The objective of this study is to investigate efficacy, safety and tolerability of ONO-8539 in patients with overactive bladder.

Inclusion Criteria:

• Patients with medical history of Overactive Bladder symptoms for > 6 months

Exclusion Criteria:

• Patients who have a history or presence of other significant diseases, which in the opinion of the investigator, might compromise the patient's safety or the evaluation of the study results