Formal Anti-Markovnikov Addition of Water to Olefins by Titanocene-Catalyzed Epoxide Hydrosilylation: From Stoichiometric to Sustainable Catalytic Reactions

Here, the evolution of the titanocene-catalyzed hydrosilylation of epoxides that yields the corresponding anti-Markovnikov alcohols is summarized. The study focuses on aspects of sustainability, efficient catalyst activation, and stereoselectivity. The latest variant of the reaction employs polymethylhydrosiloxane (PMHS), a waste product of the Müller-Rochow process as terminal reductant, features an efficient catalyst activation with benzylMgBr and the use of the bench stable Cp₂TiCl₂ as precatalyst. The combination of olefin epoxidation and epoxide hydrosilylation provides a uniquely efficient approach to the formal anti-Markovnikov addition of H₂O to olefins.

Genic-intergenic polymorphisms of CYP1A genes and their clinical impact

The humancytochrome P450 1A (CYP1A) subfamily genes, CYP1A1 and CYP1A2, encoding monooxygenases are critically involved in biotransformation of key endogenous substrates (estradiol, arachidonic acid, cholesterol) and exogenous compounds (smoke constituents, carcinogens, caffeine, therapeutic drugs). This suggests their significant involvement in multiple biological pathways with a primary role of maintaining endogenous homeostasis and xenobiotic detoxification. Large interindividual variability exist in CYP1A gene expression and/or catalytic activity of the enzyme, which is primarily due to the existence of polymorphic alleles which encode them. These polymorphisms (mainly single nucleotide polymorphisms, SNPs) have been extensively studied as susceptibility factors in a spectrum of clinical phenotypes. An in-depth understanding of the effects of polymorphic CYP1A genes on the differential metabolic activity and the resulting biological pathways is needed to explain the clinical implications of CYP1A polymorphisms. The present review is intended to provide an integrated understanding of CYP1A metabolic activity with unique substrate specificity and their involvement in physiological and pathophysiological roles. The article further emphasizes on the impact of widely studied CYP1A1 and CYP1A2 SNPs and their complex interaction with non-genetic factors like smoking and caffeine intake on multiple clinical phenotypes. Finally, we attempted to discuss the alterations in metabolism/physiology concerning the polymorphic CYP1A genes, which may underlie the reported clinical associations. This knowledge may provide insights into the disease pathogenesis, risk stratification, response to therapy and potential drug targets for individuals with certain CYP1A genotypes.

Predicting disruptions to drug pharmacokinetics and the risk of adverse drug reactions in non-alcoholic steatohepatitis patients

The liver plays a central role in the pharmacokinetics of drugs through drug metabolizing enzymes and transporters. Non-alcoholic steatohepatitis (NASH) causes disease-specific alterations to the absorption, distribution, metabolism, and excretion (ADME) processes, including a decrease in protein expression of basolateral uptake transporters, an increase in efflux transporters, and modifications to enzyme activity. This can result in increased drug exposure and adverse drug reactions (ADRs). Our goal was to predict drugs that pose increased risks for ADRs in NASH patients. Bibliographic research identified 71 drugs with reported ADRs in patients with liver disease, mainly non-alcoholic fatty liver disease (NAFLD), 54 of which are known substrates of transporters and/or metabolizing enzymes. Since NASH is the progressive form of NAFLD but is most frequently undiagnosed, we identified other drugs at risk based on NASH-specific alterations to ADME processes. Here, we present another list of 71 drugs at risk of pharmacokinetic disruption in NASH, based on their transport and/or metabolism processes. It encompasses drugs from various pharmacological classes for which ADRs may occur when used in NASH patients, especially when eliminated through multiple pathways altered by the disease. Therefore, these results may inform clinicians regarding the selection of drugs for use in NASH patients.

Lorcaserin for Dravet Syndrome: A Potential Advance Over Fenfluramine?

Lorcaserin, a selective serotonin 5-HT_2C receptor agonist, was developed as an appetite suppressant with the rationale of minimizing the risk of cardiovascular toxicity associated with non-selective serotoninergic agents such as fenfluramine. Eight years after FDA approval, however, it was withdrawn from the market, when a large safety study suggested a potential cancer risk. Following in the fenfluramine footsteps and utilizing the repurposing approach coupled with the regulatory orphan drug designation, lorcaserin is currently in clinical development for the treatment of epilepsy. This potential novel indication builds on the evidence that 5-HT_2C receptor stimulation can protect against seizures, and accounts at least in part for fenfluramine's antiseizure effects in Dravet syndrome models. In animal models, lorcaserin shows a narrower range of antiseizure activity than fenfluramine. In particular, lorcaserin is inactive in classical acute seizure tests such as maximal electroshock and subcutaneous pentylenetetrazole in mice and rats, and the 6-Hz stimulation model in mice. However, it is active in the GAERS absence seizure model, and in mutant zebrafish models of Dravet syndrome. Preliminary uncontrolled studies in patients with Dravet syndrome have yielded promising results, and a phase III, double-blind, placebo-controlled, parallel group trial is currently ongoing to assess its efficacy and safety in children and adults with Dravet syndrome.

Titanocene(III)-Catalyzed Precision Deuteration of Epoxides

We describe a titanocene(III)-catalyzed deuterosilylation of epoxides that provides β-deuterated anti-Markovnikov alcohols with excellent D-incorporation, in high yield, and often excellent diastereoselectivity after desilylation. The key to the success of the reaction is a novel activation method of Cp₂ TiCl₂ and (tBuC₅ H₄ )₂ TiCl₂ with BnMgBr and PhSiD₃ to provide [(RC₅ H₄ )₂ Ti(III)D] without isotope scrambling. It was developed after discovering an off-cycle scrambling with the previously described method. Our precision deuteration can be applied to the synthesis of drug precursors and highlights the power of combining radical chemistry with organometallic catalysis.

Non-cytochrome P450 enzymes involved in the oxidative metabolism of xenobiotics: Focus on the regulation of gene expression and enzyme activity

Oxidative metabolism is one of the major biotransformation reactions that regulates the exposure of xenobiotics and their metabolites in the circulatory system and local tissues and organs, and influences their efficacy and toxicity. Although cytochrome (CY)P450s play critical roles in the oxidative reaction, extensive CYP450-independent oxidative metabolism also occurs in some xenobiotics, such as aldehyde oxidase, xanthine oxidoreductase, flavin-containing monooxygenase, monoamine oxidase, alcohol dehydrogenase, or aldehyde dehydrogenase-dependent oxidative metabolism. Drugs form a large portion of xenobiotics and are the primary target of this review. The common reaction mechanisms and roles of non-CYP450 enzymes in metabolism, factors affecting the expression and activity of non-CYP450 enzymes in terms of inhibition, induction, regulation, and species differences in pharmaceutical research and development have been summarized. These non-CYP450 enzymes are detoxifying enzymes, although sometimes they mediate severe toxicity. Synthetic or natural chemicals serve as inhibitors for these non-CYP450 enzymes. However, pharmacokinetic-based drug interactions through these inhibitors have rarely been reported in vivo. Although multiple mechanisms participate in the basal expression and regulation of non-CYP450 enzymes, only a limited number of inducers upregulate their expression. Therefore, these enzymes are considered non-inducible or less inducible. Overall, this review focuses on the potential xenobiotic factors that contribute to variations in gene expression levels and the activities of non-CYP450 enzymes.

Is there enough evidence to classify cycloalkyl amine substituents as structural alerts?

Basic amine substituents provide several pharmacokinetic benefits relative to acidic and neutral functional groups, and have been extensively utilized as substituents of choice in drug design. On occasions, basic amines have been associated with off-target pharmacology via interactions with aminergic G-protein coupled receptors, ion-channels, kinases, etc. Structural features associated with the promiscuous nature of basic amines have been well-studied, and can be mitigated in a preclinical drug discovery environment. In addition to the undesirable secondary pharmacology, α-carbon oxidation of certain secondary or tertiary cycloalkyl amines can generate electrophilic iminium and aldehyde metabolites, potentially capable of covalent adduction to proteins or DNA. Consequently, cycloalkyl amines have been viewed as structural alerts (SAs), analogous to functional groups such as anilines, furans, thiophenes, etc., which are oxidized to reactive metabolites that generate immunogenic haptens by covalently binding to host proteins. Detailed survey of the literature, however, suggests that cases where preclinical or clinical toxicity has been explicitly linked to the metabolic activation of a cycloalkyl amine group are extremely rare. Moreover, there is a distinct possibility for the formation of electrophilic iminium/amino-aldehyde metabolites with numerous cycloalkyl amine-containing marketed drugs, since stable ring cleavage products have been characterized as metabolites in human mass balance studies. In the present work, a critical analysis of the evidence for and against the role of iminium ions/aldehydes as mediators of toxicity is discussed with a special emphasis on often time overlooked detoxication pathways of these reactive species to innocuous metabolites.

Safety and Efficacy of Weight-Loss Pharmacotherapy in Persons Living with HIV: A Review of the Literature and Potential Drug-Drug Interactions with Antiretroviral Therapy

The prevalence of obesity among persons living with human immunodeficiency virus (HIV) has increased significantly and may be linked to the use of antiretroviral therapy. Although weight-loss medications approved by the U.S. Food and Drug Administration are recommended as an adjunct to diet and exercise to treat obesity in the general population, little is known about the safety and efficacy of these drugs specifically in persons living with HIV. We review the available evidence regarding the effective use of weight-loss pharmacotherapy in persons living with HIV and its potential to interact with antiretroviral therapy. Persons living with HIV are frequently not reported or included in clinical trials for weight-loss medications; however, treatment efficacy is likely similar to the general population. Several important reported or theoretical drug-drug interactions exist between antiobesity pharmacotherapy and antiretroviral therapy. Orlistat is a weight-loss drug available in the United States without a prescription and was linked to HIV viral rebound in several case reports. Clinicians should be aware of the potential for loss of HIV viremia control when certain weight-loss pharmacotherapies are used in combination with antiretrovirals.

P450 Monooxygenases Enable Rapid Late-Stage Diversification of Natural Products via C-H Bond Activation

The biological potency of natural products has been exploited for decades. Their inherent structural complexity and natural diversity might hold the key to efficiently address the urgent need for the development of novel pharmaceuticals. At the same time, it is that very complexity, which impedes necessary chemical modifications such as structural diversification, to improve the effectiveness of the drug. For this purpose, Cytochrome P450 enzymes, which possess unique abilities to activate inert sp3-hybridised C-H bonds in a late-stage fashion, offer an attractive synthetic tool. In this review the potential of cytochrome P450 enzymes in chemoenzymatic lead diversification is illustrated discussing studies reporting late-stage functionalisations of natural products and other high-value compounds. These enzymes were proven to extend the synthetic toolbox significantly by adding to the flexibility and efficacy of synthetic strategies of natural product chemists, and scientists of other related disciplines.

Catalytic α-Selective Deuteration of Styrene Derivatives

We report an operationally simple protocol for the catalytic α-deuteration of styrenes. This process proceeds via the base-catalyzed reversible addition of methanol to styrenes in DMSO -d₆ solvent. The concentration of methanol is shown to be critical for high yields and selectivities over multiple competing side reactions. The synthetic utility of α-deuterated styrenes for accessing deuterium-labeled chiral benzylic stereocenters is demonstrated.

Challenging obesity, diabetes, and addiction: the potential of lorcaserin extended release

Obesity is a global epidemic that is a leading cause of preventable death. In addition to lifestyle modification, there are numerous obesity treatments for clinicians to consider, including medications. Lorcaserin immediate release/extended release (IR/XR) is a US Food and Drug Administration approved medication for overweight and obese patients to be used with lifestyle modifications. Lorcaserin is thought to reduce weight by targeting the serotonin (5HT2c) system to induce satiety. Lorcaserin IR has been shown to be effective in reducing weight in overweight (body mass index [BMI] > 27 kg/m2) and obese (BMI > 30 kg/m2) participants in three large Phase III trials. In addition, lorcaserin has been shown to reduce post-cessation weight gain and improved smoking cessation in a randomized placebo-controlled trial. A recent meta-analysis suggested in overweight diabetic patients lorcaserin may be added to first-line oral hypoglycemic medications to enhance reduction in glycated hemoglobin. Lorcaserin is generally well tolerated with the most common side effect being headache, which is typically self-limiting. Lorcaserin XR (once daily) was recently approved and has been shown to be bioequivalent to lorcaserin IR (twice daily) in a pivotal study. Lorcaserin XRs, main advantage over the IR formulation is the once daily dosing regimen, which likely would lead to improved adherence and thus improved clinical effectiveness. The present review will evaluate the lorcaserin clinical studies (obesity, diabetes, and addiction), XR bioequivalence studies, pharmacogenomics of the serotonin (5HT2c) system, and adherence data in once daily versus twice daily medications.

Drug metabolism by flavin-containing monooxygenases of human and mouse

INTRODUCTION

Flavin-containing monooxygenases (FMOs) play an important role in drug metabolism. Areas covered: We focus on the role of FMOs in the metabolism of drugs in human and mouse. We describe FMO genes and proteins of human and mouse; the catalytic mechanism of FMOs and their significance for drug metabolism; differences between FMOs and CYPs; factors contributing to potential underestimation of the contribution of FMOs to drug metabolism; the developmental and tissue-specific expression of FMO genes and differences between human and mouse; and factors that induce or inhibit FMOs. We discuss the contribution of FMOs of human and mouse to the metabolism of drugs and how genetic variation of FMOs affects drug metabolism. Finally, we discuss the utility of animal models for FMO-mediated drug metabolism in humans. Expert opinion: The contribution of FMOs to drug metabolism may be underestimated. As FMOs are not readily induced or inhibited and their reactions are generally detoxifications, the design of drugs that are metabolized predominantly by FMOs offers clinical advantages. Fmo1^(-/-),Fmo2^(-/-),Fmo4^(-/-) mice provide a good animal model for FMO-mediated drug metabolism in humans. Identification of roles for FMO1 and FMO5 in endogenous metabolism has implications for drug therapy and initiates an exciting area of research.

Characterization of the hepatic cytochrome P450 enzymes involved in the metabolism of 25I-NBOMe and 25I-NBOH

The dimethoxyphenyl-N-((2-methoxyphenyl)methyl)ethanamine (NBOMe) compounds are potent serotonin 5-HT2A receptor agonists and have recently been subject to recreational use due to their hallucinogenic effects. Use of NBOMe compounds has been known since 2011, and several non-fatal and fatal intoxication cases have been reported in the scientific literature. The aim of this study was to determine the importance of the different cytochrome P450 enzymes (CYP) involved in the metabolism of 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2methoxybenzyl)ethanamine (25I-NBOMe) and 2-[[2-(4-iodo-2,5dimethoxyphenyl)ethylamino]methyl]phenol (25I-NBOH) and to characterize the metabolites. The following approaches were used to identify the main enzymes involved in primary metabolism: incubation with a panel of CYP and monoamine oxidase (MAO) enzymes and incubation in pooled human liver microsomes (HLM) with and without specific CYP chemical inhibitors. The study was further substantiated by an evaluation of 25I-NBOMe and 25I-NBOH metabolism in single donor HLM. The metabolism pathways of 25I-NBOMe and 25I-NBOH were NADPHdependent with intrinsic clearance values of (CLint) of 70.1 and 118.7 mL/min/kg, respectively. The biotransformations included hydroxylation, O-demethylation, N-dealkylation, dehydrogenation, and combinations thereof. The most abundant metabolites were all identified by retention time and spectrum matching with synthesized reference standards. The major CYP enzymes involved in the metabolism of 25I-NBOMe and 25INBOH were identified as CYP3A4 and CYP2D6, respectively. The compound 25I-NBOH was also liable to direct glucuronidation, which may diminish the impact of CYP2D6 genetic polymorphism. Users of 25I-NBOMe may be subject to drug-drug interactions (DDI) if 25I-NBOMe is taken with a strong CYP3A4 inhibitor. Copyright © 2016 John Wiley & Sons, Ltd.

Discovery of a Novel Microsomal Epoxide Hydrolase-Catalyzed Hydration of a Spiro Oxetane

Oxetane moieties are increasingly being used by the pharmaceutical industry as building blocks in drug candidates because of their pronounced ability to improve physicochemical parameters and metabolic stability of drug candidates. The enzymes that catalyze the biotransformation of the oxetane moiety are, however, not well studied. The in vitro metabolism of a spiro oxetane-containing compound AZD1979 [(3-(4-(2-oxa-6-azaspiro[3.3]heptan-6-ylmethyl)phenoxy)azetidin-1-yl)(5-(4-ethoxyphenyl)-1,3,4-oxadiazol-2-yl)methanone] was studied and one of its metabolites, M1, attracted our interest because its formation was NAD(P)H independent. The focus of this work was to elucidate the structure of M1 and to understand the mechanism(s) of its formation. We established that M1 was formed via hydration and ring opening of the oxetanyl moiety of AZD1979. Incubations of AZD1979 using various human liver subcellular fractions revealed that the hydration reaction leading to M1 occurred mainly in the microsomal fraction. The underlying mechanism as a hydration, rather than an oxidation reaction, was supported by the incorporation of (18)O from H2 (18)O into M1. Enzyme kinetics were performed probing the formation of M1 in human liver microsomes. The formation of M1 was substantially inhibited by progabide, a microsomal epoxide hydrolase inhibitor, but not by trans-4-[4-(1-adamantylcarbamoylamino)cyclohexyloxy]benzoic acid, a soluble epoxide hydrolase inhibitor. On the basis of these results, we propose that microsomal epoxide hydrolase catalyzes the formation of M1. The substrate specificity of microsomal epoxide hydrolase should therefore be expanded to include not only epoxides but also the oxetanyl ring system present in AZD1979.

Identification of Human Sulfotransferases Involved in Lorcaserin N-Sulfamate Formation

Lorcaserin [(R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine] hydrochloride hemihydrate, a selective serotonin 5-hydroxytryptamine (5-HT) 5-HT(2C) receptor agonist, is approved by the U.S. Food and Drug Administration for chronic weight management. Lorcaserin is primarily cleared by metabolism, which involves multiple enzyme systems with various metabolic pathways in humans. The major circulating metabolite is lorcaserin N-sulfamate. Both human liver and renal cytosols catalyze the formation of lorcaserin N-sulfamate, where the liver cytosol showed a higher catalytic efficiency than renal cytosol. Human sulfotransferases (SULTs) SULT1A1, SULT1A2, SULT1E1, and SULT2A1 are involved in the formation of lorcaserin N-sulfamate. The catalytic efficiency of these SULTs for lorcaserin N-sulfamate formation is widely variable, and among the SULT isoforms SULT1A1 was the most efficient. The order of intrinsic clearance for lorcaserin N-sulfamate is SULT1A1 > SULT2A1 > SULT1A2 > SULT1E1. Inhibitory effects of lorcaserin N-sulfamate on major human cytochrome P450 (P450) enzymes were not observed or minimal. Lorcaserin N-sulfamate binds to human plasma protein with high affinity (i.e., >99%). Thus, despite being the major circulating metabolite, the level of free lorcaserin N-sulfamate would be minimal at a lorcaserin therapeutic dose and unlikely be sufficient to cause drug-drug interactions. Considering its formation kinetic parameters, high plasma protein binding affinity, minimal P450 inhibition or induction potential, and stability, the potential for metabolic drug-drug interaction or toxicological effects of lorcaserin N-sulfamate is remote in a normal patient population.

A Validated UPLC-MS-MS Assay for the Rapid Determination of Lorcaserin in Plasma and Brain Tissue Samples

Lorcaserin is a novel, potent and highly efficacious 5-HT2C receptor agonist, recently approved by US Food and Drug Administration for the treatment of obesity. It has some abuse potential also and is listed as a Schedule IV drug in the Controlled Substances Act. Herein, a sensitive, selective and reliable UPLC-MS-MS assay was developed and validated for the quantitative analysis of lorcaserin in rat plasma and brain tissue using carbamazepine as an internal standard (IS). After the extraction of samples by protein precipitation, both lorcaserin and IS were separated on an Acquity BEH™ C18 (50 × 2.1 mm, 1.7 µm) column using a mobile phase consisting of acetonitrile-10 mM ammonium acetate-formic acid (85:15:0.1, v/v/v) at a flow rate of 0.25 mL/min. Detection and quantification were performed on a positive electrospray ionization interface in the multiple-reaction monitoring (MRM) mode. The MS-MS ion transitions were monitored at m/z 195.99 > 143.91 for lorcaserin and m/z 237.00 > 178.97 for IS, respectively. The calibration curves were linear over a concentration range of 1.08-500 ng/mL in plasma and 3.07-500 ng/mL in brain tissue homogenates, respectively. All the validation parameters results were within the acceptable range described in guidelines for bioanalytical method validation. The assay was successfully applied in a pharmacokinetic study of lorcaserin after oral administration in rats.

MGFM: a novel tool for detection of tissue and cell specific marker genes from microarray gene expression data

Background

Identification of marker genes associated with a specific tissue/cell type is a fundamental challenge in genetic and cell research. Marker genes are of great importance for determining cell identity, and for understanding tissue specific gene function and the molecular mechanisms underlying complex diseases.

Results

We have developed a new bioinformatics tool called MGFM (Marker Gene Finder in Microarray data) to predict marker genes from microarray gene expression data. Marker genes are identified through the grouping of samples of the same type with similar marker gene expression levels. We verified our approach using two microarray data sets from the NCBI’s Gene Expression Omnibus public repository encompassing samples for similar sets of five human tissues (brain, heart, kidney, liver, and lung). Comparison with another tool for tissue-specific gene identification and validation with literature-derived established tissue markers established functionality, accuracy and simplicity of our tool. Furthermore, top ranked marker genes were experimentally validated by reverse transcriptase-polymerase chain reaction (RT-PCR). The sets of predicted marker genes associated with the five selected tissues comprised well-known genes of particular importance in these tissues. The tool is freely available from the Bioconductor web site, and it is also provided as an online application integrated into the CellFinder platform (http://cellfinder.org/analysis/marker).

Conclusions

MGFM is a useful tool to predict tissue/cell type marker genes using microarray gene expression data. The implementation of the tool as an R-package as well as an application within CellFinder facilitates its use.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1785-9) contains supplementary material, which is available to authorized users.

Ring enlargement reaction of C,N-cyclic-N'-acyl azomethine imines with sulfonium ylide: an efficient synthesis of 3-benzazepine derivatives

Highly efficient formation of 3-benzazepine derivatives has been achieved, based on the ring expansion reaction of C,N-cyclic-N'-acyl azomethine imines with sulfonium ylide generated in situ from the corresponding sulfonium salt. The reactions proceeded smoothly to afford the tricyclic 3-benzazepine derivatives in good to high yields. A wide range of C,N-cyclic N'-acyl azomethine imines were applicable to this reaction.

The in vitro metabolism of phospho-sulindac amide, a novel potential anticancer agent

Phospho-sulindac amide (PSA) is a novel potential anti-cancer and anti-inflammatory agent. Here we report the metabolism of PSA in vitro. PSA was rapidly hydroxylated at its butane-phosphate moiety to form two di-hydroxyl-PSA and four mono-hydroxyl-PSA metabolites in mouse and human liver microsomes. PSA also can be oxidized or reduced at its sulindac moiety to form PSA sulfone and PSA sulfide, respectively. PSA was mono-hydroxylated and cleared more rapidly in mouse liver microsomes than in human liver microsomes. Of eight major human cytochrome P450s (CYPs), CYP3A4 and CYP2D6 exclusively catalyzed the hydroxylation and sulfoxidation reactions of PSA, respectively. We also examined the metabolism of PSA by three major human flavin monooxygenases (FMOs). FMO1, FMO3 and FMO5 were all capable of catalyzing the sulfoxidation (but not hydroxylation) of PSA, with FMO1 being by far the most active isoform. PSA was predominantly sulfoxidized in human kidney microsomes because FMO1 is the dominant isoform in human kidney. PSA (versus sulindac) is a preferred substrate of both CYPs and FMOs, likely because of its greater lipophilicity and masked-COOH group. Ketoconazole (a CYP3A4 inhibitor) and alkaline pH strongly inhibited the hydroxylation of PSA, but moderately suppressed its sulfoxidation in liver microsomes. Together, our results establish the metabolic pathways of PSA, identify the major enzymes mediating its biotransformations and reveal significant inter-species and inter-tissue differences in its metabolism.

Identification of human papillomavirus status specific biomarker in head and neck cancer

BACKGROUND

In an attempt to improve the prognosis of patients with head and neck cancer, it could be necessary to identify biomarkers in homogeneous subgroups of patients with head and neck cancer.

METHODS

We explored the necessity of human papillomavirus (HPV) status-specific biomarkers in patients with head and neck cancer and identified an HPV status-specific gene set. The identified gene set was validated with the external microarray datasets. For this purpose, we used 4 microarray datasets obtained from a public database. One dataset was used for identifying the HPV status specific gene set, and the other datasets were used for validation.

RESULTS

The identified gene set for distinguishing head and neck cancer from head and neck normal, did not accurately discriminate the HPV specific patients with head and neck cancer from the head and neck normal group. Also, it was demonstrated that some HPV-positive (HPV+) head and neck cancer-specific genes may not be significant in HPV-negative (HPV-) head and neck cancer patients. The identified HPV specific gene sets showed good performance in validation datasets. The HPV+ head and neck cancer-specific gene set included various metabolism-related pathways, and the HPV- head and neck cancer-specific gene set included several pathways; fibroblast, collagen degradation, actin-binding, and actin cytoskeleton.

CONCLUSION

The identification of HPV status-specific significant gene set was necessary. It is expected that HPV status-specific biomarkers can be helpful in deciding therapeutic methods for patients with head and neck cancer, after biological validation and large prospective trials.

Lorcaserin: A novel antiobesity drug

Obesity is a major co-morbidity with hypertension and diabetes mellitus. There are few drugs for treatment of obesity like orlistat and recentlty approved drug lorcaserin. Lorcaserin has serotonergic properties and acts as an anorectic. It may cause serious side effects, including serotonin syndrome, particularly when taken with certain medicines that increase serotonin levels or activate serotonin receptors. Although, mainstay and first line of approach of treatment will always remain in having low calorie diet and increase in physical activity. Lorcaserin has come as a new hope to achieve success in treating obese patients but still a long road with further extensive research to be undertaken in the treatment of obesity.

New and emerging drug molecules against obesity

Obesity has become a growing pandemic of alarming proportions in the developed and developing countries over the last few decades. The most perturbing fact regarding obesity is the increased predisposition for coronary artery disease, congestive heart failure and sudden cardiac death. The modest efficacy of current anti-obesity agents such as orlistat and the increasing withdrawals of several anti-obesity agents such as sibutramine, rimonabant have led to huge gaps in the pharmacotherapy of obesity. Lorcaserin and Phentermine-topiramate combination (phen-top) are two drugs approved by US FDA in 2012. Lorcaserin, a 5HT2C agonist has moderate efficacy with an acceptable safety profile. Clinical trials with Phen-top have shown a reasonable efficacy but at the cost of risks such as teratogenicity and psychiatric disturbances. Cetilistat, a lipase inhibitor is claimed to have superior safety profile to orlistat and is in phase 3 clinical trials. Other promising anti-obesity molecules acting on the gut which are in clinical trials include exenatide and liraglutide. Drugs which act on the monoaminergic and opioid systems include bupropion-naltrexone and bupropion-zonisamide. Other novel first-in-class drugs which have been explored and have limited success in early clinical development include velneperit, tesofensine, and beloranib. Tesofensine is a triple monoamine re-uptake inhibitor, velneperit acts as a neuropeptide Y5 receptor antagonist and beloranib is a methionine amino peptidase 2 inhibitor. Novel targets such as histamine H3 receptor, VEGF, matrix-metalloproteinase, sirtuin receptors are also being investigated. This review is an attempt to describe the new and emerging molecules that are in clinical development for obesity.

Was it worth the weight? - Drug review on two new weight loss agents: lorcaserin (Belviq®) and phentermine/topiramate ER (QsymiaTM)

The prevalence of obesity in the United States (U.S.) is currently at 34%. This article will review two of the newer weight loss agents: lorcaserin and phentermine/topiramate. Mechanism of action, dosing, adverse events, and drug interactions will be discussed.

Lorcaserin Hydrochloride

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. Subscribers to The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The November 2012 monograph topics are on vincristine sulfate liposome injection; ZIV-aflibercept; icosapent ethyl; prednisone delayed-release tablets; and elvitegravir, cobicistat, emtricitabine, tenofovir DF. The DUE/MUE is on vincristine sulfate liposome.