Novel Macrocyclic NLRP3 Inhibitors.

Aberrant activation of NLRP3 due to persistent tissue damage, misfolded proteins or crystal deposits has been linked to multiple chronic inflammatory disorders such as cryopyrin-associated periodic syndrome (CAPS), neurodegenerative diseases, gouty arthritis, and numerous others. Hence, there has been an increasing interest in NLRP3 inhibitors as therapeutics. A first generation of NLRP3 inhibitors bearing a sulfonylurea core such as MCC950 (developed by Pfizer) were discovered by phenotypic screening, however their mode of action was only elucidated later.

Evaluation of the drug disposition of RO7049389 with in vitro data and human mass balance supported by physiologically based pharmacokinetic modelling.

Aims: RO7049389 (linvencorvir) is a developmental oral treatment for chronic hepatitis B virus infection. The aim of this work was to conduct mass balance (MB) and absolute bioavailability (BA) analyses in healthy volunteers, alongside in vitro evaluations of the metabolism of RO7049389 and a major circulating active metabolite M5 in human hepatocytes, and physiologically based pharmacokinetic (PBPK) modelling to refine the underlying drug disposition paradigm.

Methods: Participants in the clinical study (MB: Caucasian, male, n = 6; BA: Caucasian and Asian, male and female, n = 16, 8 in each ethnic groups) received oral [ C] or unlabelled RO7049389 (600/1000 mg) followed by 100 μg intravenous [ C]RO7049389.

Translating pharmacology models effectively to predict therapeutic benefit.

Many in vitro and in vivo models are used in pharmacological research to evaluate the role of targeted proteins in a disease. Understanding the translational relevance and limitation of these models for analyzing a drug's disposition, pharmacokinetic/pharmacodynamic (PK/PD) profile, mechanism, and efficacy, is essential when selecting the most appropriate model of the disease of interest and predicting clinically efficacious doses of the investigational drug. Selected animal models used in ophthalmology, infectious diseases, oncology, autoimmune diseases, and neuroscience are reviewed here.

BET Inhibition Enhances TNF-Mediated Antitumor Immunity.

Targeting chromatin binding proteins and modifying enzymes can concomitantly affect tumor cell proliferation and survival, as well as enhance antitumor immunity and augment cancer immunotherapies. By screening a small-molecule library of epigenetics-based therapeutics, BET (bromo- and extra-terminal domain) inhibitors (BETi) were identified as agents that sensitize tumor cells to the antitumor activity of CD8 T cells. BETi modulated tumor cells to be sensitized to the cytotoxic effects of the proinflammatory cytokine TNF.

Bioavailability and pharmacokinetic profile of balovaptan, a selective, brain-penetrant vasopressin 1a receptor antagonist, in healthy volunteers.

Background: Balovaptan is a potent, selective vasopressin 1a receptor antagonist. The early-phase pharmacokinetics (PK) of balovaptan are reported.

Research Design And Methods: Two Phase 1 studies (overall = 93) assessed single- and multiple-dose balovaptan PK in healthy adults.

How Semiphysiological Population Pharmacokinetic Modeling Incorporating Active Hepatic Uptake Supports Phase II Dose Selection of RO7049389, A Novel Anti-Hepatitis B Virus Drug.

The pharmacokinetics (PK) of RO7049389, a new hepatitis B virus (HBV) core protein allosteric modulator of class I, and of its active metabolite M5 were studied in fasted and fed conditions after single and multiple once-a-day and twice-a-day doses in healthy subjects and patients with HBV. The nonlinearity of the pharmacokinetics, the large variability, the small sample size per dose arms, the higher plasma exposure in Asians, and the heterogeneity in patient baseline characteristics seen in phase I studies made the ethnic sensitivity assessment and the selection of the recommended phase II dose difficult. A population PK model, simultaneously modeling RO7049389 and M5, was developed to characterize the complex PK, quantify ethnicity (i.

Entrectinib, a TRK/ROS1 inhibitor with anti-CNS tumor activity: differentiation from other inhibitors in its class due to weak interaction with P-glycoprotein.

Background: Studies evaluating the CNS penetration of a novel tyrosine kinase inhibitor, entrectinib, proved challenging, particularly due to discrepancies across earlier experiments regarding P-glycoprotein (P-gp) interaction and brain distribution. To address this question, we used a novel "apical efflux ratio" (AP-ER) model to assess P-gp interaction with entrectinib, crizotinib, and larotrectinib, and compared their brain-penetration properties.

Methods: AP-ER was designed to calculate P-gp interaction with the 3 drugs in vitro using P-gp-overexpressing cells.

Preclinical Reproductive and Developmental Toxicity Profile of a Glycine Transporter Type 1 (Glyt1) Inhibitor.

Bitopertin is a glycine type 1 (GlyT1) inhibitor intended for the treatment of psychiatric disorders. The principle adverse effect in the regulatory reproductive toxicity studies was peri-natal pup death when rat dams were treated during parturition at a dose resulting in five-times the human therapeutic exposure (AUC). Cessation of dosing two days before parturition prevented the pup deaths.

Pharmacology of basimglurant (RO4917523, RG7090), a unique metabotropic glutamate receptor 5 negative allosteric modulator in clinical development for depression.

Major depressive disorder (MDD) is a serious public health burden and a leading cause of disability. Its pharmacotherapy is currently limited to modulators of monoamine neurotransmitters and second-generation antipsychotics. Recently, glutamatergic approaches for the treatment of MDD have increasingly received attention, and preclinical research suggests that metabotropic glutamate receptor 5 (mGlu5) inhibitors have antidepressant-like properties.

Metabolism, excretion, and pharmacokinetics of [14c]-radiolabeled aleglitazar: a phase I, nonrandomized, open-label, single-center, single-dose study in healthy male volunteers.

Background: Aleglitazar is a dual peroxisome proliferator-activated receptor (PPAR)-α/γ agonist with a balanced activity (similar half-maximal effective concentrations) toward PPAR-α and -γ that is in clinical development for the treatment of patients who have experienced an acute coronary syndrome and have type 2 diabetes mellitus.

Objective: This study aimed to characterize the metabolic profile and the routes and rates of elimination of aleglitazar and its major metabolites in humans.

Methods: In this Phase I, nonrandomized, open-label, single-center, single-dose study, 6 healthy male subjects each received a single oral dose of 300 μg [(14)C]-labeled aleglitazar.

Pharmacokinetics and metabolism of the dipeptidyl peptidase IV inhibitor carmegliptin in rats, dogs, and monkeys.

The pharmacokinetics and excretion of carmegliptin, a novel dipeptidyl peptidase IV inhibitor, were examined in rats, dogs, and cynomolgus monkeys. Carmegliptin exhibited a moderate clearance, extensive tissue distribution, and a variable oral bioavailability of 28-174%. Due to saturation of intestinal active secretion, the area under the plasma concentration-time curve (AUC) in dogs and monkeys increased in a more than dose-proportional manner over an oral dose range of 2.

Application of modern drug metabolism structure determination tools and assays to the in vitro metabolism of imiloxan.

Imiloxan is an alpha2 adrenoceptor antagonist and was developed for depression in the 1980's. In Phase 1 clinical trials imiloxan dosing led to hypersensitivity reactions; the molecule's development was discontinued. The present study revisits the in vitro metabolism of imiloxan using modern analytical methods.

Sulfonylureido thiazoles as fructose-1,6-bisphosphatase inhibitors for the treatment of type-2 diabetes.

Sulfonylureido thiazoles were identified from a HTS campaign and optimized through a combination of structure-activity studies, X-ray crystallography and molecular modeling to yield potent inhibitors of fructose-1,6-bisphosphatase. Compound 12 showed favorable ADME properties, for example, F=70%, and a robust 32% glucose reduction in the acute db/db mouse model for Type-2 diabetes.

Modelling of patient EMS exposure: translating pharmacokinetics of EMS in vitro and in animals into patients.

In order to support the toxicological risk assessment for the ethyl methanesulfonate (EMS) exposure of patients ingesting contaminated Viracept tablets (Müller and Singer, 2009), there was a need to correlate the effects observed in in vivo genotoxicity studies with mice to EMS exposure and to estimate human exposure to EMS at the level of contamination of Viracept tablets. The species differences in volume of distribution of EMS, a key factor for determination of its C(max), were small in the species investigated (mouse, rat, monkey), the species differences in clearance, the key factor involved in AUC assessment, were large (Lavé et al., 2009).

Structure of creatine amidinohydrolase from Actinobacillus.

The crystal structure of Actinobacillus creatine amidinohydrolase has been solved by molecular replacement. The amino-acid sequence has been derived from the crystal structure. Crystals belong to space group I222, with unit-cell parameters a = 111.

Analysis and quantification of DNA adducts of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline in liver of rats by liquid chromatography/electrospray tandem mass spectrometry.

Liquid chromatography with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) was used to measure DNA adducts of the carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) with a microbore C-18 reversed-phase column. Quantification of the isomeric adducts N-(deoxyguanosin-8-yl)-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (dG-C8-MeIQx) and 5-(deoxyguanosin-N(2)-yl)-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (dG-N(2)-MeIQx) was achieved using synthetic, isotopically labeled internal standards. The reaction of the N-acetoxy ester of 2-(hydroxyamino)-3,8-dimethylimidazo[4,5-f]quinoxaline (HONH-MeIQx) with calf thymus DNA (ct DNA) resulted in formation of these adducts in a ratio of 5:1 (dG-C8-MeIQx:dG-N(2)-MeIQx).

Differential metabolism of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in rat and human hepatocytes.

Metabolism of the carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) has been compared in human and rat hepatocytes. The identities of seven metabolites were confirmed by UV and mass spectroscopy and by co-elution with reference standards using HPLC. In human hepatocytes, the major biotransformation pathway of PhIP was cytochrome P4501A2 (CYP1A2)-mediated N-oxidation to form the genotoxic metabolite 2-(hydroxyamino)-1-methyl-6-phenylimidazo[4,5-b]pyridine (HONH-PhIP), which underwent glucuronidation at the N(2) and N3 positions of PhIP to form stable conjugates.

Quantification of the heterocyclic aromatic amine DNA adduct N-(deoxyguanosin-8-yl)-2-amino-3-methylimidazo[4,5-f]quinoline in livers of rats using capillary liquid chromatography/microelectrospray mass spectrometry: a dose-response study.

Capillary liquid chromatography/microelectrospray-mass spectrometry (capillary LC/muESI-MS) was used to quantify DNA adducts of the heterocyclic aromatic amine 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in livers of male Fischer-344 rats. Animals received a single oral dose of either 0.05, 0.