A First-in-Patient, Multicenter, Double-Blind, 2-Arm, Placebo-Controlled, Randomized Safety and Tolerability Study of a Novel Oral Drug Candidate, CTP-499, in Chronic Kidney Disease.

The prevalence of chronic kidney disease (CKD) related to type 2 diabetes is increasing worldwide. In addition to standard of care, treatment with anti-inflammatory and antifibrotic agents such as CTP-499, a novel oral, multisubtype selective inhibitor of phosphodiesterases, may be important in CKD treatment. A phase 1b randomized, double-blind, placebo-controlled clinical trial of CTP-499 in CKD patients (25 active, 8 placebo) with an estimated glomerular filtration rate of 30-59 mL/min/1.73 m(2) was conducted to assess safety and tolerability. Secondary outcomes included pharmacokinetics and exploratory effects on inflammatory and hematology markers. Patients received 600 mg CTP-499 or matching placebo tablets orally once daily for 2 weeks, then twice daily for 2 additional weeks. CTP-499 was well tolerated with no serious or severe adverse events, or adverse events leading to discontinuation. CTP-499 was rapidly absorbed and produced acceptable interpatient variability. Of the 5 metabolites (M1-M5), M5 was the most abundant in plasma and urine. Exposure to CTP-499 and metabolites was higher in CKD patients than previously reported in healthy volunteers. No statistically significant differences were detected between the CTP-499- and placebo-treated groups for any of the biomarkers tested. This study provides data supporting further evaluation of CTP-499 in CKD patients.

Matrix metalloproteinase-9 activates TGF-ß and stimulates fibroblast contraction of collagen gels.

Matrix metalloproteinase-9 (MMP-9) is a matrix-degrading enzyme implicated in many biological processes, including inflammation. It is produced by many cells, including fibroblasts. When cultured in three-dimensional (3D) collagen gels, fibroblasts contract the surrounding matrix, a function that is thought to model the contraction that characterizes both normal wound repair and fibrosis. The current study was designed to evaluate the role of endogenously produced MMP-9 in fibroblast contraction of 3D collagen gels. Fibroblasts from mice lacking expression of MMP-9 and human lung fibroblasts (HFL-1) transfected with MMP-9 small-interfering RNA (siRNA) were used. Fibroblasts were cast into type I collagen gels and floated in culture medium with or without transforming growth factor (TGF)-ß1 for 5 days. Gel size was determined daily using an image analysis system. Gels made from MMP-9 siRNA-treated human fibroblasts contracted less than control fibroblasts, as did fibroblasts incubated with a nonspecific MMP inhibitor. Similarly, fibroblasts cultured from MMP-9-deficient mice contracted gels less than did fibroblasts from control mice. Transfection of the MMP-9-deficient murine fibroblasts with a vector expressing murine MMP-9 restored contractile activity to MMP-9-deficient fibroblasts. Inhibition of MMP-9 reduced active TGF-ß1 and reduced several TGF-ß1-driven responses, including activity of a Smad3 reporter gene and production of fibronectin. Because TGF-ß1 also drives fibroblast gel contraction, this suggests the mechanism for MMP-9 regulation of contraction is through the generation of active TGF-ß1. This study provides direct evidence that endogenously produced MMP-9 has a role in regulation of tissue contraction of 3D collagen gels mediated by fibroblasts.

Study of the population pharmacokinetic characteristics of once-daily trospium chloride 60 mg extended-release capsules in patients with overactive bladder and in healthy subjects.

BACKGROUND: Overactive bladder is a common disorder that affects approximately 34 million adults in the United States. Anticholinergic (antimuscarinic) agents are the most widely used pharmacological option for overactive bladder. OBJECTIVE: This study set out to identify and characterize the influence of a number of intrinsic characteristics on the pharmacokinetics of the anticholinergic agent trospium chloride (Sanctura(®)) 60 mg extended release (XR), and to evaluate the correlation between trospium chloride exposure and key efficacy and safety outcomes in subjects and patients. STUDY DESIGN: Pharmacokinetic data were obtained from three studies in which a total of 349 subjects received trospium chloride XR for up to 12 weeks. Plasma trospium chloride concentration data were pooled and a population pharmacokinetic model was derived using non-linear mixed-effects modelling. Demographic factors were assessed for influence on the model. The correlation between trospium chloride exposure and key efficacy variables was evaluated. Correlations between exposure and safety outcomes were also assessed. INTERVENTION: Trospium chloride XR 60 mg once daily for 10 days in healthy volunteers or trospium chloride 60 mg XR once daily for either 2 weeks or 12 weeks in patients with overactive bladder. RESULTS: The best population pharmacokinetic model was determined to be a two-compartment model with zero-order release into the depot compartment and first-order absorption. Body surface area (BSA) was the only covariate to significantly (P < 0.05) impact trospium chloride 60 mg XR pharmacokinetics. Significant relationships (P < 0.05) were observed between exposure [maximum plasma concentration (C(max)) and the area under the plasma concentration-time curve from time zero to 24 h (AUC(24))] and efficacy outcomes in the <65-year age group for change in average number of voids/day, change in number of incontinence episodes, and change in urgency severity, and in the ≥65-year age group statistical significance (P < 0.05) was achieved for C(max), but not for AUC(24), for these same three efficacy measures. Statistically significant relationships (P < 0.004) were also observed between exposure and both dry mouth and constipation, with increased benefit and increased incidence of adverse events (AEs) associated with higher concentrations; the correlation coefficients were low against the aggregate of AEs of interest (0.19 for AUC(24) and 0.18 for C(max)), indicating only mild strength of association. CONCLUSION: This population pharmacokinetic analysis demonstrated that the only demographic characteristic associated with trospium chloride pharmacokinetics was BSA. Thus, treatment of most patients with overactive bladder with once-daily trospium chloride 60 mg XR should not require consideration of key intrinsic demographic parameters. Furthermore, while efficacy and tolerability outcomes were found to be correlated with trospium chloride exposure, the strength of the association was modest in this study.

A Randomized Phase I Evaluation of CTP-499, a Novel Deuterium-Containing Drug Candidate for Diabetic Nephropathy.

To determine maximum tolerated dose and food effect for CTP-499, a novel agent being studied for the treatment of diabetic kidney disease. CTP-499 has demonstrated anti-inflammatory, anti-fibrotic and anti-oxidative activities in vitro as well as anti-inflammatory and renoprotective effects in a diabetic nephropathy (DN) model. Two studies were performed. Study 1 was a single-dose escalation study with 600, 1200, 1800, and 2400 mg doses of controlled-release (CR) CTP-499 and a 400 mg immediate release dose to aid in the development of prototype formulations of CTP-499. Study 2 was a food-effect study. Plasma concentrations of CTP-499 and its metabolites were measured to determine pharmacokinetic parameters in each study. Safety was assessed to determine tolerability. Doses up to and including 1800 mg were well tolerated. Cmax was either equivalent (CTP-499) or slightly lower (metabolites) for the fed condition, while overall exposure was equivalent (CTP-499) or slightly higher (metabolites) for the fed condition. The range of tolerated doses of CTP-499 and the effects of food on exposure were identified, contributing to selection of the dose for Phase II development.

Pharmacokinetics of once-daily trospium chloride 60 mg extended release and twice-daily trospium chloride 20 mg in healthy adults.

The objective of this study is to characterize the steady-state pharmacokinetics and compare the relative bioavailability of the extended-release capsule formulation of the antimuscarinic trospium chloride, developed for once-daily administration, and trospium chloride immediate-release tablets. This is a single-center, multidose, randomized, open-label, 2-period, 2-arm crossover, bioavailability study in healthy adult male and female subjects who are within 20% of their ideal body weight. Subjects receive trospium 60-mg extended-release capsules once daily and trospium 20-mg tablets twice daily for 10 days, each in a crossover manner. Twenty-four subjects are enrolled in the study. With multiple dosing of trospium 60 mg extended-release once daily versus 20 mg twice daily, lower geometric least squares mean area under the concentration-time curve from 0 to 24 hours (17 360 vs 28 590 pg.h/mL; ratio 61%; 90% confidence interval, 51-72) and maximum plasma concentration (1517 vs 2502 pg/mL; 61%; 90% confidence interval, 49-75) are observed. Furthermore, with trospium 60 mg extended-release versus 20 mg, median time to maximum plasma concentration is later (5.0 vs 4.5 hours) and half-life is longer (35.8 vs 27.2 hours). Trospium exposure is lower with multiple dosing of trospium 60 mg extended-release compared with trospium 20 mg twice daily. Thus, with the extended-release formulation, trospium concentrations are less likely to reach the threshold where adverse events may sometimes occur.

Sleep Electroencephalographic Studies After ECT: Age and Clinical Response.

Forty-one patients with major depressive disorder were treated with electroconvulsive therapy (ECT). Sleep polysomnography studies (SPSs) were performed after the course of ECT. The hypotheses tested were that age is a significant factor in post-ECT SPS results and that some SPS parameters are correlates of outcome of ECT. An interaction between age and response to ECT could not be identified; however, older patients demon strated significantly disrupted sleep post-ECT. Response to ECT was associated with lower REM activity and lower REM density. Sleep-onset REM periods post-ECT were observed in almost 50% of the patients regardless of age. The SPS monitoring of recovery after a course of ECT may identify sleep correlates of response to ECT and variables associated with poorer longitudinal outcome.