Mortality and adverse events of special interest with intravenous belimumab for adults with active, autoantibody-positive systemic lupus erythematosus (BASE): a multicentre, double-blind, randomised, placebo-controlled, phase 4 trial.

Background: Belimumab is approved for the treatment of active systemic lupus erythematosus (SLE). Although clinical trials showed a favourable benefit-risk profile, numerical differences in the incidence of mortality and adverse events of special interest (AESIs) have been reported. We assessed the frequency of these events in patients with SLE receiving belimumab or placebo plus standard therapy.

Identification of a Human Whole Blood-Based Endothelial Cell Impedance Assay for Assessing Clinical Transient Receptor Potential Vanilloid 4 Target Engagement Ex Vivo.

Transient receptor potential vanilloid 4 (TRPV4) channels expressed on pulmonary endothelial cells are activated by elevated pulmonary vascular pressure, resulting in endothelial shape change, pulmonary barrier disruption, and edema. As such, TRPV4 blocker GSK2798745 was recently investigated in phase I/IIa trials to reduce pulmonary edema caused by heart failure (HF). In the absence of a suitable TRPV4 target engagement biomarker, we hypothesized that an ex vivo assay could be used to predict pharmacological activity at the intended site of action (endothelial cells) of subjects.

Assessing the Impact of Losmapimod on Proteinuria in Idiopathic Focal Segmental Glomerulosclerosis.

Introduction: Idiopathic focal segmental glomerulosclerosis (FSGS) is a leading cause of nephrotic syndrome and end-stage renal disease. In preclinical models and biopsies of human FSGS kidneys, p38 mitogen-activated protein kinase (MAPK) has demonstrated enhanced activity; and p38 MAPK inhibition has improved disease markers. This proof-of-concept trial aimed to assess efficacy, safety, tolerability, and pharmacokinetics of losmapimod, an oral p38 MAPK inhibitor, in humans with FSGS.

Discovery of GSK2798745: A Clinical Candidate for Inhibition of Transient Receptor Potential Vanilloid 4 (TRPV4).

GSK2798745, a clinical candidate, was identified as an inhibitor of the transient receptor potential vanilloid 4 (TRPV4) ion channel for the treatment of pulmonary edema associated with congestive heart failure. We discuss the lead optimization of this novel spirocarbamate series and specifically focus on our strategies and solutions for achieving desirable potency, rat pharmacokinetics, and physicochemical properties. We highlight the use of conformational bias to deliver potency and optimization of volume of distribution and unbound clearance to enable desirable mean residence times.

The biodistribution and clearance of AlbudAb, a novel biopharmaceutical medicine platform, assessed via PET imaging in humans.

Unlabelled: Conjugation or fusion to AlbudAbs™ (albumin-binding domain antibodies) is a novel approach to extend the half-life and alter the tissue distribution of biological and small molecule therapeutics. To understand extravasation kinetics and extravascular organ concentrations of AlbudAbs in humans, we studied tissue distribution and elimination of a non-conjugated Zr-labeled AlbudAb in healthy volunteers using positron emission tomography/computed tomography (PET/CT).

Methods: A non-conjugated AlbudAb (GSK3128349) was radiolabeled with Zr and a single 1 mg (~ 15 MBq) dose intravenously administered to eight healthy males.

Development of Focal Segmental Glomerulosclerosis Patient-Reported Outcome Measures: Symptom Diary and Symptom Impact Questionnaire.

Background: Focal segmental glomerulosclerosis (FSGS) is a kidney disease that affects patients' functioning and well-being. This study aimed to develop patient-reported outcome questionnaires to measure patient experiences related to FSGS.

Study Design: Qualitative patient interviews to identify important symptoms and concepts (concept elicitation) formed the basis for the development of 2 questionnaires, one on symptoms and one on their impact.

Discovery of GSK2193874: An Orally Active, Potent, and Selective Blocker of Transient Receptor Potential Vanilloid 4.

Transient Receptor Potential Vanilloid 4 (TRPV4) is a member of the Transient Receptor Potential (TRP) superfamily of cation channels. TRPV4 is expressed in the vascular endothelium in the lung and regulates the integrity of the alveolar septal barrier. Increased pulmonary vascular pressure evokes TRPV4-dependent pulmonary edema, and therefore, inhibition of TRPV4 represents a novel approach for the treatment of pulmonary edema associated with conditions such as congestive heart failure.

TRPV4 inhibition counteracts edema and inflammation and improves pulmonary function and oxygen saturation in chemically induced acute lung injury.

The treatment of acute lung injury caused by exposure to reactive chemicals remains challenging because of the lack of mechanism-based therapeutic approaches. Recent studies have shown that transient receptor potential vanilloid 4 (TRPV4), an ion channel expressed in pulmonary tissues, is a crucial mediator of pressure-induced damage associated with ventilator-induced lung injury, heart failure, and infarction. Here, we examined the effects of two novel TRPV4 inhibitors in mice exposed to hydrochloric acid, mimicking acid exposure and acid aspiration injury, and to chlorine gas, a severe chemical threat with frequent exposures in domestic and occupational environments and in transportation accidents.

Optimization of a Novel Series of TRPV4 Antagonists with In Vivo Activity in a Model of Pulmonary Edema.

High-throughput screening and subsequent hit optimization identified 1-piperidinylbenzimidazoles, exemplified by compound 1, as TRPV4 inhibitors. Lead optimization identified potent TRPV4 blocker 19, which has good target activity and pharmacokinetic properties. Inhibitor 19 was then profiled in an in vivo rat model, demonstrating its ability to inhibit TRPV4-mediated pulmonary edema.

An orally active TRPV4 channel blocker prevents and resolves pulmonary edema induced by heart failure.

Pulmonary edema resulting from high pulmonary venous pressure (PVP) is a major cause of morbidity and mortality in heart failure (HF) patients, but current treatment options demonstrate substantial limitations. Recent evidence from rodent lungs suggests that PVP-induced edema is driven by activation of pulmonary capillary endothelial transient receptor potential vanilloid 4 (TRPV4) channels. To examine the therapeutic potential of this mechanism, we evaluated TRPV4 expression in human congestive HF lungs and developed small-molecule TRPV4 channel blockers for testing in animal models of HF.

A human disease model of drug toxicity-induced pulmonary edema in a lung-on-a-chip microdevice.

Preclinical drug development studies currently rely on costly and time-consuming animal testing because existing cell culture models fail to recapitulate complex, organ-level disease processes in humans. We provide the proof of principle for using a biomimetic microdevice that reconstitutes organ-level lung functions to create a human disease model-on-a-chip that mimics pulmonary edema. The microfluidic device, which reconstitutes the alveolar-capillary interface of the human lung, consists of channels lined by closely apposed layers of human pulmonary epithelial and endothelial cells that experience air and fluid flow, as well as cyclic mechanical strain to mimic normal breathing motions.

Voltage-gated Na+ channel blockers reduce functional bladder capacity in the conscious spontaneously hypertensive rat.

Objective: To evaluate the consequence of pharmacologic inhibition of voltage-gated Na(+) channels (Nav) in the conscious rat, based on Nav having been implicated as modulators of rodent urodynamics using knockout as well as antisense oligodeoxynucleotide approaches.

Methods: The urodynamic response to standard Nav blockers, lamotrigine, amitriptyline, mexiletine, and carbamazepine were evaluated using conscious, continuous-filling cystometry in spontaneously hypertensive rats (SHRs). As a selectivity evaluation, the activity of the Nav blockers at muscarinic receptors was assessed via effect on carbachol-evoked bladder contractions.

Enhanced sensitivity to afferent stimulation and impact of overactive bladder therapies in the conscious, spontaneously hypertensive rat.

The spontaneously hypertensive rat (SHR) has been proposed as an overactive bladder model, driven, at least partially, by alterations in bladder innervation. To assess the functional role of sensory bladder afferents we evaluated the conscious cystometric response to prostaglandin E(2) (PGE(2)) or acetic acid (AA) bladder infusion. SHR demonstrated a hypersensitivity to PGE(2) and AA, as indicated by a greater reduction in both void volume (VV) and micturition interval (MI) compared with Sprague-Dawley controls.

Novel 3-Oxazolidinedione-6-aryl-pyridinones as Potent, Selective, and Orally Active EP3 Receptor Antagonists.

High-throughput screening and subsequent optimization led to the discovery of novel 3-oxazolidinedione-6-aryl-pyridinones exemplified by compound 2 as potent and selective EP3 antagonists with excellent pharmacokinetic properties. Compound 2 was orally active and showed robust in vivo activities in overactive bladder models. To address potential bioactivation liabilities of compound 2, further optimization resulted in compounds 9 and 10, which maintained excellent potency, selectivity, and pharmacokinetic properties and showed no bioactivation liability in glutathione trapping studies.

Ion Channels as Therapeutic Targets--CHI's Fourth Annual Conference.

The Ion Channels as Therapeutic Targets meeting, held in Boston, included topics covering new therapeutic developments in the field of ion-channel drug discovery. This conference report highlights selected presentations on sensory transient receptor potential channels, potassium-channel modulation, as well as methods for chloride-channel screening and channel occupancy evaluation. Human genetic mutations observed in channelopathies and methods to predict the cardiovascular safety of ion-channel modulators were also discussed.

Effect of estrogen and progesterone on urodynamics in the conscious rat.

Objectives: To examine the effects of estrogen and/or progesterone on the cystometric profiles obtained using continuous-filling cystometry in the conscious Sprague-Dawley rat.

Methods: Sprague-Dawley rats underwent ovariectomy (OVX) and were compared with controls by conscious continuous-filling cystometry. The effect of estrogen (10 microg/kg/d for 14 days) and/or progesterone (10 mg/kg/d for 14 days) replacement on OVX urodynamics was examined (n = 7-8/group).

Functional TRPV4 channels and an absence of capsaicin-evoked currents in freshly-isolated, guinea-pig urothelial cells.

Previously we have shown that the transient receptor potential vanilloid 4 (TRPV4) channel regulates urinary bladder function, and that TRPV4 is expressed in both smooth muscle and urothelial cell types within the bladder wall.(1) Urothelial cells have also been suggested to express TRPV1 channels.(2) Therefore, we enzymatically isolated guinea-pig urothelial cells in an attempt to record TRPV4 and TRPV1-mediated currents.

Urodynamic measurements by radiotelemetry in conscious, freely moving beagle dogs.

Purpose: Urodynamics have been traditionally recorded in anesthetized or conscious animals implanted with a bladder catheter that is used to artificially fill the bladder while measuring intravesicular bladder pressure. Anesthesia alters the urodynamics and in the conscious state this methodology requires that the dogs be tethered/restrained, which evokes stress and limits the period of continuous urodynamic assessment. A more physiological and chronic method of evaluating pharmacological responses on urodynamics is necessary.

The voltage-gated sodium channel Nav1.9 is required for inflammation-based urinary bladder dysfunction.

Tetrodotoxin (TTX)-resistant sodium channels are found in small diameter primary sensory neurons and are thought to be important in the maintenance of inflammatory pain. Here we examined bladder urodynamics of Nav1.9 voltage-gated sodium channel knock out (KO) mice, and the contribution of Nav1.

Enhanced bladder capacity and reduced prostaglandin E2-mediated bladder hyperactivity in EP3 receptor knockout mice.

Nonsteroidal anti-inflammatory cyclooxygenase inhibitors that function to reduce prostaglandin E2 (PGE2) production have been widely reported as effective agents in models of urinary bladder overactivity. We therefore investigated a potential role for the PGE2 receptor, EP3, in urinary bladder function by performing conscious, freely moving cystometry on EP3 receptor knockout (KO) mice. EP3 KO mice demonstrated an enhanced bladder capacity compared with wild-type (WT) mice ( approximately 185% of WT) under control conditions, based on larger voided and infused bladder volumes.

Systemic activation of the transient receptor potential vanilloid subtype 4 channel causes endothelial failure and circulatory collapse: Part 2.

The transient receptor potential (TRP) vanilloid subtype 4 (V4) is a nonselective cation channel that exhibits polymodal activation and is expressed in the endothelium, where it contributes to intracellular Ca2+ homeostasis and regulation of cell volume. The purpose of the present study was to evaluate the systemic cardiovascular effects of GSK1016790A, a novel TRPV4 activator, and to examine its mechanism of action. In three species (mouse, rat, and dog), the i.

N-((1S)-1-{[4-((2S)-2-{[(2,4-dichlorophenyl)sulfonyl]amino}-3-hydroxypropanoyl)-1-piperazinyl]carbonyl}-3-methylbutyl)-1-benzothiophene-2-carboxamide (GSK1016790A), a novel and potent transient receptor potential vanilloid 4 channel agonist induces urinary bladder contraction and hyperactivity: Part I.

The transient receptor potential (TRP) vanilloid 4 (TRPV4) member of the TRP superfamily has recently been implicated in numerous physiological processes. In this study, we describe a small molecule TRPV4 channel activator, (N-((1S)-1-{[4-((2S)-2-{[(2,4-dichlorophenyl)sulfonyl]amino}-3-hydroxypropanoyl)-1-piperazinyl]carbonyl}-3-methylbutyl)-1-benzothiophene-2-carboxamide (GSK1016790A), which we have used as a valuable tool in investigating the role of TRPV4 in the urinary bladder. GSK1016790A elicited Ca2+ influx in mouse and human TRPV4-expressing human embryonic kidney (HEK) cells (EC50 values of 18 and 2.

Ion channels in smooth muscle: regulators of intracellular calcium and contractility.

Smooth muscle (SM) is essential to all aspects of human physiology and, therefore, key to the maintenance of life. Ion channels expressed within SM cells regulate the membrane potential, intracellular Ca2+ concentration, and contractility of SM. Excitatory ion channels function to depolarize the membrane potential.

Heteromultimeric Kv1 channels contribute to myogenic control of arterial diameter.

Inhibition of vascular smooth muscle (VSM) delayed rectifier K+ channels (K(DR)) by 4-aminopyridine (4-AP; 200 micromol/L) or correolide (1 micromol/L), a selective inhibitor of Kv1 channels, enhanced myogenic contraction of rat mesenteric arteries (RMAs) in response to increases in intraluminal pressure. The molecular identity of K(DR) of RMA myocytes was characterized using RT-PCR, real-time PCR, and immunocytochemistry. Transcripts encoding the pore-forming Kvalpha subunits, Kv1.