Discovery of 12 (BMS-986172) as a Highly Potent MGAT2 Inhibitor that Achieved Targeted Efficacious Exposures at a Low Human Dose for the Treatment of Metabolic Disorders.

A series of dihydropyridinone (DHP) compounds was prepared and evaluated for MGAT2 activity. The efforts led to the identification of novel tetrazolones with potent MGAT2 inhibitory activity and favorable in vitro profiles. Further tests of select analogues in mouse models revealed significant reduction in food intake and body weight. Subsequent studies in MGAT2 knockout mice with the lead candidate 12 (BMS-986172) showed on-target- and mechanism-based pharmacology. Moreover, its favorable pharmacokinetic (PK) profile and the lack of species variability in the glucuronidation potential resulted in a greater confidence level in the projection of a low dose for achieving targeted efficacious exposures in humans. Consistent with these projections, PK data from a phase 1 trial confirmed that targeted efficacious exposures could be achieved at a low dose in humans, which supported compound 12 as our second and potentially superior development candidate for the treatment of various metabolic disorders.

Discovery of novel pyridinones as MGAT2 inhibitors for the treatment of metabolic disorders.

Inhibition of monoacylglycerol transferase 2 (MGAT2) has recently emerged as a potential therapeutic strategy for the treatment of metabolic diseases such as obesity, diabetes and non-alcoholic steatohepatitis (NASH). Metabolism studies with our clinical lead (1) suggested variability in in vitro glucuronidation rates in liver microsomes across species, which made projection of human doses challenging. In addition, the observation of deconjugation of the C3-C4 double bond in the dihydropyridinone ring of 1 in solution had the potential to complicate its clinical development. This report describes our lead optimization efforts in a novel pyridinone series, exemplified by compound 33, which successfully addressed both of these potential issues.

Discovery of a Partial Glucokinase Activator Clinical Candidate: Diethyl ((3-(3-((5-(Azetidine-1-carbonyl)pyrazin-2-yl)oxy)-5-isopropoxybenzamido)-1H-pyrazol-1-yl)methyl)phosphonate (BMS-820132).

Glucokinase (GK) is a key regulator of glucose homeostasis, and its small-molecule activators represent a promising opportunity for the treatment of type 2 diabetes. Several GK activators have been advanced into clinical trials and have demonstrated promising efficacy; however, hypoglycemia represents a key risk for this mechanism. In an effort to mitigate this hypoglycemia risk while maintaining the efficacy of the GK mechanism, we have investigated a series of amino heteroaryl phosphonate benzamides as ''partial" GK activators. The structure-activity relationship studies starting from a "full GK activator" 11, which culminated in the discovery of the "partial GK activator" 31 (BMS-820132), are discussed. The synthesis and in vitro and in vivo preclinical pharmacology profiles of 31 and its pharmacokinetics (PK) are described. Based on its promising in vivo efficacy and preclinical ADME and safety profiles, 31 was advanced into human clinical trials.

Screening Hit to Clinical Candidate: Discovery of BMS-963272, a Potent, Selective MGAT2 Inhibitor for the Treatment of Metabolic Disorders.

MGAT2 inhibition is a potential therapeutic approach for the treatment of metabolic disorders. High-throughput screening of the BMS internal compound collection identified the aryl dihydropyridinone compound 1 (hMGAT2 IC50 = 175 nM) as a hit. Compound 1 had moderate potency against human MGAT2, was inactive vs mouse MGAT2 and had poor microsomal metabolic stability. A novel chemistry route was developed to synthesize aryl dihydropyridinone analogs to explore structure-activity relationship around this hit, leading to the discovery of potent and selective MGAT2 inhibitors 21f, 21s, and 28e that are stable to liver microsomal metabolism. After triaging out 21f due to its inferior in vivo potency, pharmacokinetics, and structure-based liabilities and tetrazole 28e due to its inferior channel liability profile, 21s (BMS-963272) was selected as the clinical candidate following demonstration of on-target weight loss efficacy in the diet-induced obese mouse model and an acceptable safety and tolerability profile in multiple preclinical species.

Gender-Related Differences in Flood Risk Perception and Behaviours among Private Groundwater Users in the Republic of Ireland.

Extreme weather events including flooding can have severe personal, infrastructural, and economic consequences, with recent evidence pointing to surface flooding as a pathway for the microbial contamination of private groundwater supplies. There is a pressing need for increasingly focused information and awareness campaigns to highlight the risks posed by extreme weather events and appropriate subsequent post-event actions. To date, little is known about the presence, directionality or magnitude of gender-related differences regarding flood risk awareness and behaviour among private groundwater users, a particularly susceptible sub-population due to an overarching paucity of infrastructural regulation across many regions. The current study investigated gender-related differences in flood risk perception and associated mitigation behaviours via a cross-sectional, national survey of 405 (168 female, 237 male) private groundwater supply users. The developed survey instrument assessed socio-demographic profile, previous flood experience, experiential and conjectural health behaviours (contingent on previous experience), and Risk, Attitude, Norms, Ability, Self-regulation (RANAS) framework questions. Statistically significant gender differences were found between both 'Norm-Descriptive' and 'Ability-Self-efficacy' RANAS elements (p < 0.05). Female respondents reported a lower level of awareness of the need for post-flood action(s) (8.9% vs. 16.5%), alongside a perceived "lack of information" as a reason for not testing their domestic well (4.9% vs. 11.5%). Conversely, male respondents were more likely to report awareness of their well location in relation to possible contamination sources (96.6% vs. 89.9%) and awareness of previous water testing results (98.9% vs. 93.0%). Gender-related gaps exist within the studied private groundwater reliant cohort, a sub-population which has to date remained under-studied within the context of climate change and extreme weather events. Accordingly, findings suggest that gender-focused communication and education may represent an effective tool for protecting current and future generations of global groundwater users.

Identification of RIPK3 Type II Inhibitors Using High-Throughput Mechanistic Studies in Hit Triage.

Necroptosis has been implicated in a variety of disease states, and RIPK3 is one of the kinases identified to play a critical role in this signaling pathway. In an effort to identify RIPK3 kinase inhibitors with a novel profile, mechanistic studies were incorporated at the hit triage stage. Utilization of these assays enabled identification of a Type II DFG-out inhibitor for RIPK3, which was confirmed by protein crystallography. Structure-based drug design on the inhibitors targeting this previously unreported conformation enabled an enhancement in selectivity against key off-target kinases.

Inhibition of AAK1 Kinase as a Novel Therapeutic Approach to Treat Neuropathic Pain.

To identify novel targets for neuropathic pain, 3097 mouse knockout lines were tested in acute and persistent pain behavior assays. One of the lines from this screen, which contained a null allele of the adapter protein-2 associated kinase 1 (AAK1) gene, had a normal response in acute pain assays (hot plate, phase I formalin), but a markedly reduced response to persistent pain in phase II formalin. AAK1 knockout mice also failed to develop tactile allodynia following the Chung procedure of spinal nerve ligation (SNL). Based on these findings, potent, small-molecule inhibitors of AAK1 were identified. Studies in mice showed that one such inhibitor, LP-935509, caused a reduced pain response in phase II formalin and reversed fully established pain behavior following the SNL procedure. Further studies showed that the inhibitor also reduced evoked pain responses in the rat chronic constriction injury (CCI) model and the rat streptozotocin model of diabetic peripheral neuropathy. Using a nonbrain-penetrant AAK1 inhibitor and local administration of an AAK1 inhibitor, the relevant pool of AAK1 for antineuropathic action was found to be in the spinal cord. Consistent with these results, AAK1 inhibitors dose-dependently reduced the increased spontaneous neural activity in the spinal cord caused by CCI and blocked the development of windup induced by repeated electrical stimulation of the paw. The mechanism of AAK1 antinociception was further investigated with inhibitors of α2 adrenergic and opioid receptors. These studies showed that α2 adrenergic receptor inhibitors, but not opioid receptor inhibitors, not only prevented AAK1 inhibitor antineuropathic action in behavioral assays, but also blocked the AAK1 inhibitor-induced reduction in spinal neural activity in the rat CCI model. Hence, AAK1 inhibitors are a novel therapeutic approach to neuropathic pain with activity in animal models that is mechanistically linked (behaviorally and electrophysiologically) to α2 adrenergic signaling, a pathway known to be antinociceptive in humans.

Discovery and Preclinical Evaluation of BMS-711939, an Oxybenzylglycine Based PPARα Selective Agonist.

BMS-711939 (3) is a potent and selective peroxisome proliferator-activated receptor (PPAR) α agonist, with an EC50 of 4 nM for human PPARα and >1000-fold selectivity vs human PPARγ (EC50 = 4.5 µM) and PPARδ (EC50 > 100 µM) in PPAR-GAL4 transactivation assays. Compound 3 also demonstrated excellent in vivo efficacy and safety profiles in preclinical studies and thus was chosen for further preclinical evaluation. The synthesis, structure-activity relationship (SAR) studies, and in vivo pharmacology of 3 in preclinical animal models as well as its ADME profile are described.

Screening for Peripheral Arterial Disease and Carotid Artery Disease in Patients With Abdominal Aortic Aneurysm.

Screening for concomitant atherosclerotic disease is important in cardiovascular risk reduction. This study assessed the prevalence of carotid artery disease (CAD) and peripheral arterial disease (PAD) in patients with known abdominal aortic aneurysms (AAAs). All patients with AAA attending the vascular laboratory between the January 1, 2007, and December 31, 2009, were eligible for a carotid ultrasound and measurement of ankle brachial indices. A total of 389 (305 males) patients were identified on the AAA surveillance program with a mean (±standard deviation) age of 76 (±8) years. The mean age of the males was 75.4 (±7.8) years, and the mean age of the females was 77 (±11) years. A total of 332 patients were assessed for CAD, and 101 (30.4%) of those were found to have significant disease. A total of 289 patients were assessed for PAD of which 131 (45.3%) were found to have PAD at rest, and 289 patients were assessed for both and 59 (20.4%) patients had significant CAD + PAD. Patients with AAAs are at high risk of other atherosclerotic disorders, and, therefore, they should receive intensive medical optimization.

Inhibition by stabilization: targeting the Plasmodium falciparum aldolase-TRAP complex.

BACKGROUND: Emerging resistance of the malaria parasite Plasmodium to current therapies underscores the critical importance of exploring novel strategies for disease eradication. Plasmodium species are obligate intracellular protozoan parasites. They rely on an unusual form of substrate-dependent motility for their migration on and across host-cell membranes and for host cell invasion. This peculiar motility mechanism is driven by the 'glideosome', an actin-myosin associated, macromolecular complex anchored to the inner membrane complex of the parasite. Myosin A, actin, aldolase, and thrombospondin-related anonymous protein (TRAP) constitute the molecular core of the glideosome in the sporozoite, the mosquito stage that brings the infection into mammals. METHODS: Virtual library screening of a large compound library against the PfAldolase-TRAP complex was used to identify candidate compounds that stabilize and prevent the disassembly of the glideosome. The mechanism of these compounds was confirmed by biochemical, biophysical and parasitological methods. RESULTS: A novel inhibitory effect on the parasite was achieved by stabilizing a protein-protein interaction within the glideosome components. Compound 24 disrupts the gliding and invasive capabilities of Plasmodium parasites in in vitro parasite assays. A high-resolution, ternary X-ray crystal structure of PfAldolase-TRAP in complex with compound 24 confirms the mode of interaction and serves as a platform for future ligand optimization. CONCLUSION: This proof-of-concept study presents a novel approach to anti-malarial drug discovery and design. By strengthening a protein-protein interaction within the parasite, an avenue towards inhibiting a previously "undruggable" target is revealed and the motility motor responsible for successful invasion of host cells is rendered inactive. This study provides new insights into the malaria parasite cell invasion machinery and convincingly demonstrates that liver cell invasion is dramatically reduced by 95 % in the presence of the small molecule stabilizer compound 24.

Synthesis and biological evaluation of novel pyrrolidine acid analogs as potent dual PPARα/γ agonists.

The design, synthesis and structure-activity relationships of a novel series of 3,4-disubstituted pyrrolidine acid analogs as PPAR ligands is outlined. In both the 1,3- and 1,4-oxybenzyl pyrrolidine acid series, the preferred stereochemistry was shown to be the cis-3R,4S isomer, as exemplified by the potent dual PPARα/γ agonists 3k and 4i. The N-4-trifluoromethyl-pyrimidinyl pyrrolidine acid analog 4i was efficacious in lowering fasting glucose and triglyceride levels in diabetic db/db mice.

Serum lipids associated with inflammation-related PET-FDG uptake in symptomatic carotid plaque.

OBJECTIVE: We hypothesized that serum lipids, which experimental data suggest may be key initiators of carotid plaque inflammation, would be associated with plaque inflammation on (18)fluorodeoxyglucose (FDG)-PET in patients with acutely symptomatic carotid stenosis. METHODS: In this cohort study, consecutive patients with acute symptomatic internal carotid artery (ICA) stenosis (≥50%) underwent carotid PET-CT. We quantified plaque FDG uptake as follows: (1) average maximum standardized uptake values (SUVmax) across 10 regions of interest (ROI); (2) highest single ROI SUV measure (SUVROImax); (3) averaged mean SUV across 10 ROIs (SUVmean). RESULTS: Sixty-one patients were included. Plaque inflammatory FDG SUVmax was associated with increasing tertiles of low-density lipoprotein (LDL) (trend p = 0.004), total cholesterol (p = 0.009), and triglycerides (p = 0.01), and with lower high-density lipoprotein (HDL) (p = 0.005). When analyzed as a continuous variable, LDL was associated with symptomatic ICA SUVmean (Spearman rho 0.44, p = 0.009), SUVROImax (rho 0.33, p = 0.01), and SUVmax (rho 0.35, p = 0.06). Total cholesterol was associated with SUVmean (rho 0.33, p = 0.009), with trends for SUVmax (rho 0.24, p = 0.059) and SUVROImax (rho 0.23, p = 0.08). Triglycerides were associated with SUVmax (rho 0.32, p = 0.01) and SUVROImax (rho 0.35, p = 0.005). HDL was associated with lower SUVmax (rho -0.37, p = 0.004) and SUVROImax (rho -0.44, p = 0.0004). On multivariable linear regression analysis adjusting for age, sex, degree of carotid stenosis, statins, and smoking, LDL (p = 0.008) and total cholesterol (p = 0.04) were independently associated with SUVmax. CONCLUSION: Serum LDL and total cholesterol were associated with acutely symptomatic carotid plaque FDG uptake, supporting experimental data suggesting lipids may promote plaque inflammation, mediating rupture and clinical events.

Carotid plaque inflammation on 18F-fluorodeoxyglucose positron emission tomography predicts early stroke recurrence.

OBJECTIVE: Symptomatic carotid stenosis is associated with a 3-fold risk of early stroke recurrence compared to other stroke subtypes. Current carotid imaging techniques rely on estimating plaque-related lumen narrowing but do not evaluate intraplaque inflammation, a key mediator of plaque rupture and thromboembolism. Using combined (18) F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography, we investigated the relation between inflammation-related FDG uptake and stroke recurrence. METHODS: Consecutive patients with a recent (median, 6.5 days; interquartile range, 4-8) stroke, transient ischemic attack (TIA), or retinal embolism and ipsilateral carotid stenosis (≥50%) were included. FDG uptake was quantified as mean standardized uptake values (SUVs, g/ml). Patients were followed prospectively for stroke recurrence. RESULTS: Sixty patients were included (25 stroke, 29 TIA, 6 retinal embolism). Twenty-two percent (13 of 60) had stroke recurrence within 90 days. FDG uptake in ipsilateral carotid plaque was greater in patients with early recurrent stroke (mean SUV, 1.85 g/ml; standard deviation [SD], 0.44 vs 1.58 g/ml; SD, 0.32, p = 0.02). On life-table analysis, 90-day recurrence rates with mean SUV greater than a 2.14 g/ml threshold were 80% (95% confidence interval [CI], 41.8-99.2) versus 22.9% (95% CI, 12.3-40.3) with SUV ≤2.14 g/ml (log-rank, p < 0.0001). In a Cox regression model including age and degree of stenosis (50-69% or ≥70%), mean plaque FDG uptake was the only independent predictor of stroke recurrence (adjusted hazard ratio, 6.1; 95% CI, 1.3-28.8; p = 0.02). INTERPRETATION: In recently symptomatic carotid stenosis, inflammation-related FDG uptake was associated with early stroke recurrence, independent of the degree of stenosis. Plaque FDG-PET may identify patients at highest risk for stroke recurrence, who may be selected for immediate revascularization or intensive medical treatment.

Molecular chaperone function for myocilin.

PURPOSE: Myocilin is thought to be a stress response protein, but its exact molecular functions have not been established. Studies were conducted to see whether myocilin can act as a general molecular chaperone. METHODS: Myocilin was isolated and purified from porcine trabecular meshwork (TM) cell culture media. Its ability to protect citrate synthase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the restriction endonuclease DrdI from thermal inactivation was evaluated. Light scattering was used to evaluate thermally induced aggregation of citrate synthase. Myocilin induction was assessed after exposure of TM cells to several types of stress treatments. RESULTS: Levels of extracellular myocilin expressed by TM cells were increased in response to mechanical stretch, heat shock, TNFα, or IL-1α. Myocilin protected citrate synthase activity against thermal inactivation for 5 minutes at 55°C in a concentration-dependent manner, with nearly full protection of 1.5 µM citrate synthase in the presence of 650 nM myocilin. Myocilin significantly reduced thermal aggregation of citrate synthase to levels 36% to 44% of control levels. Myocilin also protected GAPDH from thermal inactivation for 10 minutes at 45°C. Myocilin at 18 nM was more effective than 1 µM bovine serum albumin at protecting DrdI from thermal inactivation. CONCLUSIONS: Myocilin is induced in response to several cellular stresses and displays general molecular chaperone activity by protecting DrdI, citrate synthase, and GAPDH from thermal inactivation. Myocilin also suppresses the thermal aggregation of citrate synthase. One function of myocilin may be to serve as a molecular chaperone.

Synthesis and structure-activity relationships of 2-aryl-4-oxazolylmethoxy benzylglycines and 2-aryl-4-thiazolylmethoxy benzylglycines as novel, potent PPARalpha selective activators- PPARalpha and PPARgamma selectivity modulation.

The synthesis and follow-up SAR studies of our development candidate 1 by incorporating 2-aryl-4-oxazolylmethoxy and 2-aryl-4-thiazolylmethoxy moieties into the oxybenzylglycine framework of the PPARalpha/gamma dual agonist muraglitazar is described. SAR studies indicate that different substituents on the aryloxazole/thiazole moieties as well as the choice of carbamate substituent on the glycine moiety can significantly modulate the selectivity of PPARalpha versus PPARgamma. Potent, highly selective PPARalpha activators 2a and 2l, as well as PPARalpha activators with significant PPARgamma activity, such as 2s, were identified. The in vivo pharmacology of these compounds in preclinical animal models as well as their ADME profiles are discussed.

Discovery of an oxybenzylglycine based peroxisome proliferator activated receptor alpha selective agonist 2-((3-((2-(4-chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic acid (BMS-687453).

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) alpha agonist, with an EC(50) of 10 nM for human PPARalpha and approximately 410-fold selectivity vs human PPARgamma in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPARdelta. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPARalpha ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPARalpha in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

Design, synthesis and structure-activity relationships of azole acids as novel, potent dual PPAR alpha/gamma agonists.

The design, synthesis and structure-activity relationships of a novel series of N-phenyl-substituted pyrrole, 1,2-pyrazole and 1,2,3-triazole acid analogs as PPAR ligands are outlined. The triazole acid analogs 3f and 4f were identified as potent dual PPARalpha/gamma agonists both in binding and functional assays in vitro. The 3-oxybenzyl triazole acetic acid analog 3f showed excellent glucose and triglyceride lowering in diabetic db/db mice.

The management of mycotic femoral pseudoaneurysms in intravenous drug abusers.

Mycotic femoral pseudoaneurysms, particularly in the drug-abusing population, pose a difficult problem to the vascular surgeon. Management ranges from ligation with debridement to extra-anatomical bypass. This study reviewed the management of mycotic femoral pseudoaneurysms presenting in intravenous drug abusers to an inner city tertiary referral center. Between 2001 and 2006, 11 cases presenting in nine patients were treated. The mean age was 30.7 years with a male-to-female ratio of 1:2. Eight patients had a positive viral status for the human immunodeficiency virus and/or hepatitis C. Two patients re-presented with a contralateral pseudoaneurysm. A combination of groin pain and swelling was the most common presentation. Two patients presented with significant hemorrhage. The diagnosis was confirmed by ultrasound in the majority of cases. Nine cases were managed with arterial ligation and debridement of the necrotic tissue. The two remaining cases were managed with ultrasound-guided thrombin injection and arterial puncture closure. On follow-up, one patient required a below-knee amputation following reinjection into the postoperative wound site. One further patient underwent a fifth metatarsal amputation due to ischemia. Ligation and debridement are well tolerated in the majority of drug-abusing patients diagnosed with mycotic femoral pseudoaneurysms.