Study of Behavioral Modification Program and Mirabegron to Improve Urinary Urgency in Multiple Sclerosis

A randomized 1:1 placebo controlled 10-week study of mirabegron as add-on therapy to an educational intervention on behavioral modification including pelvic floor exercise (BM-PFE) to a cohort of 40 Multiple Sclerosis (MS) subjects with overactive bladder (OAB). Trial will last approximately 12 weeks for each subject, including screening period and treatment period. Active drug will be mirabegron 25mg daily with optional up-titration to 50mg daily after approximately 5 weeks. Subjects will be randomized at the Baseline Visit based on recordings in a voiding diary kept for 72 continuous hours in the screening period. Voiding diaries of a 72 hour period each will be utilized during the screening period, between Phone Visit 1 and Titration and between Phone Visit 2 and Final Visit. In the diaries, subjects will record the time of each micturition and/or urgency episode, urine volume with each void (when available), any episode of incontinence, and the severity of urgency (Overactive Bladder Symptom Composite Score, mean of 72 hour total daily cumulative score. Primary outcome will be average daily OAB-SCS total score, Final Visit vs. Baseline. This accounts for the frequency, urgency and incontinence components of OAB.