Development of novel cytoprotective small compounds inhibiting mitochondria-dependent cell death.

We identified cytoprotective small molecules (CSMs) by a cell-based high-throughput screening of Bax inhibitors. Through a medicinal chemistry program, M109S was developed, which is orally bioactive and penetrates the blood-brain/retina barriers. M109S protected retinal cells in ocular disease mouse models.

Exploring the inhibition of the soluble lytic transglycosylase Cj0843c of Campylobacter jejuni via targeting different sites with different scaffolds.

Bacterial lytic transglycosylases (LTs) contribute to peptidoglycan cell wall metabolism and are potential drug targets to potentiate β-lactam antibiotics to overcome antibiotic resistance. Since LT inhibitor development is underexplored, we probed 15 N-acetyl-containing heterocycles in a structure-guided fashion for their ability to inhibit and bind to the Campylobacter jejuni LT Cj0843c. Ten GlcNAc analogs were synthesized with substitutions at the C1 position, with two having an additional modification at the C4 or C6 position.

Identification of a Selective SCoR2 Inhibitor That Protects Against Acute Kidney Injury.

Acute kidney injury (AKI) is associated with high morbidity and mortality, and no drugs are available clinically. Metabolic reprogramming resulting from the deletion of S-nitroso-coenzyme A reductase 2 (SCoR2; AKR1A1) protects mice against AKI, identifying SCoR2 as a potential drug target. Of the few known inhibitors of SCoR2, none are selective versus the related oxidoreductase AKR1B1, limiting therapeutic utility.

Structure-based design of selective, orally available salt-inducible kinase inhibitors that stimulate bone formation in mice.

Osteoporosis is a major public health problem. Currently, there are no orally available therapies that increase bone formation. Intermittent parathyroid hormone (PTH) stimulates bone formation through a signal transduction pathway that involves inhibition of salt-inducible kinase isoforms 2 and 3 (SIK2 and SIK3).

Lead Optimization to Advance Protease-Activated Receptor-1 Antagonists in Early Discovery.

Vorapaxar is an approved drug for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction or with peripheral arterial disease. Subsequent to the discovery of Vorapaxar, medicinal chemistry efforts were continued to identify structurally differentiated leads. Toward this goal, extensive structure-activity relationship studies using a C-ring-truncated version of Vorapaxar culminated in the discovery of three leads, represented as , , and .

Discovery of hydroxy pyrimidine Factor IXa inhibitors.

The synthesis and structure activity relationship development of a pyrimidine series of heterocyclic Factor IXa inhibitors is described. Increased selectivity over Factor Xa inhibition was achieved through SAR expansion of the P1 element. Select compounds were evaluated in vivo to assess their plasma levels in rat.

Discovery of MK-8282 as a Potent G-Protein-Coupled Receptor 119 Agonist for the Treatment of Type 2 Diabetes.

The ever-growing prevalence of type 2 diabetes in the world has necessitated an urgent need for multiple orally effective agents that can regulate glucose homeostasis with a concurrent reduction in body weight. G-Protein coupled receptor 119 (GPR119) is a GPCR target at which agonists have demonstrated glucose-dependent insulin secretion and shows beneficial effects on glycemic control. Herein, we describe our efforts leading to the identification of a potent, oral GPR-119 agonist, MK-8282, which shows improved glucose tolerance in multiple animal models and has excellent off-target profile.

Discovery of a Tetrahydrobenzisoxazole Series of γ-Secretase Modulators.

The design and synthesis of a new series of tetrahydrobenzisoxazoles as modulators of γ-secretase activity and their structure-activity relationship (SAR) will be detailed. Several compounds are active γ-secretase modulators (GSMs) with good to excellent selectivity for the reduction of Aβ in the cellular assay. Compound was tested in a nontransgenic rat model and was found to significantly reduce Aβ in the CNS compartment compared to vehicle-treated animals (up to 58% reduction of cerebrospinal fluid Aβ as measured 3 h after an acute oral dosing at 30 mg/kg).

Discovery of the 3-Imino-1,2,4-thiadiazinane 1,1-Dioxide Derivative Verubecestat (MK-8931)-A β-Site Amyloid Precursor Protein Cleaving Enzyme 1 Inhibitor for the Treatment of Alzheimer's Disease.

Verubecestat 3 (MK-8931), a diaryl amide-substituted 3-imino-1,2,4-thiadiazinane 1,1-dioxide derivative, is a high-affinity β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor currently undergoing Phase 3 clinical evaluation for the treatment of mild to moderate and prodromal Alzheimer's disease. Although not selective over the closely related aspartyl protease BACE2, verubecestat has high selectivity for BACE1 over other key aspartyl proteases, notably cathepsin D, and profoundly lowers CSF and brain Aβ levels in rats and nonhuman primates and CSF Aβ levels in humans. In this annotation, we describe the discovery of 3, including design, validation, and selected SAR around the novel iminothiadiazinane dioxide core as well as aspects of its preclinical and Phase 1 clinical characterization.

Design and synthesis of water soluble β-aminosulfone analogues of SCH 900229 as γ-secretase inhibitors.

In this paper we describe our strategy to improve the aqueous solubility of SCH 900229, a potent PS1-selective γ-secretase inhibitor for the treatment of Alzheimer's disease. Incorporation of ionizable amino groups into the side chain terminal generates water soluble β-aminosulfone analogues of SCH 900229 that maintain robust in vitro potency and in vivo efficacy.

Structure-Based Design of an Iminoheterocyclic β-Site Amyloid Precursor Protein Cleaving Enzyme (BACE) Inhibitor that Lowers Central Aβ in Nonhuman Primates.

We describe successful efforts to optimize the in vivo profile and address off-target liabilities of a series of BACE1 inhibitors represented by 6 that embodies the recently validated fused pyrrolidine iminopyrimidinone scaffold. Employing structure-based design, truncation of the cyanophenyl group of 6 that binds in the S3 pocket of BACE1 followed by modification of the thienyl group in S1 was pursued. Optimization of the pyrimidine substituent that binds in the S2'-S2″ pocket of BACE1 remediated time-dependent CYP3A4 inhibition of earlier analogues in this series and imparted high BACE1 affinity.

Discovery of the oxazabicyclo[3.3.1]nonane derivatives as potent and orally active GPR119 agonists.

The design and synthesis of two conformationally restricted oxazabicyclo octane derivatives as GRP119 agonists is described. Derivatives of scaffold C, with syn configuration, have the best overall profiles with respect to solubility and in vivo efficacy. Compound 25a was found to have extremely potent agonistic activity and was orally active in lowering blood glucose levels in a mouse oral glucose tolerance test at a dose of 0.

Initial optimization and series evolution of diaminopyrimidine inhibitors of interleukin-1 receptor associated kinase 4.

IRAK4 plays a key role in TLR/IL-1 signaling. Previous efforts identified a series of aminopyrimidine IRAK4 inhibitors that possess good potency, but modest kinase selectivity. Exploration of substituents at the C-2 and C-5 positions generated compounds that maintained IRAK4 potency and improved kinase selectivity.

Rapid development of two factor IXa inhibitors from hit to lead.

Two high-throughput screening hits were investigated for SAR against human factor IXa. Both hits feature a benzamide linked to a [6-5]-heteroaryl via an alkyl amine. In the case where this system is a benzimidazolyl-ethyl amine the binding potency for the hit was improved >500-fold, from 9 μM to 0.

Discovery and hit-to-lead optimization of 2,6-diaminopyrimidine inhibitors of interleukin-1 receptor-associated kinase 4.

Interleukin receptor-associated kinase 4 (IRAK4) is a critical element of the Toll-like/interleukin-1 receptor inflammation signaling pathway. A screening campaign identified a novel diaminopyrimidine hit that exhibits weak IRAK4 inhibitory activity and a ligand efficiency of 0.25.

Iminopyrimidinones: a novel pharmacophore for the development of orally active renin inhibitors.

The development of renin inhibitors with favorable oral pharmacokinetic profiles has been a longstanding challenge for the pharmaceutical industry. As part of our work to identify inhibitors of BACE1, we have previously developed iminopyrimidinones as a novel pharmacophore for aspartyl protease inhibition. In this letter we describe how we modified substitution around this pharmacophore to develop a potent, selective and orally active renin inhibitor.

Himbacine-derived thrombin receptor antagonists: c7-spirocyclic analogues of vorapaxar.

We have synthesized several C7-spirocyclic analogues of vorapaxar and evaluated their in vitro activities against PAR-1 receptor. Some of these analogues showed activities and rat plasma levels comparable to vorapaxar. Compound 5c from this series showed excellent PAR-1 activity (K i = 5.

Himbacine-derived thrombin receptor antagonists: c7-aminomethyl and c9a-hydroxy analogues of vorapaxar.

We have synthesized several C7-aminomethyl analogues of vorapaxar that are potent PAR-1 antagonists. Many of these analogues showed excellent in vitro binding affinity and pharmacokinetics profile in rats. Compound 6a from this series showed excellent PAR-1 activity (K i = 5 nM).

The discovery of N-((2H-tetrazol-5-yl)methyl)-4-((R)-1-((5r,8R)-8-(tert-butyl)-3-(3,5-dichlorophenyl)-2-oxo-1,4-diazaspiro[4.5]dec-3-en-1-yl)-4,4-dimethylpentyl)benzamide (SCH 900822): a potent and selective glucagon receptor antagonist.

A novel series of spiroimidazolone-based antagonists of the human glucagon receptor (hGCGR) has been developed. Our efforts have led to compound 1, N-((2H-tetrazol-5-yl)methyl)-4-((R)-1-((5r,8R)-8-(tert-butyl)-3-(3,5-dichlorophenyl)-2-oxo-1,4-diazaspiro[4.5]dec-3-en-1-yl)-4,4-dimethylpentyl)benzamide (SCH 900822), a potent hGCGR antagonist with exceptional selectivity over the human glucagon-like peptide-1 receptor.

Drug discovery and development in the field of cardiovascular disease. An interview with Dr William Greenlee by Alexandra Hemsley.

William Greenlee, the founder and president of MedChem Discovery Consulting LLC, has over three decades of research experience in industry at Merck Research Laboratories and the Schering-Plough Research Institute. He has contributed to the advancement of 20 drug candidates into preclinical development, 11 of which have progressed into clinical studies. Dr Greenlee was a member of the team that discovered the marketed drugs Vasotec™ and Prinivil™, and has led research teams that discovered several drug candidates that are now in clinical trials.

Discovery of an Orally Available, Brain Penetrant BACE1 Inhibitor that Affords Robust CNS Aβ Reduction.

Inhibition of BACE1 to prevent brain Aβ peptide formation is a potential disease-modifying approach to the treatment of Alzheimer's disease. Despite over a decade of drug discovery efforts, the identification of brain-penetrant BACE1 inhibitors that substantially lower CNS Aβ levels following systemic administration remains challenging. In this report we describe structure-based optimization of a series of brain-penetrant BACE1 inhibitors derived from an iminopyrimidinone scaffold.

A-ring modification of SCH 900229 and related chromene sulfone γ-secretase inhibitors.

Attempts to block metabolism by incorporating a 9-fluoro substituent at the A-ring of compound 1 (SCH 900229) using electrophilic Selectfluor™ led to an unexpected oxidation of the A-ring to give difluoroquinone analog 1a. Oxidation of other related chromene γ-secretase inhibitors 2-8 resulted in similar difluoroquinone analogs 2a-8a, respectively. These quinone products exhibited comparable in vitro potency in a γ-scretase membrane assay, but were several fold less potent in a cell-based assay in lowering Aβ40-42, compared to their parent compounds.