Andrew S. Judd

Validation of diacyl glycerolacyltransferase I as a novel target for the treatment of obesity and dyslipidemia using a potent and selective small molecule inhibitor.

A highly potent and selective DGAT-1 inhibitor was identified and used in rodent models of obesity and postprandial chylomicron excursion to validate DGAT-1 inhibition as a novel approach for the treatment of metabolic diseases. Specifically, compound 4a conferred weight loss and a reduction in liver triglycerides when dosed chronically in DIO mice and depleted serum triglycerides following a lipid challenge in a dose-dependent manner, thus, reproducing major phenotypical characteristics of DGAT-1(-/-) mice.

Identification and preliminary characterization of a potent, safe, and orally efficacious inhibitor of acyl-CoA:diacylglycerol acyltransferase 1.

A high-throughput screen against human DGAT-1 led to the identification of a core structure that was subsequently optimized to afford the potent, selective, and orally bioavailable compound 14. Oral administration at doses ≥0.03 mg/kg significantly reduced postprandial triglycerides in mice following an oral lipid challenge. Further assessment in both acute and chronic safety pharmacology and toxicology studies demonstrated a clean profile up to high plasma levels, thus culminating in the nomination of 14 as clinical candidate ABT-046.

Inhibitors of diacylglycerol acyltransferase: a review of 2008 patents

Background: Postprandial hypertriglyceridemia has been identified as a major independent risk factor for future cardiovascular events. Therefore, inhibition of triglyceride synthesis has enormous therapeutic potential in the treatment of metabolic disorders. Diacylglycerol acyltransferase (DGAT) enzymes catalyze the final and only committed step in triglyceride biosynthesis and have thus been identified as potential therapeutic targets to combat human cardio-metabolic diseases. Objective/method: Significant interest in DGAT-1 inhibitors has emerged in the last several years. To provide a perspective on the exciting features of this enzyme for targeting metabolic diseases, a summary of the biology and pharmacology surrounding the DGAT enzymes is presented. Following this is a discussion of the various chemotypes that have been disclosed within relevant patent applications published in 2008. Specifically, the similarities and differences of the chemical structures and the biological data that are provided to support the corresponding claims are presented. Conclusion: Small molecule and biologic-based DGAT inhibitors have been successfully used for the preclinical validation of DGAT enzymes as targets for the treatment of metabolic diseases. Given the advanced stage in which some of the chemical matter resides, it is expected that DGAT inhibitors will enter the clinic in the coming years.

Lead Optimization Strategies and Tactics Applied to the Discovery of Melanin Concentrating Hormone Receptor 1 Antagonists

The discovery of small molecule melanin concentrating hormone receptor (MCHr1) antagonists as novel therapeutic agents for the treatment of obesity has been actively pursued across the pharmaceutical industry. While multiple chemotypes of small molecule MCHr1 antagonists have been identified and shown to deliver weight loss in animal models of obesity, many of these lead compounds have been found to cross-react with the hERG channel and/or demonstrate deleterious effects on cardiovascular hemodynamic parameters. This review describes an approach to rapidly identifying safer MCHr1 antagonists by placing assays to assess cardiovascular safety early in the lead optimization compound prioritization process. Ultimately, despite putting significant effort toward the discovery of a MCHr1 antagonist for the treatment of obesity, we were unable to deliver a candidate compound that attained an acceptable therapeutic index (TI = 30-100) in our in vivo models. Our inability to identify a compound with an acceptable therapeutic index was driven by two primary factors: 1) high levels of sustained drug exposure in the brain was required to achieve efficacy; and 2) many small molecule MCHR1 receptor antagonists suffer from receptor cross-reactivity that leads to cardiovascular toxicity at low multiples of their therapeutic plasma concentration.

Lead Optimization of Melanin Concentrating Hormone Receptor 1 Antagonists with low hERG Channel Activity

The discovery of small molecule melanin concentrating hormone receptor (MHCr1) antagonists as novel therapeutic agents has been widely pursued across the pharmaceutical industry. While multiple chemotypes of small molecule MCHr1 antagonists have been identified and shown to induce weight loss in rodent models of obesity, many of these lead compounds have been found to cross react with the hERG channel. This review describes efforts that led to the identification of two sub-series of MCHr1 antagonists with low affinity for the hERG channel. Ultimately, however, the modifications introduced to thwart hERG channel activity resulted in lead compounds with sub-optimal CNS behavior.