Discovery of MK-1439, an orally bioavailable non-nucleoside reverse transcriptase inhibitor potent against a wide range of resistant mutant HIV viruses.

The optimization of a novel series of non-nucleoside reverse transcriptase inhibitors (NNRTI) led to the identification of pyridone 36. In cell cultures, this new NNRTI shows a superior potency profile against a range of wild type and clinically relevant, resistant mutant HIV viruses. The overall favorable preclinical pharmacokinetic profile of 36 led to the prediction of a once daily low dose regimen in human.

In vitro characterization of MK-1439, a novel HIV-1 nonnucleoside reverse transcriptase inhibitor.

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) are a mainstay of therapy for treating human immunodeficiency type 1 virus (HIV-1)-infected patients. MK-1439 is a novel NNRTI with a 50% inhibitory concentration (IC50) of 12, 9.7, and 9.

Design and synthesis of potent, isoxazole-containing renin inhibitors.

The design and optimization of a novel isoxazole S(1) linker for renin inhibitor is described herein. This effort culminated in the identification of compound 18, an orally bioavailable, sub-nanomolar renin inhibitor even in the presence of human plasma. When compound 18 was found to inhibit CYP3A4 in a time dependent manner, two strategies were pursued that successfully delivered equipotent compounds with minimal TDI potential.

Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of spirocyclic piperidines.

The discovery and SAR of a novel series of spirocyclic renin inhibitors are described herein. It was found that by restricting the northern aromatic plate to the bioactive conformation through spirocyclization, increase in renin potency and decrease in hERG affinity could both be realized. When early members of this series were found to be potent time-dependent CYP3A4 inhibitors, two distinct strategies to address this liability were explored and this effort culminated in the identification of compound 31 as an optimized renin inhibitor.

Impact of passive permeability and gut efflux transport on the oral bioavailability of novel series of piperidine-based renin inhibitors in rodents.

An oral bioavailability issue encountered during the course of lead optimization in the renin program is described herein. The low F(po) of pyridone analogs was shown to be caused by a combination of poor passive permeability and gut efflux transport. Substitution of pyridone ring for a more lipophilic moiety (logD>1.

Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of tertiary alcohol-bearing piperidines.

The design and optimization of a novel series of renin inhibitor is described herein. Strategically, by committing the necessary resources to the development of synthetic sequences and scaffolds that were most amenable for late stage structural diversification, even as the focus of the SAR campaign moved from one end of the molecule to another, highly potent renin inhibitors could be rapidly identified and profiled.

Renin inhibitors for the treatment of hypertension: design and optimization of a novel series of pyridone-substituted piperidines.

An SAR campaign aimed at decreasing the overall lipophilicity of renin inhibitors such as 1 is described herein. It was found that replacement of the northern appendage in 1 with an N-methyl pyridone and subsequent re-optimization of the benzyl amide handle afforded compounds with in vitro and in vivo profiles suitable for further profiling. An unexpected CV toxicity in dogs observed with compound 20 led to the employment of a time and resource sparing rodent model for in vivo screening of key compounds.

Trisubstituted ureas as potent and selective mPGES-1 inhibitors.

A novel series of trisubstituted ureas has been identified as potent and selective mPGES-1 inhibitors. These compounds are selective over other prostanoid enzymes such as PGF synthase and TX synthase. This series of inhibitors was developed by lead optimization of a hit from an internal HTS campaign.

Naphthalene/quinoline amides and sulfonylureas as potent and selective antagonists of the EP4 receptor.

Two new series of EP(4) antagonists based on naphthalene/quinoline scaffolds have been identified as part of our on-going efforts to develop treatments for inflammatory pain. One series contains an acidic sulfonylurea pharmacophore, whereas the other is a neutral amide. Both series show subnanomolar intrinsic binding potency towards the EP(4) receptor, and excellent selectivity towards other prostanoid receptors.

Discovery of MK-7246, a selective CRTH2 antagonist for the treatment of respiratory diseases.

In this manuscript we wish to report the discovery of MK-7246 (4), a potent and selective CRTH2 (DP2) antagonist. SAR studies leading to MK-7246 along with two synthetic sequences enabling the preparation of this novel class of CRTH2 antagonist are reported. Finally, the pharmacokinetic and metabolic profile of MK-7246 is disclosed.

Biarylimidazoles as inhibitors of microsomal prostaglandin E2 synthase-1.

Microsomal prostaglandin E(2) synthase (mPGES-1) represents a potential target for novel analgesic and anti-inflammatory agents. High-throughput screening identified several leads of mPGES-1 inhibitors which were further optimized for potency and selectivity. A series of inhibitors bearing a biaryl imidazole scaffold exhibits excellent inhibition of PGE(2) production in enzymatic and cell-based assays.

The discovery of setileuton, a potent and selective 5-lipoxygenase inhibitor.

The discovery of novel and selective inhibitors of human 5-lipoxygenase (5-LO) is described. These compounds are potent, orally bioavailable, and active at inhibiting leukotriene biosynthesis in vivo in a dog PK/PD model. A major focus of the optimization process was to reduce affinity for the human ether-a-go-go gene potassium channel while preserving inhibitory potency on 5-LO.

Discovery of 4-[1-[([1-[4-(trifluoromethyl)benzyl]-1H-indol-7-yl]carbonyl)amino]cyclopropyl]benzoic acid (MF-766), a highly potent and selective EP4 antagonist for treating inflammatory pain.

The discovery of a highly potent and selective EP(4) antagonist MF-766 is discussed. This N-benzyl indole derivative exhibits good pharmacokinetic profile and unprecedented in vivo potency in the rat AIA model.

The discovery of 4-{1-[({2,5-dimethyl-4-[4-(trifluoromethyl)benzyl]-3-thienyl}carbonyl)amino]cyclopropyl}benzoic acid (MK-2894), a potent and selective prostaglandin E2 subtype 4 receptor antagonist.

The discovery of highly potent and selective second generation EP(4) antagonist MK-2894 (34d) is discussed. This compound exhibits favorable pharmacokinetic profile in a number of preclinical species and potent anti-inflammatory activity in several animal models of pain/inflammation. It also shows favorable GI tolerability profile in rats when compared to traditional NSAID indomethacin.

Discovery of disubstituted phenanthrene imidazoles as potent, selective and orally active mPGES-1 inhibitors.

Phenanthrene imidazoles 26 and 44 have been identified as novel potent, selective and orally active mPGES-1 inhibitors. These inhibitors are significantly more potent than the previously reported chlorophenanthrene imidazole 1 (MF63) with a human whole blood IC50 of 0.20 and 0.

MF63 [2-(6-chloro-1H-phenanthro[9,10-d]imidazol-2-yl)-isophthalonitrile], a selective microsomal prostaglandin E synthase-1 inhibitor, relieves pyresis and pain in preclinical models of inflammation.

Microsomal prostaglandin E synthase-1 (mPGES-1) is a terminal prostaglandin E(2) (PGE(2)) synthase in the cyclooxygenase pathway. Inhibitors of mPGES-1 may block PGE(2) production and relieve inflammatory symptoms. To test the hypothesis, we evaluated the antipyretic and analgesic properties of a novel and selective mPGES-1 inhibitor, MF63 [2-(6-chloro-1H-phenanthro-[9,10-d]imidazol-2-yl)isophthalonitrile], in animal models of inflammation.

Substituted phenanthrene imidazoles as potent, selective, and orally active mPGES-1 inhibitors.

Phenanthrene imidazole 3 (MF63) has been identified as a novel potent, selective, and orally active mPGES-1 inhibitor. This new series was developed by lead optimization of a hit from an internal HTS campaign. Compound 3 is significantly more potent than the previously reported indole carboxylic acid 1 with an A549 whole cell IC(50) of 0.

Pharmacological characterization of a selective COX-2 inhibitor MF-tricyclic, [3-(3,4-difluorophenyl)-4-(4-(methylsulfonyl)phenyl)-2-(5H)-furanone], in multiple preclinical species.

Selective type 2 cyclooxygenase (COX-2) inhibitors are often used in preclinical studies without potency and selectivity data in the experimental species. To address this issue, we assessed a selective COX-2 inhibitor MF-tricyclic in four commonly used species, namely mice, rats, guinea pigs and rabbits, in the present study. In both the guinea pig and rabbit whole blood assay, the compound inhibited lipopolysaccharide (LPS)-induced PGE(2) production with an IC(50) (COX-2) of 0.

Substituted coumarins as potent 5-lipoxygenase inhibitors.

Leukotriene biosynthesis inhibitors have potential as therapeutic agents for asthma and inflammatory diseases. A novel series of substituted coumarin derivatives has been synthesized and the structure-activity relationship was evaluated with respect to their ability to inhibit the formation of leukotrienes via the human 5-lipoxygenase enzyme.

The C3a receptor antagonist SB 290157 has agonist activity.

The anaphylatoxin C3a is an important immune regulator with a number of distinct functions in both innate and adaptive immunity. Many of these roles have been ascribed to C3a based on studies in mice genetically modified to lack its precursor, C3, or its receptor, C3aR. However, other presumed functions of C3a are based on results obtained with a recently described small molecule ligand of C3aR, SB 290157.

2,3-Diarylthiophenes as selective EP1 receptor antagonists.

The synthesis and the EP(1) receptor binding affinity of 2,3-diarylthiophene derivatives are described. The evaluation of the structure-activity relationship (SAR) in this series led to the identification of compounds 4, 7, and 12a, which exhibit high affinity for the human EP(1) receptor and a selectivity greater than 100-fold against the EP(2), EP(3), EP(4), DP, FP, and IP receptors and greater than 25-fold versus the TP receptor. These three antagonists present good pharmacokinetics in rats and significant differences in the way they are distributed in the brain.

Optimization of a tertiary alcohol series of phosphodiesterase-4 (PDE4) inhibitors: structure-activity relationship related to PDE4 inhibition and human ether-a-go-go related gene potassium channel binding affinity.

A SAR study on the tertiary alcohol series of phosphodiesterase-4 (PDE4) inhibitors related to 1 is described. In addition to inhibitory potency against PDE4 and the lipopolysaccharide-induced production of TNFalpha in human whole blood, the binding affinity of these compounds for the human ether-a-go-go related gene (hERG) potassium channel (an in vitro measure for the potential to cause QTc prolongation) was assessed. Four key structural moieties in the molecule were studied, and the impact of the resulting modifications in modulating these activities was evaluated.

Substituted 2-pyridinemethanol derivatives as potent and selective phosphodiesterase-4 inhibitors.

The synthesis and the phosphodiesterase-4 (PDE4) inhibitory activity of 2-pyridinemethanol derivatives is described. The evaluation of the structure-activity relationship (SAR) in this series of novel PDE4 inhibitors led to the identification of compound 9 which exhibits excellent in vitro activity, desirable pharmacokinetic parameters and good efficacy in animal models of bronchoconstriction.

Substituted aminopyridines as potent and selective phosphodiesterase-4 inhibitors.

The synthesis and the biological evaluation of new potent phosphodiesterase type 4 (PDE4) inhibitors are presented. This new series was elaborated by replacement of the metabolically resistant phenyl hexafluorocarbinol of L-791,943 (1) by a substituted aminopyridine residue. The structure-activity relationship of N-substitution on 3 led to the identification of (-)-3n which exhibited a good PDE4 inhibitor activity (HWB-TNFalpha=0.

Substituted 4-(2,2-diphenylethyl)pyridine-N-oxides as phosphodiesterase-4 inhibitors: SAR study directed toward the improvement of pharmacokinetic parameters.

A detailed SAR study directed toward the optimization of pharmacokinetic parameters for analogues of L-791,943 is reported. The introduction of a soft metabolic site on this structure permitted the identification of L-826,141 as a potent phosphodiesterase type 4 (PDE4) inhibitor that is well absorbed and that presents a shorter half-life than L-791,943 in a variety of animal species. The efficacy of L-826,141 is also demonstrated in different in vivo models.