International Phase III, Randomized, Double-Blind, Placebo and Active Controlled Study to Evaluate the Safety and Efficacy of Vibegron in Patients with Symptoms of Overactive Bladder: EMPOWUR.

PURPOSE

We assessed efficacy, safety and tolerability of vibegron, a novel, potent, highly selective β-adrenoceptor agonist, administered 12 weeks at 75 mg once daily to patients with overactive bladder in an international phase III trial with placebo and active control.

MATERIALS AND METHODS

Adult patients with overactive bladder with 8.0 or more micturitions per day were randomized 5:5:4 to 75 mg vibegron, placebo or extended-release 4 mg extended-release tolterodine. Up to 25% of patients could have dry overactive bladder (less than 1.0 urge incontinence episode per day). Patients completed 7-day voiding diaries at baseline and weeks 2, 4, 8 and 12.

RESULTS

Of 1,518 randomized patients 90.4% completed the trial. At 12 weeks micturitions decreased by an adjusted mean of 1.8 episodes per day for vibegron vs 1.3 for placebo (p <0.001, co-primary end point) and 1.6 for tolterodine. Among incontinent patients urge incontinence episodes decreased by an adjusted mean 2.0 episodes per day for vibegron vs 1.4 for placebo (p <0.0001, co-primary end point) and 1.8 for tolterodine. Moreover, vibegron was statistically significantly superior to placebo for key secondary measures of number of urgency episodes, volume per micturition and proportion of incontinent patients with a 75% or greater reduction in urge incontinence episodes (all p <0.01). Among vibegron treated patients 1.7% discontinued treatment because of adverse events vs 1.1% for placebo and 3.3% for tolterodine. Incidence of hypertension was 1.7% for vibegron and for placebo.

CONCLUSIONS

Once daily 75 mg vibegron provided statistically significant reductions in micturitions, urgency episodes and urge incontinence, and increased the volume per micturition. Treatment was well tolerated with a favorable safety profile.