC 90 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.

Exposure-response analyses for efficacy and safety were performed for tigecycline-treated patients suffering from community-acquired pneumonia. Data were collected from two randomized, controlled clinical trials in which patients were administered a 100-mg loading dose followed by 50 mg of tigecycline every 12 h. A categorical endpoint, success or failure, 7 to 23 days after the end of therapy (test of cure) and a continuous endpoint, time to fever resolution, were evaluated for exposure-response analyses for efficacy. Nausea/vomiting, diarrhea, headache, and changes in blood urea nitrogen concentration (BUN) and total bilirubin were evaluated for exposure-response analyses for safety. For efficacy, ratios of the free-drug area under the concentration-time curve at 24 h to the MIC of the pathogen ( f AUC 0-24 :MIC) of ≥12.8 were associated with a faster time to fever resolution; patients with lower drug exposures had a slower time to fever resolution ( P = 0.05). For safety, a multivariable logistic regression model demonstrated that a tigecycline AUC above a threshold of 6.87 mg · hr/liter ( P = 0.004) and female sex were predictive of the occurrence of nausea and/or vomiting ( P = 0.004). Although statistically significant, the linear relationship between tigecycline exposure and maximum change from baseline in total bilirubin is unlikely to be clinically significant.

The choice of an antimicrobial agent must balance optimization of efficacy endpoints with the minimization of safety events. The risk versus benefit of daptomycin for patients with Staphylococcus aureus bacteremia with or without infective endocarditis receiving daptomycin at 6, 8, and 10 mg/kg of body weight/day was assessed. The relationships between the area under the concentration-time curve over 24 h (AUC)/MIC ratio and both clinical response and time to decreased susceptibility were evaluated using data from patients with such infections who received daptomycin at 6 mg/kg/day. Using these relationships, plus the previously identified relationship between the minimum concentration and an elevation in the creatine phosphokinase (CPK) concentration (CPK elevation) (S. M. Bhavnani, C. M. Rubino, P. G. Ambrose, and G. L. Drusano, Clin Infect Dis 50:1568–1574, 2010) and Monte Carlo simulation, the probability of each outcome by MIC for daptomycin at 6, 8, and 10 mg/kg/day was calculated. The function for exposure-response relationships for clinical response ( P = 0.06) and time to decreased susceptibility ( P = 0.01) resembled U and inverted U shapes, respectively. Multivariable analyses demonstrated AUC/MIC ratio, creatinine clearance, albumin concentration, and disease category to be predictors of clinical response. The results of simulations failed to demonstrate large improvements in the probabilities of clinical success among cohorts of simulated patients defined by the above-described predictive factors or the probability of decreased susceptibility at 30 days when the daptomycin dose was increased from 6 to 10 mg/kg/day. The probability of CPK elevation increased from 0.073 to 0.156 over this dose range. These data can be used to inform risk-versus-benefit decisions for daptomycin dose selection in patients with S. aureus bacteremia with or without infective endocarditis. The risk of CPK elevation, which is reversible, should be weighed in the context of the mortality and severe morbidity associated with these types of serious staphylococcal infections.

Background. The objective of this analysis was to evaluate the relationship between daptomycin exposure and the probability of an elevation in the creatine phosphokinase (CPK) level (hereafter, “CPK elevation”) in patients with Staphylococcus aureus bacteremia with or without infective endocarditis. Methods. Phase 3 data for patients with S. aureus bacteremia, with or without infective endocarditis, who received intravenous daptomycin (6 mg/kg daily) and in whom pharmacokinetic data were collected were evaluated. On the basis of univariate logistic regression, the relationship between Bayesian post hoc exposure estimates and the probability of a CPK elevation was evaluated. Time to CPK elevation was examined with Kaplan-Meier analysis and Cox proportional hazards regression. Results. Significant relationships between the minimum concentration of drug (Cmin) and area under the plasma concentration time curve and probability of CPK elevation were observed in 108 evaluable patients. Of the 108 patients evaluated, 6 (5.56%) demonstrated a defined CPK elevation, regardless of treatment relationship. Cmin (breakpoint of 24.3 mg/L) was most significantly associated with CPK elevation (P p .002). The probabilities of a CPK elevation with a Cmin 24.3 mg/L and !24.3 mg/L were 0.5 and 0.029, respectively. Increases in Cmin, evaluated as a continuous variable, were also significantly associated with CPK elevation (P p .01). Stratified Kaplan-Meier analysis and Cox proportional hazards regression demonstrated Cmin to be a significant predictor of time to a CPK elevation (P .003). The probability of a CPK elevation was 0 and 0.01 after 7 days of treatment in patients with a Cmin 24.3 mg/L or !24.3 mg/L, respectively. After 14 days, the probabilities were 0.5 and 0.025, respectively. Conclusions. This analysis demonstrated that a daptomycin Cmin 24.3 mg/L was associated with an increased probability of a CPK elevation. Clinical trials registration. Clinical trials.gov NCT00093067.

Patients with intra-abdominal infections differ with regard to the type of infection and the severity of illness. However, the impact of these factors, together with differences in drug exposure, on clinical response is not well understood. Using phase 2 and 3 data for patients with complicated intra-abdominal infections, the relative importance of tigecycline exposure, host factors, and disease factors, alone or in combination, for the probability of clinical response was examined. Patients with complicated intra-abdominal infections who received tigecycline intravenously as a 100-mg loading dose followed by 50 mg every 12 h for 5 to 14 days and who had adequate clinical, pharmacokinetic, and response data were evaluated. Multivariable logistic regression was used to identify factors associated with clinical response. A final multivariable logistic regression model demonstrated six factors based on 123 patients to be predictive of clinical success: a weight of P = 0.026), the absence of Pseudomonas aeruginosa in baseline cultures ( P = 0.021), an APACHE II score of P = 0.029), non-Hispanic race ( P = 0.005), complicated appendicitis or cholecystitis ( P = 0.004), and a ratio of the area under the concentration-time curve (AUC) to the MIC (AUC/MIC ratio) of ≥3.1 ( P = 0.003). The average model-predicted probability of clinical success when one unfavorable factor was present was 0.940. This probability was lower (0.855) when the AUC/MIC ratio was

We determined the pharmacokinetic-pharmacodynamic (PK-PD) measure most predictive of gatifloxacin efficacy and the magnitude of this measure necessary for survival in a murine Bacillus anthracis inhalation infection model. We then used population pharmacokinetic models for gatifloxacin and simulation to identify dosing regimens with high probabilities of attaining exposures likely to be efficacious in adults and children. In this work, 6- to 8-week-old nonneutropenic female BALB/c mice received aerosol challenges of 50 to 75 50% lethal doses of B. anthracis (Ames strain, for which the gatifloxacin MIC is 0.125 mg/liter). Gatifloxacin was administered at 6- or 8-h intervals beginning 24 h postchallenge for 21 days, and dosing was designed to produce profiles mimicking fractionated concentration-time profiles for humans. Mice were evaluated daily for survival. Hill-type models were fitted to survival data. To identify potentially effective dosing regimens, adult and pediatric population pharmacokinetic models for gatifloxacin and Monte Carlo simulation were used to generate 5,000 individual patient exposure estimates. The ratio of the area under the concentration-time curve from 0 to 24 h (AUC 0-24 ) to the MIC of the drug for the organism (AUC 0-24 /MIC ratio) was the PK-PD measure most predictive of survival ( R 2 = 0.96). The 50% effective dose (ED 50 ) and the ED 90 and ED 99 corresponded to AUC 0-24 /MIC ratios of 11.5, 15.8, and 30, respectively, where the maximum effect was 97% survival. Simulation results indicate that a daily gatifloxacin dose of 400 mg for adults and 10 mg/kg of body weight for children gives a 100% probability of attaining the PK-PD target (ED 99 ). Sensitivity analyses suggest that the probability of PK-PD target attainment in adults and children is not affected by increases in MICs for strains of B. anthracis to levels as high as 0.5 mg/liter.