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Importance: Spinal cord stimulators (SCSs) are increasingly used for the treatment of chronic pain. There is a need for studies with long-term follow-up., Objective: To determine the comparative effectiveness and costs of SCSs compared with conventional medical management (CMM) in a large cohort of patients with chronic pain., Design, Setting, and Participants: This was a 1:5 propensity-matched retrospective comparative effectiveness research analysis of insured individuals from April 1, 2016, to August 31, 2018. This study used administrative claims data, including longitudinal medical and pharmacy claims, from US commercial and Medicare Advantage enrollees 18 years or older in Optum Labs Data Warehouse. Patients with incident diagnosis codes for failed back surgery syndrome, complex regional pain syndrome, chronic pain syndrome, and other chronic postsurgical back and extremity pain were included in this study. Data were analyzed from February 1, 2021, to August 31, 2022., Exposures: SCSs or CMM., Main Outcomes and Measures: Surrogate measures for primary chronic pain treatment modalities, including pharmacologic and nonpharmacologic pain interventions (epidural and facet corticosteroid injections, radiofrequency ablation, and spine surgery), as well as total costs., Results: In the propensity-matched population of 7560 patients, mean (SD) age was 63.5 (12.5) years, 3080 (40.7%) were male, and 4480 (59.3%) were female. Among matched patients, during the first 12 months, patients treated with SCSs had higher odds of chronic opioid use (adjusted odds ratio [aOR], 1.14; 95% CI, 1.01-1.29) compared with patients treated with CMM but lower odds of epidural and facet corticosteroid injections (aOR, 0.44; 95% CI, 0.39-0.51), radiofrequency ablation (aOR, 0.57; 95% CI, 0.44-0.72), and spine surgery (aOR, 0.72; 95% CI, 0.61-0.85). During months 13 to 24, there was no significant difference in chronic opioid use (aOR, 1.06; 95% CI, 0.94-1.20), epidural and facet corticosteroid injections (aOR, 1.00; 95% CI, 0.87-1.14), radiofrequency ablation (aOR, 0.84; 95% CI, 0.66-1.09), or spine surgery (aOR, 0.91; 95% CI, 0.75-1.09) with SCS use compared with CMM. Overall, 226 of 1260 patients (17.9%) treated with SCS experienced SCS-related complications within 2 years, and 279 of 1260 patients (22.1%) had device revisions and/or removals, which were not always for complications. Total costs of care in the first year were $39 000 higher with SCS than CMM and similar between SCS and CMM in the second year., Conclusions and Relevance: In this large, real-world, comparative effectiveness research study comparing SCS and CMM for chronic pain, SCS placement was not associated with a reduction in opioid use or nonpharmacologic pain interventions at 2 years. SCS was associated with higher costs, and SCS-related complications were common.

With tyrosine kinase inhibitor (TKI) therapy, chronic myelogenous leukemia (CML) is now a chronic disease. CML patients treated with TKIs ( n  = 1200) were identified from the OptumLabs ® Data Warehouse (de-identified claims and electronic health records) between 2000 and 2016 and compared with a non-cancer cohort ( n  = 7635). The 5-year cumulative incidence of all organ system outcomes was significantly greater for the TKI versus non-cancer group. In the first year, compared with imatinib, later generation TKIs were associated with primary infections (hazard ratios [HR] 1.43, 95% CI 1.02-2.00), circulatory events (HR 1.15, 95% CI 1.01-1.31), and skin issues (HR 1.43, 95% CI 1.13-1.80); musculoskeletal and nervous system/sensory issues were less common (HRs 0.83-0.84, p  < 0.05). Increased risk of infections, cardiopulmonary and skin issues associated with later generation TKIs persisted in subsequent years. In this real-world population, TKI therapy was associated with a high burden of adverse events. Later generation TKIs may have greater toxicity than imatinib.

Purpose: Given the widespread introduction of tyrosine kinase inhibitors (TKIs), we evaluated the cost associated with chronic myelogenous leukemia (CML) care compared with the cost of care for patients with hematologic malignancies (HEM) and for patients without cancer (GEN), to aid with resource allocation and clinical decision making., Methods: A retrospective cohort was constructed from the OptumLabs Data Warehouse using claims from 2000 to 2016. Eligible patients had ≥ 2 CML claims and were enrolled continuously for ≥ 6 months before diagnosis and ≥ 1 year afterward (n = 1,909). Patients with CML were frequency matched 4:1 with HEM and GEN cohorts and were observed through October 2017. We used generalized linear models to assess the variation in total mean annualized health care costs in the 3 cohorts and to examine the influence of factors associated with costs., Results: Mean annualized costs for CML were $82,054 (ie, $25,471 [95% CI, $20,808 to $30,133] more than those for HEM and $74,993 [95% CI, $70,818 to $79,167] more than those for GEN); these differences were driven by pharmacy costs in the CML group. The cost of CML care exceeded that for HEM and GEN for all index years in this study and increased over each diagnostic interval until 2015, peaking at $91,990. The mean annual cost of all TKIs increased. Imatinib's mean annualized cost was $41,546 in the period 2000-2004 but increased to $105,069 in the period 2015-2017. In multivariable analysis, percent days on TKIs had the greatest influence on cost: ≥ 75% of the time versus none showed a difference in cost of $108,716 (95% CI, $99,193 to $118,239)., Conclusion: Contemporary CML costs exceeded the cost of treatment of other hematologic malignancies. Cost was primarily driven by TKIs, whose cost continued to increase over time.

Background: Chronic conditions are common and costly for older Americans and for the health system. Adherence to daily maintenance medications may improve patient health and lead to lower health care spending., Methods: To identify predictors of adherence and to quantify associations with health care utilization and spending among older adults with chronic conditions, we conducted a longitudinal retrospective analysis using the OptumLabs Data Warehouse. This database of deidentified administrative claims includes medical and eligibility information for more than 200 million commercial and Medicare Advantage enrollees. We identified adults age 50+ years initiating treatment for atrial fibrillation (N = 33,472), chronic obstructive pulmonary disease (COPD; N = 44,130), diabetes (N =76,726), and hyperlipidemia (N= 249,391) between January 2010 and December 2014. We assessed adherence, health care utilization, and spending during the first 2 years of treatment., Results: During the first year of treatment, 13%-53% of each condition cohort was adherent (proportion of days covered ≥0.80). White race, Midwest residence, and having fewer comorbidities consistently and independently predicted adherence among enrollees initiating treatment for chronic obstructive pulmonary disease, diabetes, and hyperlipidemia. Male sex and higher net worth were also independently associated with adherence among commercial enrollees with these conditions. Patients in most condition cohorts who were adherent to treatment had significantly lower odds of hospitalization or emergency department use compared to patients who were not adherent. Additional spending on pharmacy claims by patients who were adherent was not consistently offset by lower spending on medical claims over a 2-year horizon., Conclusions: Although many patient factors are strongly associated with medication adherence, the problem of non-adherence is common across all groups and may increase risk of adverse health outcomes., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

The Canadian Institutes for Health Research (CIHR) launched the "International Collaborative Research Strategy for Alzheimer's Disease" as a signature initiative, focusing on Alzheimer's Disease (AD) and related neurodegenerative disorders (NDDs). The Canadian Consortium for Neurodegeneration and Aging (CCNA) was subsequently established to coordinate and strengthen Canadian research on AD and NDDs. To facilitate this research, CCNA uses LORIS, a modular data management system that integrates acquisition, storage, curation, and dissemination across multiple modalities. Through an unprecedented national collaboration studying various groups of dementia-related diagnoses, CCNA aims to investigate and develop proactive treatment strategies to improve disease prognosis and quality of life of those affected. However, this constitutes a unique technical undertaking, as heterogeneous data collected from sites across Canada must be uniformly organized, stored, and processed in a consistent manner. Currently clinical, neuropsychological, imaging, genomic, and biospecimen data for 509 CCNA subjects have been uploaded to LORIS. In addition, data validation is handled through a number of quality control (QC) measures such as double data entry (DDE), conflict flagging and resolution, imaging protocol checks, and visual imaging quality validation. Site coordinators are also notified of incidental findings found in MRI reads or biosample analyses. Data is then disseminated to CCNA researchers via a web-based Data-Querying Tool (DQT). This paper will detail the wide array of capabilities handled by LORIS for CCNA, aiming to provide the necessary neuroinformatic infrastructure for this nation-wide investigation of healthy and diseased aging.

BMS-823778 ( 2 ), a 1,2,4-triazolopyridinyl-methanol derived analog, was identified as a potent and selective inhibitor of human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) enzyme (IC 50 = 2.3 nM) with >10,000-fold selectivity over 11β-HSD-2. Compound 2 exhibits robust acute pharmacodynamic effects in cynomolgus monkeys (ED 50 = 0.6 mg/kg) and in diet-induced obese (DIO) mice (ED 50 = 34 mg/kg). Compound 2 also showed excellent inhibition in an ex vivo adipose DIO mouse model (ED 50 = 5.2 mg/kg). Oral bioavailability ranges from 44% to 100% in preclinical species. Its favorable development properties, pharmacokinetics, high adipose-to-plasma concentration ratio, and preclinical pharmacology profile have prompted the evaluation of 2 for the treatment of type 2 diabetes and metabolic syndrome in phase 2 clinical trials., Competing Interests: The authors declare no competing financial interest.

Background: Overutilization of low-value services (unnecessary or minimally beneficial tests or procedures) has been cited as a large contributor to the high costs of health care in the United States., Objectives: To analyze trends in utilization of low-value services from 2009 to 2014 among commercial and Medicare Advantage (MA) enrollees 50 and older., Research Design: A retrospective analysis of deidentified claims obtained from the OptumLab Data Warehouse., Subjects: Adults 50 and older enrolled in commercial plans and adults 65 and older enrolled in MA plans between 2009 and 2014., Measures: Costs and utilization of 16 low-value services in the following categories: cancer screening, imaging, and invasive procedures., Results: The most commonly performed low-value service was imaging of the head for syncope, at rates of 33%-39% in commercial enrollees and 45% in MA enrollees. The least common service was peripheral artery stenting (<1%) in commercial enrollees, and laminectomy (0.15% in 2009) and renal artery stenting in MA enrollees (0.07% in 2014). Renal artery stenting decreased by roughly 75% over the study period, the largest decrease in utilization, with ∼$30 million and $10 million in reduced spending for commercial and MA plans and enrollees, respectively. Spending on these services in 2014 totaled $317.6 million for commercial and $100.8 million for MA health plans., Conclusions: Clinicians, researchers, and policymakers should strive to reach consensus on methods for more reliably and accurately identifying low-value service utilization. Greater consistency would facilitate monitoring use of low-value services and changing clinical practice patterns over time.

Cancer immunotherapy, unlike traditional cytotoxic chemotherapeutic treatments, engages the immune system to identify cancer cells and stimulate immune responses. The Programmed Death-1 (PD-1) protein is an immunoinhibitory receptor expressed by activated cytotoxic T-lymphocytes (CTL) that seek out and destroy cancer cells. Multiple cancer types express and upregulate the Programmed Death-Ligand 1 (PD-L1) and 2 (PD-L2) which bind to PD-1 as an immune escape mechanism. Nivolumab is a fully human IgG4 anti-PD-1 monoclonal antibody (mAb) approved for treatment of multiple cancer types. This study reports the preparation and in vivo evaluation of 89 Zr labeled nivolumab in healthy non-human primates (NHP) as a preliminary study of biodistribution and clearance. The radiochemical and in vivo stabilities of the 89 Zr complex were shown to be acceptable for imaging. Three naïve NHPs were intravenously injected with tracer only or tracer co-injected with nivolumab followed by co-registered by positron emission tomography (PET) and magnetic resonance imaging (MRI), acquired for eight days following injection. Image-derived standardized uptake values (SUV) were quantified by region of interest (ROI) analysis. Radioactivity in the spleen was significantly reduced by addition of excess nivolumab compared to the tracer only study at all imaging time points. Liver uptake of the radiotracer was consistent as a clearance organ with minimal signal from other tissues: lung, muscle, brain, heart, and kidney. The results indicate specific biodistribution to the spleen, which can be blocked by co-administration of excess nivolumab. Distribution to other organs is consistent with elimination pathways of antibodies, with primary clearance through the liver., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

BMS-816336 (6n-2), a hydroxy-substituted adamantyl acetamide, has been identified as a novel, potent inhibitor against human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme (IC 50 3.0 nM) with >10000-fold selectivity over human 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). 6n-2 exhibits a robust acute pharmacodynamic effect in cynomolgus monkeys (ED 50 0.12 mg/kg) and in DIO mice. It is orally bioavailable (%F ranges from 20 to 72% in preclinical species) and has a predicted pharmacokinetic profile of a high peak to trough ratio and short half-life in humans. This ADME profile met our selection criteria for once daily administration, targeting robust inhibition of 11β-HSD1 enzyme for the first 12 h period after dosing followed by an "inhibition holiday" so that the potential for hypothalamic-pituitary-adrenal (HPA) axis activation might be mitigated. 6n-2 was found to be well-tolerated in phase 1 clinical studies and represents a potential new treatment for type 2 diabetes, metabolic syndrome, and other human diseases modulated by glucocorticoid control.

Timely identification and treatment of osteoporosis following hip fracture is recommended to mitigate future fracture risk, yet prior work has demonstrated a disconnect between evidence-based recommendations and real-world implementation. We sought to describe contemporary patterns of osteoporosis screening and initiation of pharmacotherapy following hip fracture based on medical and pharmacy claims in the OptumLabs™ Data Warehouse. From a national sample, we identified 8349 women aged 50+ years enrolled in private commercial or Medicare Advantage plans with no prior history of osteoporosis diagnosis, osteoporosis pharmacotherapy, or hip fracture who experienced a hip fracture between 2008 and 2013. Just 17.1% and 23.1% of these women had evidence of osteoporosis assessment and/or treatment within 6 or 12 months of their fractures, respectively. Women aged 80+ years were one-third less likely to utilize recommended services within 6 months, compared to those aged 50 to 79 years (13.8% versus 20.8%; p < 0.001). Utilization of bone mass measurement increased significantly among women aged 65+ years over the study period (p < 0.001) while declining among those aged 50 to 64 years (p = 0.2). In contrast, rates of osteoporosis pharmacotherapy remained steady among women aged 50 to 64 years (p = 0.8) yet declined among women aged 65 to 79 years and aged 80+ years (p = 0.07 and p = 0.004, respectively). Accounting for differences in all measured characteristics, receipt of primary care was the strongest and most consistent predictor of osteoporosis assessment or treatment following fracture. © 2017 American Society for Bone and Mineral Research., (© 2017 American Society for Bone and Mineral Research.)

Background: The United States Preventive Services Task Force recommends universal osteoporosis screening among women ages 65+ and targeted screening of younger women, but historically, adherence to these evidence-based recommendations has been suboptimal., Methods: To describe contemporary patterns of osteoporosis screening, we conducted a retrospective analysis using the OptumLabs ™ Data Warehouse, a database of de-identified administrative claims, which includes medical and eligibility information for over 100 million Medicare Advantage and commercial enrollees. Study participants included 1,638,454 women ages 50+ with no prior history of osteoporosis diagnosis, osteoporosis drug use, or hip fracture. Osteoporosis screening during the most recent 2-year period of continuous enrollment was assessed via medical claims. Patient sociodemographics, comorbidities, and utilization of other services were also determined using health insurance files., Results: Overall screening rates were low: 21.1%, 26.5%, and 12.8% among women ages 50-64, 65-79, and 80+ years, respectively. Secular trends differed significantly by age (P <.001). Between 2008 and 2014, utilization among women ages 50-64 years declined 31.4%, changed little among women 65-79, and increased 37.7% among women 80+ years. Even after accounting for socioeconomic status, health status, and health care utilization patterns, non-Hispanic black women were least likely to be screened, whereas non-Hispanic Asian and Hispanic women were most likely to undergo screening. Marked socioeconomic gradients in screening probabilities narrowed substantially over time, decreasing by 44.5%, 71.9%, and 59.7% among women ages 50-64, 65-79 and 80+ years, respectively., Conclusions: Despite significant changes in utilization of osteoporosis screening among women ages 50-64 and 80+, in line with national recommendations, tremendous deficiencies among women 65+ remain., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: to compare healthcare utilization including coronary angiography, percutaneous coronary intervention (PCI), rehospitalization, and rate of subsequent acute myocardial infarction (AMI) within 30 days, among patients presenting to the emergency department (ED) with chest pain admitted as short-term inpatient (≤2 days) versus observation (in-ED observation units combined with in-hospital observation)., Methods: We identified adults diagnosed with acute chest pain in the ED from 2010 to 2014 using administrative claims from privately insured and Medicare Advantage. Patients having AMI during the index visit were excluded. One-to-one propensity-score matching and logistic regression were used. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported., Results: A total of 774,017 chest pain visits were included. After matching, healthcare utilization was lower among observation versus short inpatient, with 10.9% versus 24.4% (OR = 0.38, 95% CI = 0.36 to 0.39) undergoing cardiac catheterization and 1.8% versus 7.6% (OR = 0.23, 95% CI = 0.21 to 0.24) having PCI. The incidence of subsequent AMI within the following 30 days was similar in patients admitted as observation versus short inpatient (0.23% vs. 0.21%; OR = 1.09, 95% CI = 0.84 to 1.42)., Conclusions: There were higher rates of cardiac catheterization and PCI among those admitted as a short inpatient compared to observation, while the incidence of subsequent AMI within 30 days was similar., (© 2016 by the Society for Academic Emergency Medicine.)

The synthesis, structural activity relationships (SAR), and selectivity profile of a potent series of phenylalanine diamide FXIa inhibitors will be discussed. Exploration of P1 prime and P2 prime groups led to the discovery of compounds with high FXIa affinity, good potency in our clotting assay (aPPT), and high selectivity against a panel of relevant serine proteases as exemplified by compound 21. Compound 21 demonstrated good in vivo efficacy (EC50=2.8μM) in the rabbit electrically induced carotid arterial thrombosis model (ECAT)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

IL-23 is an important therapeutic target for the treatment of inflammatory diseases. Adnectins are targeted protein therapeutics that are derived from domain III of human fibronectin and have a similar protein scaffold to antibodies. Adnectin 2 was found to bind to IL-23 and compete with the IL-23/IL-23R interaction, posing a potential protein therapeutic. Hydrogen/deuterium exchange mass spectrometry and computational methods were applied to probe the binding interactions between IL-23 and Adnectin 2 and to determine the correlation between the two orthogonal methods. This review summarizes the current structural knowledge about IL-23 and focuses on the applicability of hydrogen/deuterium exchange mass spectrometry to investigate the higher order structure of proteins, which plays an important role in the discovery of new and improved biotherapeutics.

Compound 2 was previously identified as a potent inhibitor of factor XIa lacking oral bioavailability. A structure-based approach was used to design analogs of 2 with novel P1 moieties with good selectivity profiles and oral bioavailability. Further optimization of the P1 group led to the identification of a 4-chlorophenyltetrazole P1 analog, which when combined with further modifications to the linker and P2' group provided compound 32 with FXIa Ki=6.7 nM and modest oral exposure in dogs., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A multidisciplinary, fragment-based screening approach involving protein ensemble docking and biochemical and NMR assays is described. This approach led to the discovery of several structurally diverse, neutral surrogates for cationic factor VIIa P1 groups, which are generally associated with poor pharmacokinetic (PK) properties. Among the novel factor VIIa inhibitory fragments identified were aryl halides, lactams, and heterocycles. Crystallographic structures for several bound fragments were obtained, leading to the successful design of a potent factor VIIa inhibitor with a neutral lactam P1 and improved permeability.

The structure-activity relationships (SAR) of six-membered ring replacements for the imidazole ring scaffold is described. This work led to the discovery of the potent and selective pyridine (S)-23 and pyridinone (±)-24 factor XIa inhibitors. SAR and X-ray crystal structure data highlight the key differences between imidazole and six-membered ring analogs., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Novel inhibitors of FXIa containing an (S)-2-phenyl-1-(4-phenyl-1H-imidazol-2-yl)ethanamine core have been optimized to provide compound 16b, a potent, reversible inhibitor of FXIa (Ki = 0.3 nM) having in vivo antithrombotic efficacy in the rabbit AV-shunt thrombosis model (ID50 = 0.6 mg/kg + 1 mg kg(-1) h(-1)). Initial analog selection was informed by molecular modeling using compounds 11a and 11h overlaid onto the X-ray crystal structure of tetrahydroquinoline 3 complexed to FXIa. Further optimization was achieved by specific modifications derived from careful analysis of the X-ray crystal structure of the FXIa/11h complex. Compound 16b was well tolerated and enabled extensive pharmacologic evaluation of the FXIa mechanism up to the ID90 for thrombus inhibition.

The precise and unambiguous elucidation and characterization of interactions between a high affinity recognition entity and its cognate protein provides important insights for the design and development of drugs with optimized properties and efficacy. In oncology, one important target protein has been shown to be the epidermal growth factor receptor (EGFR) through the development of therapeutic anticancer antibodies that are selective inhibitors of EGFR activity. More recently, smaller protein derived from the 10th type III domain of human fibronectin termed an adnectin has also been shown to inhibit EGFR in clinical studies. The mechanism of EGFR inhibition by either an adnectin or an antibody results from specific binding of the high affinity protein to the extracellular portion of EGFR (exEGFR) in a manner that prevents phosphorylation of the intracellular kinase domain of the receptor and thereby blocks intracellular signaling. Here, the structural changes induced upon binding were studied by probing the solution conformations of full length exEGFR alone and bound to a cognate adnectin through hydrogen/deuterium exchange mass spectrometry (HDX MS). The effects of binding in solution were identified and compared with the structure of a bound complex determined by X-ray crystallography.ᅟ

Successful early attrition of potential problematic compounds is of great importance in the pharmaceutical industry. The lead compound in a recent project targeting neuropathic pain was susceptible to metabolic bioactivation, which produced reactive metabolites and showed covalent binding to protein. Therefore, as a part of the backup series for this compound several structural modifications were explored to mediate the reactive metabolite and covalent binding risk. A homomorpholine containing series of compounds was identified without compromising potency. However, when these compounds were incubated with human liver microsomes in the presence of GSH, Cys-Gly adducts were identified, instead of intact GSH conjugates. This article examines the formation of the Cys-Gly adduct with AZX ([M+H]+ 486) as a representative compound for this series. The AZX-Cys-Gly-adduct ([M+H]+ 662) showed evidence of ring contraction by formation of a thiazolidine-glycine and was additionally shown to be unstable. During its isolation for structural characterization by 1H NMR spectroscopy, it was found to have decomposed to a product with [M+H]+ 446. The characterization and identification of this labile GSH-derived adduct using LC-MS/MS and 1H NMR are described, along with observations around stability. In addition, various structurally related trapping reagents were employed in an attempt to further investigate the reaction mechanism along with a methoxylamine trapping experiment to confirm the structure of the postulated reactive intermediate.

Small alkyl groups and spirocyclic-aromatic rings directly attached to the left side and right side of the 1,2,4-triazolopyridines (TZP), respectively, were found to be potent and selective inhibitors of human 11β-hydroxysteroid dehydrogenase-type 1 (11β-HSD-1) enzyme. 3-(1-(4-Chlorophenyl)cyclopropyl)-8-cyclopropyl-[1,2,4]triazolo[4,3-a]pyridine (9f) was identified as a potent inhibitor of the 11β-HSD-1 enzyme with reduced Pregnane-X receptor (PXR) transactivation activity. The binding orientation of this TZP series was revealed by X-ray crystallography structure studies.

Described herein are structure-activity relationship studies that resulted in the optimization of the activity of members of a class of cyclopropyl-fused indolobenzazepine HCV NS5B polymerase inhibitors. Subsequent iterations of analogue design and syntheses successfully addressed off-target activities, most notably human pregnane X receptor (hPXR) transactivation, and led to significant improvements in the physicochemical properties of lead compounds. Those analogues exhibiting improved solubility and membrane permeability were shown to have notably enhanced pharmacokinetic profiles. Additionally, a series of alkyl bridged piperazine carboxamides was identified as being of particular interest, and from which the compound BMS-791325 (2) was found to have distinguishing antiviral, safety, and pharmacokinetic properties that resulted in its selection for clinical evaluation.

Antithrombotic agents that are inhibitors of factor XIa (FXIa) have the potential to demonstrate robust efficacy with a low bleeding risk profile. Herein, we describe a series of tetrahydroquinoline (THQ) derivatives as FXIa inhibitors. Compound 1 was identified as a potent and selective tool compound for proof of concept studies. It exhibited excellent antithrombotic efficacy in rabbit thrombosis models and did not prolong bleeding times. This demonstrates proof of concept for the FXIa mechanism in animal models with a reversible, small molecule inhibitor.

Derived from the HTS hit 1, a series of hydroxyisoquinolines was discovered as potent and selective 11β-HSD1 inhibitors with good cross species activity. Optimization of substituents at the 1 and 4 positions of the isoquinoline group in addition to the core modifications, with a special focus on enhancing metabolic stability and aqueous solubility, resulted in the identification of several compounds as potent advanced leads., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Heterocyclic replacement of the isophthalamide phenyl ring in hydroxyethylamine (HEA) BACE-1 inhibitors was explored. A variety of indole-1,3-dicarboxamide HEAs exhibited potent BACE-1 enzyme inhibition, but displayed poor cellular activity. Improvements in cellular activity and aspartic protease selectivity were observed for 7-azaindole-1,3-dicarboxamide HEAs. A methylprolinol-bearing derivative (10n) demonstrated robust reductions in rat plasma Aβ levels, but did not lower rat brain Aβ due to poor central exposure. The same analog exhibited a high efflux ratio in a bidirectional Caco-2 assay and was likely a substrate of the efflux transporter P-glycoprotein. X-ray crystal structures are reported for two indole HEAs in complex with BACE-1., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

We have investigated phenol replacements in a series of diaryl amino piperidine delta opioid agonists. From this study we have demonstrated that the hydroxy functional group can be replaced with a primary amide group, giving enhanced activity at the delta receptor, increased selectivity versus mu and kappa as well as improved in vitro metabolic stability.

Several series of pyridine amides were identified as selective and potent 11beta-HSD1 inhibitors. The most potent inhibitors feature 2,6- or 3,5-disubstitution on the pyridine core. Various linkers (CH(2)SO(2), CH(2)S, CH(2)O, S, O, N, bond) between the distal aryl and central pyridyl groups are tolerated, and lipophilic amide groups are generally favored. On the distal aryl group, a number of substitutions are well tolerated. A crystal structure was obtained for a complex between 11beta-HSD1 and the most potent inhibitor in this series.

Introduction of the phenyl piperidinone and phenyl pyridinone P4 moieties in the anthranilamide scaffold led to potent, selective, and orally bioavailable inhibitors of factor Xa. Anthranilamide 28 displayed comparable efficacy to apixaban in the rabbit arteriovenous-shunt (AV) thrombosis model.

In the search of Factor Xa (FXa) inhibitors structurally different from the pyrazole-based series, we identified a viable series of enantiopure cis-(1R,2S)-cycloalkyldiamine derivatives as potent and selective inhibitors of FXa. Among them, cyclohexyldiamide 7 and cyclopentyldiamide 9 were the most potent neutral compounds, and had good anticoagulant activity comparable to the pyrazole-based analogs. Crystal structures of 7-FXa and 9-FXa illustrate binding similarities and differences between the five- and the six-membered core systems, and provide rationales for the observed SAR of P1 and linker moieties.

The use of sub-2-microm particle columns for fast high throughput metabolite ID applications was investigated. Three LC-MS methods based on different sub-2-microm particle size columns using the same analytical 3 min gradient were developed (Methods A, B, and C). Method A was comprised of a 1.8 microm particle column coupled to an MS, methods B and C utilized a 1.7 microm particle column (BEH 50 x 2.1 mm2 id) and 1.8 microm particle column coupled to a Q-TOF MS. The precision and the separation efficiency of the methods was compared with repeated standard injections (N=10) of reference compounds verapamil (VP), propranolol, and fluoxetine. Separation efficiency and MS/MS spectral quality were also evaluated for separation and detection of VP and its two major metabolites norverapamil (NVP) and O-demethylverapamil (ODMVP) in human-liver microsomal incubates. Results show that 1.8 microm particle columns show similar performance for separation of VP and its major metabolites and comparable spectral quality in MS(E) mode of the Q-TOF instrument compared to 1.7 microm particle columns. Additionally, the study also confirmed that sub-2-microm particle size columns can be operated with standard analytical HPLC but that performance is maximized by integrating column in UPLC method with reduced void volumes. All the methods are suitable for the determination of major metabolites for compounds with high metabolic turnover. The high throughput metabolite profile analysis using 384-well plate format of up to 48 compounds in incubates of human-liver microsomes was discussed.

1. The aim was to identify the cytochrome P450 (CYP) enzymes responsible for the N-demethylation of morphine in vitro. 2. In human liver microsomes, normorphine formation followed Michaelis-Menten kinetics with mean Km and Vmax of 12.4 +/- 2.2 mM and 1546 +/- 121 pmol min(-1) mg(-1), respectively. In microsomes from a panel of 14 human livers phenotyped for 10 CYP enzymes, morphine N-demethylation correlated with testosterone 6beta-hydroxylation (r=0.91, p<0.001) and paclitaxel 6-alpha hydroxylation (r=0.72, p<0.001), two specific markers of CYP3A4 and CYP2C8, respectively. Normorphine formation decreased when incubated in the presence of troleandomycin or quercetin (by 46 and 33-36%, respectively), which further corroborates the contribution of CYP3A4 and CYP2C8. 3. Among eight recombinant human CYP enzymes tested, CYP3A4 and CYP2C8 exhibited the highest intrinsic clearance. More than 90% of morphine N-demethylation could be accounted for via the action of both CYP3A4 and CYP2C8. 4. The in vitro findings suggest that hepatic CYP3A4, and to a lesser extent CYP2C8, play an important role in the metabolism of morphine into normorphine.

Amyloid precursor protein (APP) cleaving enzyme (BACE) is the enzyme responsible for beta-site cleavage of APP, leading to the formation of the amyloid-beta peptide that is thought to be pathogenic in Alzheimer's disease (AD). Hence, BACE is an attractive pharmacological target, and numerous research groups have begun searching for potent and selective inhibitors of this enzyme as a potential mechanism for therapeutic intervention in AD. The mature enzyme is composed of a globular catalytic domain that is N-linked glycosylated in mammalian cells, a single transmembrane helix that anchors the enzyme to an intracellular membrane, and a short C-terminal domain that extends outside the phospholipid bilayer of the membrane. Here we have compared the substrate and active site-directed inhibitor binding properties of several recombinant constructs of human BACE. The constructs studied here address the importance of catalytic domain glycosylation state, inclusion of domains other than the catalytic domain, and incorporation into a membrane bilayer on the interactions of the enzyme active site with peptidic ligands. We find no significant differences in ligand binding properties among these various constructs. These data demonstrate that the nonglycosylated, soluble catalytic domain of BACE faithfully reflects the ligand binding properties of the full-length mature enzyme in its natural membrane environment. Thus, the use of the nonglycosylated, soluble catalytic domain of BACE is appropriate for studies aimed at understanding the determinants of ligand recognition by the enzyme active site.

Nonpeptide delta opioid agonists are analgesics with a potentially improved side-effect and abuse liability profile, compared to classical opioids. Andrews analysis of the NIH nonpeptide lead SNC-80 suggested the removal of substituents not predicted to contribute to binding. This approach led to a simplified lead, N, N-diethyl-4-[phenyl(1-piperazinyl)methyl]benzamide (1), which retained potent binding affinity and selectivity to the human delta receptor (IC(50) = 11 nM, mu/delta = 740, kappa/delta > 900) and potency as a full agonist (EC(50) = 36 nM) but had a markedly reduced molecular weight, only one chiral center, and increased in vitro metabolic stability. From this lead, the key pharmacophore groups for delta receptor affinity and activation were more clearly defined by SAR and mutagenesis studies. Further structural modifications on the basis of 1 confirmed the importance of the N, N-diethylbenzamide group and the piperazine lower basic nitrogen for delta binding, in agreement with mutagenesis data. A number of piperazine N-alkyl substituents were tolerated. In contrast, modifications of the phenyl group led to the discovery of a series of diarylmethylpiperazines exemplified by N, N-diethyl-4-[1-piperazinyl(8-quinolinyl)methyl]benzamide (56) which had an improved in vitro binding profile (IC(50) = 0.5 nM, mu/delta = 1239, EC(50) = 3.6 nM) and increased in vitro metabolic stability compared to SNC-80.

The design, synthesis, and pharmacological evaluation of a novel class of delta opioid receptor agonists, N, N-diethyl-4-(phenylpiperidin-4-ylidenemethyl)benzamide (6a) and its analogues, are described. These compounds, formally derived from SNC-80 (2) by replacing the piperazine ring with a piperidine ring containing an exocyclic carbon carbon double bond, were found to bind with high affinity and exhibit excellent selectivity for the delta opioid receptor as full agonists. 6a, the simplest structure in the class, exhibited an IC(50) = 0.87 nM for the delta opioid receptors and extremely high selectivity over the mu receptors (mu/delta = 4370) and the kappa receptors (kappa/delta = 8590). Rat liver microsome studies on a selected number of compounds show these olefinic piperidine compounds (6) to be considerably more stable than SNC-80. This novel series of compounds appear to interact with delta opioid receptors in a similar way to SNC-80 since they demonstrate similar SAR. Two general approaches have been established for the synthesis of these compounds, based on dehydration of benzhydryl alcohols (7) and Suzuki coupling reactions of vinyl bromide (8), and are herewith reported.

The lactol derivative of a lactone cyclooxygenase-2 inhibitor (DFU) was evaluated in vivo and in vitro for its potential suitability as a prodrug. DFU-lactol was found to be 10 to 20 times more soluble than DFU in a variety of aqueous vehicles. After administration of DFU-lactol at 20 mg kg-1 p.o. in rats, a Cmax of 7.5 microM DFU was reached in the plasma. After oral administration, the ED50s of DFU-lactol in the carrageenan-induced paw edema and lipopolysaccharide-induced pyresis assays in rats are comparable with the ED50s observed when dosing with DFU. Incubations of DFU-lactol with rat and human hepatocytes demonstrated that the oxidation of DFU-lactol can be mediated by liver enzymes and that a competing pathway is direct glucuronidation of the DFU-lactol hydroxyl group. Assays with subcellular fractions from rat liver indicated that most of the oxidation of DFU-lactol occurs in the cytosolic fraction and requires NAD(P)+. Human liver cytosol can also support the oxidation of DFU-lactol to DFU when NAD(P)+ is added to the incubations. Fractionation of human liver cytosolic proteins showed that at least three enzymes are capable of efficiently effecting the oxidation of DFU-lactol to DFU. Incubations with commercially available dehydrogenases suggest that alcohol and hydroxysteroid dehydrogenases are involved in this oxidative process. These data together suggest that lactols may represent useful prodrugs for lactone-containing drugs.

TFIIS is a general transcription elongation factor that helps arrested RNA polymerase II elongation complexes resume transcription. We have previously shown that yeast TFIIS (yTFIIS) comprises three structural domains (I-III). The three-dimensional structures of domain II and part of domain III have been previously reported, but neither domain can autonomously stimulate transcription elongation. Here we report the NMR structural analysis of residues 131-309 of yTFIIS which retains full activity and contains all of domains II and III. We confirm that the structure of domain II in the context of fully active yTFIIS is the same as that determined previously for a shorter construct. We have determined the structure of the C-terminal zinc ribbon domain of active yTFIIS and shown that it is similar to that reported for a shorter construct of human TFIIS. The region linking domain II with the zinc ribbon of domain III appears to be conformationally flexible and does not adopt a single defined tertiary structure. NMR analysis of inactive mutants of yTFIIS support a role for the linker region in interactions with the transcription elongation complex.

Induction of cytochromes P450 (P450s) by drugs can lead to drug-drug interactions. Primary hepatocytes have been reported to retain inducible P450s. To optimize the use of primary hepatocytes for predicting induction of P450 (CYP 3A and 2B) expression in vivo, both culture conditions and expression of induction potentials were investigated. In rat hepatocytes, basal CYP 3A1/2 expression was better maintained in cells cultured on Matrigel compared with collagen when low concentrations of dexamethasone were used. However, CYP 3A1/2 induction was not affected by either matrix. In contrast, induction of CYP 2B1/2 by phenobarbital was markedly stronger in hepatocytes cultured on Matrigel. To further validate the in vitro model, Sprague-Dawley rats and isolated hepatocytes cultured on Matrigel were exposed to a series of compounds. In an attempt to minimize large variability between experiments, a novel approach for calculating induction potential was applied. In vitro results for CYP 3A1/2 and 2B1/2 induction correlated well with those observed in vivo. In contrast with rat hepatocytes, basal CYP 3A4 expression in human hepatocytes decreased rapidly in cells cultured on either Matrigel or collagen. However, CYP 3A4 inducibility was retained in cells cultured on either matrix. Interestingly, induction of CYP 3A4 in human hepatocytes by several model compounds did not correlate with the induction of CYP 3A1/2 in rat hepatocytes. This in vitro assay should facilitate the demand for a fast and reproducible method for addressing P450 induction by numerous compounds at the drug discovery stage.

Transcription elongation by RNA polymerase II is regulated by the general elongation factor TFIIS. This factor stimulates RNA polymerase II to transcribe through regions of DNA that promote the formation of stalled ternary complexes. Limited proteolytic digestion showed that yeast TFIIS is composed of three structural domains, termed I, II, and III. The two C-terminal domains (II and III) are required for transcription activity. The structure of domain III has been solved previously by using NMR spectroscopy. Here, we report the NMR-derived structure of domain II: a three-helix bundle built around a hydrophobic core composed largely of three tyrosines protruding from one face of the C-terminal helix. The arrangement of known inactivating mutations of TFIIS suggests that two surfaces of domain II are critical for transcription activity.

Electrospray ionization mass spectrometry (ESI-MS) has been used to study the noncovalent interaction of the 13.5-kDa DNA binding domain of PU.1 (PU.1-DBD) with specific double-stranded DNA (dsDNA) target molecules. Mixtures of PU.1-DBD protein and wild-type target DNA sequence yielded ESI-MS spectra showing only protein-dsDNA complex ions of 1:1 stoichiometry and free dsDNA. When PU.1-DBD protein, wild type target DNA, and a mutant target DNA lacking the consensus sequence were mixed, only the 1:1 complex with the wild-type DNA was observed, consistent with gel electrophoresis mobility shift assay results, demonstrating the observation of sequence-specific protein-dsDNA complexes using ESI-MS.

The disulphide folding pathway of bovine pancreatic trypsin inhibitor (BPTI), especially at the two-disulphide stage, has been dissected by replacing one or two particular cysteine residues by serine. This restricts which disulphide species are possible, and the observed kinetics of disulphide-coupled folding reveal the roles of the remaining species. The results obtained confirm the kinetic roles in the original BPTI pathway of the two specific two-disulphide intermediates with non-native second disulphide bonds, (30-51, 5-14) and (30-51, 5-38). Moreover, the rates of folding through each of these intermediates are shown to account quantitatively for the rate of folding of the normal protein; therefore, essentially all the molecules refold through these two particular intermediates. They are amongst the most productive on the folding pathway, and their roles are readily explicable on the basis of their conformations.

The structural stability of an amino acid fragment containing the oligomerization domain (residues 303-366) of the tumor suppressor p53 has been studied using high-precision differential scanning calorimetry (DSC) and circular dichroism spectroscopy (CD). Previous NMR solution structural determinations have revealed that the fragment forms a symmetric 29.8 kDa tetramer composed of a dimer of dimers (p53tet) [Lee, W., Harvey, T. S., Yin, Y., Yau, P., Litchfield, D., & Arrowsmith, C. H. (1994) Nature Struct. Biol. 1, 877-890]. Thermal unfolding of the tetramer is reversible and can be described as a two-state transition in which the folded tetramer is converted directly to unfolded monomers (N4<==>4U). According to the DSC and CD data, the population of intermediate species consisting of folded monomers or dimers is insignificant, indicating that isolated dimeric or monomeric structures have a much lower stability than the dimer and do not become populated during thermal denaturation under the conditions studied. The transition temperature of unfolding is found to be highly dependent on protein concentration and to follow the expected behavior for a tetramer that dissociates upon unfolding. Experiments conducted at pH 4.0 in 25 mM sodium acetate at a tetramer concentration of 145.8 microM have a transition temperature (Tm) of 75.3 degrees C while at 0.5 microM the value drops to 39.2 degrees C. The enthalpy change of unfolding at 60 degrees C is 26 kcal (mol of monomer)-1 with a heat capacity change of 387 cal (K.mol of monomer)-1. The stability of p53tet is dependent on pH and salt concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

The kinetic and thermodynamic parameters associated with the enzymatic reaction of yeast cytochrome c oxidase with its biological substrate, ferrocytochrome c, have been measured by using a titration microcalorimeter to monitor directly the rate of heat production or absorption as a function of time. This technique has allowed determination of both the energetics and the kinetics of the reaction under a variety of conditions within a single experiment. Experiments performed in buffer systems of varying ionization enthalpies allow determination of the net number of protons absorbed or released during the course of the reaction. For cytochrome c oxidase the intrinsic enthalpy of reaction was determined to be -16.5 kcal/mol with one (0.96) proton consumed for each ferrocytochrome c molecule oxidized. Activity measurements at salt concentrations ranging from 0 to 200 mM KCl in the presence of 10 mM potassium phosphate, pH 7.40, and 0.5 mM EDTA display a biphasic dependence of the electron transferase activity upon ionic strength with a peak activity observed near 50 mM KCl. The ionic strength dependence was similar for both detergent-solubilized and membrane-reconstituted cytochrome c oxidase. Despite the large ionic strength dependence of the kinetic parameters, the enthalpy measured for the reaction was found to be independent of ionic strength. Additional experiments involving direct transfer of the enzyme from low to high salt conditions produced negligible enthalpy changes that remained constant within experimental error throughout the salt concentrations studied (0-200 mM KCl). These results indicate that the salt effect on the enzyme activity is of entropic origin and further suggest the absence of a major conformational change in the enzyme due to changes in ionic strength.(ABSTRACT TRUNCATED AT 250 WORDS)

The thermal dependence of the structural stability of membrane-reconstituted yeast cytochrome c oxidase has been studied by using different techniques including high-sensitivity differential scanning calorimetry, differential detergent solubility thermal gel analysis, and enzyme activity measurements. For these studies, the enzyme has been reconstituted into dimyristoylphosphatidylcholine (DMPC) and dielaidoylphosphatidylcholine (DEPC) vesicles using detergent dialysis. The phospholipid moiety affects the stability of the enzyme as judged by the dependence of the denaturation temperature on the lipid composition of the bilayer. The enzyme is more stable when reconstituted with the 18-carbon, unsaturated phospholipid (DEPC) than with the 14-carbon saturated phospholipid (DMPC). In addition, the shapes of the calorimetric transition profiles are different in the two lipid systems, indicating that not all of the subunits are affected equally by the lipid moiety. The overall enthalpy change for the enzyme denaturation is essentially the same for the two lipid reconstitutions (405 kcal/mol of protein for the DMPC and 425 kcal/mol for the DEPC-reconstituted enzyme). In both systems, the van't Hoff to calorimetric enthalpy ratios are less than 0.2, indicating that the unfolding of the enzyme cannot be represented as a two-state process. Differential detergent solubility experiments have allowed us to determine individual subunit thermal denaturation profiles. These experiments indicate that the major contributors to the main transition peak observed calorimetrically are subunits I and II and that the transition temperature of subunit III is the most affected by the phospholipid moiety. Experiments performed at different scanning rates indicate that the thermal denaturation of the enzyme is a kinetically controlled process characterized by activation energies on the order of 40 kcal/mol.(ABSTRACT TRUNCATED AT 250 WORDS)