Safety and tolerability of the β3 -adrenoceptor agonist mirabegron, for the treatment of overactive bladder: results of a prospective pooled analysis of three 12-week randomised Phase III trials and of a 1-year randomised Phase III trial

Update on Therapies in Older Adults

Memory loss and dementia are among older adults' greatest health fears. This article provides insight into new developments to help delay the onset of dementia, to treat dementia in its earliest stages, and to manage behavioral problems that occur in persons with dementia. Urinary incontinence (UI) is another common problem in older adults that has a major impact on quality of life. This article evaluates newer medications for reducing urinary urge/UI and provides perspective in their role for managing UI.

Brown adipose tissue-derived metabolites and their role in regulating metabolism

The discovery and rejuvenation of metabolically active brown adipose tissue (BAT) in adult humans have offered a new approach to treat obesity and metabolic diseases. Beyond its accomplished role in adaptive thermogenesis, BAT secretes signaling molecules known as "batokines", which are instrumental in regulating whole-body metabolism via autocrine, paracrine, and endocrine action. In addition to the intrinsic BAT metabolite-oxidizing activity, the endocrine functions of these molecules may help to explain the association between BAT activity and a healthy systemic metabolic profile. Herein, we review the evidence that underscores the significance of BAT-derived metabolites, especially highlighting their role in controlling physiological and metabolic processes involving thermogenesis, substrate metabolism, and other essential biological processes. The conversation extends to their capacity to enhance energy expenditure and mitigate features of obesity and its related metabolic complications. Thus, metabolites derived from BAT may provide new avenues for the discovery of metabolic health-promoting drugs with far-reaching impacts. This review aims to dissect the complexities of the secretory role of BAT in modulating local and systemic metabolism in metabolic health and disease.

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.

Efficacy and safety of vibegron compared with mirabegron for overactive bladder: A systematic review and network meta-analysis

OBJECTIVES

The aim of this study was to indirectly compare the efficacy and safety of mirabegron and vibegron in patients with overactive bladder.

METHODS

A systematic search was performed on Pubmed, Web of Science, Embase, and the Cochrane Central Register of Controlled Trials databases to identify studies from the date of database inception to January 1, 2022. All randomized controlled trials comparing mirabegron or vibegron with tolterodine, imidafenacin, or placebo were eligible. One reviewer extracted data, and a second reviewer checked. Included trials were assessed for similarity, and networks were developed using Stata 16.0 software. Mean differences for continuous variables and odds ratios for dichotomous variables together with their 95% confidence intervals (CIs) were used to rank treatments and compare the differences, respectively.

RESULTS

A total of 11 randomized controlled trials and 10 806 patients were included. For each outcome, results for all licensed treatment doses were included. Both vibegron and mirabegron were more efficacious than placebo at reducing the frequency of micturition, incontinence, urgency, urgency incontinence, and nocturia. Vibegron was more efficacious than mirabegron in reducing mean voided volume/micturition (95% CI [5.15, 14.98]). Safety outcomes for vibegron and mirabegron were similar to those in the placebo group, except for mirabegron, which had a higher risk of nasopharyngitis and cardiovascular adverse events than placebo.

CONCLUSIONS

Both drugs seem to be comparable and well tolerated, particularly as direct comparisons are not available. However, vibegron may be more effective than mirabegron in reducing mean voided volume.

Thermogenic Brown Fat in Humans: Implications in Energy Homeostasis, Obesity and Metabolic Disorders

In mammals including humans, there are two types of adipose tissue, white and brown adipose tissues (BATs). White adipose tissue is the primary site of energy storage, while BAT is a specialized tissue for non-shivering thermogenesis to dissipate energy as heat. Although BAT research has long been limited mostly in small rodents, the rediscovery of metabolically active BAT in adult humans has dramatically promoted the translational studies on BAT in health and diseases. It is now established that BAT, through its thermogenic and energy dissipating activities, plays a role in the regulation of body temperature, whole-body energy expenditure, and body fatness. Moreover, increasing evidence has demonstrated that BAT secretes various paracrine and endocrine factors, which influence other peripheral tissues and control systemic metabolic homeostasis, suggesting BAT as a metabolic regulator, other than for thermogenesis. In fact, clinical studies have revealed an association of BAT not only with metabolic disorders such as insulin resistance, diabetes, dyslipidemia, and fatty liver, but also with cardiovascular diseases including hypertension and atherosclerosis. Thus, BAT is an intriguing tissue combating obesity and related metabolic diseases. In this review, we summarize current knowledge on human BAT, focusing its patho-physiological roles in energy homeostasis, obesity and related metabolic disorders. The effects of aging and sex on BAT are also discussed.

Efficacy and safety of mirabegron in the treatment of overactive bladder syndrome after radical prostatectomy: a prospective randomized controlled study

Objectives

To evaluate the effects of mirabegron in the treatment of overactive bladder syndrome (OAB) after radical prostatectomy (RP).

Patients and methods

A total of 108 post-operative RP patients were randomly assigned to either the mirabegron (study) or the placebo (control) group. The Overactive Bladder Syndrome Self-Assessment Scale (OABSS) was selected as the primary endpoint, and the International Prostate Symptom Score (IPSS) and Quality of Life (QOL) score were selected as secondary endpoints. Statistical analysis was performed using IBM SPSS Statistics 26, and the treatment effects were compared between the two groups using independent samples t-test.

Results

In total, 55 patients were included in the study group and 53 patients in the control group. The mean age was(70.08 ± 7.54)years. There was no statistical difference in the baseline data between the two groups. OABSS scores decreased significantly in the study group compared to the control group during drug treatment (6.67 ± 1.06 vs. 9.14 ± 1.83, p < 0.01) and were better than the control group during the follow-up at week 8 and week 12. In addition, the decrease in IPSS scores (11.29 ± 3.89 and 15.34 ± 3.54, p<0.01) and the increase in QOL scores (2.40 ± 0.81 vs. 3.20 ± 1.00) were statistically significant in the study group. And the patients in the study group had better improvement in voiding symptoms and quality of life than the control group during the follow-up period.

Conclusion

Daily administration of 50 mg mirabegron after RP surgery significantly improved the symptoms of OAB after surgery with fewer side effects. Additional randomized controlled trials should be conducted in the future to further evaluate the efficacy and safety of mirabegron.

Adverse events related to antimuscarinics and beta-3-agonist: "real-life" data from the Eudra-Vigilance Database

BACKGROUND

Antimuscarinic (AM) and beta-3-agonist (B3A) treatment are the standard first-line pharmacological treatment used to manage overactive bladder (OAB) patients. Aim of our study was to analyze real-life data of adverse events related to AMs and B3A reported on Eudra-Vigilance (EV) Database.

METHODS

EV database is the system for managing and analyzing information on suspected adverse reactions to medicines which have been authorized or being studied in clinical trials in the European Economic Area (EEA). We recorded the number of AEs for antimuscarinic and beta-3-agonist per category and severity until January 2021.

RESULTS

Overall, 2313 AEs were reported for oxybutinin, 5129 for solifenacin, 2483 for tolterodine, 3523 for fesoterodine, 787 for trospium, 621 for propiverine and 7213 for mirabegron. Urinary retention was higher for fesoterodine (43%) and tolterodine (23%) when compared to solifenacin (10%), mirabegron (11%) and oxybutinin (4%). Cognitive disorder was uncommon for all the analyzed drugs analyzed. Regarding anticolinergic AEs: vision blurred, dry mouth and constipation were higher for AMs when compared to mirabegron. Their prevalence was higher in female patients. Mirabegron presented a higher risk of hypertension (7%) when compared to oxybutinin (2%, P<0.01), solifenacin (2%, P<0.01), tolterodine (2%, P<0.01) and fesoterodine (1%, P<0.01); the rate of hypertension was higher in females (63%) than males (29%) (P<0.01). The risk of acute urinary retention was also significantly higher (15% vs. 10%, P<0.01) in older patients (>85 years).

CONCLUSIONS

Real life data is consistent with registry studies regarding the rate of AEs related to antimuscarinic and beta-3-agonist. However some differences were observed. Female patients present higher rates of AEs when compared to male patients. The risk of acute urinary retention was particularly evident in the octogenarians.

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.

Impact of mirabegron versus solifenacin on autonomic function and arterial stiffness in female overactive bladder syndrome: a randomized controlled trial

The study aims to elucidate the impact of mirabegron versus solifenacin on autonomic function and peripheral arterial conditions in women with overactive bladder syndrome (OAB). All consecutive women with OAB were randomized to receive 12 weeks of mirabegron 25 mg or solifenacin 5 mg once per day. Heart rate variability, cardio-ankle vascular index, ankle-brachial pressure index, blood pressure, and heart rate were compared between the two groups. There were 87 women (mirabegron, n = 43; and solifenacin, n = 44) who completed 12-week treatment and underwent heart rate variability examination. Systolic blood pressure (median: − 4.5 to − 5.5 mmHg) and diastolic blood pressure (median: − 0.5 to − 3.5 mmHg) decreased after solifenacin treatment, and heart rate (median: + 2 bpm) increased after mirabegron treatment, despite of no between-group difference. In addition, posttreatment heart rate variability, cardio-ankle vascular index, and ankle-brachial pressure index did not differ compared with baseline; and there were no between-group differences. In conclusion, solifenacin might decrease blood pressure, and mirabegron might increase heart rate. Nonetheless, there were no significant impacts of 12-week mirabegron versus solifenacin treatment on autonomic function and arterial stiffness.

The involvement of the adrenergic nervous system in activating human brown adipose tissue and browning

Obesity is a chronic condition of multifactorial etiology characterized by excessive body fat due to a calorie intake higher than energy expenditure. Given the intrinsic limitations of surgical interventions and the difficulties associated with lifestyle changes, pharmacological manipulation is currently one of the main therapies for metabolic diseases. Approaches aiming to promote energy expenditure through induction of thermogenesis have been explored and, in this context, brown adipose tissue (BAT) activation and browning have been shown to be promising strategies. Although such processes are physiologically stimulated by the sympathetic nervous system, not all situations that are known to increase adrenergic signaling promote a concomitant increase in BAT activation or browning in humans. Thus, a better understanding of factors involved in the thermogenesis attributed to these tissues is needed to enable the development of future therapies against obesity. Herein we carry out a critical review of original articles in humans under conditions previously known to trigger adrenergic responses-namely, cold, catecholamine-secreting tumor (pheochromocytoma and paraganglioma), burn injury, and adrenergic agonists-and discuss which of them are associated with increased BAT activation and browning. BAT is clearly stimulated in individuals exposed to cold or treated with high doses of the β3-adrenergic agonist mirabegron, whereas browning is certainly induced in patients after burn injury or with pheochromocytoma, as well as in individuals treated with β3-adrenergic agonist mirabegron for at least 10 weeks. Given the potential effect of increasing energy expenditure, adrenergic stimuli are promising strategies in the treatment of metabolic diseases.

Current pharmacotherapy of overactive bladder

Overactive bladder is a symptom complex consisting of bothersome storage urinary symptoms that is highly prevalent among both sexes and has a significant impact on quality of life. Various antimuscarinic agents and the beta-3 agonists mirabegron and vibegron are currently available for the treatment of OAB. Each drug has specific pharmacologic properties, dosing schedule and tolerability profile, making it essential to individualize the medical treatment for the patient's characteristics and expectations. In this manuscript, we review the most important factors involved in the contemporary pharmacological treatment of OAB.

Cardiovascular Risk in Users of Mirabegron Compared with Users of Antimuscarinic Treatments for Overactive Bladder: Findings from a Non-Interventional, Multinational, Cohort Study

INTRODUCTION

During clinical trials, mirabegron, a β3-adrenoreceptor agonist, was associated with increased vital signs vs placebo in patients with overactive bladder.

OBJECTIVE

The purpose of this study was to compare incidence rates of adverse cardiovascular (CV) outcomes following mirabegron or antimuscarinic use.

METHODS

We conducted an observational post-marketing safety study utilising real-world data. The study population was identified within five sources: Danish and Swedish National Registers, Clinical Practice Research Datalink (UK), Optum (USA) and Humana (USA). Episodes of time when patients were new users of mirabegron or antimuscarinics (October 2012-December 2018) were sourced from prescriptions and matched on propensity scores. Occurrences of major adverse cardiovascular events (MACE), acute myocardial infarction (AMI), stroke, CV mortality and all-cause mortality were identified. Outcome incidence rates and hazard ratios from Cox models were estimated.

RESULTS

Overall, 152,026 mirabegron and 152,026 antimuscarinic episodes were matched. The population consisted of 63.1% women and 72.6% were ≥ 65 years old. There were no appreciable differences in the incidence rates of MACE, AMI or stroke between users of mirabegron and antimuscarinics. Incidence rates of CV mortality (hazard ratio 0.83, 95% confidence interval 0.73-0.95) and all-cause mortality (hazard ratio 0.80, 95% confidence interval 0.76-0.84) were no higher with mirabegron vs antimuscarinics. Results restricted to episodes at high risk for CV events or stratified by age (< 65 years, ≥ 65 years) or prior overactive bladder medication use were consistent with overall findings.

CONCLUSIONS

This large, multinational study found no higher risk of MACE, AMI, stroke, CV mortality or all-cause mortality among users of mirabegron relative to users of antimuscarinics.

Pioglitazone does not synergize with mirabegron to increase beige fat or further improve glucose metabolism

BACKGROUND

Beige and brown adipose tissue (BAT) are associated with improved metabolic homeostasis. We recently reported that the β₃-adrenergic receptor agonist mirabegron induced beige adipose tissue in obese insulin-resistant subjects, and this was accompanied by improved glucose metabolism. Here we evaluated pioglitazone treatment with a combination pioglitazone and mirabegron treatment and compared these with previously published data evaluating mirabegron treatment alone. Both drugs were used at FDA-approved dosages.

METHODS

We measured BAT by PET CT scans, measured beige adipose tissue by immunohistochemistry, and comprehensively characterized glucose and lipid homeostasis and insulin sensitivity by euglycemic clamp and oral glucose tolerance tests. Subcutaneous white adipose tissue, muscle fiber type composition and capillary density, lipotoxicity, and systemic inflammation were evaluated by immunohistochemistry, gene expression profiling, mass spectroscopy, and ELISAs.

RESULTS

Treatment with pioglitazone or the combination of pioglitazone and mirabegron increased beige adipose tissue protein marker expression and improved insulin sensitivity and glucose homeostasis, but neither treatment induced BAT in these obese subjects. When the magnitude of the responses to the treatments was evaluated, mirabegron was found to be the most effective at inducing beige adipose tissue. Although monotherapy with either mirabegron or pioglitazone induced adipose beiging, combination treatment resulted in less beiging than either alone. The 3 treatments also had different effects on muscle fiber type switching and capillary density.

CONCLUSION

The addition of pioglitazone to mirabegron treatment does not enhance beiging or increase BAT in obese insulin-resistant research participants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02919176.

FUNDING

NIH DK112282 and P20GM103527 and Clinical and Translational Science Awards grant UL1TR001998.

Mirabegron: The most promising adipose tissue beiging agent

Accumulation of white adipose tissue (WAT) underlies the obesity epidemic, leading to current therapeutic techniques that are being investigated for their ability to activate/“beige” this tissue. Adipose tissue (AT) beiging has been reported through intermittent cold exposure (CE), exercise, and β3‐Adrenergic Receptor (β3AR) agonists. But how AT beiging can help in the treatment of metabolic disorders like obesity and type 2 diabetes (T2D) remains largely unexplored. This review summarizes recent research on the use of β3AR agonist, mirabegron (Myrbetriq®), in stimulating beiging in AT. Researchers have only recently been able to determine the optimal therapeutic dose of mirabegron for inducing beiging in subcutaneous/ inguinal WAT, where the benefits of AT activation are evident without the undesired cardiovascular side effects. To determine whether the effects that mirabegron elicits are metabolically beneficial, a comparison of the undisputed findings resulting from intermittent CE‐induced beiging and the disputed findings from exercise‐induced beiging was conducted. Given the recent in vivo animal and clinical studies, the understanding of how mirabegron can be metabolically beneficial for both lean and obese individuals is more clearly understood. These studies have demonstrated that circulating adipokines, glucose metabolism, and lipid droplet (LD) size are all positively affected by mirabegron administration. Recent studies have also demonstrated that mirabegron has similar outcomes to intermittent CE and displays more direct evidence for beiging than those produced with exercise. With these current findings, mirabegron is considered the most promising and safest β3AR agonist currently available that has the potential to be used in the therapeutic treatment of metabolic disorders, and future studies into its interaction with different conditions may prove to be useful as part of a treatment plan in combination with a healthy diet and exercise.

The role of mirabegron in relieving double-J stent-related discomfort: a randomized controlled clinical trial

Introduction

The aim of this study was to investigate the effect of 50 mg mirabegron once daily in relieving ureteral double-J (DJ) stent-related discomfort after ureteroscopy (URS) or retrograde intrarenal surgery (RIRS).

Material and methods

A total of 210 patients who underwent DJ ureteral stent insertion after URS or RIRS were randomized 1:1 to receive either no treatment (Group B) or mirabegron 50 mg once daily (Group A) during the stenting period. At time of stent removal, all patients were evaluated for stent-related symptoms using the Arabic translated and validated ureteral stent symptom questionnaire (USSQ). The severity of stent-related symptoms (SRS) was compared between the two groups.

Results

The mean age was 46.6 ±8.2 years in Group A and 44.7 ±9.4 (26-64) years in the control group (p = 0.13). The stone characteristics, stent size, and position were similar in both groups. Compared to the control group, the mirabegron group had significantly lower daytime frequency, nocturia and urgency (p = 0.028, p = 0.008 and p = 0.012, respectively). As for stent-related pain, Group A had significantly less flank and abdominal pain (p = 0.007 and p = 0.001, respectively). The mirabegron versus control group showed significant difference in mean analgesics use and quality of life (QoL) scores during the stenting period (p = 0.005 and p = 0.003, respectively). Three patients (2.9%) in Group A encountered minor adverse effects (two experienced dry mouth and one presented with constipation).

Conclusions

For patients with indwelling DJ stent, postoperative mirabegron 50 mg use was effective and well-tolerated for the treatment of lower urinary tract symptoms and stent-related pain.

Cardiovascular safety of mirabegron add-on therapy to tamsulosin for the treatment of overactive bladder in men with lower urinary tract symptoms: A post hoc analysis from the MATCH study

Objectives

To investigate the cardiovascular safety of mirabegron add‐on treatment to tamsulosin in male patients with residual overactive bladder symptoms.

Methods

This was a post hoc analysis of MATCH, the first double‐blind, placebo‐controlled study comparing mirabegron and placebo as add‐on therapy to tamsulosin for treatment of overactive bladder in men with lower urinary tract symptoms. The analysis focused on treatment‐emergent adverse events relating to the cardiovascular system or blood pressure, and changes in vital signs during 12 weeks of follow‐up.

Results

Cardiovascular‐related treatment‐emergent adverse events were reported by 6/566 patients, although only one serious treatment‐emergent adverse event was related to treatment (unstable angina in the tamsulosin + placebo group). Hypertension (two patients) and increased blood pressure (one patient) were reported in the tamsulosin + placebo group, but there were no blood pressure‐related treatment‐emergent adverse events among tamsulosin + mirabegron patients. There were no clinically meaningful changes from baseline in blood pressure, and changes in pulse rate were small (+1.2 bpm in the tamsulosin + mirabegron group). Increased pulse rate was more frequent with tamsulosin + mirabegron than with tamsulosin + placebo in older patients, although within the normal range.

Conclusions

Cardiovascular‐related adverse events were uncommon in both treatment groups. Mirabegron is a well‐tolerated add‐on therapy to tamsulosin in Japanese and Korean males with residual overactive bladder symptoms.

Efficacy of adding mirabegron to alpha-adrenoreceptor blocker in patients with benign prostatic hyperplasia with persistent overactive bladder symptoms: A prospective study

Purpose

To compare the efficacies of mirabegron 50 mg addition after alpha-adrenoreceptor blocker in terms of reducing storage symptoms in patients with BPH.

Materials and Methods

Fifty-eight patients that had been taking alpha-adrenoreceptor blocker for more than 8 weeks, but had an OABSS of greater than 3 points, were initially enrolled. One group added any alpha-adrenoreceptor blocker with mirabegron 50 mg (n=39; the mirabegron group) and the other group received alpha-adrenoreceptor blocker only (n=19; the control group) for 8 weeks.

Results

In the control group, mean total IPSS decreased from 15.7 to 13.1 (p=0.298) and in mirabegron group, mean total IPSS decreased from 19.4 to 16.5 (p=0.024). Mean storage symptom scores reduced in the control and mirabegron groups from 8.5 to 7.9 (p=0.584) and from 9.1 to 7.6 (p=0.015), respectively, and mean QoL scores from 3.7 to 3.1 (p=0.052) and 3.6 to 3.2 (p=0.027), respectively. Mean overall OABSS in the control and mirabegron groups reduced from 8.4 to 7.2 (p=0.173) and from 8.8 to 7.3, respectively (p=0.005); mean OABSS Q3 from 3.6 to 2.9 (p=0.073) and from 3.5 to 2.7 (p=0.002), respectively; and mean OABSS Q4 from 2.4 to 2.0 (p=0.306) and from 2.7 to 2.0 (p=0.016), respectively. The change of mean Qmax and PVR was insignificant in 2 groups.

Conclusions

IPSS total scores, storage symptom scores, QoL, overall OABSS, OABSS Q3 and Q4 were more improved significantly by alpha-adrenoreceptor blocker with mirabegron 50 mg in BPH patients with persistent overactive symptoms. Mirabegron 50 mg addition is considered to patients with persistent storage symptoms after alpha-adrenoreceptor blocker.

The clinical pharmacology of the medical treatment for overactive bladder in adults

INTRODUCTION

Overactive bladder is a prevalent symptom complex that affects the patient's quality of life. Any disruption between the neuronal micturition pathway can lead to bladder overactivity. Neurogenic causes, myogenic causes, aging, bladder outlet obstruction, sex, and psychological factors are some of the factors contributing to bladder overactivity. The complaint of any symptoms of OAB, which is highly prevalent and affects overall QOL, often needs therapeutic interventions. When conservative therapy methods fail, the addition of medications is recommended. The most commonly used agents for the treatment of OAB are antimuscarinic drugs. New classes of drugs, such as beta-3 agonists, have enriched our pharmacologic armamentarium.

AREAS COVERED

In this review, with a special focus on oral pharmacological treatments, we discussed the definition, etiology, symptoms, diagnosis, and management of OAB.

EXPERT OPINION

OAB is a multifactorial condition with every patient presenting with a different collection of symptoms and signs. Medical therapies should be given in conjunction with behavioral therapies. Using high or low doses, flexible doses, and stopping or changing the medications are interchangeable strategies based on the level of treatment efficacy and patient satisfaction.

The β3-adrenergic receptor agonist mirabegron improves glucose homeostasis in obese humans

BACKGROUNDBeige adipose tissue is associated with improved glucose homeostasis in mice. Adipose tissue contains β3-adrenergic receptors (β3-ARs), and this study was intended to determine whether the treatment of obese, insulin-resistant humans with the β3-AR agonist mirabegron, which stimulates beige adipose formation in subcutaneous white adipose tissue (SC WAT), would induce other beneficial changes in fat and muscle and improve metabolic homeostasis.METHODSBefore and after β3-AR agonist treatment, oral glucose tolerance tests and euglycemic clamps were performed, and histochemical analysis and gene expression profiling were performed on fat and muscle biopsies. PET-CT scans quantified brown adipose tissue volume and activity, and we conducted in vitro studies with primary cultures of differentiated human adipocytes and muscle.RESULTSThe clinical effects of mirabegron treatment included improved oral glucose tolerance (P < 0.01), reduced hemoglobin A1c levels (P = 0.01), and improved insulin sensitivity (P = 0.03) and β cell function (P = 0.01). In SC WAT, mirabegron treatment stimulated lipolysis, reduced fibrotic gene expression, and increased alternatively activated macrophages. Subjects with the most SC WAT beiging showed the greatest improvement in β cell function. In skeletal muscle, mirabegron reduced triglycerides, increased the expression of PPARγ coactivator 1 α (PGC1A) (P < 0.05), and increased type I fibers (P < 0.01). Conditioned media from adipocytes treated with mirabegron stimulated muscle fiber PGC1A expression in vitro (P < 0.001).CONCLUSIONMirabegron treatment substantially improved multiple measures of glucose homeostasis in obese, insulin-resistant humans. Since β cells and skeletal muscle do not express β3-ARs, these data suggest that the beiging of SC WAT by mirabegron reduces adipose tissue dysfunction, which enhances muscle oxidative capacity and improves β cell function.TRIAL REGISTRATIONClinicaltrials.gov NCT02919176.FUNDINGNIH: DK112282, P30GM127211, DK 71349, and Clinical and Translational science Awards (CTSA) grant UL1TR001998.

Effectiveness and tolerability of mirabegron in children with overactive bladder: A retrospective pilot study

AIMS

Mirabegron has promising results for OAB symptoms in adults, although the potential for cardiovascular side effects has caused concern. Efficacy and tolerability in children have not been extensively studied. Effectiveness, tolerability, and side effects of Mirabegron are reported in children with refractory OAB.

METHODS

A retrospective review of children receiving Mirabegron between February 2014 and November 2018 was completed. Frequency, urgency, nocturnal (NE), and daytime incontinence (DI) were analyzed at baseline and 6 months.

RESULTS

70 children (50 females), median age 15 [range 8-16] years, commenced Mirabegron 25 mg (n = 29) or 50 mg (n = 41). 37 (53%) were still receiving treatment at 6 months: monotherapy n = 30, and combination therapy n = 7 (Solifenacin n = 4, Desmopressin n = 2, both n = 1). Where undertaken, blood pressure monitoring and ECGs were normal. For patients on monotherapy, 6 of 17 (35%) had improvement in NE, 11 of 19 (58%) in DI, 12 of 20 (60%) in frequency, and 8 of 21 (38%) in urgency symptoms. For patients receiving combination therapy, 2 of 6 (33%) had improvement in NE, 2 of 4 in DI (50%), 2 of 4 (50%) in frequency, and 4 of 6 (67%) had improvement in urgency. Reasons for treatment discontinuation (entire cohort) were: ineffectiveness (n = 28), worse symptoms (n = 4) and/or adverse reactions (n = 7), including dry mouth (n = 2), headaches (n = 4), dizziness (n = 1), nausea/vomiting (n = 3), increased seizures (n = 1), and rash (n = 1).

CONCLUSION

Mirabegron improved symptoms in 70% of patients with refractory OAB. A prospective RCT should be the next step to establish the role of Mirabegron for the treatment of OAB in children.

LEVEL OF EVIDENCE

Level II.

Cardiovascular safety of antimuscarinic add-on therapy in patients with overactive bladder who had a suboptimal response to mirabegron monotherapy: A post hoc analysis from the Japanese MILAI II study

Objective

This analysis was conducted to investigate the cardiovascular (CV) safety outcomes from the MILAI II study. MILAI II was conducted to evaluate the long‐term safety and efficacy of antimuscarinic add‐on therapy to mirabegron over 52 weeks in patients with overactive bladder (OAB) symptoms.

Methods

MILAI II consisted of a 2‐week screening period (patients received mirabegron 50 mg once daily) plus a 52‐week treatment period (patients were randomized to receive a combination of mirabegron 50 mg/d plus solifenacin 5 mg/d, propiverine 20 mg/d, imidafenacin 0.2 mg/d, or tolterodine 4 mg/d). CV safety was assessed using treatment‐emergent adverse events (TEAEs), vital signs, and 12‐lead electrocardiograms (ECGs). Vital signs and ECG data were evaluated for each patient using worst post‐baseline values reported.

Results

Of 647 patients, 570 (88.1%) were female with a mean age of 65 years. CV history at baseline and CV‐related concomitant medication use throughout the study were balanced between groups. The incidences of overall and drug‐related CV TEAEs were ≤8.1% and ≤6.2%, respectively, for all groups. The most common TEAEs were ECG T wave amplitude decreased, ECG QT prolonged, and ventricular extrasystoles. Overall, 36 TEAEs of interest related to the CV system that were possibly/probably related to treatment were reported with similar incidences for each group. For the worst post‐baseline vital signs and ECGs, no relationships were noted in terms of either timing or treatment group.

Conclusion

A favorable CV safety profile was observed following long‐term combination treatment with mirabegron and an antimuscarinic in patients with OAB symptoms.

Drug-induced endocrine blood pressure elevation

Patients with uncontrolled hypertension are at risk for cardiovascular complications. The majority of them suffers from unidentified forms of hypertension and a fraction has so-called secondary hypertension with an identifiable cause. The patient's medications, its use of certain herbal supplements and over-the-counter agents represent potential causal factors for secondary hypertension that are often overlooked. The current review focuses on drugs that are likely to elevate blood pressure by affecting the human endocrine system at the level of steroid synthesis or metabolism, mineralocorticoid receptor activity, or by affecting the catecholaminergic system. Drugs with known adverse effects but where benefits outweigh their risks, drug candidates and market withdrawals are reviewed. Finally, potential therapeutic strategies are discussed.

Investigation of the reasons for withdrawal from long-term treatment with mirabegron of treatment-naïve Japanese female patients with overactive bladder in the real-world clinical setting

Purpose:

The persistence of treatment with mirabegron and the reasons for withdrawal from the treatment among treatment-naïve Japanese female patients with overactive bladder (OAB) were prospectively investigated for 3 years in the real-world clinical setting.

Materials and Methods:

A total of 62 treatment-native Japanese female patients clinically diagnosed with OAB were treated with mirabegron and prospectively followed for 3 years. The persistence rate was estimated using the Kaplan-Meier method. If mirabegron had to be terminated or a patient did not come to the hospital to receive a prescription, the reasons for withdrawal from treatment were determined.

Results:

The 6-month, 1-year, 2-year, and 3-year persistence rates were 51.6%, 38.7%, 32.3%, and 25.8%, respectively. The most frequent reasons for withdrawal from treatment with mirabegron were symptom resolution (38.7%), deterioration of comorbidity unrelated to OAB (12.9%), lack of efficacy (8.1%), and adverse events (4.8%).

Conclusions:

The persistence rate of treatment with mirabegron among treatment-naïve Japanese female patients with OAB is low for 3 years in the real-world clinical setting. Many patients discontinue the treatment for various reasons, the most frequent of which is symptom resolution. These findings provide important considerations for clinicians whose patients are continuing medication for OAB.

Management of Overactive Bladder Symptoms After Radical Prostatectomy

PURPOSE OF REVIEW

Post-prostatectomy overactive bladder (OAB) is a common and challenging condition to manage. The aim of the present report was to review the recent evidences regarding OAB symptoms that develop in men after prostatectomy and how to manage them.

RECENT FINDINGS

The prevalence of OAB after radical prostatectomy may range from 15.2 to 37.8%. Recent studies have highlighted the role of the urethrogenic mechanism (facilitation of the urethrovesical reflex due to stress urinary incontinence (SUI)) in the genesis of post-prostatectomy OAB in a significant proportion of patients. Several other pathophysiological factors such as iatrogenic decentralization of the bladder, defunctionalized bladder due to severe SUI, detrusor underactivity, or bladder outlet obstruction might be involved. The evaluation should aim to identify the underlying mechanism to tailor the treatment, which could range from SUI surgery, to fixing a urethral stricture, improving bladder emptying or using the conventional spectrum of OAB therapies. There is a paucity of data for OAB therapies specific to post-prostatectomy patients, with the exception of solifenacin, tolterodine, and botulinum toxin. There is currently no data on how preoperative management or surgical technique may prevent post-prostatectomy OAB.

Individualizing medical treatment of overactive bladder

Overactive bladder (OAB) syndrome is highly prevalent in both men and women and might have negative impact on quality of life. Clinical trials of OAB usually highly select participants that may not reflect the real-world practice of OAB patients. The spectrum of OAB includes patients with idiopathic, neuropathic, with bladder outlet obstruction, and patients in elderly and medical comorbidities. Patients might have poor response to OAB medication or have adverse events after treatment. Therefore, treatment of OAB should be individualized to obtain therapeutic efficacy and avoid unacceptable adverse events. This article reviews the recently published literature and provides a guide for physicians to choose the appropriate treatment for different OAB patients.

Human adipose beiging in response to cold and mirabegron

BACKGROUND

The induction of beige adipocytes in s.c. white adipose tissue (WAT) depots of humans is postulated to improve glucose and lipid metabolism in obesity. The ability of obese, insulin-resistant humans to induce beige adipose tissue is unknown.

METHODS

We exposed lean and obese research participants to cold (30-minute ice pack application each day for 10 days of the upper thigh) or treated them with the β3 agonist mirabegron. We determined beige adipose marker expression by IHC and quantitative PCR, and we analyzed mitochondrial bioenergetics and UCP activity with an Oxytherm system.

RESULTS

Cold significantly induced UCP1 and TMEM26 protein in both lean and obese subjects, and this response was not associated with age. Interestingly, these proteins increased to the same extent in s.c. WAT of the noniced contralateral leg, indicating a crossover effect. We further analyzed the bioenergetics of purified mitochondria from the abdominal s.c. WAT of cold-treated subjects and determined that repeat ice application significantly increased uncoupled respiration, consistent with the UCP1 protein induction and subsequent activation. Cold also increased State 3 and maximal respiration, and this effect on mitochondrial bioenergetics was stronger in summer than winter. Chronic treatment (10 weeks; 50 mg/day) with the β3 receptor agonist mirabegron induces UCP1, TMEM26, CIDEA, and phosphorylation of HSL on serine660 in obese subjects.

CONCLUSION

Cold or β3 agonists cause the induction of beige adipose tissue in human s.c. WAT; this phenomenon may be exploited to increase beige adipose in older, insulin-resistant, obese individuals.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02596776, NCT02919176.

FUNDING

NIH (DK107646, DK112282, P20GM103527, and by CTSA grant UL1TR001998).

Mirabegron in patients with Parkinson disease and overactive bladder symptoms: A retrospective cohort

INTRODUCTION

This study aimed to assess the outcomes of mirabegron for the treatment of overactive bladder (OAB) symptoms in patients with Parkinson disease (PD).

METHODS

A retrospective study was conducted including patients with PD who received mirabegron 50 mg once daily for OAB symptoms between 2012 and 2017. The primary endpoint was clinical success defined as any improvement in overactive bladder symptoms self-assessed by the patients 6 weeks after mirabegron initiation. Secondary endpoints included number of pads per day, number of nocturia episodes and adverse events.

RESULTS

Fifty patients (mean 74 years old) were included. Before being treated with mirabegron, 56% had failed prior anticholinergic therapy. After 6 weeks of mirabegron 50 mg, five patients (11.4%) had a complete resolution of their OAB symptoms; 25 patients (50%) reported improvement, 23 (46%) reported no change and 2(4%) reported worsening of their OAB symptoms. The number of pads per day decreased from 1.5 to 0.9 (p = 0.01) and so did the number of nocturia episodes (from 3 to 2.6/night; p = 0.02). Only 2 adverse events were reported during mirabegron treatment (4%): one dizziness and one diaphoresis, that disappeared after mirabegron discontinuation. After a median follow-up of 19 months, 23 patients (46%) persisted on mirabegron. Persistence rates were 51.5%, 44.6% and 36.4% at 1, 2 and 3 years respectively.

CONCLUSION

Mirabegron has an excellent safety profile and appears to be an effective treatment for overactive bladder symptoms in patients with PD. Further prospective randomized trials are needed to properly assess mirabegron in PD patients.

Lower Urinary Tract Symptoms: What's New in Medical Treatment?

CONTEXT

Pharmacological treatment is a cornerstone in the management of patients with lower urinary tract symptoms (LUTS).

OBJECTIVE

To review emerging evidence in the medical treatment of LUTS.

EVIDENCE ACQUISITION

An Embase/Pubmed-based literature search was conducted in December 2017, screening for randomized controlled trials (RCTs), prospective and retrospective series, animal model studies, and reviews on medical treatment of LUTS.

EVIDENCE SYNTHESIS

The main medical innovation in recent years in overactive bladder (OAB) has been the approval of the first β₃-adrenoceptor agonists (mirabegron) and intradetrusor onabotulinum toxin A, while several other drugs such as antiepileptics, phosphodiesterase inhibitors, or other β₃-agonists have brought promising results in phase 3 trials. Intraprostatic injections of various drugs for LUTS/benign prostatic hyperplasia have been investigated, but results of phase 3 trials are still pending, while combination therapies of phosphodiesterase type 5 inhibitors+α-blockers or finasteride have been proved as superior to single therapies in RCTs conducted in these patients. Two new formulations of desmopressin have been approved for nocturia in the USA (desmopressin nasal spray) and Europe/Canada/Australia (desmopressin orally disintegrated tablet). Fedovapagon, a vasopressin V₂ receptor agonist, has recently completed a large phase 3 trial in male patients with nocturia. Other phase 3 trials are ongoing in bladder pain syndrome (AQX 11-25, a SHIP-1 activator) and in neurogenic detrusor overactivity (mirabegron and abobotulinum toxin A).

CONCLUSIONS

Medical treatment of LUTS is a very active research field with recently approved drugs for nocturia (desmopressin acetate nasal spray/orally disintegrated tablet) and numerous emerging drugs currently investigated in OAB, LUTS/benign prostatic hyperplasia, nocturia, bladder pain syndrome, and neurogenic detrusor overactivity.

PATIENT SUMMARY

Medical treatment of lower urinary tract symptoms is a very active research field with recently approved drugs for nocturia (desmopressin acetate nasal spray/orally disintegrated tablet) and numerous emerging drugs in overactive bladder, nocturia, neurogenic detrusor overactivity, bladder pain syndrome, or benign prostatic hyperplasia.

Mirabegron 25 mg Monotherapy Is Safe but Less Effective in Male Patients With Overactive Bladder and Bladder Outlet Obstruction

OBJECTIVE

To compare the therapeutic efficacy and safety of mirabegron monotherapy in male patients with overactive bladder (OAB) with and without bladder outlet obstruction (BOO).

MATERIALS AND METHODS

Male patients with OAB aged ≥20 years, with or without BOO, receiving mirabegron 25 mg monotherapy once daily, were prospectively enrolled. The treatment results were assessed using global response assessment, international prostate symptom score and subscores, overactive bladder symptom score, patient perception on intensity of urgency scale, patient perception of bladder condition, and quality of life index at 1 and 3 months after treatment.

RESULTS

Of the 289 enrolled patients (mean age, 71.2 years), 207 did not have BOO (71.6%) and 82 had BOO (28.4%). The baseline OAB symptoms were similar between patients with and without BOO. After mirabegron treatment, the satisfactory rate (global response assessment score ≧1) were similar between those without BOO (61.3%) and with BOO (57.1%). The improvement of quality of life index and patient perception of bladder condition was also found in both groups. However, only patients without BOO had significantly improved international prostate symptom score and subscores, overactive bladder symptom score, and patient perception on intensity of urgency scale. Although most adverse events (AEs) were mild, patients with BOO had significantly higher AEs rate (18.6%) than those without BOO (8.2%, P = .026).

CONCLUSION

Mirabegron monotherapy in male patients with OAB and BOO was safe. However, the storage symptoms improvement was less in patients with BOO and AEs rate was higher.

A strategy utilizing ambulatory monitoring and home and clinic blood pressure measurements to optimize the safety evaluation of noncardiovascular drugs with potential for hemodynamic effects: a report from the SYNERGY trial

Supplemental Digital Content is available in the text.

Objective

The aim of this study was to perform a blood pressure (BP) safety evaluation in patients with an overactive bladder receiving solifenacin (an antimuscarinic agent), mirabegron (a β₃-adrenoceptor agonist), or both compared with placebo in the SYNERGY trial.

Patients and methods

Patients were randomized to receive solifenacin 5 mg+mirabegron 50 mg (combination 5+50 mg); solifenacin 5 mg+mirabegron 25 mg (combination 5+25 mg); solifenacin 5 mg; mirabegron 50 mg; mirabegron 25 mg; or placebo for a double-blind 12-week treatment period. Systolic BP, diastolic BP, and heart rate were measured by ambulatory BP monitoring, and in the clinic or home.

Results

A total of 715 patients were analyzed in an ambulatory BP monitoring substudy. At the end of treatment, ambulatory BP monitoring measurements showed no consistent increases from baseline in the mean 24-h systolic BP or diastolic BP for combination versus monotherapy groups or for monotherapy groups versus placebo. Analysis of 1-h BP averages during the 6 h range that included the T_max values of both study drugs showed no significant BP effects. Shift analysis (switch between different normotension/hypertension stages) did not show differences among the active and placebo groups, nor did outlier analysis of major BP changes differ between placebo and active treatment. Similarly, there were no significant signals in the 24-h heart rate. Office and home measurements were consistent with ambulatory BP monitoring findings.

Conclusions

A paradigm of ambulatory BP monitoring analysis designed to test BP safety of noncardiovascular drugs showed that solifenacin plus mirabegron combination therapy during 12 weeks produced no meaningful changes in BP or heart rate.

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.

No. 353-Treatments for Overactive Bladder: Focus on Pharmacotherapy - An Addendum

OBJECTIVE

This technical update addendum reviews success rates and comparative evidence of the anticholinergic fesoterodine, as well as mechanism of action, safety profile, success rates, and comparative evidence of the β3 agonist mirabegron in the treatment of non-neurogenic overactive bladder syndrome (OAB). This adds to OAB pharmacotherapy recommendations initially published in 2012.

INTENDED USERS

Residents and other trainees, primary care practitioners, gynaecologists, urologists, urogynaecologists, and other health care providers who assess, counsel, and treat women with OAB.

TARGET POPULATION

Adult women with symptomatic OAB.

OPTIONS

This addition relates to fesoterodine, mirabegron, and anticholinergic-β3 agonist combination pharmacotherapy.

OUTCOMES

The outcomes of interest are clinical efficacy of fesoterodine compared with no treatment or other OAB therapies; mechanism of action and safety profile of mirabegron, clinical efficacy of mirabegron compared to no treatment or other OAB therapies; clinical efficacy of anticholinergic-β3 agonist combination pharmacotherapy for OAB.

EVIDENCE

PubMed, Medline, and the Cochrane Database were searched using the key words "fesoterodine" and "mirabegron." Results were restricted to English or French and human clinical and pharmacological research. Animal research and clinical studies including only male participants were excluded. Articles were included until the end of December 2016. Grey literature was not searched. Clinical practice guidelines, guidelines of specialty societies, and systematic reviews were included. RCTs and observational studies were included when evidence for the outcome of interest or in the target population was not available from systematic reviews. New studies not yet included in systematic reviews were also included. References of included articles were also searched to ensure comprehensive inclusion of relevant literature.

VALUES

The content and recommendations were drafted and agreed upon by the principal author, as well as members of the Urogynaecology Committee. The Board of the SOGC approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology framework. The Summary of Findings is available upon request.

BENEFITS, HARMS, AND/OR COSTS

It is expected that this technical update will benefit patients with OAB by providing physicians and other interested health care providers with additional options for and knowledge of safe and effective OAB pharmacotherapy. The benefits clearly outweigh the potential harms or costs of implementation of this technical update, although there are no direct harms or costs identified. UPDATES: "Evidence will be reviewed 5 years after publication to decide whether all or part of the document should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations."

SPONSORS

Not applicable.

RECOMMENDATIONS

Economic Impact of Mirabegron Versus Antimuscarinics for the Treatment of Overactive Bladder in the UK

PURPOSE

Our objective was to estimate the economic outcomes of using mirabegron versus antimuscarinics in the treatment of patients with overactive bladder (OAB) from a societal perspective in the UK.

MATERIALS AND METHODS

A Markov model was developed using Microsoft Excel^®. The time horizon and cycle length are 12 and 1 months, respectively; and the hypothetical cohort size 100 patients. Antimuscarinic comparators are fesoterodine, oxybutynin extended release (ER) and immediate release (IR), solifenacin, tolterodine ER/IR, trospium ER/IR, darifenacin and flavoxate. Model inputs included real-world treatment patterns data, healthcare resource use (e.g. clinic visits) and direct and indirect costs (e.g. drug acquisition and productivity loss). Model outputs included patient disposition, healthcare resource use, drug acquisition costs and other treatment-related costs over a 1-year time horizon. A one-way sensitivity analysis was performed to determine the key drivers of the model.

RESULTS

In a hypothetical cohort of 100 patients, total annual costs per patient were lower with mirabegron than with all antimuscarinics (£1270.84 vs. 1321.71-1607.48). Healthcare resource use was lower with mirabegron than with all antimuscarinics (115 vs. 119-123 general practitioner visits; 173 vs. 178-185 specialist visits and 0.0042 vs. 0.0050-0.0060 surgical operations) and fewer work hours were lost (4017 vs. 5114-6990 [all per 100 patients]). Sensitivity analysis showed the model was sensitive to persistence and switching rates, although the impact on the overall results was minimal.

CONCLUSIONS

In the UK, using mirabegron to treat OAB may improve persistence and lead to reductions in switching treatment, healthcare resource utilization, productivity costs, and overall treatment costs versus antimuscarinics.

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.

Persistence and Adherence with Mirabegron versus Antimuscarinic Agents in Patients with Overactive Bladder: A Retrospective Observational Study in UK Clinical Practice

BACKGROUND

Persistence with antimuscarinic therapy in overactive bladder (OAB) is poor, but may be different for mirabegron, a β₃-adrenoceptor agonist with a different adverse event profile.

OBJECTIVE

To compare persistence and adherence with mirabegron versus tolterodine extended release (ER) and other antimuscarinics in routine clinical practice over a 12-mo period.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective, longitudinal, observational study of anonymised data from the UK Clinical Practice Research Datalink GOLD database. Eligibility: age ≥18 yr, ≥1 prescription for target OAB drug (between May 1, 2013 and June 29, 2014), and 12-mo continuous enrolment before and after the index prescription date.

INTERVENTIONS

Mirabegron, darifenacin, fesoterodine, flavoxate, oxybutynin ER or immediate-release (IR), propiverine, solifenacin, tolterodine ER or IR, and trospium chloride.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was persistence (time to discontinuation). Secondary endpoints included 12-mo persistence rates and adherence (assessed using medication possession ratio, MPR). Cox proportional-hazards regression models and logistic regression models adjusted for potential confounding factors were used to compare cohorts. Analyses were repeated after 1:1 matching.

RESULTS AND LIMITATIONS

The study population included 21996 eligible patients. In the unmatched analysis, the median time-to-discontinuation was significantly longer for mirabegron (169 d, interquartile range [IQR] 41-not reached) compared to tolterodine ER (56 d, IQR 28-254; adjusted hazard ratio [HR] 1.55, 95% confidence interval 1.41-1.71; p<0.0001) and other antimuscarinics (range 30-78 d; adjusted HR range 1.24-2.26, p<0.0001 for all comparisons). The 12-mo persistence rates and MPR were also significantly greater with mirabegron than with all the antimuscarinics. Limitations include the retrospective design, use of prescription records to estimate outcomes, and inability to capture reasons for discontinuation.

CONCLUSIONS

Persistence and adherence were statistically significantly greater with mirabegron than with tolterodine ER and other antimuscarinics prescribed for OAB in the UK.

PATIENT SUMMARY

This study assessed persistence and adherence (or compliance) with medications prescribed for OAB in a large UK population. We found that patients prescribed mirabegron remained on treatment for longer and showed greater adherence than those prescribed traditional antimuscarinics.

[Not Available]

Zusammenfassung. OAB (overactive bladder syndrome) ist zwar ein häufiges Leiden, doch wird es oft nicht diagnostiziert und deshalb nicht behandelt. Die Behandlung erfolgt symptomatisch. Im Praxisalltag muss vorgängig eine Basis-(Ausschluss)-Diagnostik durchgeführt werden. Das Führen eines Blasentagebuchs ist sowohl für die Diagnostik als auch für den Verlauf wichtig. Eine urogynäkologische Abklärung mit Urodynamik empfiehlt sich in unklaren Situationen und beim Vorliegen einer gemischten Symptomatik mit Symptomen einer Belastungsinkontinenz oder bei gleichzeitigem Vorliegen einer Blasenentleerungsstörung. Die Therapie erfolgt Schritt für Schritt. Schon einfache Verhaltensänderungen und ein Blasen- und Beckenbodentraining können die Symptomatik deutlich verbessern. Viele Patientinnen profitieren aber zusätzlich von der medikamentösen Therapie. Jahrzehntelang standen dazu alleinig Anticholinergika zur Verfügung. Doch die Langzeitcompliance ist unter diesen Medikamenten gering. Neu erweitern β3-Adrenorezeptor-Agonisten das therapeutische Spektrum: Bei ähnlicher Wirkung unterscheidet sich das Nebenwirkungsprofil unter anderem durch das Fehlen von Mundtrockenheit. Bei therapierefraktärer OAB steht die intravesikale Injektion von Onabotulinumtoxin A als sehr effektive Therapie zur Verfügung. In seltenen Fällen ist auch eine Neuromodulation indiziert.

Safety and tolerability of β3-adrenoceptor agonists in the treatment of overactive bladder syndrome - insight from transcriptosome and experimental studies

INTRODUCTION

We have reviewed the safety and tolerability of β3-adrenoceptor agonists, specifically mirabegron and solabegron, a newly emerging drug class for the treatment of the overactive bladder syndrome. We discuss them mechanistically in the context of expression and other preclinical data.

AREAS COVERED

Based on a systematic PubMed search, incidence of overall adverse events, hypertension, dry mouth, and constipation are comparable between mirabegron or solabegron and placebo. Hypertension is the most frequently observed adverse event, but has a similar incidence with mirabegron and placebo. Nevertheless, severe uncontrolled hypertension has become a contraindication for use of mirabegron based on observation of severe hypertension in association with mirabegron exposure. The overall incidence of adverse events is also similar between mirabegron and the muscarinic receptor antagonist tolterodine, but the incidence of dry mouth is much lower with mirabegron.

EXPERT OPINION

The high β3-adrenoceptor mRNA expression in the human ovaries is not associated with reproductive side effects. Generally, β3-adrenoceptors exhibit a rather restricted expression in human tissues, which may explain the overall good tolerability of agonists acting on this receptor. We propose that expression profiles and functional preclinical studies can be important tools in the prediction of adverse event profiles in first-in-class drugs.