Discovery history and clinical development of mirabegron for the treatment of overactive bladder and urinary incontinence

Medicinal plants and natural products for treating overactive bladder

BACKGROUND

Overactive bladder (OAB) presents a high prevalence of 16-18% worldwide. The pathophysiology of OAB is still poorly understood while effective therapy or countermeasure are very limited. On the other hand, medicinal plants and herbal remedies have been utilized for treating lower urinary tract symptoms (LUTS) in both Eastern and Western cultures since ancient times. In recent years, accumulating progress has also been made in OAB treatment research by using medicinal plants.

METHODS

Relevant literature on the studies of medicinal plants and herbs used to treat OAB was reviewed. The medicinal plants were summarized and categorized into two groups, single-herb medications and herbal formulations.

RESULTS

The present review has summarized current understanding of OAB's pathophysiology, its available treatments and new drug targets. Medicinal plants and natural products which have been used or have shown potential for OAB treatment were updated and comprehensively categorized. Studies on a wide variety of medicinal plants showed promising results, although only a few phytochemicals have been isolated and identified. Until now, none of these herbal compounds have been further developed into clinical therapeutics for OAB.

CONCLUSIONS

This review provides the basis for discovering and designing new phytopharmaceutical candidates with effective and well-tolerated properties to treat OAB. Increasing evidences indicate new strategies with alternative herbal treatment for OAB have high efficacy and safety, showing great promise for their clinical use. Future studies in a rigorously designed controlled manner will be beneficial to further support the eligibility of herbal treatment as OAB therapeutics.

Distinct Conformations of Mirabegron Determined by MicroED

Mirabegron, commonly known as "Myrbetriq", has been widely prescribed as a medicine for overactive bladder syndrome for over a decade. However, the structure of the drug and what conformational changes it may undergo upon binding its receptor remain unknown. In this study, the authors employed microcrystal electron diffraction (MicroED) to reveal its elusive three-dimensional (3D) structure. They find that the drug adopts two distinct conformational states (conformers) within the asymmetric unit. Analysis of hydrogen bonding and packing demonstrated that the hydrophilic groups are embedded within the crystal lattice, resulting in a hydrophobic surface and low water solubility. Structural comparison revealed the presence of trans- and cis- forms in conformers 1 and 2, respectively. Comparison of the structures of Mirabegron alone with that of the drug bound to its receptor, the beta 3 adrenergic receptor (β3AR) suggests that the drug undergoes major conformational change to fit in the receptor agonist binding site. This research highlights the efficacy of MicroED in determining the unknown and polymorphic structures of active pharmaceutical ingredients (APIs) directly from powders.

Distinct Conformations of Mirabegron Determined by MicroED

Mirabegron, commonly known as "Myrbetriq", has been widely prescribed as a medicine for overactive bladder syndrome for over a decade. However, the structure of the drug and what conformational changes it may undergo upon binding its receptor remain unknown. In this study, we employed microcrystal electron diffraction (MicroED) to reveal its elusive three-dimensional (3D) structure. We find that the drug adopts two distinct conformational states (conformers) within the asymmetric unit. Analysis of hydrogen bonding and packing demonstrated that the hydrophilic groups were embedded within the crystal lattice, resulting in a hydrophobic surface and low water solubility. Structural comparison revealed the presence of trans- and cis- forms in conformers 1 and 2, respectively. Comparison of the structures of Mirabegron alone with that of the drug bound to its receptor,1 the beta 3 adrenergic receptor (β3AR) suggests that the drug undergoes major conformational change to fit in the receptor agonist binding site. This research highlights the efficacy of MicroED in determining the unknown and polymorphic structures of active pharmaceutical ingredients (APIs) directly from powders.

Adherence to Overactive Bladder Syndrome Treatments Recent Developments and Future Perspectives

Overactive bladder (OAB) is a common and distressing condition which is known to have a significant effect on Health-Related Quality of Life (HRQoL). Whilst all patients complaining of overactive bladder symptoms will, in theory, initially benefit from conservative measures, many will require pharmacological therapy. Antimuscarinics currently remain the most commonly used drugs to treat OAB although compliance and persistence can be poor due to concerns regarding adverse events and lack of efficacy. This review will explore the common management strategies for OAB with a particular focus on patient adherence to therapy including compliance and persistence. The role of antimuscarinics and the B3-agonist, mirabegron, will be considered along with barriers to their efficacy and adoption. For those patients in whom conservative and pharmacological treatment proves ineffective or is unsuitable, the management of refractory OAB will also be considered. In addition, the role of current and future developments will be examined.

Assessing Quality-of-Life of Patients Taking Mirabegron for Overactive Bladder

Lower urinary tract symptoms (LUTS), including urgency, frequency, and urgency incontinence, are highly prevalent in the general population and increase in prevalence with increasing age. All LUTS, but notable urgency and urgency incontinence, are associated with negative impact on quality-of-life (QoL), with multiple aspects of QoL affected. Urgency and urgency incontinence are most commonly caused by overactive bladder (OAB), the clinical syndrome of urinary urgency, usually accompanied by increased daytime frequency and/or nocturia in the absence of infection or other obvious etiology, which may be treated with conservative and lifestyle interventions, bladder antimuscarinic drugs, and, more recently, by mirabegron, a β3 agonist. This narrative review describes the impact of OAB on QoL, quantifies this impact, and outlines the evidence for the use of mirabegron in the treatment of, and improvement in QoL in, people with OAB.

Mirabegron in the Management of Overactive Bladder Syndrome

Overactive bladder (OAB) negatively affects work productivity and quality of life in sufferers. Its overall impact is likely to increase as a result of increasing prevalence in an ageing population. The pathophysiology of OAB is not completely understood but the β3-adrenoceptor, which is highly expressed in the urinary bladder, is thought to be important for mediating human detrusor relaxation during the storage phase. Clinical trial results have demonstrated that mirabegron, a selective β3-adrenoceptor agonist offers substantial clinical efficacy and good adherence rates over 12 months. Furthermore, due to its different mechanism of action, it is likely to offer a favourable tolerability profile when compared with antimuscarinic agents, resulting in improved persistence over long-term treatment. Finally, from a health economic perspective, despite its higher drug acquisition cost, mirabegron has been found to be cost-effective, owing to the greater increase in quality-adjusted-life-years gained, when compared to antimuscarinic medications. The PubMed database was searched for English language articles published between 1 January 2005 to 31 January 2022, on the subject of mirabegron. Search terms included "mirabegron", "overactive bladder", "β3-adrenoceptor agonist", "urinary incontinence". This review summarises the evidence for mirabegron as a treatment option for the management of OAB.

Browning Epicardial Adipose Tissue: Friend or Foe?

The epicardial adipose tissue (EAT) is the visceral fat depot of the heart which is highly plastic and in direct contact with myocardium and coronary arteries. Because of its singular proximity with the myocardium, the adipokines and pro-inflammatory molecules secreted by this tissue may directly affect the metabolism of the heart and coronary arteries. Its accumulation, measured by recent new non-invasive imaging modalities, has been prospectively associated with the onset and progression of coronary artery disease (CAD) and atrial fibrillation in humans. Recent studies have shown that EAT exhibits beige fat-like features, and express uncoupling protein 1 (UCP-1) at both mRNA and protein levels. However, this thermogenic potential could be lost with age, obesity and CAD. Here we provide an overview of the physiological and pathophysiological relevance of EAT and further discuss whether its thermogenic properties may serve as a target for obesity therapeutic management with a specific focus on the role of immune cells in this beiging phenomenon.

Cold Exposure Drives Weight Gain and Adiposity following Chronic Suppression of Brown Adipose Tissue

Therapeutic activation of thermogenic brown adipose tissue (BAT) may be feasible to prevent, or treat, cardiometabolic disease. However, rodents are commonly housed below thermoneutrality (~20 °C) which can modulate their metabolism and physiology including the hyperactivation of brown (BAT) and beige white adipose tissue. We housed animals at thermoneutrality from weaning to chronically supress BAT, mimic human physiology and explore the efficacy of chronic, mild cold exposure (20 °C) and β3-adrenoreceptor agonism (YM-178) under these conditions. Using metabolic phenotyping and exploratory proteomics we show that transfer from 28 °C to 20 °C drives weight gain and a 125% increase in subcutaneous fat mass, an effect not seen with YM-178 administration, thus suggesting a direct effect of a cool ambient temperature in promoting weight gain and further adiposity in obese rats. Following chronic suppression of BAT, uncoupling protein 1 mRNA was undetectable in the subcutaneous inguinal white adipose tissue (IWAT) in all groups. Using exploratory adipose tissue proteomics, we reveal novel gene ontology terms associated with cold-induced weight gain in BAT and IWAT whilst Reactome pathway analysis highlights the regulation of mitotic (i.e., G2/M transition) and metabolism of amino acids and derivatives pathways. Conversely, YM-178 had minimal metabolic-related effects but modified pathways involved in proteolysis (i.e., eukaryotic translation initiation) and RNA surveillance across both tissues. Taken together these findings are indicative of a novel mechanism whereby animals increase body weight and fat mass following chronic suppression of adaptive thermogenesis from weaning. In addition, treatment with a B3-adrenoreceptor agonist did not improve metabolic health in obese animals raised at thermoneutrality.

Pharmacological Management of Urinary Incontinence: Current and Emerging Treatment

Pharmacological management of urinary incontinence (UI) is currently based on antimuscarinic and beta-3-agonist drugs. Botulinum toxin A detrusor injections represent an effective but more invasive alternative. This review covers the latest developments of the currently available drugs and the emerging compounds for the treatment of UI. Evidence shows that new antimuscarinics and beta-3-agonists with improved safety profiles may offer unique options to patients intolerant to currently available drugs. Combination therapy proved to be a non-invasive alternative for patients refractory to first-line monotherapy. Exciting advances are ongoing in the research to improve the efficacy/tolerability profile of botulinum toxin, through innovative routes of administration. Several new agents emerged from preclinical studies, some of which have now entered the clinical phase of development and could represent, in the coming years, a new way for the treatment of UI. Recent evidence on the existence of different overactive bladder phenotypes could be the key to tailored treatment. Rather than discovering new molecules, reaching the ability to identify the right drug for the right patient could be the real gamechanger of the future.

Long-term effectiveness of an intervention to enhance mirabegron use revision and its deprescribing: 36-month follow-up of a quasi-experimental trial in primary care

OBJECTIVE

This is a follow-up study from a multicenter, prospective, before-and-after quasi-experimental, controlled trial to assess effectiveness at 36 months of an intervention designed to promote the revision and deprescribing of mirabegron in primary care in patients with overactive bladder.

METHODS

Intervention included patients who attended in 17 PHCs located in North Barcelona; control included patients who attended in the other 34 PHCs located in South, East and West Barcelona. The primary endpoint was mirabegron review and deprescribing when GPs considered appropriate, which was measured by the percentage of change of the number of patients with treatment at 36 months compared to the baseline. The intervention consisted of meetings with all the directors of the PHCs; distribution of the infographic to the GPs; providing information regarding the intervention for urologist and gynaecologist; and review of the treatments by the GPs. A monthly follow-up was done during the first year, and every three months thereafter until month 36.

RESULTS

Overall, 1932 patients were included, mean age 71.6 years (female 53.8%). A total of 540 patients included in the intervention discontinued mirabegron at some point during the 36 months follow-up (540/762, 70.8%) compared to 759 patients in the control (759/1170, 64.9%), (p < 0.001). A total of 324/433 patients (74.8%) who discontinued mirabegron use at 12 months remained without pharmacological treatment at 36 months. With respect to the baseline cohort, there was a lower introduction of new patients with mirabegron in the intervention (546/762, 71.6%) compared to the control (1246/1170, 106.5%), (p < .001). Regarding the treated patients, there was an increase of 41.6% in the control and a slight increase of 0.8% in the intervention at 36 months, (p < .001).

CONCLUSION

Our data indicate that an intervention can enhance the review use of mirabegron in the primary care setting, and promote their deprescribing.

2-aminothiazoles in drug discovery: Privileged structures or toxicophores?

The 2-aminothiazole functionality has long been established as a privileged structural feature and therefore frequently exploited in the process of drug discovery and development. It has been introduced into numerous compounds due to its capacity for targeting a wide range of therapeutic target proteins. On the other hand, the aminothiazole group has also been classified as a toxicophore susceptible to metabolic activation and the ensuing reactive metabolite formation, hence caution is warranted when used in drug design. This review is divided into three parts entailing: (i) the general characteristics of the aminothiazole group, (ii) the advantages of the aminothiazole group in medicinal chemistry, and (iii) the impact of the integrated aminothiazole group on compound safety profile.

Evaluating vibegron for the treatment of overactive bladder

INTRODUCTION

Vibegron is a very selective new β3-adrenergic receptor agonist introduced recently to clinical practice for OAB patients, which offers an alternative option for to antimuscarinic drugs.

AREAS COVERED

This review presents the current knowledge concerning the mechanism of action, pharmacokinetics, and pharmacodynamics of vibegron. Moreover, it presents an overview of preclinical and phase II and phase III clinical studies on the efficacy, tolerability, and safety of this agent in patients suffering from OAB.

EXPERT OPINION

Clinical studies confirmed efficacy and safety of vibegron in OAB patients. Vibegron differ from well-known mirabegron with regards to its pharmacological profile because it is metabolized independently from CYP3A4, 2D6, or 2C9 and therefore is less likely to cause a drug-drug interaction. Moreover, since this drug does not penetrate the blood-brain barrier, it could become the drug of choice in OAB patients with cognitive impairment. These properties have paved the way in near future for better-tailored treatments for OAB patients.

Managing overactive bladder

Overactive bladder (OAB) is a common and distressing condition which is known to increase with age and has a significant effect on quality of life. Whilst OAB is a symptomatic diagnosis, many patients will require basic investigations prior to initiating the appropriate management. This article will review the initial clinical assessment and management of women complaining of OAB including conservative measures and drug therapy, and will also focus on the role of estrogen. In addition, the management of refractory OAB will also be discussed including more invasive strategies such as neuromodulation, Botulinum Toxin, and reconstructive surgery.

Mirabegron in the Treatment of Overactive Bladder: Safety and Efficacy in the Very Elderly Patient

Lower urinary tract symptoms, including urgency, urgency incontinence, frequency, and nocturia, are highly prevalent in older adults and are associated with significant morbidity and impairment in quality of life. When conservative measures such as bladder training fail to improve symptoms, pharmacological management is recommended by national and international guidelines. Mirabegron, an agonist of the β3 adrenergic receptor, demonstrates similar efficacy to the anticholinergic drugs without the risk of anticholinergic effects, but experience and evidence in the very elderly population are limited. This narrative review examines the current evidence base for mirabegron in very elderly adults.

Combination drug therapy against OAB normalizes micturition parameters and increases the release of nitric oxide during chemically induced cystitis

Today, monotherapy is the most common pharmacological treatment option for patients suffering from overactive bladder (OAB). Recent reports have indicated potential benefits of combination therapy, using a muscarinic antagonist and a β3 -adrenoceptor agonist. This may be of particular interest for therapy-resistant patients with OAB and concomitant cystitis. The objective of the current study was to assess how combination therapy affects bladder parameters in health and cystitis and if the efficacy of the drugs can be linked to altered release of nitric oxide (NO). Rats were pretreated with either a combination of the muscarinic antagonist tolterodine and β3 -selective adrenoceptor agonist mirabegron or saline for 10 days. Forty-eight hours prior to assessing micturition parameters in a metabolic cage, the rats were intraperitoneally injected with cyclophosphamide, causing cystitis, or saline. Urine samples were collected and analyzed for NO content. Bladder contractile properties were assessed in an organ bath setup. Induction of cystitis led to bladder overactivity. Combination therapy normalized bladder parameters. Both induction of cystitis and drug treatment increased the release of NO. The innate contractile properties of the bladder were unaffected by combination therapy. This study demonstrates positive effects of combination drug therapy on symptoms of OAB, possibly indicating it to be a good option for treatment of OAB during concomitant cystitis. It remains to be determined if increased release of NO is crucial for successful pharmacological treatment of bladder overactivity during cystitis.

Beneficial Metabolic Effects of Mirabegron In Vitro and in High-Fat Diet-Induced Obese Mice

Mirabegron, a β3-adrenergic receptor agonist, has been shown to stimulate the activity of brown fat and increase the resting metabolic rate in humans. However, it is unknown whether mirabegron can reduce body weight and improve metabolic health. We investigated the antiobesity effects of mirabegron using both in vitro and in vivo models. Mouse brown preadipocytes and 3T3-L1 cells were treated with different concentrations of mirabegron (0.03-3 µg/ml), and the expression of brown fat-related genes was measured by quantitative real-time polymerase chain reaction. Furthermore, male C57BL/6J mice were fed a high-fat diet for 10 weeks, and mirabegron (2 mg/kg body weight) or a vehicle control was delivered to the interscapular brown adipose tissue (iBAT) using ALZET osmotic pumps from week 7 to 10. The metabolic parameters and tissues were analyzed. In both mouse brown preadipocytes and 3T3-L1 cells, mirabegron stimulated uncoupling protein 1 (UCP1) expression. In animal studies, mirabegron-treated mice had a lower body weight and adiposity. Lipid droplets in the iBAT of mirabegron-treated mice were fewer and smaller in size compared with those from vehicle-treated mice. H&E staining and immunohistochemistry indicated that mirabegron increased the abundance of beige cells in inguinal white adipose tissue (iWAT). Compared with vehicle-treated mice, mirabegron-treated mice had a higher gene expression of UCP1 (14-fold) and cell death-inducing DNA fragmentation factor alpha-like effector A (CIDEA) (4-fold) in iWAT. Furthermore, mirabegron-treated mice had improved glucose tolerance and insulin sensitivity. Taken together, mirabegron enhances UCP1 expression and promotes browning of iWAT, which are accompanied by improved glucose tolerance and insulin sensitivity and prevention from high-fat diet-induced obesity.

Managing urinary incontinence in women - a review of new and emerging pharmacotherapy

INTRODUCTION

The pharmacological treatment of urinary incontinence and overactive bladder (OAB) has been, for a longer time, based on antimuscarinic agents. In recent years, two other pharmacological principles have been introduced for the treatment of OAB and urgency urinary incontinence: the β3-adrenergic agent mirabegron and botulinum neurotoxin. Meanwhile, there is lack of effective drugs for the treatment of stress incontinence.

AREAS COVERED

This literature review presents synthetic compounds aimed to treat female urinary incontinence that are in phase II-III clinical development.

EXPERT OPINION

Antimuscarinic agents will continue to represent the current gold standard for the first-line pharmacological management of OAB and urgency urinary incontinence. The class of β3-agonists will certainly expand with the discovery and clinical development of novel agents. Combination therapy of antimuscarinic agents and β3-agonists could offer an alternative treatment in these patients, including those with symptoms refractory to first-line monotherapy. A huge number of preclinical studies are underway in this field exploring the therapeutic potential of many novel compounds while some have advanced to clinical phases of development.

Mirabegron, alone and in combination, in the treatment of overactive bladder: real-world evidence and experience

Overactive bladder (OAB), the syndrome characterized by urgency, with or without urgency incontinence, usually with frequency and nocturia, in the absence of infection or other pathology, is a common, distressing and often debilitating condition with a high prevalence in the general population. For many years, the only available pharmacological treatment for OAB were the antimuscarinic agents. More recently, mirabegron, a selective agonist of the β3 adrenergic receptor, has become available. In this article we review the current evidence and experience of its use.

Recent advances in pharmacological management of urinary incontinence

Lower urinary tract symptoms-in particular, storage disorders (for example, urinary incontinence) as well as bladder underactivity-are major health-related problems that increase with age. Yet lower urinary tract symptoms remain under-diagnosed and poorly managed, and incontinence has been cited as the major reason for institutionalization in elderly populations and is one of the most common conditions in primary care practice. Although lifestyle and behavior therapy has been used as a useful treatment regimen for urge incontinence, medications (often used as adjunct) can provide additional benefit. This review will include current therapies used for treatment of urinary incontinence.

Mirabegron Toxicosis in Dogs: a Retrospective Study

Mirabegron is a selective beta (B)₃ adrenoreceptor agonist marketed for human treatment of an overactive bladder (OAB). It has a wide margin of safety in humans, but in dogs, severe adverse effects have occurred. We sought to determine the effects and outcome of mirabegron toxicosis in dogs. A retrospective review of all calls within the Pet Poison Helpline (PPH), an international animal poison control center, database was performed for mirabegron exposures between 2013 and 2015. Potential ingested doses ranging from 1.31 to 8.3 mg/kg. Many dogs remained asymptomatic and no fatalities occurred in any dogs. The most commonly reported signs were tachycardia and erythema. While mirabegron was found to have a very narrow margin of safety and high toxicity risk to dogs during preclinical trials, effects appear to differ greatly in the nonclinical field environment and further study is needed.

Discovery of Novel Indazole Derivatives as Orally Available β3-Adrenergic Receptor Agonists Lacking Off-Target-Based Cardiovascular Side Effects

We previously discovered that indazole derivative 8 was a highly selective β₃-adrenergic receptor (β₃-AR) agonist, but it appeared to be metabolically unstable. To improve metabolic stability, further optimization of this scaffold was carried out. We focused on the sulfonamide moiety of this scaffold, which resulted in the discovery of compound 15 as a highly potent β₃-AR agonist (EC₅₀ = 18 nM) being inactive to β₁-, β₂-, and α_1A-AR (β₁/β₃, β₂/β₃, and α_1A/β₃ > 556-fold). Compound 15 showed dose-dependent β₃-AR-mediated responses in marmoset urinary bladder smooth muscle, had a desirable metabolic stability and pharmacokinetic profile (C_max and AUC), and did not obviously affect heart rate or mean blood pressure when administered intravenously (3 mg/kg) to anesthetized rats. Thus, compound 15 is a highly potent, selective, and orally available β₃-AR agonist, which may serve as a candidate drug for the treatment of overactive bladder without off-target-based cardiovascular side effects.

Cost-effectiveness of mirabegron compared to tolterodine ER 4 mg for overactive bladder in Canada

INTRODUCTION

This analysis compared the cost-effectiveness of once-daily regimens of mirabegron 50 mg and generic tolterodine ER 4 mg in a hypothetical cohort of previously treated patients with overactive bladder (OAB) in Canada.

METHODS

A Markov model was developed to represent different health states according to OAB symptoms (frequency, incontinence), presence/absence of adverse events (AEs; dry mouth, constipation, blurred vision), and treatment status (on-treatment, discontinue treatment, restart previous treatment). The time horizon used was one year, with monthly transitions between health states. The model was populated using data from a phase 3, placebo-controlled trial of mirabegron that included tolterodine as an active comparator (SCORPIO), as well as other published literature and expert opinion. Cost-effectiveness was calculated from Canadian public payer (based on Quebec list prices) and societal perspectives.

RESULTS

The incremental one-year cost per patient for mirabegron over tolterodine was $182 CAD and $157 CAD from the payer and societal perspectives, respectively. The incremental quality-adjusted life year (QALY) gain for mirabegron was 0.0066 when using EQ-5D health-state utilities. Mirabegron was cost-effective compared with tolterodine, from both payer and societal perspectives, and remained cost-effective vs. tolterodine across the majority of sensitivity analyses. The model was based on limited clinical trial evidence supplemented with expert opinion and assumptions; a select number of OAB symptoms, AEs, and direct and indirect medical costs associated with OAB; and a timeframe of only one year.

CONCLUSIONS

From the payer and societal perspectives, the health economic model indicates that in Canada, mirabegron is a cost-effective treatment strategy compared with tolterodine, leading to improved health outcomes (QALYs) at an acceptable incremental cost.

Investigation of piperazine benzamides as human β3 adrenergic receptor agonists for the treatment of overactive bladder

The synthesis of a novel class of piperazine benzamide (reverse amides) targeting the human β₃-adrenergic receptor for the treatment of overactive bladder (OAB) is described. The SAR studies directed towards maintaining well established β₃ potency and selectivities while improving the overall pharmacokinetic profile in the reverse amide class will be evaluated. The results and consequences associated with functional activity at the norepinephrine transporter (NET) will also be discussed.

'Browning' the cardiac and peri-vascular adipose tissues to modulate cardiovascular risk

Excess visceral adiposity, in particular that located adjacent to the heart and coronary arteries is associated with increased cardiovascular risk. In the pathophysiological state, dysfunctional adipose tissue secretes an array of factors modulating vascular function and driving atherogenesis. Conversely, brown and beige adipose tissues utilise glucose and lipids to generate heat and are associated with improved cardiometabolic health. The cardiac and thoracic perivascular adipose tissues are now understood to be composed of brown adipose tissue in the healthy state and undergo a brown-to-white transition i.e. during obesity which may be a driving factor of cardiovascular disease. In this review we discuss the risks of excess cardiac and vascular adiposity and potential mechanisms by which restoring the brown phenotype i.e. “re-browning” could potentially be achieved in clinically relevant populations.

•

Epicardial, paracardial and thoracic perivascular adipose tissues resemble BAT at birth.

•

Despite ‘whitening’ in early life these depots remain metabolically active and potentially thermogenic into adulthood.

•

Obesity induces further ‘whitening’ and inflammation in these depots likely driving the atherogenesis.

•

Maintaining or inducing the brown phenotype in these depots could prevent atherosclerotic disease.

A Mouse Model of Furosemide-Induced Overactive Bladder

Detailed in this unit is a mouse model of overactive bladder and urinary incontinence based on diuretic stress-induced urination. The procedure involves the use of a unique, highly sensitive, and automated urine capturing method to measure urinary latency, frequency, and void volume. Although this method was first described and validated using an anti-muscarinic drug used for treating overactive bladder, subsequent work has shown that effective non-cholinergic agents can be detected. These findings indicate good predictive value for this model regarding the possible clinical utility of test agents as treatments for overactive bladder, regardless of their site of action. © 2016 by John Wiley & Sons, Inc.

Discovery of benzamides as potent human β3 adrenergic receptor agonists

The paper will describe the synthesis and SAR studies that led to the discovery of benzamide (reverse amide) as potent and selective human β3-adrenergic receptor agonist. Based on conformationally restricted pyrrolidine scaffold we discovered earlier, pyrrolidine benzoic acid intermediate 22 was synthesized. From library synthesis and further optimization efforts, several structurally diverse reverse amides such as 24c and 24i were found to have excellent human β3-adrenergic potency and good selectivity over the β1 and β2 receptors. In addition to human β1, β2, β3 and hERG data, PK of selected compounds will be described.

Emerging drugs for overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a common problem which can have disastrous effects on the quality of life of the sufferer. There are established treatments for the problem but they have significant adverse effects. Better drugs and new treatment modalities are necessary to deal with OAB.

AREA COVERED

Antimuscarinics, mirabegron and intravesical injection of botulinum toxin A are established treatments for OAB. Sacral neuromodulation is more invasive but has been successful in treating OAB. Phase II and III trials are in progress for newer β3-agonists and various combinations of antimuscarinics, β3-agonists and antidiuretics. Targeted secretion inhibitors (TSI) can increase efficacy and reduce adverse effects. Liposome integrated botulinum toxin A has an advantage of effective administration by intravesical instillation. Both medicines are in Phase II trials. Many other drugs which have promising results are discussed.

EXPERT OPINION

Newer antimuscarinics have better tolerability. Long-term data for mirabegron has shown that it is more effective in severe OAB. Combination drugs may prove to be more effective with less adverse effects. Emerging treatments with TSI, lipotoxin and gene therapy appear promising.

Pioneering drugs for overactive bladder and detrusor overactivity: Ongoing research and future directions

The ongoing research on pioneering drug candidates for the overactive bladder (OAB) aimed to overcome the limitations of currently licensed pharmacotherapies, such as antimuscarinics, β3-adrenergic agents, and botulinum neurotoxin, has been reviewed performing a systematic literature review and web search. The review covers the exploratory agents alternative to available medications for OAB and that may ultimately prove to be therapeutically useful in the future management of OAB patients based on preclinical and early clinical data. It emerges that many alternative pharmacological strategies have been discovered or are under investigation in disease-oriented studies. Several potential therapeutics are known for years but still find obstacles to pass the clinical stages of development, while other completely novel compounds, targeting new pharmacological targets, have been recently discovered and show potential to translate into clinical therapeutic agents for idiopathic and neurogenic OAB syndrome. The global scenario of investigational drugs for OAB gives promise for the development of innovative therapeutics that may ultimately prove effective as first, combined or second-line treatments within a realistic timescale of ten years.

Innovative pharmacotherapies for women with overactive bladder: where are we now and what is in the pipeline?

INTRODUCTION AND HYPOTHESIS

The impressive prevalence of overactive bladder (OAB) and the relevant limitations of current treatments urge the need for novel therapeutic approaches.

METHODS

A systematic literature and web search was performed to identify investigational drugs that entered the early and late phases of clinical development for women with OAB symptoms.

RESULTS

Approved pharmacological therapies for OAB (antimuscarinics, beta-3 agonists, and botulinum toxin) are evolving with the development of alternative administration methods, combination strategies, and novel compounds, expected to improve effectiveness, bladder selectivity, and dose flexibility. A wealth of investigational compounds, developed with both public and companies' indoor nonclinical disease-oriented studies, entered the early and late stages of clinical development in the last decade. Most non-anticholinergic compounds in ongoing clinical trials target central and peripheral neurotransmitter receptors involved in neurological modulation of micturition, nonadrenergic-noncholinergic mechanisms, cyclic nucleotide metabolism, different subtypes of ion channels or peripheral receptors of prostaglandins, vanilloids, vitamin D3, and opioids. Fascinating advances are ongoing also in the field of genetic therapy.

CONCLUSIONS

New pharmaceutical formulations and drug combinations are expected to be available in the next decade in order to overcome the limitations of current drugs for OAB. Although proof-of-concept, patient-oriented studies yielded disappointing results for several tentative drugs, a lot of clinical research is ongoing that is expected to provide clinicians with novel therapeutic agents in the near future.