Once-Daily Vibegron 75 mg for Overactive Bladder: Long-Term Safety and Efficacy from a Double-Blind Extension Study of the International Phase 3 Trial (EMPOWUR).

PURPOSE: The long-term safety, tolerability and efficacy of vibegron in adults with overactive bladder were evaluated in the 40-week phase 3 EMPOWUR extension study.

MATERIALS AND METHODS: Patients who completed 12 weeks of once-daily vibegron 75 mg or tolterodine 4 mg extended release in EMPOWUR continued double-blind treatment; patients who completed 12 weeks of placebo were randomly assigned 1:1 to receive double-blind vibegron or tolterodine. The primary outcome was safety, measured by incidence of adverse events. Secondary outcomes included change from baseline at week 52 in average daily number of micturitions and urgency episodes (all patients), and urge and total urinary incontinence episodes (patients with overactive bladder wet) based on 7-day diary data.

RESULTS: Of 506 patients randomized 505 received ≥1 dose of medication, and 430 (85%) completed the study. A total of 12 patients (2.4%) discontinued owing to adverse events. The most common adverse events with vibegron/tolterodine (>5% in either group) were hypertension (8.8%/8.6%), urinary tract infection (6.6%/7.3%), headache (5.5%/3.9%), nasopharyngitis (4.8%/5.2%) and dry mouth (1.8%/5.2%). Improvements in efficacy end points were maintained for patients receiving vibegron for 52 weeks; least squares mean change from baseline to week 52 in micturitions was ‒2.4 for vibegron vs ‒2.0 for tolterodine; in urge urinary incontinence episodes ‒2.2 vs ‒1.7 (p <0.05); in urgency episodes ‒3.4 vs ‒3.2; and in total incontinence episodes ‒2.5 vs ‒1.9 (p <0.05). Among patients with overactive bladder wet 61.0% receiving vibegron experienced ≥75% reduction in urge urinary incontinence episodes after 52 weeks of treatment vs 54.4% with tolterodine, while 40.8% vs 34.2% experienced a 100% reduction.

CONCLUSIONS: Vibegron demonstrated favorable long-term safety, tolerability and efficacy in patients with overactive bladder, consistent with results of the 12-week study.