The primary purpose of this study is to assess the efficacy and safety of THVD-201(Combination of tolterodine and pilocarpine) in patients with Overactive bladder during the period of treatment, 12 weeks.

This study also includes an open label extension period of an additional 12 weeks following the treatment to assess long-term efficacy and safety of THVD-201 in patients with Overactive bladder.

Inclusion Criteria:

• 20 - 85 years
• History of OAB (pure urge or mixed urinary incontinence with predominant urge incontinence) for ≥ 6 months.
• In the case of females, at least 2 years has passed since menopause. Or all pre-menopausal female subjects must have been using a highly effective method of birth control during the study. Subject of childbearing potential must have had a negative pregnancy test prior to enrollment.

Exclusion Criteria:

• Predominate stress incontinence, insensate incontinence (those incapable of distinguishing discrete incontinence episodes) and overflow incontinence, as major reason for urine loss or urinary frequency as determined by the investigator.
• History of neurogenic bladder.
• PVR > 200mL
• History of clinically significant renal disease or estimated creatinine clearance defined by Cockcroft and Gault formula < 30 mL/min.
• History of malignant tumor within the past 5 years.
• History or presence of tachyarrhythmia or cardiac disease that in the opinion of the investigator might have confounded the results of the study or posed additional risk to the subject. Subjects who had a value for QTc > 450 msec at the Screening visit.
• Patient with asthma
• PSA ≥ 10 ng/mL in male who is 50 years and over.