A phase I study of Hemay022, an irreversible dual EGFR/HER2 tyrosine kinase inhibitor in Chinese patients with HER2-positive advanced breast cancer.

Objective: Hemay022 is a novel small-molecule and an irreversible tyrosine kinase inhibitor with the target of epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER2), which demonstrated anti-tumor activity in preclinical studies. This first-in-human study evaluated the safety, pharmacokinetics, tolerability and preliminary anti-tumor activity of Hemay022 in HER2-positive advanced breast cancer patients.

Methods: Heavily pretreated patients with HER2-positive advanced breast cancer were assigned to eight dose cohorts in a 3+3 dose-escalation pattern at doses of 50-600 mg QD and 300 mg BID.

Potential role of CYP2D6 in the central nervous system.

1. Cytochrome P450 2D6 (CYP2D6) is a pivotal enzyme responsible for a major drug oxidation polymorphism in human populations. Distribution of CYP2D6 in brain and its role in serotonin metabolism suggest that CYP2D6 may have a function in the central nervous system.

Control of steroid 21-oic acid synthesis by peroxisome proliferator-activated receptor alpha and role of the hypothalamic-pituitary-adrenal axis.

A previous study identified the peroxisome proliferator-activated receptor alpha (PPARalpha) activation biomarkers 21-steroid carboxylic acids 11beta-hydroxy-3,20-dioxopregn-4-en-21-oic acid (HDOPA) and 11beta,20-dihydroxy-3-oxo-pregn-4-en-21-oic acid (DHOPA). In the present study, the molecular mechanism and the metabolic pathway of their production were determined. The PPARalpha-specific time-dependent increases in HDOPA and 20alpha-DHOPA paralleled the development of adrenal cortex hyperplasia, hypercortisolism, and spleen atrophy, which was attenuated in adrenalectomized mice.

Metabolomic and genetic analysis of biomarkers for peroxisome proliferator-activated receptor alpha expression and activation.

Peroxisome proliferator-activated receptor alpha (PPARalpha) is a nuclear receptor with manifold effects on intermediary metabolism. To define a set of urinary biomarkers that could be used to determine the efficacy of PPARalpha agonists, a metabolomic investigation was undertaken in wild-type and Pparalpha-null mice fed for 2 wk either a regular diet or a diet containing the PPARalpha ligand Wy-14,643 ([4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid), and their urine was analyzed by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry. Principal components analysis of 6393 accurate mass positive ions revealed clustering as a single phenotype of the treated and untreated Pparalpha (-/-) mice plus two additional discrete phenotypes for the treated and untreated Pparalpha (+/+) mice.

3,4-Dehydrodebrisoquine, a novel debrisoquine metabolite formed from 4-hydroxydebrisoquine that affects the CYP2D6 metabolic ratio.

Considerable unexplained intersubject variability in the debrisoquine metabolic ratio (urinary debrisoquine/4-hydroxydebrisoquine) exists within individual CYP2D6 genotypes. We speculated that debrisoquine was converted to as yet undisclosed metabolites. Thirteen healthy young volunteers, nine CYP2D6*1 homozygotes [extensive metabolizers (EMs)] and four CYP2D6*4 homozygotes [poor metabolizers (PMs)] took 12.

A novel assay of cell rubidium uptake using graphite furnace atomic absorption: application to rats on a magnesium-deficient diet.

The [Na,K]ATPase or sodium pump (SP) is a ubiquitous membrane cation transport system. Because of its potential participation in the pathophysiology of essential hypertension and cataract formation, the SP is under active investigation to detail its function and control. In this paper, we describe a novel, nonradioactive method of measuring SP ion transport activity in intact red blood cells (RBCs) using graphite furnace atomic absorption measurement of rubidium ion (Rb) uptake.