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

Inclusion Criteria:

- Patient is willing and able to complete the micturition diary and questionnaires
correctly

- Patient has symptoms of overactive bladder (OAB) for ≥ 3 months

- Patient must experience frequency of micturition on average ≥ 8 times per 24-hour
period during the 3-day micturition diary period

- Patient 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:

- Patient 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

- Patient has significant stress incontinence or mixed stress/urge incontinence where
stress is the predominant factor

- Patient is using medications intended to treat OAB

- Patient has an indwelling catheter or practices intermittent self-catheterization

- Patient has diabetic neuropathy

- Patient has evidence of 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

- Patient receives non-drug treatment including electro-stimulation therapy

- Patient has severe hypertension

- Patient has participated in a clinical study within 30 days, or had participated in
any previous study with mirabegron

- Patient had an average total daily urine volume > 3000 mL as recorded in the 3-day
micturition diary period

- Patient has serum creatinine of >150 μmol/L, or aspartate aminotransferase (AST) or
alanine aminotransferase (ALT) > 2x upper limit of normal range (ULN), or
gamma-glutamyl transpeptidase (γ-GT) > 3x ULN

- Patient has a clinically significant abnormal electrocardiogram (ECG)