Study to Assess the Efficacy and Safety of the Beta-3 Agonist Mirabegron (YM178) in Patients With Symptoms of Overactive Bladder

Inclusion Criteria: * Subject is willing and able to complete the micturition diary and questionnaires correctly * Subject has symptoms of overactive bladder (urinary frequency and urgency with or without urge incontinence) for ≥ 3 months * Subject experiences frequency of micturition on average ≥ 8 times per 24-hour period during the 3-day micturition diary period * Subject must experience at least 3 episodes of urgency (grade 3 or 4) with or without incontinence, during the 3-day micturition diary period Exclusion Criteria: * Subject is breastfeeding, pregnant, intends to become pregnant during the study, or of childbearing potential, sexually active and not practicing a highly reliable method of birth control * Subject has significant stress incontinence or mixed stress/urge incontinence where stress is the predominant factor * Subject has an indwelling catheter or practices intermittent self-catheterization * Subject has diabetic neuropathy * Subject has evidence of a symptomatic urinary tract infection, chronic inflammation such as interstitial cystitis, bladder stones, previous pelvic radiation therapy or previous or current malignant disease of the pelvic organs * Subject receives non-drug treatment including electro-stimulation therapy * Subject has severe hypertension * Subject has a known or suspected hypersensitivity to tolterodine, other anticholinergics, YM178, other beta-adrenoreceptor (ß-AR) agonists, or lactose or any of the other inactive ingredients * Sub…