A Study to Evaluate the Overall Effect of Solifenacin 5mg and 10mg on Bladder Wall Thickness and urinary Nerve Growth Factor in Female Subjects with Overactive Bladder and a Diagnosis of Detrusor Overactivity – A double-blind, randomized, placebo-controlled, parallel group, multicentre study - SHRINK

INTERVENTION: Trade Name: Vesicare Pharmaceutical Form: Film‐coated tablet Pharmaceutical form of the placebo: Film‐coated tablet Route of administration of the placebo: Oral use CONDITION: Overactive bladder ; MedDRA version: 12.0 Level: LLT Classification code 10059617 Term: Overactive bladder PRIMARY OUTCOME: Main Objective: 1. To evaluate the effect of solifenacin versus placebo on bladder wall thickness (BWT) after 12 weeks of treatment.; 2. To evaluate the effect of solifenacin versus placebo on urinary Nerve Growth Factor (uNGF) normalized by urine creatinine level (uNGF/Cr) after 12 weeks of treatment in subjects with uNGF above laboratory quantification limit at baseline. Primary end point(s): 1. Change from baseline to week 12 LOCF in bladder wall thickness measured with TVUS.; 2. Value at week 12 LOCF in urinary nerve growth factor / creatinine.; Secondary Objective: 1. To evaluate the effect on bladder wall thickness (BWT) of; a. Solifenacin versus placebo after six (6) weeks of treatment.; b. 5mg and 10mg of solifenacin (dose response).; 2. To evaluate the relationship of bladder wall thickness (BWT) and; a. OAB symptoms at baseline and changes observed during the study.; b. Changes observed in subject perceived satisfaction scales.; 3. To evaluate the effect on urinary nerve growth factor (uNGF) / creatinine (Cr) of; a. Solifenacin versus placebo after six (6) weeks of treatment.; b. 5mg and 10mg of solifenacin (dose response).; 4. To evaluate the relationship of urinary nerve growth factor (uNGF) / creatinine (Cr) and; a. OAB symptoms at baseline and changes observed during the study.; b. Changes observed in subject perceived satisfaction scales.; 5. To evaluate the relationship between bladder wall thickness (BWT) and urinary nerve growth factor (uNGF) / creatinine (Cr).; 6. To evaluate the safety and tolerability of 5mg and 10mg solifenacin. INCLUSION CRITERIA: Subject is eligible for the study if all of the following apply: 1. The subject should be female aged greater than or equal to 18 years of age. 2. The subject should have symptoms of overactive bladder (OAB), including urinary frequency, urgency or urge incontinence, for greater than or equal to 3 months. 3. The subject should have an urodynamic diagnosis of detrusor overactivity (DO). 4. The subject should be either naïve to anti‐muscarinic treatment (i.e. no prior history of use of antimuscarinic agents) or 6‐months anti‐muscarinic treatment free i.e. have had no anti‐muscarinic treatment within 6 months) prior to the screening visit. 5. The subject should have a bladder post‐void residual volume of less than 30ml. 6. The subject has provided Independent Ethics Committee (IEC)‐approved written informed consent and privacy language as per national regulations (e.g., HIPAA Authorization for U.S. sites) prior to any study‐related procedures.