A Study With Mirabegron 50 mg and 25 mg in Chinese Participants With Overactive Bladder

Inclusion Criteria

• Participant should exhibit symptoms of OAB for at least 12 weeks before initiation of the screening period.
• Participant should have an average of ≥ 8 micturitions/24 hours.
• Participant should have an average of ≥ 1 episode of grade 3 or 4 (PPIUS) urgency or urgency incontinence/24 hours, during a 3-day micturition diary period.
• Female participant is not pregnant and at least one of the following conditions apply:
• Not a woman of childbearing potential (WOCBP)
• WOCBP who agrees to follow the contraceptive guidance from the time of informed consent through at least 30 days after final investigational product (IP) administration.
• Female participant must agree not to breastfeed starting at screening and throughout the study period and for 30 days after final IP administration.
• Female participant must not donate ova starting at first dose of investigational product (IP) and throughout the study period and for 30 days after final IP administration.
• Male participant with female partner(s) of childbearing potential (including breastfeeding partner) must agree to use contraception throughout the treatment period and 30 days after final IP administration.
• Male participant must not donate sperm during the treatment period and for 30 days after final IP administration.
• Male participant with pregnant partner(s) must agree to remain abstinent or use a condom for the duration of the pregnancy throughout the study period and for 30 days after final IP administration.
• Participant agrees not to participate in another interventional study while participating in the present study, defined as 28 days prior screening until completion of the last study visit.

Exclusion Criteria

Exclusion at Visit 1/Week -2 (Screening)

• Participant has stress urinary incontinence as a predominant symptom.
• Participant has an average total daily urine volume > 3000 mL (as recorded in a 3-day voiding diary period).
• Participant has indwelling catheter or practices intermittent self-catheterization.
• Participant has neurogenic detrusor overactivity or indicated pathology other than OAB.
• Participant as monosymptomatic enuresis.
• Participant has post void residual (PVR) volume of ≥ 100 mL or a clinically significant lower urinary tract obstructive disease, except if successfully treated.
• Participant has anatomical anomalies (surgically treated or untreated) that affect lower urinary tract function.
• Participant with hematuria on dipstick test. In the case of hematuria on dipstick test in a female during menstruation, the test can be repeated before randomization (after the end of menstruation).
• Participant has lower urinary tract stones or clinically significant kidney stones requiring treatment.
• Participant has interstitial cystitis.
• Participant has suffered from chronic urinary tract infection (UTI) or has had more than 3 ETIs in the 2 months prior to visit 1/week -1 to -2 (screening).
• Participant has uncontrolled hypertension (sitting systolic blood pressure [SBP] ≥ 180 mmHg or diastolic blood pressure [DBP] ≥ 110 mmHg).
• Participant has pulse rate ≥ 110 beats per minute (bpm) or 440 msec on screening ECG or a risk of QT prolongation (e.g., hypokalemia, long QT syndrome [LQTS] or family history of LQTS or exercise-induced syncope).
• Participant's aspartate aminotransferase (AST) or alanine aminotransferase (ALT) is ≥ 2 × upper limit of normal (ULN) or total bilirubin (TBL) is ≥ 1.5 × ULN according to age and sex (participants with Gilbert's syndrome are excepted from the bilirubin threshold).
• Participant has moderate or severe renal impairment.
• Participant has a symptomatic (symptoms can include pain, fever, hematuria, new onset foul-smelling urine) UTI. Note: if the UTI is treated successfully (clinical recovery: confirmed by dipstick test and repeated dipstick test after 14 days [both should be negative]), the participant can be rescreened.
• Participant has a history or presence of any malignanc