Milton L. Hammond

Discovery of MK-7655, a β-lactamase inhibitor for combination with Primaxin®

β-Lactamase inhibitors with a bicyclic urea core and a variety of heterocyclic side chains were prepared and evaluated as potential partners for combination with imipenem to overcome class A and C β-lactamase mediated antibiotic resistance. The piperidine analog 3 (MK-7655) inhibited both class A and C β-lactamases in vitro. It effectively restored imipenems activity against imipenem-resistant Pseudomonas and Klebsiella strains at clinically achievable concentrations. A combination of MK-7655 and Primaxin® is currently in phase II clinical trials for the treatment of Gram-negative bacterial infections.

Synthesis and SAR of thioester and thiol inhibitors of IMP-1 Metallo-β-Lactamase

Potent thioester and thiol inhibitors of IMP-1 metallo-β-lactamase have been synthesized employing a solid-phase Mitsunobu reaction as the key step.

Dicationic 2-fluorenonylcarbapenems: Potent anti-MRS agents with improved solubility and pharmacokinetic properties

The synthesis and biological evaluation of a series of dicationic-substituted 2-fluorenonylcarbapenems is described. This class of compounds showed enhanced water solubility while maintaining potent activity against MRS. Introduction of a 1-beta-methyl substituent was found to improve pharmacokinetics.

Biphenyl-Substituted Oxazolidinones as Cholesteryl Ester Transfer Protein Inhibitors: Modifications of the Oxazolidinone Ring Leading to the Discovery of Anacetrapib

The development of the structure-activity studies leading to the discovery of anacetrapib is described. These studies focused on varying the substitution of the oxazolidinone ring of the 5-aryloxazolidinone system. Specifically, it was found that substitution of the 4-position with a methyl group with the cis-stereochemistry relative to the 5-aryl group afforded compounds with increased cholesteryl ester transfer protein (CETP) inhibition potency and a robust in vivo effect on increasing HDL-C levels in transgenic mice expressing cynomolgus monkey CETP.

Discovery of novel tricyclic full agonists for the G-protein-coupled niacin receptor 109A with minimized flushing in rats.

Tricyclic analogues were rationally designed as the high affinity niacin receptor G-protein-coupled receptor 109A (GPR109A) agonists by overlapping three lead structures. Various tricyclic anthranilide and cycloalkene carboxylic acid full agonists were discovered with excellent in vitro activity. Compound 2g displayed a good therapeutic index regarding free fatty acids (FFA) reduction and vasodilation effects in rats, with very weak cytochrome P450 2C8 (CYP2C8) and cytochrome P450 2C9 (CYP2C9) inhibition, and a good mouse pharmacokinetics (PK) profile.

Total synthesis of 1-156,602, a novel cyclic hexadepsipeptide antibiotic

Abstract The total synthesis of the naturally occurring cyclic hexadepsipeptide antibiotic L-156,602 ( 1 ) is described.

2-Arylbenzoxazoles as CETP inhibitors: Substitution of the benzoxazole moiety

A series of 2-arylbenzoxazole inhibitors of the cholesterol ester transfer protein (CETP) is described. Structure-activity studies focused on variation of the substitution of the benzoxazole moiety. Substitution at the 5- and 7-positions of the benzoxazole moiety was found to be beneficial for CETP inhibition. Compound 47 was found to be the most potent inhibitor in this series and inhibited CETP with an IC(50) of 28nM.

Discovery of a Biaryl Cyclohexene Carboxylic Acid (MK-6892): A Potent and Selective High Affinity Niacin Receptor Full Agonist with Reduced Flushing Profiles in Animals as a Preclinical Candidate

Biaryl cyclohexene carboxylic acids were discovered as full and potent niacin receptor (GPR109A) agonists. Compound 1e (MK-6892) displayed excellent receptor activity, good PK across species, remarkably clean off-target profiles, good ancillary pharmacology, and superior therapeutic window over niacin regarding the FFA reduction versus vasodilation in rats and dogs.

(1aR,5aR)1a,3,5,5a-Tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic acid (MK-1903): a potent GPR109a agonist that lowers free fatty acids in humans.

G-protein coupled receptor (GPCR) GPR109a is a molecular target for nicotinic acid and is expressed in adipocytes, spleen, and immune cells. Nicotinic acid has long been used for the treatment of dyslipidemia due to its capacity to positively affect serum lipids to a greater extent than other currently marketed drugs. We report a series of tricyclic pyrazole carboxylic acids that are potent and selective agonists of GPR109a. Compound R,R-19a (MK-1903) was advanced through preclinical studies, was well tolerated, and presented no apparent safety concerns. Compound R,R-19a was advanced into a phase 1 clinical trial and produced a robust decrease in plasma free fatty acids. On the basis of these results, R,R-19a was evaluated in a phase 2 study in humans. Because R,R-19a produced only a weak effect on serum lipids as compared with niacin, we conclude that the beneficial effects of niacin are most likely the result of an undefined GPR109a independent pathway.

Side Chain Sar of Bicyclic Beta-Lactamase Inhibitors (Blis). 1. Discovery of a Class C Bli for Combination with Imipinem.

Bridged monobactam beta-lactamase inhibitors were prepared and evaluated as potential partners for combination with imipenem to overcome class C beta-lactamase mediated resistance. The (S)-azepine analog 2 was found to be effective in both in vitro and in vivo assays and was selected for preclinical development.