Vibegron (RVT-901/MK-4618/KRP-114V) Administered Once Daily as Monotherapy or Concomitantly with Tolterodine in Patients with an Overactive Bladder: A Multicenter, Phase IIb, Randomized, Double-blind, Controlled Trial

Antimuscarinics have shown modest efficacy with unwanted side effects in patients with overactive bladder (OAB). Efficacy of vibegron, a new β3-adrenergic receptor agonist, for OAB is unknown. To evaluate the efficacy of once-daily oral vibegron in OAB patients (primary), and its safety, tolerability, and efficacy when administered alone or concomitantly with tolterodine (secondary). International, phase IIb, randomized, double-blind, placebo- and active comparator–controlled, two-part superiority trial (2011–2013) in OAB-wet or OAB-dry patients aged 18–75 yr (NCT01314872). Part 1: once-daily oral vibegron monotherapy (3 [V3], 15 [V15], 50 [V50], or 100 [V100] mg), tolterodine extended release 4mg (TER4), or placebo for 8 wk, or combination V50/TER4 for 4 wk and then V50 for 4 wk; part 2: V100/TER4, V100, TER4, or placebo for 4 wk. Average daily micturitions at week 8 of part 1 (primary); urge incontinence episodes, total incontinence episodes, and urgency episodes (secondary). Overall, 1395 patients were randomized. From baseline to week 8, V50 and V100 significantly decreased average daily micturitions (least square mean difference [95% confidence interval], −0.64 [−1.11, −0.18]; p=0.007 and −0.91 [−1.37, −0.44]; p