A Trial Comparing Combination Treatment (Solifenacin Plus Mirabegron) With One Treatment Alone (Solifenacin)

Inclusion Criteria:

- Main Inclusion at Screening:

1. Subject has symptoms of OAB (urinary frequency and urgency with urgency
incontinence) for >= 3 months prior to the screening visit

2. Subject is willing and able to complete the micturition diary and questionnaires
correctly, including collection and measurement of urine output for 3 days prior
to each visit;

3. Subject has symptoms of "wet" OAB (urinary frequency and urgency with
incontinence or mixed incontinence with predominant urgency incontinence), and
reports an average of at least 2 incontinence episodes per day.

- Main Inclusion at Run-in (Visit 2):

1. Subject experiences on average at least 1 episode of urgency (grade 3 or 4) with
or without incontinence per 24-hour period during the 3-day micturition diary
period.

2. Subject experiences on average at least 2 incontinence episodes per 24-hour
period during the 3-day micturition diary period.

3. Subject experiences on average at least 8 micturitions (excluding incontinence
episodes) per 24-hour period during the 3-day micturition diary period.

- Main Inclusion at Randomization (Visit 3):

1. Subject experiences at least 1 incontinence episode during the 3-day micturition
diary period and wishes to increase their treatment for OAB symptoms.

Exclusion Criteria:

- Main Exclusion at Screening:

1. Subject in the opinion of the investigator has clinically significant Bladder
Outlet Obstruction (BOO).

2. Subject has significant Post-void residual (PVR) volume (PVR > 150 ml).

3. Subject has significant stress incontinence or mixed stress/urgency incontinence
where stress is the predominant factor as determined by the investigator

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

5. Subject has evidence of a UTI.

6. Subject has chronic inflammation such as interstitial cystitis, bladder stones,
previous pelvic radiation therapy, or previous or current malignant disease of
the pelvic organs

7. Subject has moderate to severe hepatic impairment

8. Subject has severe renal impairment or End Stage Renal disease

9. Subject has a clinically significant abnormal Electrocardiogram (ECG)

10. Subject has a concurrent malignancy or history of cancer (except noninvasive skin
cancer) within the last 5 years prior to screening.

11. Subject has a QTcF interval > 450 ms for males or > 470 ms for females or is at
risk of QT prolongation (e.g., family history of long QT syndrome, hypokalaemia).

12. Subject has received intravesical treatment in the past 12 months with e.g.,
botulinum toxin, resiniferatoxin, capsaicin.

13. Subject has severe uncontrolled hypertension, which is defined as a sitting
average systolic blood pressure ≥ 180 mmHg and/or average diastolic blood
pressure ≥ 110 mmHg.

- Main Exclusion at Randomization (visit 3):

1. Subject has achieved 100% continence from Visit 2 to Visit 3 (no incontinence
episodes are recorded in the 3 day diary administered for 3 days prior to Visit
3).

2. Subject does not desire an increase in study medication.

3. Subject has an average total daily urine volume > 3000ml as recorded in the
micturition diary.

4. Subject has severe uncontrolled hypertension, which is defined as a sitting
average systolic blood pressure ≥ 180 mmHg and/or average diastolic blood
pressure ≥ 110 mmHg.

5. Subject has a clinically significant abnormal ECG