Study to Evaluate the Efficacy, Safety, and Tolerability of Mirabegron in Older Adult Subjects With Overactive Bladder (OAB)

Inclusion Criteria assessed at Visit 1 (Screening):

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

- Subject has symptoms of wet overactive bladder (OAB) (urinary frequency and urgency
with incontinence) for greater than or equal to 3 months prior to Screening.

- Subject agrees not to participate in another interventional study from the time of
screening until the final study visit.

Inclusion Criteria assessed after placebo run-in period at Visit 3 (Baseline):

- Subject continues to meet all inclusion criteria of Visit 1.

- Subjects must experience at least one incontinence episode in the placebo run-in
period based on the 3-day micturition diary.

- Subject must experience at least 3 episodes of urgency (grade 3 or 4) based on the
3-day micturition diary.

- Subject must experience an average of greater than or equal to 8 micturitions/day
based on the 3-day micturition diary.

Exclusion Criteria assessed at Visit 1 (Screening):

- Subject has ongoing symptoms suggestive of bladder outlet obstruction (BOO) or history
of BOO that is currently not well controlled.

- Subject has Post-Void Residual Volume (PVR) greater than 150 mL.

- Subject has neurogenic bladder or neurological dysfunction or injury which could
affect the lower urinary tract or nerve supply.

- Subject has significant stress incontinence or mixed stress/urgency incontinence where
stress is the predominant factor as determined by the Investigator (for female
subjects confirmed by a cough provocation test). Subjects with a history of stress
incontinence that is currently treated (e.g. remote history of surgery for stress
incontinence) may be included as long as they pass cough provocation test.

- Subject has an indwelling catheter or practices intermittent self-catheterization.

- Subject has evidence of Urinary Tract Infection (UTI). Urine culture and sensitivity
will be performed for positive leukocytes, or nitrites, or turbidity, or at the
investigator's discretion and will be confirmed with a culture greater than 100,000
cfu/mL. If a subject has a UTI at Screening (Visit 1), the subject can be rescreened
after successful treatment of the UTI (confirmed by a laboratory result of negative
urine culture).

- Subject has a chronic inflammatory condition such as interstitial cystitis, bladder
stones, previous pelvic radiation therapy, or previous or current malignant disease of
the pelvic organs (i.e., within the confines of the pelvis including the bladder and
rectum in both sexes and the uterus, ovaries, and fallopian tubes in females; organs
of the lower gastrointestinal tract are not necessarily considered pelvic organs as
the distal ascending colon, the full transverse colon and proximal portion of the
descending colon are in the abdomen).

- Subject resides in a nursing home.

- Subject is likely to enter a hospital or nursing home due to medical instability
within the next 6 months in the opinion of the Investigator.

- Subject has received intravesical injection in the past 12 months with botulinum
toxin, resiniferatoxin, or capsaicin.

- Subject has received electro-stimulation therapy for OAB (e.g. sacral nerve
stimulation or Percutaneous Tibial Nerve Stimulation [PTNS]).

- Subject began or has changed a bladder training program or pelvic floor exercises less
than 30 days prior to Screening.

- Subject has moderate or severe hepatic impairment defined as Child-Pugh Class B or C.

- Subject has severe renal impairment defined as estimated creatinine clearance less
than 29 mL/min determined by Estimated Glomerular Filtration Rate (eGFR,
Cockroft-Gault, or MDRD formulae). A subject with end stage renal disease or
undergoing dialysis is also not a candidate for the study.

- Subject has severe uncontrolled hypertension, which is defined as a sitting systolic
blood pressure greater than or equal to 180 mmHg and/or diastolic blood pressure
greater than or equal to 110 mmHg.

- Subject has evidence of QT prolongation on electrocardiogram (ECG) defined as QTc
greater than 450 msec for males, QTc greater than 470 msec for females or a known
history of QT prolongation.

- Subject has a clinically significant ECG abnormality, as determined by the
Investigator.

- Subject has aspartate aminotransferase (AST) or alanine aminotransferase (ALT) greater
than 2x upper limit of normal (ULN), or γ-GT greater than 3x ULN and considered
clinically significant by the Investigator.

- Subject has a hypersensitivity to any components of mirabegron, other β-AR agonists,
or any of the inactive ingredients.

- Subject has any clinically significant condition, which in the opinion of the
Investigator makes the subject unsuitable for study participation.

- Subject has been treated with an experimental device within 28 days or received an
investigational agent within 28 days or 5 half-lives, whichever is longer, prior to
Screening.

- Subject has a concurrent malignancy or history of any malignancy (within the past 5
years), except non-metastatic basal or squamous cell carcinoma of the skin that has
been treated successfully.

- Subject with current history of alcohol and/or drug abuse.

- Subject is using prohibited medications which cannot be stopped safely during the
period.

- Subject has stopped, started or changed the dose of a restricted medication within the
last 30 days prior to Screening.

- Subject is involved in the conduct of the study as an employee of the Astellas group,
third party associated with the study, or the study site team.

- Subject has previously received mirabegron.

Exclusion Criteria assessed after placebo run-in period at Visit 3 (Baseline):

- Subject fulfills any exclusion criteria of Visit 1 (subject does not need to repeat
screening assessments [PVR, cough provocation test, chemistry/hematology/urinalysis]).

- Subject was non-compliant during 2-week placebo run-in period, defined as taking less
than 80% or greater than 120% of study medication.

- Subject has any systolic blood pressure measurement > 180 mmHg or diastolic blood
pressure measurement > 110 in the 3-day diary or during the baseline visit.