Immuno-PET Imaging to Assess Target Engagement: Experience from Zr-Anti-HER3 mAb (GSK2849330) in Patients with Solid Tumors.

PET imaging with radiolabeled drugs provides information on tumor uptake and dose-dependent target interaction to support selection of an optimal dose for future efficacy testing. In this immuno-PET study of the anti-human epidermal growth factor receptor (HER3) mAb GSK2849330, we investigated the biodistribution and tumor uptake of Zr-labeled GSK2849330 and evaluated target engagement as a function of antibody mass dose. Zr-GSK2849330 distribution was monitored in 6 patients with HER3-positive tumors not amenable to standard treatment.

Effects of vercirnon on the activity of CYP3A4, CYP2C19 and CYP2C8 enzymes and BCRP and OATP1B1 transporters using probe substrates.

Purpose: Vercirnon is a CCR9 chemokine receptor antagonist being developed for the treatment of Crohn's disease. As a variety of concomitant medications are often required for the treatment of Crohn's disease, it is important to characterise the drug interaction profile of vercirnon. To confirm the results of previous in vitro inhibition studies, this study assessed the in vivo effect of vercirnon on the activity of cytochrome P450 enzymes (CYP3A4, CYP2C19 and CYP2C8) and drug transport proteins (BCRP and OATP1B1) using probe substrates.

Single-Dose Pharmacokinetics of the CCR9 Receptor Antagonist Vercirnon in Healthy US and Japanese Subjects.

Two randomized, single-dose, crossover studies were carried out to assess different formulations and doses of the CCR9 receptor antagonist vercirnon in healthy subjects. US study (n = 24): a five-period crossover study in healthy US subjects to assess the bioavailability of four new GlaxoSmithKline formulations compared with a "reference" formulation. Each subject received a single 500 mg dose of each of the five vercirnon formulations in a fed state.

Endothelium-dependent vasodilation in myogenically active mouse skeletal muscle arterioles: role of EDH and K(+) channels.

As smooth muscle cell (SMC) membrane potential (E(m)) is critical for vascular responsiveness, and arteriolar SMCs are depolarized at physiological intraluminal pressures, we hypothesized that myogenic tone impacts on dilation mediated by endothelium-derived hyperpolarization (EDH). Studies were performed on cannulated mouse cremaster arterioles [diameter, 33+/-2 microm (n=23) at 60 mmHg; SMC Em -34.6+/-1.

A role for heterocellular coupling and EETs in dilation of rat cremaster arteries.

Objective: The authors probed endothelium-dependent dilation and endothelial cell Ca2+ handling in myogenically active resistance arteries.

Methods: First-order arteries were removed from rat cremaster muscles, cannulated, and pressurized (75 mmHg). Vessel diameter and endothelial cell Ca2+ were monitored using confocal microscopy, and arterial ultrastructure was determined using electron microscopy.

Endothelial cell Ca2+ increases are independent of membrane potential in pressurized rat mesenteric arteries.

In rat mesenteric arteries, the ability of ACh to evoke hyperpolarization of smooth muscle cells and consummate dilatation relies on an increase in endothelial cell cytosolic free [Ca2+] and activation of Ca2+-activated K+ channels (KCa). The time course of average and spatially organized rises in endothelial cell [Ca2+]i and concomitant effects on membrane potential were investigated in individual cells of pressurized arteries and isolated sheets of native cells stimulated with ACh. In both cases, ACh stimulated a sustained and oscillating rise in endothelial cell [Ca2+]i.