Mike Lizarzaburu

Discovery and optimization of a novel series of GPR142 agonists for the treatment of type 2 diabetes mellitus.

The discovery and initial optimization of a series of phenylalanine based agonists for GPR142 is described. The structure-activity-relationship around the major areas of the molecule was explored to give agonists 90 times more potent than the initial HTS hit in a human GPR142 inositol phosphate accumulation assay. Removal of CYP inhibition by exploration of the pyridine A-ring is also described.

Identification of piperazine-bisamide GHSR antagonists for the treatment of obesity

Piperazine-bisamide analogs were discovered as partial agonists of human growth hormone secretagogue receptor (GHSR) in a high throughput screen. The partial agonists were optimized for potency and converted into antagonists through structure-activity relationship (SAR) studies. The efforts also led to the identification of potent antagonist with favorable PK profile suitable as a tool compound for in vivo studies.

Potent and Orally Bioavailable GPR142 Agonists as Novel Insulin Secretagogues for the Treatment of Type 2 Diabetes

GPR142 is a G protein-coupled receptor that is predominantly expressed in pancreatic β-cells. GPR142 agonists stimulate insulin secretion in the presence of high glucose concentration, so that they could be novel insulin secretagogues with reduced or no risk of hypoglycemia. We report here the optimization of HTS hit compound 1 toward a proof of concept compound 33, which showed potent glucose lowering effects during an oral glucose tolerance test in mice and monkeys.

Discovery of a new class of ghrelin receptor antagonists.

A series of benzodiazepine antagonists of the human ghrelin receptor GHSR1a were synthesized and their antagonism and metabolic stability were evaluated. The potency of these analogs was determined using a functional aequorin (Euroscreen) luminescent assay measuring the intracellular Ca(2+) concentration, and their metabolic stability was measured using an in vitro rat and human S9 hepatocyte assay. These efforts led to the discovery of a potent ghrelin antagonist with good rat pharmacokinetic properties.

Phenylalanine derivatives as GPR142 agonists for the treatment of type II diabetes.

GPR142 is a novel GPCR that is predominantly expressed in pancreatic β-cells. GPR142 agonists potentiate glucose-dependent insulin secretion, and therefore can reduce the risk of hypoglycemia. Optimization of our lead pyridinone-phenylalanine series led to a proof-of-concept compound 22, which showed in vivo efficacy in mice with dose-dependent increase in insulin secretion and a decrease in glucose levels.

Aminopyrazole-Phenylalanine Based GPR142 Agonists: Discovery of Tool Compound and in Vivo Efficacy Studies.

Herein, we report the lead optimization of amrinone-phenylalanine based GPR142 agonists. Structure-activity relationship studies led to the discovery of aminopyrazole-phenylalanine carboxylic acid 22, which exhibited good agonistic activity, high target selectivity, desirable pharmacokinetic properties, and no cytochrome P450 or hERG liability. Compound 22, together with its orally bioavailable ethyl ester prodrug 23, were found to be suitable for in vivo proof-of-concept studies. Compound 23 displayed good efficacy in a mouse oral glucose tolerance test (OGTT). Compound 22 showed GPR142 dependent stimulation of insulin secretion in isolated mouse islets and demonstrated a statistically significant glucose lowering effect in a mouse model bearing transplanted human islets.

Optimization of triazoles as novel and potent nonphlorizin SGLT2 inhibitors

Previous efforts have led to the identification of a potent, selective, and nonphlorizin based SGLT2 inhibitor 1. This Letter describes efforts to further optimize the potency, microsomal stability, solubility and pharmacokinetic properties of this series of SGLT2 inhibitors. From these efforts, compounds 28 and 32 have improved solubility and pharmacokinetic properties compared to compound 1.