Effect of ß3-adrenoceptor agonist on the micromotion of bilateral major pelvic ganglion-excised rat bladder.

AIMS: Micromotion is an autonomous intramural movement of the bladder, and is believed to be an initial step in the generation of urinary urgency. Therefore, controlling micromotion may be a novel target in overactive bladder (OAB) treatment. However, developing micromotion treatment has been limited by the absence of a standardized animal model. We attempted to create a micromotion animal model and investigated the effectiveness of a ß3 -adrenoceptor agonist (CL316,243) on micromotion. METHODS: Bilateral major pelvic ganglia (MPGs) were excised in 18 male Sprague-Dawley rats, resulting in an almost completely denervated bladder. On postoperative Day 7, cystometry was performed. Rats were divided into three treatment groups: CL316,243; ß3- adrenoceptor antagonist (SR59230A) pretreated CL316,243; and a nonselective antimuscarinic agent (oxybutynin). Changes in micromotion were evaluated after the intra-arterial administration of each agent. RESULTS: Low-amplitude oscillations in intravesical pressure (micromotion) were observed 1 week after MPGs excision. Micromotion frequency significantly (p = 0.003) decreased (2.17 ± 3.54 times/5 min) with CL316,243 compared with vehicle (6.33 ± 1.97 times/5 min). Micromotion amplitude also decreased with CL316,243 (1.15 ± 1.93 cmH2 O) compared with vehicle (5.96 ± 5.12 cmH2 O), approaching conventional significance (p = 0.090). No significant decreases in frequency or amplitude were observed with oxybutynin treatment. CONCLUSIONS: Systemic administration of the ß3 -adrenoceptor agonist CL316,243 effectively controlled micromotion in bilateral MPGs-excised, almost completely denervated rat bladders. This result indicates that ß3 -adrenoceptor agonist may affect the bladder directly, suggesting that it might be effective for overall OAB, regardless of the presence or level of neurological deficits. Bilateral MPGs-excised rats are considered a plausible micromotion animal model suitable for future research.

Continuous administration of mirabegron has advantages in inhibition of central sensitization compared with short-term treatment cessation in a mouse model of overactive bladder.

AIMS: There is no clear pathophysiologic evidence determining how long overactive bladder (OAB) medication should be continued. We, therefore, investigated the effect of mirabegron using cessation (CES) or continuation (CON) treatment in an OAB animal model. METHODS: Female C57BL/6 mice were divided into four groups (N = 8 each): Sham, OAB, CES, and CON groups. The OAB-like condition was induced by three times weekly intravesical instillations of KCl mixture with hyaluronidase. After the last intravesical instillation for inducing OAB, mirabegron (2 mg/kg/day) was administered in CES and CON groups for 10 and 20 days, respectively. Final experiments were carried out on 20 days from the last intravesical instillation in all groups. After cystometry, mRNA levels of bladder muscarinic, ß-adrenergic, and P2X purinergic receptors were measured to investigate bladder efferent and afferent activity. In addition, mRNA levels of CCL2 and CCR2 in L6-S1 dorsal root ganglia (DRG) were measured to assess afferent sensitization. Immunofluorescent staining of CX3CR1, GFAP, and CCR2 in the L6 spinal cord was also conducted to investigate glial activation and central sensitization. RESULTS: OAB mice showed bladder overactivity evidenced by decreased intercontraction interval (3.56 ± 0.51 vs. 5.76 ± 0.95 min in sham mice), increased non-voiding contractions (0.39 ± 0.11 vs. 0.13 ± 0.07/min in sham mice), and inefficient voiding (72.1 ± 8.6% vs. 87.1 ± 9.5% in sham mice). Increased M2, M3, ß2, ß3, P2X2 , P2X3 , P2X4 , and P2X7 levels in the bladder and increased CCL2 and CCR2 in DRG indicate bladder efferent and afferent hyperexcitability. In addition, CX3CR1, GFAP, and CCR2 in the L6 spinal cord were upregulated in OAB mice. However, the CON group exhibited reduced ß2, ß3, P2X2 , P2X3 , P2X4 , and P2X7 levels in the bladder, reduced CCL2 and CCR2 in DRG, which are markers of afferent hyperexcitability, and reduced immunoreactivities of CX3CR1, GFAP, and CCR2 in the L6 spinal cord, which are markers of the central sensitization. Moreover, the CON group showed better improvements in nonvoiding contractions (0.16 ± 0.09 vs. 0.44 ± 0.17/min) and voiding efficiency (93.9 ± 7.4% vs. 76.5 ± 13.1%) and reductions in bladder ß3 receptors and CCL2 of L6-S1 DRG, and immunoreactivities of CX3CR1 and GFAP in the L6 spinal cord compared to the CES group. CONCLUSIONS: Continuous mirabegron treatment seems to prevent central sensitization and, thus, might be desirable for long-term disease control of OAB.

Mirabegron for overactive bladder in frail patients 80 years or over (HOKUTO study).

BACKGROUND: We assessed the efficacy and safety of mirabegron, a ß3-adrenoceptor agonist, in older adults (≥ 80 years old) with overactive bladder (OAB). METHODS: OAB patients aged ≥ 80 years were enrolled in this prospective, single-arm observational study. OAB was diagnosed based on the OAB symptom score (OABSS); i.e., a total score of ≥ 3 points and an urgency score of ≥ 2 points. Patients who received 50 mg mirabegron once daily were evaluated at the baseline and at 4, 8, and 12 weeks. The changes from the baseline in the OABSS, International Prostate Symptom Score (IPSS), OAB questionnaire (OAB-q) score, and Vulnerable Elders Survey (VES-13) score were determined. Adverse events, laboratory tests, 12-lead electrocardiography, the QT interval according to Fridericia's formula (QTcF), uroflowmetry, the post-void residual urine volume (PVR), and the Mini-Mental State Examination (MMSE) score were used to assess safety. RESULTS: Forty-three patients (median age: 84 years, range: 80-96 years) were examined. They had high rates of comorbidities and polypharmacy. Mirabegron significantly improved in total score of the OABSS, including urgency and urge incontinence. The total IPSS, IPSS quality-of-life (QOL) index, and OAB-q scores also significantly improved. Mirabegron improved in the VES-13 score. There were no significant changes in laboratory test values, uroflowmetry findings, PVR, the QTcF, or MMSE score. Two patients (4.7%) withdrew from the study after experiencing adverse events. CONCLUSIONS: Mirabegron was well tolerated and significantly improved in OAB symptoms, and QOL in older patients. Trial registration The present clinical study was approved by University of Yamanashi Institutional Review Board prior to study initiation (ID1447) and was retrospectively registered with the UMIN Clinical Trials Registry (UMIN-CTR), Japan (UMIN000045996) on Nov 6, 2021.

Efficacy and safety of mirabegron, a ß3-adrenoceptor agonist, for treating neurogenic bladder in pediatric patients with spina bifida: a retrospective pilot study.

PURPOSE: Antimuscarinics are the first pharmacological treatment option for neurogenic bladder in children with spina bifida but side effects limit their use. Mirabegron, a new ß-3 adrenoceptor agonist with a distinct mechanism of action, is a potential agent for the treatment of neurogenic bladder; however, it has yet to be studied in the pediatric population. This study evaluated the efficacy and safety of mirabegron for treating neurogenic bladder in children with spina bifida. MATERIALS AND METHODS: Clinical and urodynamic parameters were retrospectively studied in 66 children (under 18 years of age) with spina bifida who were treated for neurogenic bladder with mirabegron at Severance Children's Hospital between July 2015 and December 2017. Pediatric patients received 50 mg mirabegron daily for at least 6 weeks either in addition to or instead of antimuscarinic therapy. Urodynamic parameters, including compliance, involuntary detrusor contraction, and maximum cystometric capacity, as well as patient-reported efficacy and adverse events, were measured. RESULTS: In both groups post-treatment, incontinence significantly improved. In addition, maximum cystometric capacity and compliance significantly increased post-treatment. Six patients reported side effects (constipation, 4.5%; headache, 3.0%; and hypertension, 1.5%) and three patients discontinued treatment. CONCLUSION: We evaluated the efficacy and safety of mirabegron for treating neurogenic bladder in pediatric patients with spina bifida. All clinical and urodynamic parameters improved with treatment. Prospective, placebo-controlled studies are necessary to confirm these findings.

Efficacy and safety of non-ablative vaginal erbium:YAG laser treatment as a novel surgical treatment for overactive bladder syndrome: comparison with anticholinergics and ß3-adrenoceptor agonists.

PURPOSE: To examine the efficacy and safety of non-ablative vaginal erbium:YAG laser (VEL) for the treatment of overactive bladder syndrome (OAB) compared with those of two other common pharmacotherapies, namely, anticholinergics and ß3-adrenoceptor agonists. METHODS: Female subjects aged 60-69 years who presented with symptoms of OAB from 2015 to 2017 were assigned to three groups (n = 50) receiving treatment with an anticholinergic agent (4 mg fesoterodine), a ß3-adrenoceptor agonist (25 mg mirabegron), or VEL (20 min/session of VEL performed thrice). The OAB symptom score (OABSS), Vaginal Health Index Scale (VHIS), and occurrence of adverse effects were examined prior to and at 1 year following treatment initiation. RESULTS: The three groups showed significant improvement (p < 0.001) for all items of the OABSS questionnaire. Improved VHIS scores were observed only in the VEL group. Furthermore, after VEL treatment, a negative correlation was observed between questions 3 (urinary urgency) and 4 (urgency urinary incontinence) of the OABSS and VHIS. Regarding safety, no adverse events were observed in the VEL group. However, subjects in the other two groups complained of constipation, as indicated by the Constipation Assessment Scale scores, and mouth dryness. The therapeutic effects were inadequate for one and two subjects in the VEL and ß3-adrenoceptor agonist groups, respectively. CONCLUSIONS: VEL safely and effectively improved OABSS through a different mechanism than that involved in pharmacotherapy. We propose the use of VEL as a novel surgical treatment option in the field of urology.

Acute metabolic and cardiovascular effects of mirabegron in healthy individuals.

AIMS: To quantify acute energy expenditure, supraclavicular skin temperature and cardiovascular responses to four doses of the ß3-adrenoceptor agonist, mirabegron. MATERIALS AND METHODS: A total of 17 individuals (11 men, six women) participated in this ascending-dose study, receiving single 50-, 100-, 150- and 200-mg doses of mirabegron on four separate days with 3 to 14 days wash-out between each dose. All variables were measured each visit from baseline to 180 minutes post mirabegron treatment. To determine brown adipose tissue (BAT) thermogenic efficacy at each dose, energy expenditure and supraclavicular skin temperature were compared from baseline to 180 minutes post mirabegron treatment. To examine safety, changes in cardiovascular variables at 100, 150 and 200 mg were compared with the standard clinical dose of 50 mg. RESULTS: Energy expenditure significantly increased after the 100- (35.6 ± 5.4 kJ/h) and 200-mg (35.6 ± 13.1 kJ/h) doses (P ≤ 0.05), and trended towards an increase after 150 mg (24.1 ± 13.6 kJ/h). Supraclavicular skin temperature increased after 50- (0.22 ± 0.1°C), 100- (0.30 ± 0.1°C) and 150-mg mirabegron doses (0.29 ± 0.1°C; P ≤ 0.05). The change in systolic blood pressure was greater after 150- (7.1 ± 1.3 mm Hg) and 200-mg doses (9.3 ± 1.9 mm Hg) than after the 50-mg dose (2.2 ± 1.3 mm Hg; P ≤ 0.05). The change in heart rate was greater after 200 mg (9.0 ± 2.2 bpm) compared with 50 mg (2.9 ± 1.4 bpm; P ≤ 0.05). CONCLUSIONS: A 100-mg dose of mirabegron increases energy expenditure and supraclavicular skin temperature in a ß3-adrenoceptor-specific manner, without the off-target elevations in blood pressure or heart rate observed at higher doses.

Patient-reported outcomes from SYNERGY, a randomized, double-blind, multicenter study evaluating combinations of mirabegron and solifenacin compared with monotherapy and placebo in OAB patients.

AIMS: To evaluate patient-reported outcomes (PROs) of combinations of solifenacin and mirabegron compared with solifenacin and mirabegron monotherapy and with placebo in patients with overactive bladder (OAB) from the SYNERGY trial. METHODS: Following a 4-week placebo run-in, period patients (≥18 years) with OAB were randomized 2:2:1:1:1:1 to receive solifenacin 5 mg + mirabegron 25 mg (combination 5 + 25 mg), solifenacin 5 mg + mirabegron 50 mg, (combination 5 + 50 mg), solifenacin 5 mg, mirabegron 25 mg, mirabegron 50 mg or placebo for 12 weeks, followed by a 2-week washout period. At each visit, PROs related to quality of life, symptom bother, and treatment satisfaction were assessed, including OAB-q Symptom Bother score, health-related quality of life (HRQOL) Total score, treatment satisfaction-visual analogue scale (TS-VAS), and patient perception of bladder condition (PPBC) questionnaires. RESULTS: Overall, 3527 patients were randomized into the study, with 3494 receiving double-blind treatment. At end of treatment (EoT), both combination groups showed greater improvements in OAB-q Symptom Bother score compared with the monotherapy groups (nominal P < 0.001). Statistically significant improvements in HRQOL Total scores were observed in the combination groups versus monotherapy groups (P ≤ 0.002). For both combination groups, the OAB-q Symptom Bother score responder rates at EoT were statistically significantly higher versus mirabegron monotherapy (P < 0.05). The mean adjusted changes from baseline to EoT for PPBC were greater in the combination groups compared with monotherapy groups. CONCLUSIONS: PROs showed that combination therapy provided clear improvements and an additive effect for many HRQOL parameters, including OAB-q Symptom Bother score, HRQOL Total score, and PPBC.

Clinical efficacy and safety of mirabegron and imidafenacin in women with overactive bladder: A randomized crossover study (the MICRO study).

AIMS: We aimed to compare the efficacy and safety of mirabegron, a ß3-adrenoceptor agonist, and imidafenacin, an anticholinergic agent, in overactive bladder patients. METHODS: We conducted a multicenter, prospective randomized cross-over study at 5 hospitals in Japan from December 2012 to June 2015. We enrolled female patients with overactive bladder aged ≥50 years, who had never received treatment for the condition. The patients were assigned to Group A or B. Group A patients were administered mirabegron (50 mg per day) for 8 weeks, followed by a 2-week washout period, and then imidafenacin (0.2 mg per day) for 8 weeks. This order of drug administration was reversed in Group B. RESULTS: A total of 33 and 18 patients in Group A and 37 and 26 patients in Group B continued to receive treatment at weeks 8 and 18, respectively. Mirabegron administration significantly improved overactive bladder symptom score (OABSS), the urinary frequency per 24 hr, voided volume per micturition, and number of nocturia episodes per night at week 8. Moreover, imidafenacin administration improved all these variables, except for the number of nocturia episodes per night at week 8. No significant difference was observed in the drug effects between mirabegron and imidafenacin. Although imidafenacin administration significantly increased the scores for dry mouth, blurred vision, and constipation, mirabegron administration did not. CONCLUSIONS: Mirabegron and imidafenacin have the same efficacy. Imidafenacin administration is associated with a higher rate of dry mouth, blurred vision, and constipation as compared to mirabegron administration. Neurourol. Urodynam. 36:1097-1103, 2017. © 2016 Wiley Periodicals, Inc.

Patient-reported outcomes with the ß3 -adrenoceptor agonist mirabegron in a phase III trial in patients with overactive bladder.

AIMS: To assess patient-reported outcomes (PROs) in patients with overactive bladder (OAB) receiving the novel ß3 -adrenoceptor agonist mirabegron. METHODS: Data from a randomised, double-blind, controlled phase III trial in 1,987 patients aged ≥18 years with OAB symptoms for ≥3 months were analysed. Patients received placebo, mirabegron 50 or 100 mg/day, or tolterodine extended release (ER) 4 mg orally once daily for 12 weeks after a 2-week placebo run-in. Prespecified analysis of PROs (changes in OAB Questionnaire [OAB-q], Patient Perception of Bladder Condition [PPBC], and Work Productivity and Activity Impairment: Specific Health Problem [WPAI-SHP] instrument) in patients treated with mirabegron 50 mg/day, tolterodine ER 4 mg/day or placebo is reported. Post-hoc analyses of OAB-q, PPBC and the Treatment Satisfaction-Visual Analogue Scale (TS-VAS) in patients who were incontinent at baseline are also reported. RESULTS: Significant improvements over placebo in OAB-q coping and concern from baseline to final visit were observed with mirabegron 50 mg/day. No significant improvements in these parameters were observed with tolterodine ER 4 mg/day. Mirabegron 50 mg/day significantly increased the proportion of patients showing a PPBC improvement over placebo. Mirabegron 50 mg/day also produced greater improvements in WPAI-SHP presenteeism and greater reductions in absenteeism and overall work impairment than placebo or tolterodine ER 4 mg/day. The impact of mirabegron 50 mg/day treatment on PROs in the incontinent population appears to be greater than that in the overall OAB population. CONCLUSIONS: At the approved dose of 50 mg/day, mirabegron significantly improves OAB patients' perception of disease and quality of life, independent of whether they are incontinent at baseline. Neurourol. Urodynam. 35:987-994, 2016. © 2015 The Authors. Neurourology and Urodynamics published by Wiley Periodicals, Inc.

Real-world cardiovascular assessment of mirabegron treatment in patients with overactive bladder and concomitant cardiovascular disease: Results of a Japanese post-marketing study.

OBJECTIVES: To assess the effect of 25 or 50 mg mirabegron on cardiovascular end-points and adverse drug reactions in real-world Japanese patients with overactive bladder and cardiovascular disease. METHODS: Participants had overactive bladder, a history of/coexisting cardiovascular disease and a 12-lead electrocardiogram carried out ≤7 days before initiating 4 weeks of mirabegron treatment. Patients with "serious cardiovascular disease" (class III or IV on the New York Heart Association functional classification and further confirmed by expert analysis) were excluded. Patient demographics, physical characteristics and cardiovascular history were recorded. After 4 weeks, patients underwent another electrocardiogram. Incidence of cardiovascular adverse drug reactions and change from baseline in electrocardiogram parameters (RR, PR, QRS intervals, Fridericia's corrected QT and heart rate) were assessed. RESULTS: Of 316 patients registered, 236 met criteria and had baseline/post-dose electrocardiograms: 61.9% male; 60.2% aged ≥75 years; 93.6% with coexisting cardiovascular disease, notably, arrhythmia (67.8%) and angina pectoris (19.1%). Starting mirabegron daily doses were 25 mg (19.9%) or 50 mg (80.1%). The incidence of cardiovascular adverse drug reactions was 5.51%. After 4 weeks, the mean heart rate increased by 1.24 b.p.m. (statistically significant, but clinically acceptable as per previous trials). No significant changes were observed in PR, QRS or Fridericia's corrected QT. No significant correlations in the total population or age-/sex-segregated subgroups were observed between baseline Fridericia's corrected QT and change at 4 weeks. No correlation for heart rate versus change from baseline heart rate with treatment was observed. CONCLUSIONS: Mirabegron was well tolerated in real-world Japanese patients with overactive bladder and coexisting cardiovascular disease. No unexpected cardiovascular safety concerns were observed.

Cold-Induced Browning Dynamically Alters the Expression Profiles of Inflammatory Adipokines with Tissue Specificity in Mice.

Cold exposure or ß3-adrenoceptor agonist treatment induces the adipose tissues remodeling, relevant for beige adipogenesis within white adipose tissue (WAT). It remains unclear whether this process influences inflammatory adipokines expression in adipose tissues. We determine the temporal profile of cold or ß3-adrenoceptor agonist (CL316,243)-induced changes in the expression of inflammatory adipokines in adipose tissues in mice or primary mice adipocytes. Male C57BL/6J mice at eight weeks old were exposed to 4 °C for 1-5 days. Interscapular brown adipose tissue (iBAT), inguinal subcutaneous WAT (sWAT) and epididymal WAT (eWAT) were harvested for gene and protein expression analysis. In addition, cultured primary mice brown adipocyte (BA) and white adipocyte (WA) treated with or without CL316,243 were harvested for gene expression analysis. The inflammatory adipokines expressed significantly higher in WAT than BAT at baseline. They were rapidly changed in iBAT, while down-regulated in sWAT and up-regulated in eWAT during the cold acclimation. Upon CL316,243 treatment, detected inflammatory adipokines except Leptin were transiently increased in both BA and WA. Our in vivo and in vitro data demonstrate that the browning process alters the inflammatory adipokines expression in adipose tissues, which is acutely responded to in iBAT, dynamically decreased in sWAT whilst increased in eWAT for compensation.

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.

Comparison of the effects of ß3 -adrenoceptor agonism on urinary bladder function in conscious, anesthetized, and spinal cord injured rats.

AIMS: To compare the dose effect relationship of a selective ß3 -adrenoceptor agonist (CL-316,243) on cystometric parameters in anesthetized and conscious rats and to evaluate its effect in a model of neurogenic bladder overactivity induced by spinal cord injury (SCI). METHODS: Experiments were performed in anesthetized and conscious normal rats and in conscious rats after complete transection at the T8 level of the spinal cord. The jugular vein and urinary bladder were catheterized and the bladder infused with saline. CL-316,243 was tested intravenously at 0.01, 0.03, and 0.1 mg/kg in anesthetized and conscious rats and at 0.01 mg/kg in sham and SCI rats. Intravesical pressure was recorded for 1 hr following drug administration. Intercontraction interval (ICI), amplitude of micturition (AM), micturition frequency (MF) and non-voiding contractions (NVC) were analyzed. RESULTS: In anesthetized and conscious normal rats, CL-316,243 significantly increased ICI in a dose-dependent manner. In anesthetized rats, AM was significantly decreased at all doses tested whereas in conscious rats, a significant decrease (-19 ± 6%) in AM was only observed at the highest dose (0.1 mg/kg). In conscious sham and SCI rats, CL-316,243 significantly increased ICI (42 ± 17% and 49 ± 17%, respectively) and decreased MF without affecting AM. In SCI rats, CL-316,243 reduced the frequency of NVC (-53 ± 14%) without significant effects on amplitude. CONCLUSIONS: The current results suggest that anesthesia can alter the effects of ß3 -adrenoceptor agonists in experimental models. In addition, this is the first demonstration that stimulation of ß3 -adrenoceptors can produce decreases in micturition frequency and NVC in SCI rats without affecting AM.

Phase III, randomised, double-blind, placebo-controlled study of the ß3-adrenoceptor agonist mirabegron, 50 mg once daily, in Japanese patients with overactive bladder.

OBJECTIVE: To evaluate the efficacy and safety of the ß3-adrenoceptor agonist mirabegron, in a Japanese population with overactive bladder (OAB). PATIENTS AND METHODS: This randomised, double-blind, placebo-controlled phase III study enrolled adult patients experiencing OAB symptoms for ≥24 weeks. Patients with ≥ 8 micturitions/24 h and ≥1 urgency episode/24 h or ≥1 urgency incontinence episode/24 h were randomised to once-daily placebo, mirabegron 50 mg or tolterodine 4 mg (as an active comparator, without testing for non-inferiority of efficacy and safety) for 12 weeks. The primary endpoint was the change in the mean number of micturitions/24 h from baseline to final assessment. Secondary endpoints included micturition variables related to urgency and/or incontinence and quality-of-life domain scores on the King's Health Questionnaire. Safety assessments included adverse events (AEs), post-void residual urine volume, laboratory variables, vital signs and 12-lead electrocardiogram. RESULTS: A total of 1139 patients were randomised to receive placebo (n = 381), mirabegron 50 mg (n = 380) or tolterodine 4 mg (n = 378). Demographic and baseline characteristics were similar among the treatment groups. At final assessment, mirabegron was significantly superior to placebo in terms of mean [sd] change from baseline in number of micturitions/24 h (-1.67 [2.212] vs -0.86 [2.354]; P < 0.001) and mean [sd] change from baseline in number of urgency episodes/24 h (-1.85 [2.555] vs -1.37 [3.191]; P = 0.025), incontinence episodes/24 h (-1.12 [1.475] vs -0.66 [1.861]; P = 0.003), urgency incontinence episodes/24 h (-1.01 [1.338] vs -0.60 [1.745]; P = 0.008), and volume voided/micturition (24.300 [35.4767] vs 9.715 [29.0864] mL; P < 0.001). The incidence of AEs in the mirabegron group was similar to that in the placebo group. Most AEs were mild and none were severe. CONCLUSIONS: Mirabegron 50 mg once daily is an effective treatment for OAB symptoms, with a low occurrence of side effects in a Japanese population.

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

AIMS: Mirabegron, the first ß3 -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.

Mirabegron 50 mg once-daily for the treatment of symptoms of overactive bladder: an overview of efficacy and tolerability over 12 weeks and 1 year.

The aim of the present review article was to summarize the efficacy and tolerability for mirabegron 50 mg over 12 weeks and 1 year versus placebo (SCORPIO) or tolterodine ER 4 mg (SCORPIO and TAURUS). After a 2-week placebo run-in, adults with overactive bladder symptoms for ≥3 months were randomized if, during a 3-day micturition diary period before baseline, they had an average of ≥8 micturitions/24 h and ≥3 urgency episodes. Efficacy end-points were change from baseline to each study visit and final visit in incontinence, micturitions, volume voided/micturition, urgency incontinence, urgency (grades 3 or 4), level of urgency and nocturia. Additional secondary efficacy variables included patient-reported outcomes. Safety variables included changes in treatment-emergent adverse events and vital signs. For SCORPIO, statistically significant improvements from baseline in efficacy variables and patient-reported outcomes were seen with mirabegron versus placebo from week 4, and were maintained over time. For TAURUS, numerical improvements in efficacy were evident from month 1, and were maintained throughout 12 months. Treatment-emergent adverse events incidence was similar between groups, except for dry mouth, which was reported by fourfold (SCORPIO) and threefold (TAURUS) more patients taking tolterodine than mirabegron. Mirabegron 50 mg for 12 weeks was associated with statistically significant improvements in objective measures of efficacy and patient-reported outcomes. At final visit, improvements with mirabegron 50 mg were statistically greater versus placebo. The efficacy profile of mirabegron 50 mg appears to be maintained over 12 months.

Treatment Patterns with Mirabegron and Antimuscarinics for Overactive Bladder: A Prospective, Registry Study in Taiwan and South Korea (FAITH).

INTRODUCTION: This study aimed to assess overactive bladder (OAB) treatment patterns and factors associated with effectiveness and persistence. METHODS: A prospective, longitudinal, observational registry study of adults starting OAB therapy with mirabegron or antimuscarinics was undertaken. Primary endpoints were time from treatment initiation to discontinuation/switching; proportion who discontinued/switched; and reasons for discontinuation/switching. Secondary endpoints included OAB Symptom Score (OABSS), OAB Questionnaire: Short Form, and OAB Bladder Assessment Tool scores; factors associated with effectiveness and persistence; and safety. RESULTS: In total, 556 patients initiating mirabegron and 250 initiating antimuscarinics were enrolled. There was no treatment switch, change, or discontinuation in 68.5% of the mirabegron initiator group and median time to treatment change was not reached. Mean initial treatment duration was 130.8 days. In multivariable models, baseline OABSS was the only variable significantly associated with change from baseline in OABSS, and patients with mild and moderate OAB had significantly better persistence with mirabegron than those with severe OAB. Urinary tract infection was the most common adverse event with mirabegron. There was no treatment switch, change, or discontinuation in 60.4% of the antimuscarinics initiator group and median time to treatment change was not reached. Solifenacin was the most frequent initial treatment (66.0%). Mean treatment duration was 122.2 days. In multivariable models, baseline OABSS was the only variable significantly associated with change from baseline in OABSS, while patients with OAB medication in the 12 months before enrollment had significantly better persistence with antimuscarinics than those with no previous OAB medication. Dry mouth was the most common adverse event with antimuscarinics. CONCLUSIONS: Mirabegron and solifenacin were commonly prescribed as first-line OAB medications. There was no treatment switch, change, or discontinuation in more than 60% of the mirabegron initiator and antimuscarinics initiator groups. Mean initial treatment duration was 130.8 days and 122.2 days for mirabegron and antimuscarinics, respectively. Graphical Abstract available for this article. TRIAL REGISTRATION: ClinicalTrials.gov NCT03572231.

A proof-of-concept study: mirabegron, a new therapy for overactive bladder.

AIMS: To evaluate the potential of mirabegron, a selective ß3-adrenoceptor agonist, for treatment of overactive bladder (OAB) symptoms. METHODS: A multicenter, randomized, double-blind, double-dummy, parallel group, placebo and active-controlled, Phase 2, proof-of-concept study was conducted. Eligible patients (n = 314) were enrolled into a single-blind, 2-week placebo run-in period followed by a randomized, double-blind, placebo-controlled treatment period. Patients received mirabegron 100 or 150 mg twice-daily (BID), placebo or tolterodine 4 mg extended release (ER) once-daily for 4 weeks. Primary endpoint was change from baseline to end-of-treatment in mean number of micturition episodes per 24 hr. Secondary endpoints included changes in mean volume voided per micturition; mean number of urinary incontinence, urgency urinary incontinence, and urgency episodes per 24 hr; severity of urgency; nocturia, and quality of life measures. Safety parameters included adverse events, laboratory tests, electrocardiogram parameters and post-void residual volume. RESULTS: Mirabegron 100 and 150 mg BID resulted in a statistically significant improvement versus placebo in mean change from baseline to end-of-treatment in the primary endpoint of micturition frequency (2.2 micturitions/24 hr vs. 1.2 micturitions/24 hr for both doses, adjusted P ≤ 0.01 for both comparisons). Mirabegron had a statistically significant effect versus placebo for most secondary endpoints, including quality of life variables. Despite a small increase in pulse rate, mirabegron demonstrated good safety and tolerability. CONCLUSIONS: Mirabegron was efficacious and well tolerated in patients with OAB symptoms and heralds the first of a new class of oral pharmacological therapy for OAB for more than 30 years.

Expression and functional role of ß3 -adrenoceptors in the human ureter.

OBJECTIVES: To investigate the presence of ß-adrenoceptor subtypes in the human ureter, and to examine whether ß(3) -adrenoceptors modulate relaxation of the human ureter. METHODS: Expression of messenger ribonucleic acid of ß-adrenoceptors in the human ureter was determined by reverse transcription polymerase chain reaction, and distribution of ß-adrenoceptors was examined by immunohistochemistry. In functional studies, the relaxant effects of isoproterenol, procaterol, TRK-380, salbutamol and BRL 37344 on KCl-induced contraction of the human ureter were evaluated, and the inhibitory effects of isoproterenol, procaterol and TRK-380 on electrical field stimulation-induced contractions were determined. RESULTS: Expression of ß(1) -, ß(2) - and ß(3) -adrenoceptor messenger ribonucleic acid in the human ureter was confirmed by reverse transcription polymerase chain reaction. Positive staining for ß(1) -, ß(2) - and ß(3) -adrenoceptor was identified not only in smooth muscle, but also in the urothelium of the human ureter. All ß-adrenoceptor agonists decreased the tone of KCl-induced contractions of the human ureter with a rank order of relaxant effects of isoproterenol > procaterol > TRK-380 > salbutamol > BRL 37344. Furthermore, isoproterenol, procaterol and TRK-380 significantly decreased the amplitude of electrical field stimulation-induced contractions with a rank order of inhibitory effects of isoproterenol > procaterol > TRK-380. CONCLUSIONS: Human ureteral relaxation is mediated by both ß(2) - and ß(3) -adrenoceptor stimulation. ß(3) -Adrenoceptor agonists have the potential to relax the human ureter, and their clinical application in the treatment of ureteral stones is expected.

Cost-effectiveness of overactive bladder treatments from a US commercial and payer perspective.

Aim: The cost-effectiveness of treatment options (anticholinergics, ß3-adrenoceptor agonists, onabotulinumtoxinA, sacral nerve stimulation and percutaneous tibial stimulation [the latter two including new rechargeable neurostimulators]) for the management of overactive bladder (OAB) were compared with best supportive care (BSC) using a previously published Markov model. Materials & methods: Cost-effectiveness was evaluated over a 15-year time horizon, and sensitivity analyses were performed using 2- and 5-year horizons. Discontinuation rates, resource utilization, and costs were derived from published sources. Results: Using Medicare and commercial costs over a 15-year time period, onabotulinumtoxinA 100U had incremental cost-effectiveness ratios (ICERs) gained of $39,591/quality-adjusted life-year (QALY) and $42,255/QALY, respectively, versus BSC, which were the lowest ICERs of all assessed treatments. The sensitivity analyses at 2- and 5-year horizons also showed onabotulinumtoxinA to be the most cost-effective of all assessed treatments versus BSC. Conclusion: OnabotulinumtoxinA 100U is currently the most cost-effective treatment for OAB.