Patient-reported reasons for discontinuing overactive bladder medication

Economic evaluation of pharmacological treatments for overactive bladder from the perspective of the UK National Health Service

OBJECTIVE

To evaluate the costs and outcomes associated with different sequences of oral anti-muscarinic agents and the selective β(3)-adrenoceptor agonist, mirabegron, for the treatment of overactive bladder (OAB).

METHODS

A Markov model with monthly cycle length and time horizon up to 3 years was designed to compare two different sequences of up to three lines of oral therapy for OAB. Patients who discontinued one oral medication could switch to another oral medication or could discontinue treatment. Patients whose symptoms were not controlled were considered for botulinum toxin or sacral nerve stimulation. Outcomes were measured by (a) number of patients with controlled symptoms (no incontinence episodes and <8 micturitions per 24 h); (b) patients with no incontinence episodes per 24 hours; and (c) patients with <8 micturitions per 24 h.

RESULTS

Including a third-line oral medication before considering other treatment options improved all patient outcomes, irrespective of the specific drugs used. A three-line sequence including two generic (oxybutynin first line and tolterodine extended-release second line) and one branded drug (solifenacin 5 mg third line) resulted in inferior patient outcomes at costs similar to a sequence of branded drugs (mirabegron first line, solifenacin 5 mg second line, solifenacin 10 mg third line): controlled patients (generic 29.6/1000 vs branded 38.7/1000); patients with no incontinence episodes (103.6/1000 vs 123.7/1000); patients with <8 micturitions (228.7/1000 vs 262.1/1000). Annual treatment costs per patient were similar (generic £1299 vs branded £1385).

CONCLUSIONS

In the treatment of OAB, low-cost generic treatments are not necessarily more cost-effective than branded drugs, primarily because a better efficacy and tolerability balance improves both symptom control and persistence.

Safety and efficacy of mirabegron as 'add-on' therapy in patients with overactive bladder treated with solifenacin: a post-marketing, open-label study in Japan (MILAI study)

OBJECTIVE

To examine the safety and efficacy of mirabegron as 'add-on' therapy to solifenacin in patients with overactive bladder (OAB).

PATIENTS AND METHODS

This multicentre, open-label, phase IV study enrolled patients aged ≥20 years with OAB, as determined by an OAB symptom score (OABSS) total of ≥3 points and an OABSS Question 3 score of ≥2 points, who were being treated with solifenacin at a stable dose of 2.5 or 5 mg once daily for at least 4 weeks. Study duration was 18 weeks, comprising a 2-week screening period and a 16-week treatment period. Patients meeting eligibility criteria continued to receive solifenacin (2.5 or 5 mg once daily) and additional mirabegron (25 mg once daily) for 16 weeks. After 8 weeks of treatment, the mirabegron dose could be increased to 50 mg if the patient's symptom improvement was not sufficient, if he/she was agreeable to the dose increase, and the investigator judged that there were no safety concerns. Safety assessments included adverse events (AEs), laboratory tests, vital signs, 12-lead electrocardiogram, QT corrected for heart rate using Fridericia's correction (QTcF) interval and post-void residual (PVR) volume. Efficacy endpoints were changes from baseline in OABSS total score, OAB questionnaire short form (OAB-q SF) score (symptom bother and total health-related quality of life [HRQL] score), mean number of micturitions/24 h, mean number of urgency episodes/24 h, mean number of urinary incontinence (UI) episodes/24 h, mean number of urgency UI episodes/24 h, mean volume voided/micturition, and mean number of nocturia episodes/night. Patients were instructed to complete the OABSS sheets at weeks -2, 0, 8 and 16 (or at discontinuation), OAB-q SF sheets at weeks 0, 8 and 16 (or at discontinuation) and patient voiding diaries at weeks 0, 4, 8, 12 and 16 (or at discontinuation).

RESULTS

Overall incidence of drug-related treatment-emergent AEs (TEAEs) was 23.3%. Almost all TEAEs were mild or moderate. The most common TEAE was constipation, with similar incidence in the groups receiving a dose increase to that observed in the groups maintained on the original dose. Changes in PVR volume, QTcF interval, pulse rate and blood pressure were not considered to be clinically significant and there were no reports of urinary retention. Significant improvement was seen for changes in efficacy endpoints from baseline to end of treatment (EOT) in all groups (patients receiving solifenacin 2.5 or 5 mg + mirabegron 25 or 50 mg).

CONCLUSIONS

Add-on therapy with mirabegron 25 mg once daily for 16 weeks, with an optional dose increase to 50 mg at week 8, was well tolerated in patients with OAB treated with solifenacin 2.5 mg or 5 mg once daily. There were significant improvements from baseline to EOT in OAB symptoms with combination therapy with mirabegron and solifenacin. Add-on therapy with mirabegron and an antimuscarinic agent, such as solifenacin, may provide an attractive therapeutic option.

Refractory overactive bladder: a common problem?

INTRODUCTION AND HYPOTHESIS

Unsatisfactory treatment outcome sometimes is described as frequently occurring in patients treated with first-line therapy for overactive bladder (OAB). The present article reviews the different circumstances which may result in failure to respond to lifestyle interventions, behavioral therapy, and/or antimuscarinic treatment.

METHODS

An extensive literature search was conducted to identify relevant articles on pathophysiological, clinical, and pharmacological aspects of refractory OAB.

RESULTS

Missing definition, unrealistic individual expectation of treatment outcomes, lack of communication between physician and patient as well as pathophysiological and pharmacological processes were identified as relevant for failure to respond to first-line OAB treatment. Increase of patient's motivation to adhere to the prescribed treatment, critical examination of the patient in regard to the initial diagnosis, and individual adjustment of antimuscarinic therapy may be appropriate tools to improve treatment outcome in OAB patients.

CONCLUSIONS

Overall, the incidence of refractory OAB seems to be overestimated. There are several approaches to improve therapy results.

The potential role of stem cells in the treatment of urinary incontinence

Voiding dysfunction encompasses a wide range of urologic disorders including stress urinary incontinence and overactive bladder that have a detrimental impact on the quality of life of millions of men and women worldwide. In recent years, we have greatly expanded our understanding of the pathophysiology of these clinical conditions. However, current gold standard therapies often provide symptomatic relief without targeting the underlying etiology of disease development. Recently, the use of stem cells to halt disease progression and reverse underlying pathology has emerged as a promising method to restore normal voiding function. Stem cells are classically thought to aid in tissue repair via their ability for multilineage differentiation and self-renewal. They may also exert a therapeutic effect via the secretion of bioactive factors that direct other stem and progenitor cells to the area of injury, and that also possess antiapoptotic, antiscarring, neovascularization, and immunomodulatory properties. Local injections of mesenchymal, muscle-derived, and adipose-derived stem cells have all yielded successful outcomes in animal models of mechanical, nerve, or external urethral sphincter injury in stress urinary incontinence. Similarly, direct injection of mesenchymal and adipose-derived stem cells into the bladder in animal models of bladder overactivity have demonstrated efficacy. Early clinical trials using stem cells for the treatment of stress urinary incontinence in both male and female patients have also achieved promising functional results with minimal adverse effects. Although many challenges remain to be addressed prior to the clinical implementation of this technology, novel stem-cell-based therapies are an exciting potential therapy for voiding dysfunction.

Patients' preferences for visuals: differences in the preferred level of detail, type of background and type of frame of icons depicting organs between literate and low-literate people

OBJECTIVE

To evaluate icons of organs with systematic variations in design to provide directions for the development of pictograms that support patient leaflets targeted at a low-literate audience.

METHODS

In interview questionnaires, 191 pharmacy visitors (IJsselstein, The Netherlands), indicated for four organs in which image the organ was represented most clearly. The icons vary in level of detail of the depicted organ, in the organs that are shown in the background, and in how much of the body is shown as frame. Participants' literacy was determined through the Dutch Rapid Estimate of Adult Literacy in Medicine (REALM-D).

RESULTS

For the three internal organs, the intestines, lungs and kidneys, low-literate participants were more likely than literate participants to opt for less context in the form of the frame of the body.

CONCLUSION

When the meaning of the visual is given, low-literate people prefer organ icons with less context of the body over a depiction of the whole body.

PRACTICE IMPLICATIONS

Since literate and low-literate people differ in perceptual preferences, continued involvement of people with limited literacy skills in the design process is essential to target the visuals to their needs.

Medication adherence in the management of nocturia: challenges and solutions

OBJECTIVE

Nocturia affects millions of men and women. No prior reviews or meta-analyses have explored the issue of adherence in nocturia patients. The objective of our study was to examine the attributes and their interaction that might impact pharmacological adherence in nocturia care using a conceptual model of adherence.

MATERIALS AND METHODS

A literature search of the Medline, PubMed, Embase, PsycInfo, and CINAHL databases for studies published between January 1990 and June 2014 was conducted. We developed a conceptual model in order to facilitate our review.

RESULTS

Currently, multiple treatment options for nocturia exist, depending on the underlying cause. Adherence to nocturia treatment and outcomes are complex and intertwined, and nonadherence to nocturia treatment is common. In 15 studies meeting eligibility criteria, behavioral and pharmacologic interventions for nocturia were associated with reduced nocturia symptoms. Urinary symptoms that are associated with nocturia need individualized management depending on renal and hepatic function, medical comorbidities, and ongoing medication use in a patient. Another important factor related to adherence is the bother. Although nocturia is defined as nighttime-voiding frequency of one or more, not all persons may find this bothersome. The degree of bother is subjective, and may change from person to person. However, there is no information related to the association between bother and adherence to medication or behavioral treatments for nocturia. Medication dosing convenience, preference, and cost play important roles in adherence. We present a patient-centered conceptual model that brings together the various dimensions of medication adherence for nocturia.

CONCLUSION

Few studies have explored adherence to medication and related factors in the care of nocturia. Our conceptual model can aid development of interventions to improve adherence to nocturia medications.

Drug adherence and clinical outcomes for patients under pharmacological therapy for lower urinary tract symptoms related to benign prostatic hyperplasia: population-based cohort study

BACKGROUND

Little is known about drug adherence in men treated for lower urinary tract symptoms (LUTS). Benign prostatic hyperplasia (BPH) is one of the causes of LUTS.

OBJECTIVE

To examine adherence to pharmacological therapy and its clinical value in men with LUTS.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study using an administrative prescription database and hospital discharge codes for 1.5 million men aged ≥40 yr treated with alpha blockers (ABs) and 5-alpha reductase inhibitors (5ARIs) alone or in combination (CT).

INTERVENTIONS

Therapy with ABs and/or 5ARIs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The 1-yr and long-term adherence; hospitalization rates for BPH and BPH surgery. Multivariate Cox proportional hazards regression model, propensity score matching, and sensitivity analyses.

RESULTS AND LIMITATIONS

The 1-yr adherence was 29% in patients exposed to at least 6-mo therapy. Patients on CT had a higher discontinuation rate in the first 2 yr compared to those on monotherapy (p<0.0001). Overall hospitalization rates for BPH and BPH surgery were 9.04 and 12.6 per 1000 patient-years, respectively. A lower risk of hospitalization was observed for 5ARI compared to AB therapy (hazard ratio [HR] 0.46 and 0.23; p<0.0001). CT was associated with a reduced risk of hospitalization for BPH surgery (HR 0.94; p<0.0001) compared to AB. Discontinuation of drug treatment was an independent risk factor for hospitalization for BPH and BPH surgery (HR 1.65 and 2.80; p<0.0001) regardless of therapeutic group. Limitations include the paucity of clinical measures and the absence of patient-reported outcomes.

CONCLUSIONS

Adherence to pharmacological therapy for BPH is low and could affect clinical outcomes. Long-term 5ARI and CT use was associated with an independent reduced risk of hospitalization for BPH surgery. Our findings suggest the need for new strategies to increase patient adherence to prescribed treatment and more appropriate prescribing by physicians.

PATIENT SUMMARY

Our research shows that adherence to prescribed pharmacological therapy is crucial in the management of patients suffering from lower urinary tract symptoms. Moreover, pharmacological therapy can prevent disease progression.

[Use of botulinum toxin type A in non-neurogenic overactive bladder. Recommendations of the Working Group Urological Functional Diagnostics and Urology in Women]

The use of botulinum toxin for the treatment of neurogenic detrusor overactivity was first described in 2000 and thereafter botulinum toxin has also been used in non-neurogenic overactive bladder. In current guidelines intravesical injection of onabotulinumtoxin A in refractory patients is recommended. Our aim is to provide some clinically relevant recommendations from the Working Group Urologische Funktionsdiagnostik und Urologie der Frau for diagnostics and treatment with onabotulinumtoxin A of patients with non-neurogenic overactive bladder.

Mirabegron in the treatment of overactive bladder

INTRODUCTION

Mirabegron is a selective β3-adrenergic receptor agonist recently developed for the treatment of patients with overactive bladder (OAB), which offers an alternative pharmacological option to the well-established treatment with antimuscarinics (AMs).

AREAS COVERED

This review offers an explanation of the mechanism of action, of the pharmacokinetics and pharmacodynamics of mirabegron and gives readers a complete overview of Phase II and III studies on the clinical efficacy, tolerability and safety of this agent in the setting of OAB treatment.

EXPERT OPINION

Both Phase II and III trials have shown that mirabegron is efficacious and safe in treating patients with OAB. Future research should focus on the assessment of mirabegron concentrations in the CNS and on the evaluation of the potential of the combination of mirabegron with AMs. Another field for future research is represented by the investigation of the interaction of mirabegron with CYP2D6 inhibitors. Furthermore, current literature completely lacks studies on the efficacy and safety of mirabegron in the pediatric population and such trials are awaited.

Healthcare resource use and costs of privately insured patients who switch, discontinue, or persist on anti-muscarinic therapy for overactive bladder

OBJECTIVES

To compare the healthcare costs of patients with overactive bladder (OAB) who switch vs persist on anti-muscarinic agents (AMs), describe resource use and costs among OAB patients who discontinue AMs, and assess factors associated with persisting vs switching or discontinuing.

METHODS

OAB patients initiating an AM between January 1, 2007 and March 31, 2012 were identified from a claims database of US privately insured beneficiaries (n ≈ 16 million) and required to have no AM claims in the 12 months before AM initiation (baseline period). Patients were classified as persisters, switchers, or discontinuers, and assigned a study index date based on their AM use in the 6 months following initiation. Baseline characteristics, resource use, and costs were compared between persisters and the other groups. Resource use and costs in the 1 month before and 6 months after the study index date (for switchers, the date of index AM switching; for persisters, a randomly assigned date to reflect the distribution of the time from AM initiation to switching among switchers) were also compared between persisters and switchers in unadjusted and adjusted analyses. Factors associated with persisting vs switching or discontinuing were assessed.

RESULTS

After controlling for baseline characteristics and costs, persisters vs switchers had significantly lower all-cause and OAB-related costs in both the month before (all-cause $1222 vs $1759, OAB-related $142 vs $170) and 6 months after the study index date (all-cause $7017 vs $8806, OAB-related $642 vs $797). Factors associated with switching or discontinuing vs persisting included index AM, younger age, and history of UTI.

CONCLUSION

A large proportion of OAB patients discontinue or switch AMs shortly after initiation, and switching is associated with higher costs.

OnabotulinumtoxinA 100U provides significant improvements in overactive bladder symptoms in patients with urinary incontinence regardless of the number of anticholinergic therapies used or reason for inadequate management of overactive bladder

INTRODUCTION

A prespecified pooled analysis of two placebo-controlled, phase 3 trials evaluated whether the number of prior anticholinergics used or reason for their discontinuation affected the treatment response to onabotulinumtoxinA 100U in overactive bladder (OAB) patients with urinary incontinence (UI).

METHODS

Patients with symptoms of OAB received intradetrusor injections of onabotulinumtoxinA 100U or placebo, sparing the trigone. Change from baseline at week 12 in UI episodes/day, proportion of patients reporting a positive response ('greatly improved' or 'improved') on the treatment benefit scale (TBS), micturition and urgency were evaluated by number of prior anticholinergics (1, 2 or ≥ 3) and reason for their discontinuation (insufficient efficacy or side effects). Adverse events (AE) were assessed.

RESULTS

Patients had taken an average of 2.4 anticholinergics before study enrolment. OnabotulinumtoxinA reduced UI episodes/day from baseline vs. placebo, regardless of the number of prior anticholinergics (-2.82 vs. -1.52 for one prior anticholinergic; -2.58 vs. -0.58 for two prior anticholinergics; and -2.92 vs. -0.73 for three or more prior anticholinergics; all p < 0.001). The proportion of TBS responders was higher with onabotulinumtoxinA vs. placebo (69.0% vs. 37.2% for one prior anticholinergic; 58.8% vs. 24.8% for two prior anticholinergics and 56.4% vs. 22.5% for three or more prior anticholinergics; all p < 0.001). Similar results were observed regardless of the reason for discontinuation. OnabotulinumtoxinA reduced the episodes of urgency and frequency of micturition vs. placebo in all groups. AEs were well tolerated, with a comparable incidence in all groups.

CONCLUSION

In patients with symptoms of OAB who were inadequately managed by one or more anticholinergics, onabotulinumtoxinA 100U provided significant and similar treatment benefit and safety profile regardless of the number of prior anticholinergics used or reason for inadequate management of OAB. ClinicalTrials.gov: NCT00910845, NCT00910520.

A randomized controlled study of the efficacy of tamsulosin monotherapy and its combination with mirabegron for overactive bladder induced by benign prostatic obstruction

PURPOSE

We evaluated the efficacy and safety of add-on treatment with a β3-adrenoceptor agonist (mirabegron) for overactive bladder symptoms remaining after α1-blocker (tamsulosin) treatment in men with benign prostatic obstruction.

MATERIALS AND METHODS

Patients with benign prostatic obstruction with urinary urgency at least once per week and a total OABSS of 3 or more points after 8 or more weeks of treatment with tamsulosin were enrolled in the study. They were randomly allocated to receive 0.2 mg tamsulosin daily or 0.2 mg tamsulosin and 50 mg mirabegron daily for 8 weeks. The primary end point was change in total OABSS. Safety assessments included change in post-void residual urine volume and adverse events.

RESULTS

From January 2012 through September 2013 a total of 94 patients were randomized. Of these patients 76 completed the protocol treatment. In the full analysis set the change in total OABSS during the treatment period was significantly greater in the combination group than in the monotherapy group (-2.21 vs -0.87, p=0.012). The changes in scores for urinary urgency, daytime frequency, International Prostate Symptom Score storage symptom subscore and quality of life index at 8 weeks were significantly greater in the combination group. The change in post-void residual urine volume was significantly greater in the combination group. Although 6 patients experienced adverse events in the combination group, urinary retention was observed in only 1 patient.

CONCLUSIONS

Combined tamsulosin and mirabegron treatment is effective and safe for patients with benign prostatic obstruction who have overactive bladder symptoms after tamsulosin monotherapy.

Efficacy and safety of fesoterodine 8 mg in subjects with overactive bladder after a suboptimal response to tolterodine ER

AIMS

To assess fesoterodine 8 mg efficacy over time and vs. placebo in subjects with overactive bladder (OAB) who responded suboptimally to tolterodine extended release (ER) 4 mg.

METHODS

In a 12-week, double-blind trial, subjects with self-reported OAB symptoms for ≥ 6 months, mean of ≥ 8 micturitions and ≥ 2 to < 15 urgency urinary incontinence (UUI) episodes/24 h, and suboptimal response to tolterodine ER 4 mg (defined as ≤ 50% reduction in UUI episodes during 2-week run-in) were randomised to fesoterodine (4 mg for 1 week, 8 mg for 11 weeks) or placebo once daily. Change from baseline to week 12 in UUI episodes (primary end-point) was analysed in step-wise fashion: first, baseline vs. week 12 for fesoterodine; if significant, then change from baseline to week 12 for fesoterodine vs. placebo.

RESULTS

By week 12, subjects receiving fesoterodine 8 mg had significantly greater improvement from baseline vs. placebo in UUI episodes, urgency episodes and scores on the Patient Perception of Bladder Control, Urgency Perception Scale and OAB Questionnaire Symptom Bother and Health-Related Quality of Life scales and domains (all p < 0.05). 50% and 70% UUI responder rates were also significantly higher with fesoterodine 8 mg vs. placebo at week 12 (p < 0.05). Dry mouth (placebo, 4%, 12/301; fesoterodine, 16.6%, 51/308) and constipation (placebo, 1.3%, 4/301; fesoterodine, 3.9%, 12/308) were the most frequent adverse events.

CONCLUSIONS

Subjects who responded suboptimally to tolterodine ER 4 mg showed significant improvements in UUI and other OAB symptoms and patient-reported outcomes, with good tolerability, during treatment with fesoterodine 8 mg vs. placebo.

The role of electrical stimulation techniques in the management of the male patient with urgency incontinence

PURPOSE OF REVIEW

Overactive bladder affects 10-27% of men, a significant portion of whom report urge urinary incontinence that is inadequately treated with first-line and second-line treatments. There is thus a substantial need to critically evaluate the alternative means of clinical management.

RECENT FINDINGS

This review presents the current evidence for the use of sacral neuromodulation and percutaneous tibial nerve stimulation in the treatment of men with urge incontinence, as well as evaluates the financial implications of these treatments. Other alternative modes of electrical stimulation for urge incontinence are also briefly reviewed.

SUMMARY

Both sacral neuromodulation and percutaneous tibial nerve stimulation prove to be viable, durable options for treating patients with refractory urge incontinence. Alternative modes of stimulation are also beginning to show promise.

Results of a randomized, double-blind, parallel-group, placebo- and active-controlled, multicenter study of mirabegron, a β3-adrenoceptor agonist, in patients with overactive bladder in Asia

AIMS

To assess the efficacy and safety of mirabegron 50 mg once daily compared with placebo and the active control, tolterodine extended-release (ER) 4 mg once daily, in patients with symptoms of overactive bladder (OAB) in Taiwan, Korea, China, and India.

METHODS

A 12-week multinational, randomized, double-blind, parallel-group placebo- and active-controlled trial. The primary efficacy endpoint was change from baseline to final visit in mean number of micturitions/24 hr. Secondary endpoints were: mean number of urgency episodes, incontinence episodes and urge incontinence episodes/24 hr, mean number of nocturia episodes per night, mean volume voided per micturition, and quality-of-life (QoL) scores as assessed by the King's Health Questionnaire (KHQ).

RESULTS

Of 1,126 patients who were randomized to receive double-blind study drug, 921 patients (300, 311, and 310 in the placebo, mirabegron 50 mg, and tolterodine ER 4 mg groups, respectively) completed the treatment period. Demographic characteristics were similar across treatment groups. A statistically significant improvement versus placebo in mean number of micturitions/24 hr was seen with mirabegron 50 mg at all timepoints (P < 0.05) as well as final visit (-0.57 with 95% confidence intervals [CIs] of [-1.04, -0.09], P = 0.019). There was no significant difference between treatment groups in improvement from baseline to final visit in any of the secondary outcome measures except volume voided per micturition. The overall incidence of drug-related adverse events was 17.2%, 15.8%, and 21.3%, in the placebo, mirabegron 50 mg, and tolterodine ER 4 mg groups, respectively.

CONCLUSIONS

Mirabegron 50 mg once daily for 12 weeks was superior to placebo in reducing the frequency of micturitions in patients with symptoms of OAB in Taiwan, Korea, China, and India.

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

AIMS

To evaluate the safety and tolerability of the β3 -adrenoceptor agonist, mirabegron, in patients with overactive bladder (OAB).

METHODS

Tolerability and safety data from three 12-week, randomised, placebo-controlled, double-blind, Phase III trials (Studies 046, 047 and 074) were pooled by treatment group. The three studies were of a similar design, although the assessed doses of mirabegron [25, 50 or 100 mg once daily (qd)] varied, and tolterodine extended release (ER) 4 mg was included as an active-control arm in Study 046 only. Tolerability and safety data from a 1-year, randomised, double-blind, Phase III trial (Study 049) are also presented. Safety variables included the incidence and severity of treatment-emergent adverse events (TEAEs), vital signs and electrocardiogram data.

RESULTS

Mirabegron (25, 50 or 100 mg qd) was safe and well-tolerated in patients with OAB over 12-week (n = 2736) and 1-year (n = 1632) periods. The incidence of TEAEs and treatment discontinuations as a result of TEAEs was low; the majority were mild in severity and few were serious. Hypertension, nasopharyngitis and urinary tract infection were the most common TEAEs with mirabegron. The mirabegron tolerability profile was similar to that seen with placebo and tolterodine ER 4 mg, except for dry mouth, which occurred, on average, five times less frequently with mirabegron than tolterodine ER 4 mg. In the pooled 12-week analysis, mirabegron 50 mg was associated with placebo-adjusted mean increases of 0.4-0.6 mmHg in blood pressure and approximately one beat per minute in pulse rate, both reversible upon treatment discontinuation. The incidence of Major Adverse Cardiovascular Events as adjudicated by an independent cardiovascular committee was low and similar across treatment groups.

CONCLUSION

The favourable tolerability profile of mirabegron in patients with OAB may allow improved treatment compliance compared with antimuscarinics, with important implications for patient outcomes.

OnabotulinumtoxinA for the treatment of overactive bladder

OnabotulinumtoxinA injection is a safe and effective treatment for adults with refractory overactive bladder. There is sufficient level 1 evidence to support offering onabotulinumtoxinA injections as a second-line treatment to patients who have failed behavioral therapy and oral medications such as antimuscarinics and β3 agonists. An intradetrusor injection of 100 U of onabotulinumtoxinA is likely the optimal dose to balance risks and benefits, and this is the dose approved by the US Food and Drug Administration. Improvement in urgency urinary incontinence episodes, as well as symptom scores and quality of life, were seen in around 60%-65% of patients, and were significantly improved compared with those on placebo. Most studies have reported a duration of symptom relief ranging from 6 to 12 months, with repeat injections being safe and efficacious. Overall, the risk of urinary retention was around 6% across the study populations.

Understanding clinic options for overactive bladder

Overactive bladder (OAB) is a symptom complex of urinary frequency, nocturia and urgency with or without urgency incontinence that adversely impacts patient's quality of life. Conservative management begins in the outpatient clinic, often with significant improvement and patient satisfaction. In this review we will discuss the evaluation of OAB and review treatment options focusing on behavioral modification, medical therapy, and neuromodulation. These treatment options are offered in a stepwise fashion, remembering that more than one may be needed and can be used concomitantly.

Phase II drugs that target cholinergic receptors for the treatment of overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a term used to describe the symptom syndrome of urgency, with or without urgency incontinence, usually associated with frequency and nocturia. Antimuscarinics are the most widely prescribed class of drugs for OAB, although their systemic adverse effects limit their use in clinical practice as compliance. This has led to developments in the field.

AREAS COVERED

In this review, the authors describe Phase II drugs that target cholinergic receptors. First, the authors present the new antimuscarinics (tarafenacin and afacifenacin). This is followed by reports on a combination drug (tolenix) containing a muscarinic antagonist (tolterodine) associated with a muscarinic agonist (pilocarpine). Further, the authors discuss the trials of well-known drugs in either new combination therapy (solifenacin and mirabegron) or with new routes of delivery (oxybutynin vaginal ring). Finally, the authors examine the option of targeting nicotinic acetylcholine receptors (dexmecamylamine).

EXPERT OPINION

Different strategies have been adopted to improve the efficacy and tolerability of therapeutics for OAB. Nicotinic receptors represent a novel therapeutic target; however, it is unlikely that antimuscarinic agents will be replaced as standard first-line therapy in the near future.

The patient perspective on overactive bladder: a mixed-methods needs assessment

BACKGROUND

While overactive bladder is often managed in the primary care setting, a number of barriers including embarrassment, poor communication, and low patient adherence contribute to the under-treatment of patients with burdensome urinary symptoms. In order to address these challenges, it is crucial to have a fundamental understanding of patient perspectives toward OAB and urinary symptoms. To meet this aim, researchers designed and conducted a study to identify patients' knowledge, experiences and attitudes, barriers to treatment adherence, and desires and tendencies regarding patient/clinician communications.

METHODS

A mixed-methods qualitative/quantitative needs assessment of patients with overactive bladder and/or urinary symptoms. Researchers conducted in-depth qualitative interviews via telephone with 40 patients. Interview results informed the design and dissemination of a quantitative survey, which was completed by 200 self-selected respondents who had previously identified themselves as having overactive bladder or bladder problems. Statistical and qualitative analysis of results were conducted.

RESULTS

Among survey respondents, an average of 3.5 years elapsed between symptom onset and seeking diagnosis by a physician. In the long term most patients do not experience improvement in symptoms. Medication non-adherence is common and is related to therapy effectiveness and adverse effects. Patients clearly indicate that communication and patient/physician relationships are important to them and they would prefer the clinician initiate the conversation on overactive bladder. Patient experiences, perspectives, and attitudes toward their bladder symptoms differ in many ways from clinicians' assumptions.

CONCLUSIONS

The significant time gap between symptom onset and diagnosis indicates ongoing need for screening and diagnosis of overactive bladder. Contrary to guideline recommendations, urinalysis and physical examination are not widely used in clinical practice. Many patients experience no improvement in symptoms over time. Patients indicate that clinician/patient relationships and communication regarding their condition are important.

Contemporary issues with pharmacotherapy for lower urinary tract symptoms

Two articles appeared in the November 2012 edition of the journal evaluating aspects relating to the use of two important pharmacotherapeutic classes for lower urinary tract symptoms (LUTS) in real life clinical practice. LUTS is a non-specific term that encompasses urine storage, voiding and postmicturition symptoms. LUTS is a common bothersome problem affecting both men and women with a comparable prevalence in age-matched patients of both sexes that increases with ageing.

The efficacy and safety of onabotulinumtoxinA in treating idiopathic OAB: A systematic review and meta-analysis

AIM

We carried out a systematic review and meta-analysis to assess the efficacy and safety of the drug for treating idiopathic OAB.

METHODS

A literature review was performed to identify all published randomized double-blind, placebo-controlled trials of onabotulinumtoxinA for the treatment of idiopathic OAB. The search included the following databases: MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated.

RESULTS

Eight publications involving a total of 1,320 patients were used in the analysis, including six RCTs that compared onabotulinumtoxinA with placebo. OnabotulinumtoxinA significantly decreased the mean number of urinary incontinence (UI) per day -2.77 versus -1.01 (the standardized mean difference (SMD) = -1.68, 95% CI = -2.06 to -1.31, P < 0.00001); the mean number of micturitions per day -1.61 versus -0.87 (SMD = -1.82, 95% CI = -2.61 to -1.02, P < 0.00001); maximum cystometric capacity (MCC) 91.39 versus 32.32 (SMD = 63.82, 95% CI = 38.14 to 89.50, P < 0.00001) and volume voided 44.29 versus 7.36 (SMD = 33.05, 95% CI = 22.45 to 43.66, P < 0.00001) versus placebo and 29.20% versus 7.95% of patients became incontinence-free (odds ratio [OR] = 4.89, 95% confidence interval [CI] = 3.11 to 7.70, P < 0.00001). Safety assessments primarily localized to the urinary tract indicated onabotulinumtoxinA were often associated with complications resulting from postvoid residuals (PVR; P < 0.00001), urinary tract infections (UTI; P < 0.00001) and clean intermittent catheterization (CIC; P < 0.00001).

CONCLUSION

This meta-analysis indicates that onabotulinumtoxinA to be an effective treatment for idiopathic overactive bladder symptoms with side effects primarily localized to urinary tract.

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

INTRODUCTION

Overactive bladder (OAB) and urinary incontinence, although not life-threatening, are very bothersome chronic health conditions. The limitations of current pharmacological treatment urge the need for novel drugs with alternative mechanisms of action. Huge efforts in this area of research led to the synthesis of several selective and potent β3-adrenoceptor agonists that gained relevance through research during the late 80s and 90s. Mirabegron was the first compound of this new class of drugs that showed preclinical efficacy in several models of storage bladder dysfunction, together with a favorable human pharmacological profile. Having passed the proof-of-concept stage, an extensive clinical development and pharmacology program was performed during the last 10 years, involving >10,000 individuals, before mirabegron was granted marketing approval.

AREAS COVERED

In this case history, the authors review the milestones in mirabegron's discovery based on a systematic literature review.

EXPERT OPINION

Thanks to its tolerability and safety/efficacy balance, mirabegron has potential to fill a need for new treatment options for OAB, and paves the way for further development of a completely new class of drugs aimed to treat this condition. However, the exact role of mirabegron in clinical practice has yet to be defined. Further studies are needed in order to clarify, together with post-launch information, critical safety issues and cost-effectiveness in head-to-head comparison with current standard treatments.

Combination treatment with mirabegron and solifenacin in patients with overactive bladder: efficacy and safety results from a randomised, double-blind, dose-ranging, phase 2 study (Symphony)

BACKGROUND

Combining the β3-adrenoceptor agonist mirabegron and the antimuscarinic (AM) agent solifenacin may improve efficacy in the treatment of overactive bladder (OAB) while reducing the AM side effects.

OBJECTIVE

The primary objective was to evaluate the efficacy of combinations of solifenacin/mirabegron compared with solifenacin 5mg monotherapy. The secondary objective was to explore the dose-response relationship and the safety/tolerability compared with placebo and monotherapy.

DESIGN, SETTING, AND PARTICIPANTS

A phase 2, factorial design, randomised, double-blind, parallel-group, placebo- and monotherapy-controlled trial, conducted at 141 sites in 20 European countries. Male and female patients were aged ≥18 yr with symptoms of OAB for ≥3 mo.

INTERVENTION

A total of 1306 patients (66.4% female) were randomised to 12 wk of treatment in 1 of 12 groups: 6 combination groups (solifenacin 2.5, 5, or 10 mg plus mirabegron 25 or 50 mg), 5 monotherapy groups (solifenacin 2.5, 5, or 10 mg, or mirabegron 25 or 50 mg), or placebo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Change from baseline to end of treatment in mean volume voided per micturition (MVV) (primary end point) and mean numbers of micturitions per 24 h, incontinence episodes per 24 h, and urgency episodes per 24 h were analysed using an analysis of covariance model. Safety assessments included treatment-emergent adverse events (TEAEs), blood pressure, pulse rate, postvoid residual (PVR) volume, and laboratory and electrocardiography (ECG) parameters.

RESULTS AND LIMITATIONS

Compared with solifenacin 5 mg monotherapy, all combinations with solifenacin 5 or 10 mg significantly improved MVV, with adjusted differences ranging from 18.0 ml (95% confidence interval [CI], 5.4-30.0) to 26.3 ml (95% CI, 12.0-41.0). Three combination groups significantly reduced micturition frequency compared with solifenacin 5 mg, ranging from -0.80 (95% CI, -1.39 to -0.22) to -0.98 (95% CI, -1.68 to -0.27). Five of six combinations significantly reduced urgency episodes compared with solifenacin 5 mg, ranging from -0.98 (95% CI, -1.78, to -0.18) to -1.37 (95% CI, -2.03 to -0.70). No dose-related trends in TEAEs, blood pressure, pulse rate, PVR volume, or laboratory or ECG parameters were observed between combination and monotherapy groups, although the incidence of constipation was slightly increased with combination therapy.

CONCLUSIONS

Combination therapy with solifenacin/mirabegron significantly improved MVV, micturition frequency, and urgency compared with solifenacin 5 mg monotherapy. All combinations were well tolerated, with no important additional safety findings compared with monotherapy or placebo.

PATIENT SUMMARY

To improve treatment of overactive bladder (OAB), mirabegron/solifenacin in combination was compared with each drug alone and placebo. Combination therapy improved OAB symptoms and had similar safety and acceptability.

TRIAL REGISTRATION

Clinical trials.gov: NCT01340027.

New agents to treat lower urinary tract and pelvic floor disorders

For patients with overactive bladder and a suboptimal response to antimuscarinic therapy, there are several options to consider including alteration of the antimuscarinic regimen, switching to an agent with an alternate mechanism of action (i.e., mirabegron), posterior tibial nerve stimulation, or botulinum toxin. These options are summarized in this brief review.

Onset of action of the β3-adrenoceptor agonist, mirabegron, in Phase II and III clinical trials in patients with overactive bladder

Purpose

Long-term persistence with pharmacotherapy for overactive bladder (OAB) requires a drug with an early onset of action and good efficacy and tolerability profile. Although antimuscarinics improve OAB symptoms within 1–2 weeks of initiating treatment, adherence after 3 months is relatively poor due to bothersome side effects (e.g., dry mouth and constipation). Mirabegron, a β₃-adrenoceptor agonist, has demonstrated significant improvements in key symptoms of OAB and good tolerability after 12 weeks in Phase III studies.

Methods

This was a prespecified pooled analysis of three randomized, double-blind, placebo-controlled, 12-week studies, and a Phase II study, to evaluate efficacy and tolerability of mirabegron 25 and 50 mg versus placebo. The main efficacy endpoints were change from baseline to week 1 (Phase II only), week 4, and final visit in mean number of incontinence episodes/24 h, micturitions/24 h, and mean volume voided/micturition (MVV).

Results

A significant benefit for mirabegron 25 and 50 mg versus placebo was evident at the first assessment point, 4 weeks after initiation of therapy, in Phase III studies for incontinence, micturitions, and MVV. The earliest measured benefit was after 1 week, in the Phase II study. Quality-of-life parameters also significantly improved with mirabegron 25 and 50 mg as early as week 4. Significant benefits continued throughout the studies. Mirabegron was well tolerated.

Conclusions

The early onset of action and good overall efficacy and tolerability balance that mirabegron offers may lead to high rates of persistence with mirabegron in the long-term treatment of OAB.

Understanding patients' adherence-related beliefs about medicines prescribed for long-term conditions: a meta-analytic review of the Necessity-Concerns Framework

BACKGROUND

Patients' beliefs about treatment influence treatment engagement and adherence. The Necessity-Concerns Framework postulates that adherence is influenced by implicit judgements of personal need for the treatment (necessity beliefs) and concerns about the potential adverse consequences of taking it.

OBJECTIVE

To assess the utility of the NCF in explaining nonadherence to prescribed medicines.

DATA SOURCES

We searched EMBASE, Medline, PsycInfo, CDSR/DARE/CCT and CINAHL from January 1999 to April 2013 and handsearched reference sections from relevant articles.

STUDY ELIGIBILITY CRITERIA

Studies using the Beliefs about Medicines Questionnaire (BMQ) to examine perceptions of personal necessity for medication and concerns about potential adverse effects, in relation to a measure of adherence to medication.

PARTICIPANTS

Patients with long-term conditions.

STUDY APPRAISAL AND SYNTHESIS METHODS

Systematic review and meta-analysis of methodological quality was assessed by two independent reviewers. We pooled odds ratios for adherence using random effects models.

RESULTS

We identified 3777 studies, of which 94 (N = 25,072) fulfilled the inclusion criteria. Across studies, higher adherence was associated with stronger perceptions of necessity of treatment, OR = 1.742, 95% CI [1.569, 1.934], p<0.0001, and fewer Concerns about treatment, OR = 0.504, 95% CI: [0.450, 0.564], p<0.0001. These relationships remained significant when data were stratified by study size, the country in which the research was conducted and the type of adherence measure used.

LIMITATIONS

Few prospective longitudinal studies using objective adherence measures were identified.

CONCLUSIONS

The Necessity-Concerns Framework is a useful conceptual model for understanding patients' perspectives on prescribed medicines. Taking account of patients' necessity beliefs and concerns could enhance the quality of prescribing by helping clinicians to engage patients in treatment decisions and support optimal adherence to appropriate prescriptions.

Comparative efficacy and safety of medical treatments for the management of overactive bladder: a systematic literature review and mixed treatment comparison

CONTEXT

Overactive bladder (OAB) treatment guidelines recommend antimuscarinics as first-line pharmacologic therapy. Mirabegron is a first-in-class β3-adrenoceptor agonist licensed for the treatment of OAB and has shown to be well tolerated and effective in the treatment of OAB symptoms.

OBJECTIVE

To assess the relative efficacy and tolerability of OAB medications, specifically mirabegron 50 mg versus antimuscarinics in patients with OAB.

EVIDENCE ACQUISITION

A systematic literature search was performed on published peer-reviewed articles from 2000 to 2013. This review included randomised controlled trials (RCTs) studying changes in symptoms (micturition frequency, incontinence, and urgency urinary incontinence [UUI] episodes) and incidence of the most frequently reported adverse events (dry mouth, constipation) associated with current OAB medications. The following drugs were considered in addition to mirabegron: darifenacin, tolterodine immediate release (IR) and extended release (ER), oxybutynin IR/ER, trospium, solifenacin, and fesoterodine. Bayesian mixed treatment comparisons (MTCs) were performed for efficacy (micturition, incontinence, UUI) and tolerability (dry mouth, constipation, blurred vision).

EVIDENCE SYNTHESIS

Overall, 44 RCTs involving 27,309 patients were included. The MTCs showed that mirabegron 50 mg was as efficacious as antimuscarinics in reducing the frequency of micturition incontinence and UUI episodes, with the exception of solifenacin 10 mg that was more efficacious than mirabegron 50 mg in improving micturition frequency and frequency of UUI. Mirabegron 50 mg had an incidence of dry mouth similar to placebo and significantly lower than all included antimuscarinics.

CONCLUSIONS

Mirabegron 50 mg had similar efficacy to most antimuscarinics and lower incidence of dry mouth, the most common adverse event reported with antimuscarinics and one of the main causes of discontinuation of treatment. Despite being a powerful tool for evidence-based health care evaluation, the Bayesian MTC method has limitations. Further head-to-head comparisons between mirabegron and antimuscarinics should be conducted to confirm our results.

Do β-adrenoceptor agonists induce homologous or heterologous desensitization in rat urinary bladder?

β3-Adrenoceptor agonists have recently been introduced for the symptomatic treatment of the overactive bladder syndrome. As such treatment is not curative, long-term treatment is anticipated to be required. As the susceptibility of β3-adrenoceptors to undergo agonist-induced desensitization is cell type- and tissue-dependent, we have explored whether pre-treatment with a β-adrenoceptor agonist will attenuate subsequent relaxation responses to freshly added agonist using rat urinary bladder as a model. We have used the prototypical β-adrenoceptor agonist isoprenaline, the β2-selective fenoterol and the β3-selective CL 316,243 and mirabegron as well as the receptor-independent bladder relaxant forskolin. We show that a 6-h pre-treatment with agonist can significantly reduce subsequent relaxation against KCl-induced smooth muscle tone, but agonist-induced desensitization was also observed with longer pre-treatments or against passive tension. The agonist-induced desensitization was prominent for the β2 component of rat bladder relaxation but much weaker or even absent for the β3 component. Moreover, β-adrenoceptor agonist pre-treatment reduced contractile responses to the muscarinic agonist carbachol and the receptor-independent stimulus KCl. Taken together these data do not support the hypothesis that the long-term clinical efficacy of β3-adrenoceptor agonists in the treatment of the overactive bladder syndrome will be limited by receptor desensitization. Rather they raise the possibility that such treatment may not only cause smooth muscle relaxation but also may attenuate hyper-contractility of the bladder.

Evidence available on the use of the selective β3-adrenoceptor agonist mirabegron for the treatment of overactive bladder

CONTEXT

Mirabegron, the selective β3-adrenoceptor agonist, heralds the latest development for the treatment of overactive bladder (OAB).

OBJECTIVE

To present the evidence available on the efficacy and tolerability of mirabegron and to discuss this treatment's potential in our setting.

EVIDENCE ACQUISITION

We reviewed 11 studies conducted with mirabegron in patients with OAB (2 phase II, 9 phase III), all studies were compared to placebo with 6 studies also including tolterodine as an additional arm. Greater emphasis shall be given to the main phase III trials performed in Europe, the USA and Australia evaluating efficacy and safety after 12 weeks (NCT00662909, NCT00689104, NCT00912964) and safety after 12 months (NCT00688688). The combined analyses of these 12 week studies is also available, with emphasis on global efficacy (FAS), efficacy with regard to incontinence (FAS i) and safety (SAF). More than 50% of patients had previously discontinued anticholinergics medication for OAB, thus allowing us to obtain data on the effectiveness of mirabegron in patients already treated with anticholinergics.

EVIDENCE SYNTHESIS

Mirabegron is an efficacious drug which presents a statistically significant reduction in the number of incontinence episodes and in urinary frequency as of 4 weeks, with a higher percentage of dry patients and a higher percentage of patients with reduction ≥50% in the number of incontinence episodes than placebo. The efficacy of mirabegron 50 and 100mg in the reduction of incontinence episodes occurs in de novo patients and who have received antimuscarinics, with adjusted mean difference and improvement in urinary frequency greater in treated patients. Its tolerability is very similar to placebo particularly for the adverse effects of the antimuscarinics (dry mouth, constipation and blurred vision). A minimal, non-clinically significant change is observed in systolic and diastolic blood pressure and pulse. Its efficacy is long-term. Mirabegron at the doses of 50 and 100mg presents an improvement versus placebo in patient satisfaction, health-related quality of life (HRQoL), symptom bother and patient's perception of bladder condition (PPBC). In the 12 week Phase III European study tolterodine delivered a lesser degree of improvement than mirabegron versus placebo in patient satisfaction, HRQoL, symptom bother and PPBC.

CONCLUSIONS

Mirabegron is the first of a new class of compounds with a novel mechanism of action that is different to the antimuscarinics. It presents significant and clinically important efficacy in the treatment of the symptoms of OAB. It has advantages with regard to the results described by the patient in treatment satisfaction. Studies on its combined use with anticholinergics are ongoing.

Health economics perspective of fesoterodine, tolterodine or solifenacin as first-time therapy for overactive bladder syndrome in the primary care setting in Spain

Background

Overactive bladder (OAB) is associated with high healthcare costs, which may be partially driven by drug treatment. There is little comparative data on antimuscarinic drugs with respect to resource use and costs. This study was conducted to address this gap and the growing need for naturalistic studies comparing health economics outcomes in adult patients with OAB syndrome initiating treatment with different antimuscarinic drugs in a primary care setting in Spain.

Methods

Medical records from the databases of primary healthcare centres in three locations in Spain were assessed retrospectively. Men and women ≥18 years of age who initiated treatment with fesoterodine, tolterodine or solifenacin for OAB between 2008 and 2010 were followed for 52 weeks. Healthcare resource utilization and related costs in the Spanish National Health System were compared. Comparisons among drugs were made using multivariate general linear models adjusted for location, age, sex, time since diagnosis, Charlson comorbidity index, and medication possession ratio.

Results

A total of 1,971 medical records of patients (58.3% women; mean age, 70.1 [SD:10.6] years) initiating treatment with fesoterodine (n = 302), solifenacin (n = 952) or tolterodine (n = 717) were examined. Annual mean cost per patient was €1798 (95% CI: €1745; €1848). Adjusted mean (95% bootstrap CI) healthcare costs were significantly lower in patients receiving fesoterodine (€1639 [1542; 1725]) compared with solifenacin (€1780 [€1699; €1854], P = 0.022) or tolterodine (€1893 [€1815; €1969], P = 0.001). Cost differences occurred because of significantly fewer medical visits, and less use of absorbent products and OAB-related concomitant medication in the fesoterodine group.

Conclusions

Compared with solifenacin and tolterodine, fesoterodine was a cost-saving therapy for treatment of OAB in the primary care setting in Spain.

Long-term adherence to antimuscarinic therapy in everyday practice: a systematic review

PURPOSE

Antimuscarinic drug treatment is known to have side effects and, consequently, poor adherence in therapeutic regimens. In this systematic review we study the long-term (greater than 6 months) adherence to antimuscarinic drugs in daily clinical practice, and identify factors contributing to poor adherence and persistence.

MATERIALS AND METHODS

This systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A literature search was performed using PubMed® and Embase™ using synonyms for incontinence, overactive bladder and antimuscarinics combined with synonyms for medication adherence. We chose to include only pharmaceutical database studies (using prescription/insurance claim data) and patient self-report studies, using established pharmacoepidemiological parameters such as persistence rate and medication possession rate.

RESULTS

A total of 1,245 titles were screened, of which 102 abstracts were assessed. Fourteen studies were ultimately included, comprising 190,279 unique patients (mean age 69.5 years). Regardless of which specific antimuscarinic drug is studied, persistence rates are usually poor. Considering all drugs together, median persistence rates were 12.0% to 39.4% (with an outlier of 75.5%) at 12 months, 8.0% to 15.0% at 18 months and 6.0% to 12.0% at 24 months. At 36 months persistence rates ranged from 0.0% (darifenacin) to 16.0% (trospium). Mean reported medication possession rates were also low, with a mean of 0.37 at 12 months. Risk factors for discontinuation were identified, with the most important being younger age group, use of oxybutynin and use of immediate release formulations.

CONCLUSIONS

Improvement in adherence and persistence with antimuscarinic medication should be an important goal in the development of new drugs for overactive bladder and urinary incontinence.

Mirabegron in overactive bladder: a review of efficacy, safety, and tolerability

AIMS

Mirabegron, the first β3 -adrenoceptor agonist to enter clinical practice, has a different mechanism of action from antimuscarinic agents. This review presents data on the efficacy, safety, and tolerability of mirabegron in studies conducted to date.

METHODS

All clinical data on mirabegron that are currently in the public domain are included, including some in-press manuscripts.

RESULTS

In Phase III clinical trials in patients with overactive bladder (OAB), mirabegron at daily doses of 25, 50, and 100 mg demonstrated significant efficacy in treating the symptoms of OAB, including micturition frequency, urgency incontinence, and urgency. Significant improvements in micturition frequency, urgency incontinence, and mean volume voided/micturition were seen as early as the first assessment (week 4) for mirabegron 50 and 100 mg, and were maintained throughout treatment. Responder analyses showed a significant improvement with mirabegron 50 and 100 mg in terms of dry rates, ≥50% reduction in mean number of incontinence episodes/24 hr, and the proportion of patients with ≤8 micturitions/24 hr at final visit. The benefit of mirabegron 50 and 100 mg was also evident in patients ≥65 years of age, and in both treatment-naïve patients and those who previously discontinued antimuscarinic therapy. These data therefore demonstrate a clinically meaningful benefit with mirabegron in the objective endpoints of OAB. Assessment of measures of health-related quality of life and treatment satisfaction showed that patients perceived treatment with mirabegron as meaningful. In OAB clinical trials of up to 12 months mirabegron appeared to be well tolerated. The most common adverse events (AEs) observed with mirabegron in clinical trials of up to 12 months were hypertension, nasopharyngitis, and urinary tract infection. The incidence of dry mouth was similar to placebo, and was between three and fivefold less than for tolterodine extended release 4 mg. Since dry mouth is the most bothersome AE associated with antimuscarinic drugs and often a reason for treatment discontinuation, mirabegron may be a valuable treatment option for these patients.

CONCLUSIONS

In Phase III clinical trials, mirabegron at daily doses of 25, 50, and 100 mg demonstrated significant efficacy in treating symptoms of OAB and, at doses of 50 and 100 mg, demonstrated significant improvements versus placebo on key secondary endpoints, as early as the first assessment (week 4), and these were maintained throughout treatment. In OAB clinical trials of up to 12 months, mirabegron appeared to be well tolerated.

Long-term patterns of use and treatment failure with anticholinergic agents for overactive bladder

BACKGROUND

Overactive bladder (OAB) involves a complex set of symptoms with a lifetime prevalence of any symptom in ~30% of women and 20% of men. Anticholinergic agents are associated with poor medication persistence in OAB treatment.

OBJECTIVE

This study evaluated the long-term patterns of use and treatment failure in patients prescribed anticholinergic agents for OAB.

METHODS

This was a nonexperimental, retrospective cohort study. Medical, pharmacy, and eligibility data from the IMS LifeLink Health Plans Claims Database were used. Men and women aged ≥18 years were eligible for inclusion with an International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis of OAB in any field during the patient study period from January 2005 to June 2010. First documentation of a prescription filled between July 2005 and June 2008 for an anticholinergic agent was defined as the index prescription. Other inclusion criteria were: ≥1 pharmacy claim for an anticholinergic drug between July 2005 and June 2008; continuous enrollment 6 months before the index date, during which no anticholinergic drugs were filled; and 24 months of follow-up from the index prescription. Study outcomes were treatment failure, discontinuation, switch, reinitiation, and adherence. Treatment failure was defined as having a treatment discontinuation (ie, treatment gap of ≥45 days) or switching anticholinergic therapy.

RESULTS

The analytic cohort comprised 103,250 patients with a mean age of 58.7 years. A majority were female (73%) and privately insured (75%). The vast majority of patients (91.7%) failed to meet their treatment goals with their index anticholinergic agent over the 24-month follow-up period. Of these, 5.8% switched, 51.3% permanently discontinued all anticholinergic agents, and 34.6% reinitiated treatment sometime after 45 days. The mean (SD) time to treatment failure was 159 (216.0) days, with a mean of 1.3 (0.5) unique anticholinergic agents per patient. Forty-eight percent of patients demonstrated appropriate adherence as determined by a medication possession ratio ≥80%.

CONCLUSIONS

This study provides real-world data on treatment patterns over 2 years in a large cohort of patients diagnosed with OAB. Despite the potential for better adherence with some anticholinergic agents, these analyses suggest that such benefits have not yet been realized, and many patients end up without effective pharmacotherapy. Thus, there is a need for new therapies and strategies to increase persistence and adherence to improve outcomes in OAB.

Efficacy of mirabegron in patients with and without prior antimuscarinic therapy for overactive bladder: a post hoc analysis of a randomized European-Australian Phase 3 trial

Background

Antimuscarinic agents are currently the predominant treatment option for the clinical management of the symptoms of overactive bladder (OAB). However, low rates of persistence with these agents highlight the need for novel, effective and better-tolerated oral pharmacological agents. Mirabegron is a β₃-adrenoceptor agonist developed for the treatment of OAB, with a mechanism of action distinct from that of antimuscarinics. In a randomized, double-blind, placebo- and active-controlled Phase 3 trial conducted in Europe and Australia (NCT00689104), mirabegron 50 mg and 100 mg resulted in statistically significant reductions from baseline to final visit, compared with placebo, in the co-primary end points – mean number of incontinence episodes/24 h and mean number of micturitions/24 h. We conducted a post hoc, subgroup analysis of this study in order to evaluate the efficacy of mirabegron in treatment-naïve patients and patients who had discontinued prior antimuscarinic therapy because of insufficient efficacy or poor tolerability.

Methods

Patients were randomized to placebo, mirabegron 50 or 100 mg, or tolterodine extended release (ER) 4 mg orally, once-daily, for 12 weeks. For the post hoc analysis, the primary patient population was divided into the following subgroups: (1) patients who had not received any prior antimuscarinic OAB medication (treatment-naïve) and (2) patients who had received prior antimuscarinic OAB medication. The latter subgroup was further subdivided into patients who discontinued due to: (3) insufficient efficacy or (4) poor tolerability. Analysis of the co-primary efficacy endpoints by subgroup was performed using analysis of covariance with treatment group, subgroup, sex, geographical region, and subgroup-by-treatment interaction as fixed factors; and baseline value as a covariate.

Results

Mirabegron, 50 mg and 100 mg once-daily, demonstrated similar improvements in the frequency of incontinence episodes and micturitions in OAB patients who were antimuscarinic-naïve and who had discontinued prior antimuscarinic therapy. While mirabegron demonstrated improvements in incontinence and micturition frequency in patients who had discontinued prior antimuscarinic therapy due to insufficient efficacy, the response to tolterodine was similar to that of placebo.

Conclusion

In this post hoc subgroup analysis, mirabegron provided treatment benefits in OAB patients who were antimuscarinic treatment-naïve and in patients who had received prior antimuscarinic treatment.

New developments in the medical management of overactive bladder

Overactive bladder (OAB) is a clinical syndrome describing the symptom complex of urgency, with or without urgency incontinence and is usually associated with frequency and nocturia. Whilst the majority of women will benefit from initial management with conservative and behavioural intervention a significant number will require medical therapy. Antimuscarinics are currently the most widely prescribed drugs for OAB although very often persistence with medication is limited due to lack of efficacy or intolerable adverse effects. The review, whilst giving a brief overview of OAB syndrome, will focus on new developments in drug therapy for OAB. In addition to evaluating new drugs with different methods of action it will also specifically focus on alternative modalities of treatment and how they may benefit patients with this troublesome and distressing condition.

The efficacy and safety of mirabegron in treating OAB: a systematic review and meta-analysis of phase III trials

PURPOSE

Mirabegron, a potent and selective β3-adrenoceptor agonist, has been developed for the treatment of overactive bladder (OAB). We carried out a systematic review and meta-analysis to assess the efficacy and safety of the drug for treating OAB.

METHODS

A literature review was performed to identify all published randomized double-blind, placebo-controlled phase III trials of mirabegron for the treatment of OAB. The search included the following databases: MEDLINE, EMBASE and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated. A systematic review and meta-analysis of phase III trials were conducted.

RESULTS

Four publications involving a total of 5,761 patients were used in the analysis, including four phase III RCTs that compared mirabegron with placebo. We found that mirabegron was effective in treating OAB in our meta-analysis. Co-primary efficacy end points: the mean number of incontinence episodes per 24 h (the standardized mean difference (SMD) = -0.44, 95 % confidence interval (CI) -0.59 to -0.29, p < 0.00001); the mean number of micturitions per 24 h (SMD = -0.62, 95 % CI -0.80 to -0.45, p < 0.00001) and key secondary efficacy end points: mean volume voided per micturition; mean number of urgency episodes per 24 h indicated that mirabegron was more effective than the placebo. Safety assessments included common treatment-emergent adverse events (TEAEs) [OR 1.10, 95 % CI 0.93-1.31, p = 0.25), hypertension, cardiac arrhythmia TEAEs, urinary retention and discontinuations due to adverse event indicated that mirabegron was well tolerated.

CONCLUSIONS

This meta-analysis indicates that mirabegron to be an effective and safe treatment for OAB symptoms with a low occurrence of side effects. It offers promise as an effective oral agent for the treatment of OAB with a distinct efficacy/tolerability balance.